The Ram's Eye - A Driver's Blog

Monday, 24 October 2016

2017 Camaro ZL1 Beats Previous Generation’s Nürburgring Lap Time

The new 2017 +Chevrolet Camaro ZL1, expected in showrooms by the end of this year, just beat the benchmark set by the last generation ZL1. With a lap time of 7:29.60, it is 11.67 faster faster than the last generation and even beat the last generation Z/28's time of 7:37.9 - which was done on Pirelli P Zero Trofeo R tires, far grippier than the Eagle F1 Supercar used on the ZL1. The car used is unchanged from the one you'll be able to buy, aside from the installation of data acquisition equipment, a roll hoop, and Sparco racing seats with six-point harnesses. Otherwise, the car was production stock and included the following:

  • 6.2-liter supercharged LT4 V-8 making 650 horsepower and 650 lb-ft of torque
  • All-new 10R90 10-speed automatic transmission (set to Track mode to enable Performance Algorithm Shift calibration, providing optimal gear selection without the need to manually select gears)
  • FE4 Suspension with Magnetic Ride Control
  • Performance Traction Management
  • Forged 20-inch wheels with Goodyear Eagle F1 Supercar 3 tires
  • Brembo brakes with front 15.4-inch rotors and six-piston calipers and rear 14.4-inch rotors and four-piston calipers
  • Lift-reducing front fascia elements with cooling ducts and Chevrolet “flowtie”
  • Full underbody shielding
  • ZL1-specific rear spoiler and diffuser
  • 11 heat exchanger

And best of all, with the exception of the 10 speed auto, all the above is included as standard, with no requirement to purchase additional performance packages. On a track like the 'Ring, the auto would have been worth a few seconds, I figure, with the number of shifts required so if you get it with the manual, you might close the gap compared to the last gen Z/28, but the time is still phenomenal and runs with plenty of very capable cars. A lot of times aren't official on Wikipedia or Fastest Laps aren't manufacturer official so they're hard to compare, but a notable victim is an AMG-confirmed lap time of lap time of 7:30.0 for a 2013 SLS AMG GT.  Plus, beating the mighty 5th gen Z/28 by over 8 seconds is quite a feat, since we've seen that Z/28 beat cars like the GT-R, 991 Turbo S, and Mercedes-AMG GT S when tested by Motor Trend or Car and Driver. This should be one heck of a tough car to beat on track. I can't wait to see how it does in a comparison test. Until then, here's a video of the lap:

Saturday, 22 October 2016

Limited Slip Differentials - The Basics

I'm finishing up a comparison post (link to introduction: Intro: Focus RS vs Golf R vs WRX STI vs Evo X) and, throughout the post, I realized that I have to go off topic a lot to talk about how each type of differential changes the way the car drives. As a result, I thought I'd write a separate post to go into more detail before I post the other one to keep the other more focused on the cars and avoid veering off topic too much.

By saying "Limited Slip Differentials" in the title, I am including torque vectoring diffs because, although current conventional terminology treats them differently, a torque vectoring differential is, in essence, a very sophisticated limited slip diff (LSD) that can be manipulated to actively help the car handle better. And while non of the cars in the comparison use open (without help from the brakes) or non-gear mechanical LSD’s, I’ll briefly discuss them so that the post is more inclusive. I’ll only focus on using power to help the handling or how a diff can handicap that, since the reason I started to write this post is to demonstrate how the differentials help each car. I won’t talk about other techniques that could help you manage a car’s weaknesses, such as changing turn in points, apexes, trailbraking, etc.

So how do traditional LSD's and torque vectoring diffs (TVD) help the car? Let's first start with open differentials.

Open Differentials

These are the most common differentials and they are the best at being differentials. The differential's job is to allow two wheels on the same axle to spin at different speeds so a car could smoothly go around a corner since each wheel has to travel a different path and, therefore, at a different speed - hence the name - to reach the end point of the turn at the same time. The video below has been used countless times to demonstrate how a diff works and, although made by GM almost 80 years ago, is still one of the best videos I've found that explains very simply and visually how a differential works (fast forward to about 2:00 in).

I don't want to get into the internals and workings of a differential, but I wanted to share that video because understanding the basics will help with understanding the impacts of various types of differentials. As you can see in the video, an open diff allows one wheel to spin endlessly, even if the other is completely stationary. The demonstration at 5:30 into the video shows that. If one wheel has a lot of traction, it's harder to spin, much like being held still in the video relative to the other one, (the road is "holding" the tire, in effect). If the other has little traction for some reason, the diff will spin it, since it is easier to spin. The diff transfers virtually equal amounts of torque to both wheels so the wheel with little traction will dictate how much torque the wheel with a lot of traction gets because if you give more torque than the low traction wheel can hold, it will spin, reducing your traction even more as well as lateral grip.

This is a double whammy if you have uneven available grip between two wheels on the same axle. When you have one wheel that has relatively little torque carrying capacity, but no way to unevenly distribute torque, you can more easily overpower it. Moreover, the wheel with a lot of traction and, therefore, good torque carrying/transfer capacity is underutilized. The result is limiting how much power you can use to move (accelerate) and increased likelihood of reducing your grip by spinning the low-grip wheel, which still contributes to the car's overall lateral and forward grip available. If that happens at the rear axle (RWD), that spinning low-traction wheel means less grip at the rear end and more likely to oversteer. On the front axle, it's understeer. This is assuming that, in either scenario, you're applying power.

How does this work on track? When you're going around a turn, the inside wheel is unloaded because weight is transferred to the outside wheel, which means the inside wheel has less grip. That means it can transfer less torque than the outside and if you exceed that, it will spin. If it starts to spin (excessively), it will have even less grip. Less grip means you'll be able to use even less power and your corner speed has to come down since one of the tires now has less grip. In short, an open diff works really well at allowing different speeds between the two wheels but limits how much you power you can put down and makes it easier to spin under power.

So what does that mean if you're pushing the car? When approaching a turn, as you start to turn in, you come off the power. Typically.. The reason I say typically is that with some of the other differentials, you can actually start using more than maintenance throttle as soon as you come off the brakes, but more on that later. For an open diff, you are off, aside from maintenance throttle. If you can add power and gain speed between turn in and apex (where you start to unwind), you lost more speed than you needed on the brakes. Assuming optimal entry, you shouldn’t be able to add speed without understeer, oversteer, or a neutral drift, depending on the balance of the car. The diff can’t help you here. Worse yet, on a FWD car, you can’t use the power to help the car rotate. Unlike RWD, where you could judiciously overpower the rear wheels, inducing slip and rotating the car that way, if you overpower the driven wheels in a FWD car, there’s no way to go but straight. And this is very easy to do in an open diff while going around a turn, with the inside wheel being unloaded.

Need more bad news? The vast majority of FWD cars have a transverse engine layout, placing the engine far outside the wheelbase of the car. The Dodge and Chrysler Intrepid come to mind as exceptions, with longitudinal engine, FWD layout. Audi A4s, too, if you don't get the AWD option. But even those still put the engine basically entirely in front of the front axle. This generates very nasty forces and moments that do their best at pulling the car straight when you want to turn. Then, of course, you have typical OEM suspension tuning that favours the front end letting go before the rear end for safe limit-understeer. The result is frustration and anger, perhaps some cursing, and eventually vowing against open differentials on the track and maybe even FWD all together (which can actually be made to work very well on a track).

