I recently had a crazy idea: let’s let you all pick my next dual-purpose car using Instagram polls. There were four options: Lexus ISF, Cadillac ATS-V, Camaro SS 1LE, and a F82 BMW M4. Well, the first round of votes is in, and the ISF and ATS V are out. That leaves the F82 vs the SS.
Today, I want to do a deep dive on the top five traits I look for when buying a new-to-me car for tracking. I hope this serves as a checklist to help you objectively decide on your next vehicle.
Chassis Torsional Rigidity
Arguably one of the most overlooked metrics out there. Torsional rigidity is the resistance of the chassis to twisting forces applied to its longitudinal axis. It is measured as the amount of torque, often in Nm, required to twist the chassis by one degree. Typically, the OEMs will include these on a promotional and marketing basis for sports cars and halo cars. A stiffer chassis improves consistency through corners, reduces unpredictable handling at the limit, and allows you to tune the suspension more precisely. The higher the number, the better.
Things like roll cages and stitch welding improve the rigidity as well (if designed correctly). Unfortunately, this makes it harder for older cars that never had them published. These sports cars aren’t the halo cars (like the Camaro), and when you ask AI, it sometimes blurts out an estimated number or a guess from a forum member, so it’s not super reliable. Fun fact, if the convertible has a coupe version, 9/10 the coupe will be more rigid.
The good news is the BMW F82 is 40,000 Nm/Deg, which is phenomenal. For example, the LC500 is Toyota’s most rigid chassis to date at 32,000 N · m. The GR Supra is 27,000 according to a press release from Toyota in Europe.
Sadly, there aren’t any public numbers on the Camaro, but the Alpha chassis that it was built on was reported to be 32% stiffer than the previous generation. I’ll have to chalk this up as a win for the BMW.
Winner: M4Â
Why Suspension Geomeotry is Important
At its core, suspension geometry controls the tire’s contact patch under dynamic load, which is what happens while you’re driving on track.
As the suspension moves steering, compressing, extending, and transferring load, it directly influences how the car behaves during cornering, braking, and acceleration.
In well-designed suspension geometry, one of the key traits you want is camber gain. During hard cornering, the outside suspension should gain negative camber as it compresses. This allows the outside tire to tilt inward and stay flat against the road, maintaining the largest possible contact patch and maximizing grip.
You also want to manage the roll center location. Keeping roll centers in a proper range helps avoid erratic handling. A straightforward way to do this? Don’t slam the car too low.
Beyond factory geometry, there are ways to refine and improve things. Brands like SPL Parts and AKG Motorsports offer bump steer correction tie rods, which help maintain proper tie rod angle and length as the suspension travels. Without this correction, unintended toe changes can occur during compression or extension, leading to instability, especially under braking or over bumps.
Suspension Layouts Explained
Here’s a breakdown of the most common suspension layouts used in motorsports and the main positives that they provide.
Double Wishbone, which is arguably the best. Double wishbone systems deliver excellent camber gain, stable roll center behavior, and minimal bump steer. The only negative is that there are more parts, and the packaging can be complicated at times.
Multi-link systems are common in modern IRS designs. With enough links, you can fine-tune camber gain, toe behavior, and anti-squat independently. They shine under braking and acceleration, allowing you to balance ride and grip simultaneously. Typically, they are in higher-end sports cars like the Supra. The downside is that with more links, alignments become a bit more challenging; one link affects toe and camber to some extent.
The most common front suspension in production cars is the McPherson strut. While it lacks natural camber gain and has a more volatile roll center, it’s cheap, lightweight, and compact. Some cars, like the Porsche 987 Cayman, exclusively use this front and rear. The negatives are Limited camber gain and high roll center migration.
Semi-Trailing Arm and Trailing Arm. Although outdated, it is still seen in classic and economy platforms. These layouts are simple but suffer from excessive toe change and limited geometry control under load.
Solid Axle with Panhard Live axles are strong, predictable, and effective in straight lines. But they’re fundamentally limited in lateral grip because they allow no independent wheel movement. Watt’s linkages help control side-to-side motion better than Panhard bars, but both are a compromise.
Where does that leave us in the M4 vs Camaro? Leads us at tie. They both have a McPherson strut front with bump steer correction courtesy of SPL. They both have multi-link rear suspensions. In fact, someone once said it looks like the Camaro just has a slightly different suspension than the E9X M3s, so maybe GM took some notes from their German counterparts.
Verdict: Tie, both the Camaro and M4 have very similar suspension geometry.