Limited Slip Differentials

There are many types of limited slip differentials and, like I mentioned, I won't get into how they operate, just how they affect the car. I'm referring strictly to mechanical, non-gear type limited slip differentials here. These differentials are typically open differentials at heart with modifications or additions. Those modifications are designed to resist a speed variance across the differential. The result is a limit to how much faster a wheel can spin relative to the other, overcoming the limitations I mentioned for an open diff. This is achieved by locking the two axles together (to an extent). That extent depends on the design and spec of the differential - typically referred to in a percentage (%) number and occasionally as a Torque Bias Ratio (TBR). That % number is the difference in torque (in % of total) the diff can provide between the two axles. TBR is the ratio between the torque sent to the outside wheel to the inside wheel that the diff can deliver. The higher either number, the better the diff will be at putting power down as it allows more lock up. But higher isn't always better.

Limiting slip of a low traction wheel is great, as it can be the difference between accelerating and backing off the power when exiting a turn on a track. Trouble is, when under power, a limited slip diff of this type can't differentiate between turning and a slipping wheel. If you're going around a turn and starting to feed in power, the outside wheel is spinning faster than the inside wheel, which is normal. But the diff will start to lock up, in response to the speed differential, thereby transfering torque to the inside wheel. That means the unloaded wheel gets more torque, the opposite of what you want, and generates a steering moment in the opposite direction of the turn. Moreover, by locking up, there is resistance to the wheels spinning at different speeds, which is resistance to turning (i.e. understeer) since that requires each wheel travels a different arc at a different speed around a turn.

So how do these help, considering all that? You can go faster by using more power earlier in corner exit and, due to limiting inside wheel spin, you won't lose traction as easily which means you can better maintain your available grip. The downside is understeer on a RWD car. This is introduced by three factors:

- Locking up to any degree provides less speed differentiation than no lock up at all, which we've established is required for the car to turn.

- Putting more power down means more weight transfer to the rear end, which results in less grip at the front end; more understeer.

- You can maintain your grip for longer due to no inside wheel spin. If the rear axle can hold on for longer, you'll increase understeer.

- Torque transfer to inside rear wheel in a turn prior to it slipping generates negative steering moment (in opposite direction to the turn), resulting in understeer.

With that said, a car without a LSD will be slower than one with because, even if your corner speeds come down a little, you can get back on the power much sooner and more aggressively and that's where you make most of your time. Moreover, you can tune the suspension and chassis to reduce understeer so you typically only notice the understeer on a car that had a LSD added but is otherwise unchanged. And most good summer/track tires generate their highest grip with a very small amount of slip, meaning that if you're aggressive with the throttle, enough to just barely overpower the inside wheel where the diff is working as intended, that very small amount of slip is not hurting you and now the inside wheel is beginning to slip, causing lockup and torque transfer to the outside. As a result, you'll find that most good handling RWD cars actually have LSD's, such as modern Camaros and Mustangs, Corvettes, BMW's, Subaru BRZ/Toyota 86, etc. 

It gets even better on a FWD car, since you only have the first two factors against you. The other two are actually helping you; more grip at the front is less understeer and torque delivered by either front tire generates positive steering moment.  That means a LSD typically curbs understeer on a FWD car, even with all else being the same. The one caveat is that the axle locking can make it difficult to steer, if aggressive.

Torque sensing or gear type differentials

Torsen and Quaife are probably the most common of these types of differentials. They are very similar in function to more common LSDs discussed above, except rely on gears configured in a way to bind and provide locking. A gear type LSD is torque sensitive, hence the name Torsen (Tor for Torque and sen for Sensing). Torsen has two major designs T1 (first gen) and T2 (shown above). T2's are very similar to Quaife design (main picture above introduction). They all operate based on friction between the gears and the differential casing. Due to the inherent angle of the teeth on a helical gear, transmitting torque from gear to gear also generates thrust forces. These forces pushes the "pinion" helical gears against the differential case, providing lockup, instead of using a clutch pack to lock the axles to the case, for instance. The great thing about them is that they transfer torque even before slip occurs, since they progressively lock up as gear thrust forces increase and these forces are proportional to torque transferred by the diff and independent of speed differential across axles. In other words, as you apply more power, the diff progressively locks up and its capacity to carry torque increases, regardless of whether one of the wheels has begun to slip or not.

Both Torsen generations, T1 and T2, use the same basic principle but T1's are very rarely used now in new applications, if at all, and they rely on a different design that increases lock up. They utilize two different types of gears (helical and worm). Inherent to the design and arrangement of gears, the gears will progressively bind as speed difference between the wheels increases when there is excessive or uneven slip. Due to this nature, T1 LSD's typically have very high TBR's and provide a lot of lock-up.

The downside to gear type differentials is that they typically can't take as much abuse. They don't like to be launched hard and high hp, high grip cars seem to have issues with them since they operate on the principal of binding gears and diff cases. With that said, they are low maintenance and last longer in more forgiving cars. That's not necessarily slow, pedestrian cars - the list of high hp, high performance cars that includes them as OEM diffs includes 5th gen Camaro Z/28, the '12-13 Mustang Boss 302's, and the current Shelby GT350's, all of which utilize the T2 generation.

So how do these differ from the more conventional LSD's in operation? The main difference is how it locks. As discussed earlier, they lock because of the helical gears generating thrust forces that push the gears against the diff case, effectively binding and locking it up. Since the force generated is proportional to the force (torque) being transferred by the gears, lock up is proportional to input power (i.e. how much power you're applying). If you're off the gas, it's basically an open differential. As you roll into the power, it progressively and smoothly locks up. The benefit to that is, because lock up is smoother and the diff is more open off power, you can typically get away with higher torque bias ratios than non gear LSD's at maximum lockup without seeing as much of the side effects of higher locking. The higher TBR allows better traction performance.

Moreover, the fact that lock up is proportional to input power means the diff locks up as you send more power, without the need for slip. Non-gear LSD's need slip to work as intended. If you are going around a turn with no inside wheel slip at all, the outside wheel is traveling faster and the traditional LSD is locking up, slowing it down and speeding up the inside wheel, therefore, transferring more torque to the inside wheel. As you increase power, the inside wheel begins to slip and only as its speed passes the outside does the diff begin to slow it down. In other words, the inside wheel must slip first and then be limited. The diff will go through the sequence of little lock up (outside wheel faster than inside), then no lock up (inside wheel beginning to get over powered, spin, and accelerate to match outside, which from the diffs perspective is like the car going straight), then lock up again as the inside wheel speed starts to exceed outside. In a Torsen, the inside wheel is limited before it slips, since lock up happens before slip. Subtle differences, but can change how the car feels, plus the higher TBR means cars can better put power down, accelerate faster out of turns, and generally perform better on track.

Brake-based Differential Lock

A car that uses brake-based limit slip action utilizes an open differential just like described above but attempts to solve the shortcomings by applying the brakes to individual wheels. If you go on the power and one wheel spins, the car realizes that and applies the brakes at the spinning wheel. From the differential's perspective, that wheel now is harder to turn and more torque will get transferred to it. Fortunately, just as much torque will get transferred to the wheel with grip, giving better traction performance.