Weight
As Newton said, force = mass x acceleration. The lighter the mass, the faster you can accelerate it, given the same horsepower or torque. I’m going to stand on a hill and say that the lighter car is always better for a track car or a car in competition. The lighter car will not only require smaller brakes, which will be important with unsprung weight. The lighter car will require less momentum to decelerate and much less kinetic energy. A lighter car transitions faster and carries more corner speed for a given tire size. Lighter cars generate less heat everywhere (powertrain, brakes, and tires). The lighter the vehicle, the less fatigue of dampers, hub bearings, and bushings. My rule of thumb is always to make your car as light as possible without compromising structural rigidity or using exotic materials.
Now there are some negatives at times. A light car can be unstable at high speed without aerodynamic support. When you get to really light cars, things like crosswinds start to affect them and can catch you off guard. Heavier cars “press” tires into the pavement, while ultralight cars may bounce or skate over imperfections if the dampers are optimized correctly. In some power-to-weight classes, heavier cars can be detuned to maximize their power across the entire powerband. Additionally, they can be physically larger and wider, which enhances cornering and stability.
The Camaro SS 1LE with its 6-speed manual transmission has a curb weight of 3,685 pounds. The BMW M4 with a DCT has a curb weight of 3,554 pounds. Curb weight is the total weight of a vehicle with all standard equipment and full operating fluids. My rule of thumb is that I can take out 5% of the curb weight without getting too crazy. Every 100 lbs is reportedly worth 1-2 tenths around a given race track.
Verdict: M4, even with the turbskis.
Powertrain Reliability & Aftermarket Support
Powertrain reliability is about more than just the engine’s internal strength. It’s about how the entire system (engine, trans, and differentials) performs over time under heat, load, vibration, and repeated abuse. A powertrain can make 500 whp, but if it overheats in one lap or blows up at 0.7 lateral G load, then what are we doing?
Aftermarket support is the ecosystem: parts availability, tuning, diagnostics, and community knowledge that make it viable to diagnose, repair, and improve efficiently. As I always say, being the first person to do something means you’ll be the one most hurt by the resource costs (time, money, effort).
I like to go over if there are documented failures of components, and if so, are there well-engineered solutions for the OEMs or the aftermarket? Personally, I don’t like to build engines; there are so many variables, and so I look at what the block, pistons, rods, crank, etc, are made out of. The goal is to run any engine 15-25% less than what’s common on a street engine or what’s typically accepted for the components’ material.
The Camaro has an LT1 in it, which is an aluminum direct-injected small block V8 from the infamous LS series. Let’s be honest, the aftermarket for these things is massive. There is so much information on them that I’m not sure that one person has enough time in a lifetime to read it all. Not to mention that, in the event of any shortcomings, the aftermarket has 10-25 companies that will support it. They can also make about 600 horsepower with bolt-ons.
The M4 is tiny in comparison, but the S55 is no slouch. It has some excellent internals, but what it can suffer is the electrical side of things, and BMW is well known for its various leaks; this one is no different. Before replacing turbos, it can also make just south of 600 horsepower with bolt-ons, so again, it’s no slouch.
Verdict: Camaro, come on now, can you really go against the LT1?
Purpose
Every great build starts with one question: “What is this car for?” Answer it with absolute clarity and honesty. If you have a class in mind, ensure you are optimizing your purchase for it. Let’s say it’s Street Mod. Make sure you can achieve a 6:1 weight-to-power ratio, fit 285 tires on it, and so on. If it’s an HPDE car, ensure you have the necessary support to make it reliable, and that consumables are affordable to hone your craft. Do you need to drive it to the track? Realistic amount of resources you want to allocate to this thing. The more questions you ask yourself, the disciplines and class constraints become a clear yay or nay. Misalignment here will cost you more than horsepower or weight ever will. BE HONEST WITH YOURSELF ON YOU AND YOUR RESOURCES (TIME, MONEY, EFFORT).
When it comes to the Maro and M4. I’m looking to build a car to chase a lap time (sub 1:35 at Gingerman) and play with my other friends in Street Mod. Not only that, it needs to be able to drive downtown with my wife and not be divorced by the time I get back home. That means the interior has to be nice enough that she doesn’t feel like it’s a gutted-out race car. Easily fit 285s under the stock fenders. Achieve a 6:1 power-to-weight ratio without compromising reliability due to excessive variance. Plus everything else we talked about in this article.
The Verdict: M4 Slightly, only because the interior is more suited to my purpose in the dual roll mode. However, if track performance were the priority, the Camaro would have won. Being N/A and a GM product simplifies potential issues, which can be raised higher on the Reliability side.
What did we leave off?
What do you think we should have added to our core 5 of picking a track car? You should leave it in the comments; you never know, we may make a top ten instead.
As for the comparison, I’m leaving it up to you, so feel free to vote on IG on 8/4 and let me know. If you are reading this from the future, I’m sorry you missed out. Now you should follow us for the next one.
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