In high performance driving, this solves the two shortcomings of an open differential, loss of grip due to a spinning wheel and under utilizing good grip at the loaded, outside tire. As we've established, an open diff transfers equal torque to both wheels. In order to distribute torque where you want it (unevenly), the brakes are engaged to slow down the one wheel spinning excessively. It is artificially creating resistance at the low traction wheel (i.e. the brakes "grip" the wheel instead of the road through the tire). This increases the torque holding capacity of that wheel, and the diff as a whole, thereby allowing the diff to transfer more torque overall, half of which goes to the outside wheel where it can all be used. The downside is wasting some power simply spinning the low traction wheel against the brakes. The second problem is, as a result of trying to power the low traction wheel against the brakes, the brakes can over heat and prematurely wear.

What's it like to drive? The tech is extremely flexible because it provides complete uncoupling and independence between the two wheels when no lock up is needed and infinitely variable and adjustable bias when you do. You have non of the shortcomings of mechanical LSD's. But you'll hear a lot of owners and reviewers complain about their effectiveness, or lack thereof. The problem is the application, not the tech. In a Focus ST or a Golf GTI (non PP), you don't have liberally sized brakes, brake cooling, brake system capacity, etc. In reality, an optimized brake based set up can work very well. McLaren uses them, for example. You won't hear too many people complain about their performance.

When you already have massive braking thermal capacity, cooling air flow, braking power, etc, you could rely on this system and avoid a similarly flexible torque vectoring system. That would not only save cost and complexity since all you're adding is the programming to control the brakes the car already has, it also saves weight since a torque vectoring differential can be heavy. The one Lexus uses on the RC F and GS F, for instance, adds almost 70 lbs compared to the standard Torsen differential offered, itself a heavier system than open differentials. But brake-based lockup does have issues, otherwise, on non optimal cars - think non mid-engine, cost constrained, limited in space, or just about every other car that us mere mortals can buy.. And you waste the engine's power spinning the inside wheel.

To put that into perspective, my car has a Torsen diff with a bias ratio of 2.7 - meaning it can allow the outside wheel to get 2.7 times the amount of torque the inside wheel has while remaining locked up (which is equivalent to a 46% clutch type LSD, if you're curios). My car has 380 lb-ft of torque. That means, in an ideal traction scenario, at peak torque and lockup, going WOT, the engine is sending 380 lb-ft of torque to the diff and the diff is transferring all of it - 103 lb-ft will go to the inside wheel and 277 lb-ft will go to the outside - a difference of 174 lb-ft. To achieve the same bias with brake lock, each axle has to get the same amount of torque - the difference is that some will be used to spin the brakes. How much? 50% of the difference goes to the brakes or 87 lb-ft.  That translates to 75 hp (at 4,500 rpm where peak torque occurs), in effect turning my car down from a 444 hp car to a 369 hp car. Bad.. very bad. Moreover, those 75 hp have to be transferred into heat by the brakes and once those brakes overheat, they back off and you approach an open differential. This extent of power loss would be rare and if it were to happen, wouldn't last long, but it demonstrates how bad it can be. In a mid-engine car like a McLaren, where you have gobs of traction due to rear weight and optimal suspension tuning, you may not need as aggressive a torque bias and you have brakes the size of the moon that can handle the heat. But in every day cars, it doesn't work very well. Not yet anyway.


eLSD is typically used as short for electronic limited slip differentials. They basically combine the benefits of all the above without any of the downsides. It can take more abuse than a gear type. It can lock up smoothly like a gear type. It doesn't have the same resistance to speed differentiation (unless activated) so it can have a higher lock-up with no downside. It is electronically controlled so it can selectively lock and unlock as needed based on real time calculations and inputs from various sensors. It doesn't have to worry about brakes overheating. Its only downside, really, is complexity.

Unlike a mechanical LSD, it can distinguish between a faster spinning outside wheel as you turn (with no slip) and a faster spinning inside wheel due to slip. It won't lockup unless slip is happening, eliminating the negative moment due to torque sent to the inside rear wheel before slip occurs - what mechanical LSD will do. It can give you high lock when you need, say, exiting a slow narrow turn, and low lock around a fast sweeper, reducing understeer you'd get with a high lock. In summary, it gives you higher traction performance while reducing understeer when you don't need lockup.

Torque Vectoring Differential

A torque vectoring differential is very similar to an eLSD. The main difference is that eLSD's only transfer torque from slower to faster. An eLSD is a basically a typical LSD, say a clutch-type, where the clutches, and therefore amount of lockup, are electronically controlled instead of passively based on the difference in speed between the two wheels on an axle. That means that they can control when and how much to lock up but after that, the same principles apply and torque is biased from the faster spinning wheel to the slower wheel. However, a torque vectoring diff can transfer torque either way and can do so independently of a speed differential. The benefit is better control (from the car) and wider range of adjustability, allowing the car to correct and/or improve more frequently. Moreover, a torque vectoring differential typically doesn't transfer torque by locking up. Instead, it utilizes actuators (clutches and/or motors) and gear sets to overdrive or under-drive each wheel independently.

What does this mean? It means you have no resistance to speed differentiation (i.e. understeer) but as much torque transfer to either wheel (can be up to 100% of torque sent to the diff) as you want. The downside of lockup (understeer) is eliminated, a huge plus to start with. Then you get the best torque bias (basically infinite if designed to allow 100%) you could get, allowing you to utilize every last bit of traction available, and to top it off, you can have individual wheel torque control to help the car handle. For example, if the back end is coming out, you could vector torque to the inside to bring it in. This has the same effect as a stability control system applying individual braking to a wheel or more to bring the car back in shape but braking means scrubbing off speed. Torque vectoring doesn't. You could also transfer torque to the outside wheel to help the car rotate if the car is understeering, without forcing lock up. It's a technically wonderful system. The range of adjustments is huge. Opportunities to improve the handling are plentiful. It can make a huge difference in how the car handles. The only downsides, really, are even more complexity and a less "mechanical" feel.


Which one is best? Well, brake-based systems are hugely variable and I'd only take one if I had to choose between one and an open diff. Otherwise, my preference is the gear type LSDs, even though they aren't as capable as electronic controlled ones. They provide the best performance without going to an electronically controlled system. Compared to electronically controlled ones, they're more natural feeling, simpler, and cheaper to maintain. They demand more of you, expect less of the car. But the same can be said for better tires, better shocks, stiffer chassis, etc. so I can see arguing both ways. I would imagine that someone learning on and sticking to torque vectoring tech on track would see it as natural and consider it a baseline, anything else is a compromise. That wasn't the case for me, so they will always seem like the deviation from norm - the cool tech that manipulates the car to your advantage, not the bare essentials.

With that said, in a FWD (never seen one) or FWD-based AWD car, I would absolutely and unquestionably give in and take torque vectoring and/or eLSD's. In a heart beat. The drivetrain layout is working very hard against you to prevent the car from doing what you want it to do. The tech does its best to mitigate the limitations. The way I see it: it almost undoes the crime that is FWD-based, transverse engine layout as opposed to improve the text book longitudinal front engine, RWD layout.

Friday, 30 September 2016

Chevrolet 1LE & Grand Sport - How do they do it? Part 1

Recently, Chevrolets seem to have been punching far above their weights and a lot of people (myself included) are impressed. Sure, Corvettes have always been formidable track cars, but they're low, light, purpose-built, and didn't blow expectations - just provided excellent value. Now, all +Chevrolet  track cars, especially Camaros, seem to be overreaching and, combined with excellent chassis tuning, have been doing wonders for GM's chassis engineers' image. I decided to take the time and do some research to try and figure out what GM is doing that others aren't (or can't). Before I start, I'd like to point out that this is based only on my own understanding and research, not an interview or publication by GM, so take that for what it's worth.

Since I haven't posted about the latest of Chevy's track-focused models/trim packages, I thought I'd first take this opportunity and talk about what you get. Whether you're looking at a Camaro V6, Camaro SS, or Corvette, choosing the 1LE package or Grand Sport will not bring extra power. Instead, those packages help you make the most of what's already available. You get no extra power but better track performance and longevity. Here's what you get, as best as I could find:

Camaro (V6) 1LE
- Functional front splitter (unique design to the V6)
- Functional rear spoiler (shared by V6 and SS)
- 245/40/20 front and 275/35/20 rear tires, mounted on forged wheels
- Oil cooler, bigger engine coolant capacity, and rear differential cooler
- Upgraded fuel pump and tank from the SS
- Upgraded dampers, rear sub-frame mounts, ball-jointed rear toe links, and anti roll bar, all taken from the standard SS
- Four piston front brembo calipers. Rears are unchanged, presumably one piston sliding calipers.
- Limited slip differential (standard on all V6 Camaros with the 6-speed manual)

Camaro SS 1LE
- Functional front splitter (unique design to the SS)
- Functional rear spoiler (shared by V6 and SS)
- 285/30/20 front and 305/20/20 rear tires, mounted on forged wheels
- SS already has oil cooler, bigger engine coolant capacity, rear diff cooler, plus transmission cooler so 1LE does not provide additional cooling capacity.
- Upgraded (magnetic) shocks and springs.
- Upgraded anti roll bars, rear toe links, rear trailing arms, and rear sub-frame mounts all taken from the ZL1
- Six piston front brembo calipers clamping on two piece, aluminum hat front rotors and four piston rear brembo calipers with one piece rotors
- Electronic limited slip differential (standard SS all get mechanical limited slip differentials).

Corvette Grand Sport
- The wide body of the Z06 (in other words, wide fenders to fit fat sticky tires) along with all cooling and aero ducts and passages
- 285/30/19 front and 335/25/20 rear tires, mounted on forged wheels
- Carbon ceramic brake rotors
- Upgraded aero package - the same spec as the stage 2 aero package on the Corvette Z06 (i.e. a Z06 with the Z07 package but not the Performance aero kit or stage 3). Stage 3 brings larger end plates to the front splitter and an adjustable, transparent wicker bill/gurney flap on the rear spoiler. Chevy determined that Stage 3 brings too much drag that isn't welcome without the additional thrust that the Z06 brings to the party.
- Dry sump oiling system (you can get with Z51 package)
- Dual mode exhaust with 460 hp (you can get with the Z51 package)
- Electronic limited slip differential (you can get with the Z51 package)
- Bigger brakes (you can get with the Z51 package)
- Upgraded springs, dampers, and anti-roll bars (you can get with the Z51 package, but the Grand Sport package then turns up the suspension stiffness a notch to sit nicely between the Z51 and Z06)
- Differential and transmission cooling (you can get with the Z51 package)
- Increased engine cooling capacity (you can get with the Z51 package)

So, in summary, all three cars provide downforce, or at least reduce lift for the Camaros (I haven't found data stating downforce numbers), additional cooling where necessary, more braking power, bigger tires, and stiffer suspension tuning. Additionally, except for the V6 Camaro, the cars can put more power down thanks to the electronic limited slip differentials. But what is special about Chevys? Every manufacturer addresses the same areas, if to different extents, but they can't seem to catch up.

The Corvette Grand Sport, for example, is only one tenth behind the GT3 RS, basically a dead heat at 2:47.1 for the Vette vs 2:47 flat for the Porsche, despite the Corvette having LESS power and weighing MORE. Consider this too: both use the same Michelin Pilot Sport Cup 2 tires, albeit tailored specifically for each car. The SS 1LE, at 2:54.8, is nearly tied with a Cayman GT4 (0.8 s behind), despite the GT4 being far lighter, enough to give it a superior power to weight ratio, and using even better tires - the same Pilot Sport Cup 2 vs the Camaro using Goodyear's equivalent to Michelin's Pilot Super Sport (that testing and reviews rate even lower than the Super Sport). How does Chevy do it?

Well, we can tell right off the bat that power isn't the answer. These Chevys are typically outright under-powered on raw numbers or at least power to weight ratio compared to cars they can beat or keep up with. Braking? Highly unlikely. Competitors use gigantic rotors and calipers that can (safely) be assumed to be sized properly with appropriate brake boosters and system pressure. Handling? Read a review of a Cayman GT4 or a 991 GT3 RS and tell me they're lacking. They're stable, yet neutral, handle road undulations, put power down well, etc. Could one be a little bit better than the other? Sure, but we aren't comparing a Corvette to a Beetle here. Plus, declaring them better means stating that Chevy can better design cars to handle than Porsche..

Aero? I hate making assumptions based on such superficial observations.. I really do. But I'll challenge you to this: take a gooood long look at the spoiler on the back of a Cayman GT4. Now look at the.. let's be kind and say relatively handicapped deck-lid spoiler on the trunk of a Camaro 1LE. Then tell yourself that the Camaro has more downforce than the GT4. Can you keep a straight face? I'm not saying that spoilers are the be all end all as far as downforce. There are many ways of managing air flow to change speed and create areas of relative low and high pressures to generate downforce. But it gets harder to do in a compromised car, such as the Camaro, where there are more space constraints than, say, a 2 seater mid-engine car like the Cayman. Plus, a spoiler, an airfoil one in particular, is a very effective way of generating aerodynamic forces. Planes use them (wings). Wind turbines use them (blades). You get the point.

On a side note, you should never underestimate the capability of deck lid or lip spoiler to generate downforce. While pedestal spoilers are far more common in racing, deck lid spoilers can still generate serious downforce. The one on the back of the Camaro 1LEs is simply not very large, the lip doesn't stand very tall, and angle of attack doesn't seem aggressive. Compare it to the last generation Z/28 for example. Here it is, below, with the optional wicker bill or Gurney flap, without which Randy Pobst in Motor Trend testing found the Camaro Z/28 loose and unstable, even though the spoiler alone has a much larger surface area and more aggressive angle of attack than the one on the current Camaro 1LE. So, without real test data, I am making a somewhat-educated guess that they don't have superior downforce.

A comparison of the Corvette Grand Sport vs 911 GT3 RS tells a similar story. Although, in this case, we actually do have numbers. The Corvette Z06 with the Z07 package and Performance Aero Kit (i.e. Stage 3 aero) produces 350 lbs of downforce at 150 mph, according to an article posted by Jalopnik about testing the Z06 at Spring Mountain Motorsports Park, being invited by Chevrolet (link: 2015 Corvette Z06: A 650 HP All-American Middle Finger To Euro Supercars). Meanwhile, the GT3 RS produces 772 lbs at 186 mph, 386 lbs at 93 mph, and vary linearly in between, according to Porsche’s GT division boss, and ‘Mr. GT3’, Andreas Preuninger, who was interviewed by Car Magazine (link: A guided tour of the 2015 Porsche 911 GT3 RS – by the boss). That works out to 622 lbs at 150 mph for the GT3 RS - nearly double what the Z06 makes with its most aggressive aero package, which the Grand Sport does without and makes do with stage 2, as mentioned above.

What about traction? Maybe these pesky Chevys have great traction, allowing them to put power down better and, therefore, outperform their competitors despite being relatively down on power. They could be making better use of what they have, saddling and employing every single horse coming out of their more humble power plants whereas competitors don't. Perhaps.. but there is one big problem. The humble Chevy engines also find themselves placed in cars with more humble layouts - front engine RWD cars. Whereas the GT3 RS has a whopping 62% of its weight over the rear wheels, the Corvette has a relatively measly 51% (impressive for a front engine car). Likewise, the GT4 has a far superior 56% compared to the Camaro's 46%. Without better weight distribution, more downforce, or better tires, and possibly even handling, they couldn't have more traction.. Or Could they? Here's where it gets interesting. I think that it is possible they have better traction. But it's not just traction, I think they have more grip overall, allowing every component to perform better. How do they do that, despite (probably) being relatively handicapped or equivalent at best in all aspects mentioned above? Stay tuned to find out in Part 2!

Saturday, 24 September 2016

Car and Driver Lightning Lap 2016 - A Closer Look

Where did the time go? I unfortunately missed last year's feature. I did intend to post about it this year but haven't had the chance and it's already time for this year's feature. I thought I'd get this one done first and then go back to last year's (hopefully). The full article for this year's LL is here: Car and Driver - Lightning Lap 2016. As always, my car picks aren't necessarily very quick or slow. They simply did much better or much worse than I excepted them to. 

The Highs

BMW M2 - 3:01.9: Last year, a BMW M4 did 3:00.7. 1.2 seconds is all that separate the iconic M4 (an M3 coupe, really.. doesn't that sound better?) from this M2. And that one had the dual clutch transmission and carbon ceramic brakes. Opt for the manual, and you could very well be neck and neck. But you save *ahem* about $30,000 in the process, a little more if you're in Canada. That's what you need to get an M4 with the competition package, dual clutch auto, and carbon ceramic brakes. The M2 is also lighter and seems to be hailed as the true spiritual successor to the BMW 2002. The lack of carbon ceramic brakes is not only impressive, but will also make it much cheaper to run at the track. If you want the best BMW M track car, this is the one to get, not the M4. 

Chevy Camaro LT 1LE - 3:04.0: I don't know if I should be surprised. Year after year, the GM team has been destroying expectations of how much track performance you can get for your money. Sure, the Corvette has always been a bargain for what it offered but that's a low, lightweight, two seater, purpose-built car. 

Both 1LE Camaros are knock outs in their own rights and class, but the V6 has more of a David-and-Goliath story to tell. Both cars are huge value and underpowered compared to most of the cars they beat or run with, but the other one has an SS badge and V8 noise and power. This is "just a V6 Camaro." And it is one tenth of a second behind a 2012 Porsche Cayman R. Think about that for a bit. It beats heavy hitters like an Audi RS5, BMW M5, last generation TT RS and, embarrassingly, a current Mustang GT PP. As Car and Driver has been saying for a while now about the 6th gen Camaro; there is no longer shame in buying the V6.

Chevy Camaro SS 1LE - 2:54.8: I'm looking at this a little differently. You want phenomenal value in a track car, you buy a Camaro 1LE. Chevy will generously let you choose two engine options, depending on your thirst for power and the level of car you want to embarrass, although it'll probably really depend on how deep your pockets are. Not a single car that beat either Camaro costs less. It's not possible to go faster for less (off the showroom floor). The SS? Well, that beat the R8 V10 Plus that ran with it this year and was less than a second behind a Cayman GT4.. the GT4. That's despite the Camaro having worse power to weight ratio, weighing around 700 lbs MORE, AND having less sticky Goodyear Eagle F1 Supercar tires vs Michelin Pilot Sport Cup 2's. Swap the tires, and the Camaro is ahead, I have no doubt,  despite the weight and power to weight ratio. Unbelievable. Stay tuned for an upcoming post on how GM works its track magic!

The Lows

Acura NSX -  2:50.2: Three electric motors, mid-engine layout, aluminum and carbon fibre space frame, twin turbo V6, Pirelli Trofeo R tires.. what am I missing? Oh yes, a nearly $200k price tag. The last NSX was well under $100k when it came out. After accounting for inflation, or if you compare to how much cheaper it was than other cars that are still in production (i.e. a 911 turbo, a comparable Ferrari, etc.) or more expensive (i.e. a Corvette or a Viper), this car should cost about $60k less. What do you get for the added money? It's certainly not performance. This car will get beat by a now out of production Ferrari 458 Italia. I remember reading somewhere that this was one of their benchmarks during development. I always assumed that they were referring to driving experience, not performance.. The 911 GT3 (non RS) is two tenths of a second slower. That's zero point two. And it is about $60k less. Since when does a special track edition Porsche qualify as good value? It now does, thanks to Acura.

I get this car, despite how harsh I am. It is a step in the direction of less reliance on gas. The way to look at it is that it is showing us the future can still be fast and fun, despite (some) electrification and hybridization. In day to day driving, it should be more efficient than a GT3 but you give up no performance at the track. But, because of the price, the target buyer isn't buying to save on fuel costs so you buy it because you want to make a statement or you truly care and think it will make a difference. If you are in that latter group, thank you for being the early tech adopter, even though it doesn't make sense on paper, to allow automakers to develop them. Otherwise, there are far more exciting cars for the money that give up nothing in performance, some of which also beat the Acura for far less.

BMW M4 GTS - 2:52.9: Unlike the Acura, this has no excuses. Why doesn't this match the GT350 or Z/28? Why is it over 1 second and 2 seconds slower than those cars? It has half a cage, power turned up to nearly 500 hp, big sticky Michelin Cup 2 tires, functional aero upgrades, and costs more than twice as much as a base M4. All of that adds up to the impression that BMW left no stone unturned. I'm left with only one conclusion; BMW cannot make it quicker. They either need wider tires and/or track but couldn't fit them in the fenders, more power but the transmission, axles, or diff couldn't take it, or stiffer suspension but it was determined to be too stiff for the street, or something else. I really don't like to judge a car by performance on only one track and I expected it to do better at Laguna Seca with Motor Trend, but *SPOILER ALERT* it was only slightly quicker on LS than a Z/28 (less than two tenths is the difference) but slower than a GT350R. Is this the best BMW can do?

Lexus GS F - 3:05.9: This shouldn't really be listed because I (and you should've) more or less expected it to put a time right around what it did, basically tying the RC F from last year that has basically the same drivetrain, including torque vectoring diff, and weighs basically the same. I couldn't help but shake my head, though. Forget the heavy hitters like the CTS-V and E63 AMG S, with times of 2:56.8 and 3:00.1. Why couldn't this beat a humble 2015 Mustang GT that also has a naturally aspirated 5.0 litre V8 that so happens to be more than 30 hp down on power? 

I think Lexus is hoping people compare this car to the competition from Cadillac, Mercedes, and BMW much like comparing a Cayman to a Corvette. The Cayman is supposed to be more focused on driving while the Corvette is more focused on performance. Trouble is, while the Cayman can make a huge statement for itself due to lighter weight, mid engine layout, and more direct feel, this car offers nothing for a purist beyond a naturally aspirated engine. But even that, they took and dulled by a comfort-oriented transmission tuning. No manual, DCT, or at least a more crisp and quicker shift map for the transmission.

I think this car doesn't know what to be. Lexus probably couldn't afford to delay it until they develop a boosted unit so they gave it the older N/A one (albeit, with updates). That means they couldn't compete on raw numbers so had to make sure it's more comfort oriented in suspension and transmission tuning. That isn't a cool selling point in this segment, though, so they tried to sell it off as more of a "purist" choice because of the N/A engine. It's a half-hearted attempt that only exists because they needed a GS F, in my opinion. I'm typically a sucker for a good naturally aspirated V8. Here, though, I can't help but ignore it, because the looks say it's trying (far) too hard while the rest of the car says it's not trying hard enough and the price.. that is just screaming: there are far better options!

Tesla Model S P85D - 3:17.4: A humble FWD, 4 cylinder turbo Focus ST is but two tenths of a second behind this. The Focus is more or less 3 seconds slower to 60 mph and to cover a 1/4 mile, and it's also laughably traction limited, being FWD with an open differential (and only brake-based limited slip programming) vs this mighty multi-electric-motor AWD Tesla. I admit, it's very cool to keep giving this car more power and better launch programming to see how quick it can go from 0-60 mph but the fun AND shock of it is getting old. I hope Tesla starts putting some money and effort into developing a proper battery pack with cooling that can allow the battery to function at peak despite track abuse. This slow time was even despite having part of the lap (first 40 seconds) with full power before battery protection kicked in. Imagine a second, full lap, entirely with reduced power. Tesla gave us the first long range car, charging infrastructure, and good, desirable performance, but all is moot so far for the large (and growing) market of track-day enthusiasts around the world.

Where is my car??

You might be wondering where some cars are or why they didn't make the list. A couple were close calls for me so I thought I'd mention them.

Focus RS - 3:03.9: The RS put down a blistering time and most people probably were expecting to read it in the high list or were at least surprised by the time. I, too, was very surprised at first, then I saw it was done on the optional Michelin Pilot Sport Cup 2 tires. It's hard to say what those are worth but 3-5 seconds seem reasonable to me on a track of this length. Half way in the middle, 4 seconds, would give this car a time of 3:07.9 about 2.5 seconds quicker than an STI. That's very good and, as a Ford fan, I couldn't be happier that it's the quickest car in the segment, and by a large margin, but we already knew it handles better, has more power, and better power distribution bias, so that's more or less where you'd expect it.

Shelby GT350R - 2:51.8: I was disappointed when I first read this, because it couldn't beat the last generation Z/28. I was planning to put it under The Lows. Then I started to read more. The Shelby and Corvette Grand Sport have the same model Michelin tires. However, they found those on the Grand Sport to be more peaky, with great grip for a few laps, and then grips falls off slightly as they get hotter. There is nothing wrong with that. Most tires are like that. You always expect to lose some grip when the tires get hot. In fact, the ones on the Vette were actually good because the tires were very consistent after giving up some edge. The interesting thing, though, is that the Shelby-specific tires were designed to have more longevity than ultimate grip, and the tires never seemed to lose any grip as the laps piled on. This is not only very useful, but also refreshing - to see an automaker committed to something you will probably see very little promotion on (besides Ford advertising they're Shelby-specific spec) but a serious driver will appreciate. And that something could hurt lap times, the one thing most people will remember and reiterate, for the sake of having a more consistent and confident inspiring car. Moreover, as I said under the M4 GTS, when cars are this close in performance, you can't judge based on lap times on only one track and, as you may have read, Motor Trend's Best Driver's Car results are published and *SPOILER ALERT* they're different and the 350R does beat the Z/28 by about a second and a half.

Corvette Grand Sport - 2:47.1: This is more or less the same story as the Focus RS. It seems like a surprising time at first, but then you think about it, and it makes perfect sense - much bigger and stickier tires, upgraded suspension, and more downforce. It sits between the Stingray Z51 and the Z06 in terms of lap times, although it's much closer to the Z06 - 6.7 seconds faster than the Z51 and only 2.5 seconds slower than the Z06 - while being much closer in price to the former - about $11,000 more expensive than the Z51 and $18,000 less than the Z06. But it is justified because, with the Grand Sport, you only get the track performance but not the power. With that said, with apologies to the overlords of automotive power, you don't want the extra power here.. If the Z06 were still naturally aspirated, sure, but I will always prefer a naturally aspirated engine on track than otherwise. And you'll give up very little comfort, thanks to the excellent magnetic shocks and dual mode exhaust, but gain so much in performance. This is basically tying a Porsche 911 GT3. The RS one - costing two and a half times as much, producing 35 more hp, and weighing about 350 lbs less. Both have sticky track-oriented tires and real aero-improving parts. The Corvette does more with (a lot) less. And it's a V8 with a manual..

Friday, 16 September 2016

2016 Camaro SS vs 2016 Mustang GT - Road Test

If you've come here for a new instrument head-to-head test, I'm afraid you'll be disappointed. Although, for the sake of those who do want numbers, here they are from the most recent Car and Driver comparison test:

2016 Camaro SS 2016 Mustang GT
0-30 mph 1.6 s 1.7 s
0-60 mph 3.9 s 4.4 s
0-100 mph 8.9 s 10.5 s
1/4 mile 12.3 s @ 116 mph 13.0 s @ 112 mph
braking 70-0 mph 147 ft 157 ft
300-ft dia.skidpad 0.98 g 0.94 g
610-ft slalom 43.9 mph 43.3 mph

For some reason, Car and Driver tested an 8-speed auto Camaro and a 6-speed manual Mustang, so figure you'll lose a tenth or two with a manual; the gap is still clear. The new Camaro SS out accelerates, out brakes, and out grips the new (now almost two years old) Mustang. And I'm not here to tell you otherwise. If you're reading this, chances are, you've already read plenty of other reviews so I will try to give a different perspective. The perspective of a guy who owns this type of car, enjoys it the way it was intended to be enjoyed, but also daily drives it.

I had an opportunity to test drive a new +Chevrolet Camaro SS the other day as well as a new +Ford Mustang GT. Both cars were manual but, while the SS was a loaded 2SS model, the GT was a no-options base model. And by no options, I mean no options - not one. The Camaro, on the other hand, had plenty of options, including, crucially, the Magnetic shocks and dual-mode performance exhaust. I decided to take this opportunity to write my impressions of both cars. Don't consider this a foregone conclusion because of the disparity in options. 



Let's first address the elephant in the room; Camaro visibility. I came in expecting to hate it, especially after hearing that it's worse than the last generation, which I have driven a couple of times. To be honest, it wasn't that bad. I think it is very overblown. Sure, sight lines are tight and if you like a lot of space, you will probably feel claustrophobic because you can't see as much of outside as.. uh.. normal cars. But the parts that are blocked are not typically what you need to see to drive properly. Imagine having your sun visor down and then imagine stretching it across your windshield. Rotate it and put it against the side windows too. You now have a rough idea - the Camaro is a little bit better than that. You won't see as much of the sky, but unless you plan on taking off, that shouldn't be much of a concern.

As far as seeing what you need to see, it's mostly all there. The only bad blind spot is over the shoulder but if you have your mirrors setup properly, you shouldn't need to see much anyway and most people now get blind spot monitoring, cross traffic alert, etc. anyway, which is available (not that I like to rely on those features instead). The A pillar is thick but there are plenty of new cars like that now so it's no different. Point is, if you think you might get claustrophobic, it is bad. But don't dismiss it because you think you won't be able to see out of it. You can still see what you need to see. It isn't ideal but far from a deal breaker in my opinion.

With that said, the Mustang feels like a cathedral in comparison. I have never sat in a Mustang before and thought: "Look at all the space!" It feels very spacious relative to the Camaro, despite interior dimensions looking closer on paper. Although, like I said, it isn't a deal breaker for me, the Mustang interior is easily the better place to be. Interior design is nicer, too, and more cohesive. And inside and out, I feel like the Mustang manages to better capture retro design cues from classic Mustangs while looking more modern. Mustang +1.


With that out of the way, the first thing you notice - assuming you're eager to start them car up like me instead of playing with gizmos - is the noise. Press the start button, and the Camaro roars into life in a way that belies a completely stock car. It's hard to miss when you startup. It's hard to miss when you get into it. It is very easy to miss, though, when you're just cruising under light load and the dual mode exhaust isn't shouting. The Mustang, on the other hand, doesn't have the same vocal range. It's more or less as quiet as the Camaro under light load so you aren't giving up much, if any, in that department but get into it, and there's a very noticeable difference. The beauty, here, is the dual mode exhaust, which means the noise will never get tiring because it quiets down when you're taking it easy. Not that V8 noise should ever get tiring...

And there is power everywhere in the rev range. In true Chevy V8 fashion, power comes on down low and stays, relentlessly, throughout the rev range. The Mustang never failed to please when you put your foot down, with plenty of power that is very linear and the noise is a little more hairy-chested-machine-gun (albeit, relatively quiet) than the Camaro, which is accompanied with a faint wail. Despite that, it doesn't quite have the same low end shove that you get at low engine speeds with the 2-valve, big displacement, Chevy small block. Camaro +1

The Drive


Surprisingly, driving the Camaro is where things actually disappointed. Before you curse or dismiss this review, hear me out. Based on what I've read, I feared (and was expecting) to leave feeling blown away, contemplating whether I should trade in. I had extremely high expectations. That was problem number one. Problem number two: I didn't get a chance to take the car out on a nice back road or, even better, the track, where I have no doubt the car would shine.

There was plenty to like. The noise is awesome like I said. You can't complain about the power. The car is stiff, but never punishing, and very composed. Body roll and movements in general are far better controlled compared to my '12 Boss 302, let alone the base GT I drove. It has great turn in and is very responsive. It seems to put power down really well. I tried a very aggressive throttle roll-in in 1st gear and the car executed beautifully. A lot of things seemed text book perfect during the drive. What went wrong, then?

It provided exactly no additional reward over driving the Mustang. In fact, it was a little less entertaining. The engine, for example, feels very lazy at street speeds, barely having to rev above idle to get you moving and never needing or, more importantly, feeling like it wants to. Don't get me wrong, I love a good ole' low-effort V8. But the eagerness of Ford's 5.0 litre Coyote is more fun, especially here on the street where four or four and a half seconds to 60 mph makes no difference. Both will take off with satisfying grunt, both will sound good, and both will have no trouble reaching any speed you demand with your right foot. And the Mustang isn't exactly light on mid-range power, either. The car could easily cruise around town in 5th gear at speeds of 40-50 km/h and never break a sweat (don't do it). The Camaro otherwise also feels extremely unstressed in day to day driving. You get very little sensation of speed. Body movements are extremely limited at a reasonable pace on the street. The compromised visibility doesn't help, as it dulls the sensation of speed even more by limiting feedback from outside.

On the other hand, the Mustang is noticeably more comfortable, a big advantage on the street. The engine is a lot more eager to rev, with much shorter gears. In fact, the Mustang only has one over drive gear, with 5th being 1:1, but the Camaro has two, with 4th being 1:1. The Mustang's soft suspension and airy cabin, both relative to the Camaro, make it feel quicker and, combined with the more eager engine, more entertaining. The trunk is also another huge advantage, where the Camaro has a narrow long space that's less than two thirds the size of the Mustang. Mustang +1


Does the Mustang win 2:1, then? Not exactly.. Although these cars have been competing for years, sell in comparable numbers, have the same number of doors, seats, engine cylinders, gears, and driven wheels, are close in performance and size, and even cost comparable amounts of money, they are very different in their current generations. The Camaro was optimized for the track. You can tell by the compromise in the trunk. The rear shock towers appear to be tilted further inward, to better transfer loads towards the centre of the car and less up/down. The battery is in the back. The engine is placed further back about 3/4 of the way behind the front axle, whereas the Mustang's engine is about 1/2 way - sitting basically on top of the axle. This is evident in the Mustang having shorter wheelbase but more interior room.

But, as a result, everything that I "complained" about would make sense on a track. The lazy engine means there is a lot of power regardless of rpm and gear. The long gears mean you don't have to shift as often. The stiffer and more buttoned down suspension means better tire wear, stability, and performance. The Mustang, on the other hand, would feel relatively heavy, low on grip, and sloppy. You may not notice if you drive the Mustang alone, as it is a very capable and composed car. But drive them back to back on a track, and I guarantee you, you will want out of the Mustang and into the Camaro. The Camaro also has coolers for all drivetrain components - engine oil, transmission, and differential. The Mustang only has an engine oil cooler.

The conclusion here is that the two cars serve very different purposes. If you just want a fun, V8 coupe for the street, storming a good back road, a nice Sunday drive, or even a couple High Performance Driving School (HPDS) or lapping days here and there, do NOT buy the test numbers (i.e. the Camaro). The airy, better looking, and more comfortable interior of the Mustang plus the relative practicality makes it a much better street car and, base cars or comparably equipped, it's cheaper to boot. Plus, the lower grip and body motions will provide a much better car to learn on. Cross country trip? I bet the Mustang would be sublime, equally comfortable cruising for hours or letting you enjoy all the back country and coastal roads you want. If you get the Camaro and you're planning to ever take a road trip in it with your better half, measure your suit cases and map out the trunk. You may be able to only fit a suitcase and a half back there..

But if you are planning on frequent track events, walk away from the Ford dealer. Go to Chevy, they'll happily give you a Camaro SS in exchange for some of your money. It's a better track car. And forget about the Mustang performance pack. It isn't enough. If you don't believe me, ask yourself this: why did Ford stop calling it the Track Pack and switched to Performance Pack (PP)? I test drove a current Mustang with the Performance Pack and it is not enough (alone) for someone who does more than a couple track days a year. Sure, if you get the Camaro, I have no doubt you'll find weak points and start planning modifications. Every car has weaknesses, even race prepped cars. The difference is that you'll find weaknesses a lot sooner in the Mustang. The PP is very good if you go drive a GT without it and think: "it's a perfect car, I just wish it had a little more edge." Or, if you're like me - a Mustang guy who wants to track the car, as it provides a great upgrade or a much better starting point. Otherwise, save yourself the premium and leave the box unchecked as it will make the Mustang a better, more comfortable street car.

I am a Mustang guy. I would take the Mustang. I wish I could leave it at that, but objectively, it isn't as track ready out of the box as the Camaro. It has an excellent chassis and provides a great starting point towards a formidable track assault vehicle, with vast aftermarket support and even great factory-backed upgrades from Ford Racing (stay tuned for a post on how I'd spec a new Mustang GT with Ford upgrades!). But if you want minimal or no modifications, the Camaro SS is the one to get. Their trim names could not have been more spot-on than they are now; the Mustang GT is truly a world class Grand Tourer but the Camaro SS is the one for Super Sport .

Sunday, 4 September 2016

Mods and Update: Focus RS vs Golf R vs WRX STI vs Evo X

Earlier this month, I introduced the cars that we'll be testing in a comparison. The cars included a Focus RS, a Mk7 Golf R, a 4th gen WRX STI and an Evo X. Unfortunately, the Evo X will not be making it, but the other three are still in, so I thought I'd take some time to post the update and shed more light on the cars. I wanted to have a 100% stock car comparison. I really did. Unfortunately, that isn't going to happen. Well, for most of the cars anyway.

The Golf R and the STI are modified, whereas the RS is stock. If you're curious, the Evo X was also modified. All have very few modifications. The Golf R went the way that seems to be very popular - tune and exhaust. It also has an intake. I asked the owner to return the tune to stock, which he agreed to do, and said he might take the intake out too. Exhaust, though, is a lot tougher to get out. He has a full turbo back exhaust so he didn't want to take it out. I can't blame him. As a result, the car will be running with it. How much performance is it worth? I don't know. I'll do some research. I suspect it will be 10-15 whp, considering the aftermarket downpipe. I don't know how much time that will be worth on the track but will try to estimate somehow.

The STI, on the other hand, has no modifications under the hood. The engine is stock, exhaust is stock, intake is stock, and it is running the stock tune. The owner only made two modifications - camber bolts and tires. Tires are Bridgestone Potenza RE-71R. They are the hot tire right now. The one to have. They have a tread wear rating of 200, making them legal tires for plenty of competition classes, yet they seem to out grip and out class every other tire in its category. Think more of a Michelin Sport Cup tire competitor than Pilot Super Sport. Everyone I have talked to who has tried these tires said they are comparable to DOT legal track tires with a tread wear rating sub 100. Hard to say how much exactly they're worth, but I hear 2 seconds on our track is more or less how much you can cut out of a lap with them. As far as camber, it's much tougher to gauge. The owner is running -2.5 deg all around. I seem to be running about 1 second faster per lap at the same pace as before getting camber plates and I am at about -2.3 deg on the front, rears are obviously zero, being a solid axle. Is it fair to say the STI would be about 3 seconds slower, stock? Don't know if it's fair, but I don't think it's far fetched.

The RS, though, as mentioned is stock.. I know, I know, it's not fair but the alternative is to not run at all. Which would you rather? I'd rather get a time, at least as a baseline for the future if another one comes our way to test and gauge modifications. Plus, if you're an RS fan, imagine it winning, stock, vs modified cars! That would be a home run. And if it loses, you can always blame on the modifications. Win-win.

Tomorrow, I will be getting some (non-official) lap times and logs in the RS and getting to know it on the track. Then, the first weekend of October, we'll have all three cars at the track, and an Evo X if we can find another, to get official lap times and see how they stack up. Stay tuned!

Saturday, 27 August 2016

2016 Porsche Cayman GT4 - First Ride

I had an opportunity to take a track ride on the last lapping day I went to on Natal Day (lapping day post here) to ride in a +Porsche Cayman GT4. Needless to say, I took it. Although there is a lot you can't tell about a car from the passenger seat, you can still judge quite a few things. Plus, I have been a passenger in a lot of cars on the track, stock and modified, ranging from humble SRT4's and Evos to Corvettes and 911s, the highlight of all would probably be a 997 GT2 RS, so I learned to gather a lot of information about a car while acting as a ballast. The Cayman GT4 lands somewhere in the top-middle portion of that range in terms of pace. The way it manages that pace, though, is different. Very different.

Driving cars fast is similar to playing and composing music. You can't produce good music in all genres in the same way. You have to pay attention to scales, beats, appropriate tempo, chords, etc. In much the same way, different types of cars like to be driven differently to reward you. Depending on the handling balance of the car (understeer, neutral, or oversteer), weight distribution, polar moment, yaw axis location, driven wheels, etc.

In one extreme, you have FWD, front end heavy, safely tuned (i.e. limit understeer) cars. You rely a lot on trail braking to rotate the car. You can't use power mid corner to help the car rotate. You have to be patient with the throttle on exit. Things like that. At the other end of the scale, you have 911's. Phenomenal braking balance due to the weight of the engine on the rear wheels. Phenomenal traction for exactly the same reason. But, once again due to that very same reason, you have very high rear polar moment. Man handle it (with the nannies turned off) and it'll bite. You can use the power to rotate the car. But you have to be careful; it'll first want to understeer as you take weight off the front wheels and the solid traction in the back lets you just put power down. You'll you give it more, but it'll just put that power to the ground. Then give it some more. Until you get to the point you want, where the rear wheels begin to slip and help you rotate. Remember all that weight in the back that was helping you brake and put power down? It now wants to swap ends with you. Good luck keeping it back there.

What, you might ask, is this guy blabbering on about and what is the point of all this? The point is that you need to remember all of it before you can appreciate the GT4. The GT4 takes all of those notions, all of those concerns, techniques, and (let's be kind), say, character attributes, and throws them all away.. You could just forget about all that when you get in. It doesn't matter. The GT4 is so stable and so forgiving that you feel like you can get away with everything.

Now, Caymans are known for being forgiving and stable. They're great cars to drive fast in. What's special here is the very high dose of grip and immediacy. The car responds so fast that you except it to bite if you take it by surprise but it just doesn't. That was the one thing that stuck with me most after the drive. The speed isn't impressive. There are plenty of cars that have the same pace. Ultimate grip? It has big, fat, sticky tires, what do you expect? The combination of high grip, stability, and immediacy was the most impressive. The owner was still learning the car as he bought it recently so not all inputs were smooth, yet the car just took it all. No oversteer, no understeer, no drifts, just goes where he pointed it. The very same moment he pointed, it seems.

He wasn't driving at the limit so I didn't see what it's like when the tires do let go (or approach that point) but, being mid engine and so stable, I suspect the balance would tilt a little towards understeer. With that said, I expect that to be remedied "with a boot full of power", to quote Jeremy Clarkson. A little throttle would probably rotate the car beautifully at the limit. I also can't comment on the steering since I didn't drive it, but I could tell a lot about what's happening at the contact patches and suspension loading through the chassis. The suspension is very stiff, although not punishing, and the chassis can talk a lot through the seat, especially (I suspect) when so equipped with the optional fixed-back buckets.

Power? Well, no one can call 385 hp low, especially in a car that basically weighs 3,000 lbs. In fact, this car has slightly better power to weight ratio than a Boss 302 like mine, with 444 hp and a curb weight of approximately 3,600 lbs. It's also still naturally aspirated and, of course, comes from a proper-sounding flat six, both are unlike the new turbo and 4 cylinder 718 Caymans. But.. the car could use more. A lot more. There is enough power for someone to put down a really good lap time but not enough for the chassis. It could use a lot more. It's begging for a lot more. Especially if that extra power still comes linearly, with no forced induction, and keeps on building with revs. A GT4 RS perhaps? 450 hp wouldn't hurt..

After the drive, Alan - the gentleman who owns the car - asked me what I think the car could do. I expect the car to be able to run 1:15's, easily and consistently, and maybe dip below 1:15 but I wouldn't be surprised if it were even a tick quicker. If I remember correctly, he seemed to be running between 1:23's to 1:24's when I was with him, with the occasional high 1:22 lap. In my experience, a passenger that shares my curb weight adds about a second a lap, so that would drop to a range of 1:21's to 1:23's. He was able to dip into the teens and got just under 1:20 on a lap in the morning in cooler temperatures, in what I have no doubt was the same pace as the afternoon. Despite that, the car didn't feel like the it was breaking a sweat.

Faults? Hmm.. It's only available as a manual. You can't have it as an AWD. It's a little loud. I don't think you can get some features like leather seats or sunroof and.. Oh wait, I'm supposed to be listing faults. I don't know. Let me know if you find them.