- Imbalanced Modifications - This is an easy one. In general, when I see imbalanced modifications, it's a car with too much additional horsepower, and not enough brakes, suspension, and tire to back it up. An obvious example would be Lebanon Ford's "700 HP Mustang GT for $40,000" promotion, which, according to a dealer rep, has been wildly successful. Let me get this straight: $40,000 will get you a basic, non-Track Pack Mustang GT with all-season tires, standard brakes, and the power of a Mustang GT plus a Mustang Ecoboost. Well, if you want to see how a car like that looks when you try to take it on the race track, you can watch my video here, or I can just tell you: it's awful. Adding forced induction to pretty much any car that came without it really means you need to upgrade your brakes to haul down that extra speed, your tires to harness the brakes and the added power on acceleration, and probably your suspension to deal with the increase in cornering speeds. An imbalance can occur the other way as well. In our recent Tuner Shootout, the HPA Motorsports Golf R32 arrived with what HPA owner Marcel Horn referred to as "NASCAR Spec Brake Pad Material." I have no idea what that means in scientific terms, but I can tell you the brakes felt weird as fuck on the road, with no initial bite, followed by a centimeter of pedal travel, and then your sunglasses hit the windshield and you felt about to vomit on the steering wheel. Our resident hot shoe Leh Keen agreed, and felt the R32 would have been both faster and more predictable with less brake pad.
- Turning a Reliable Car into an Unreliable Car - As someone who has scheduled hundreds upon hundreds of shoots weeks or months in advance, I'm used to cancellations for all kinds of reasons, and I'm quite understanding if someone has to bail for, really, any reason. But modified cars breaking down at the last minute is a shockingly common occurrence in my world. I don't select cars based on reliability; I select cars based on what I think the audience will find interesting, so when a Neon SRT4 breaks, I'm not surprised. But cars clearly have design limits from the factory, and modification-hungry people will continue to push those limits, and even over-step them. Let's look at the example of the Ford Fiesta ST, which comes from the factory with an advertised 197 HP and 202 torque at the crank. I dyno tested my Fiesta ST at 189 WHP and 229 wheel TQ when it was stock, and over the course of a year, modified it to 248 WHP and 320 wheel TQ using a few bolt-on parts from COBB Tuning (Full Disclosure: I did not pay for these parts). The car, during my tenure, was perfectly reliable, as it has been with its new owners in Ohio, who now have over 30,000 miles on the car. But I recently drove a modified Fiesta ST with a bigger turbo making 300 Wheel HP, 50 more than mine, who was on his third transmission in a year. Was the car fast? Sure. But for how long? A car is only as reliable as its weakest component, and, as this example shows, engineered bits are often quite reliable inside their tolerance zone. Once that tolerance is pushed-either by heat, horsepower, rotational force or G-force-you reach the fail point quickly. While it's true you have to break stuff to learn the limits of these parts, do you really want to find that limit on your own car?
- Sacrificing the Driving Experience for Style - Here's where I throw myself under the bus. You should be realistic about what your actual needs are for your car before you start modifying. For instance, if you have a modern car and are using it for street driving, leave the fucking street belts in. I've now installed racing harnesses on two different street cars: my Corvette and my Mustang. And while, yes, the combination of racing seats and harnesses did improve my lap times a bit in the Corvette, and yes, they do look pretty cool, the headache of using either of those cars simply as cars is often not worth it. Same goes for removing interior panels like rear seats, carpeting, sound dampening, and headliner. With rare exception, the weight savings from stripping out your street car is negligible. I've now removed large percentages of interior from two cars in my life, and you know what? I've made the cars worse, both times. No street car I've ever driven, up to and including the deliciously lightweight Project Nasty 911 by Joey Seeley, was made better because it was missing interior panels, and all of them were made worse. But the biggest Style over Substance offender is obviously suspension. Look, even I can admit that nearly every car looks just a bit better sitting a bit lower than it came. There's a reason manufacturer concept cars have chopped rooflines, low ride heights, and big rims-it looks aggressive. But unlike those concept cars, which sport "getting photographed" as their only true design feature, you actually have to drive your car. And if you're remotely serious about driving, your car should not, under any circumstances, rub. Rub is when you hit a bump, and the tire on your lowered car rubs on the inside of the wheel well, because you've removed all the travel and the clearance. In a worst-case scenario, you ignore the rubbing, or you tell people like me, "don't worry, it's supposed to do that," and when I look at your tire I can see that the wheel well is slicing right through it. Sooner or later, you're going to tear that tire wide open and you'll have a blowout, a scraped rim, a crashed car, and a poo-filled interior.
- Not Knowing When to Stop - I understand as well or better than anyone on this Earth the urge to modify your car. I like objects, especially cars, to be "mine." It's not enough to have a Focus RS; I need my Focus RS to be different from all the other Focus RS's I might see on the road. I get that. But you have to also accept when you've sufficiently changed your car, and where that tipping point might be; where you cross the point of no return. In my most successful "stop yourself" moment, I present my 1998 Corvette. I bought it brand new, and left it stock from December of 1998 until June of 2006. In 2006, I enlisted the help of a local Corvette specialist to make the engine breathe a bit better, and flow a bit more fuel, for a bit more power and sound. I had the suspension converted to coil overs. I did big brakes, good tires, lightweight wheels, and changed out the awful stock seats for Sparco's. Then, I stopped. I went from stock, to modified, all at once, and then stopped. It was about $10,000 worth of modifications, 8 years into the car's life. Aside from fluids and tires, I haven't had to change a thing on the car once since. It's fast, fun, and dead-to-nuts reliable. I changed its character, added a bit more performance, potential and personality, and then stopped. In one of my more failed moments of not knowing when to stop, feel free to go back and read 2,000 more words about my project Mustang. For street cars, there are two major indicators that I like to share, red flags, if you will, for knowing when to stop. Red Flag #1: Built Internals - If your car is so heavily modified that your next move is pulling out a fully functional engine and installing stronger internals, you should probably just stop before you do that. I'm not against stronger internals per se, but there is a time and a place. Rebuilding an engine is either very time consuming or very expensive, but most likely it's both. Red Flag #2: Tuning Yourself Into the Next Price Bracket - Before you get deep into the aftermarket on your BMW M4, you should realize you're about to tune yourself into Porsche Turbo territory. There are two real sweet spots for tuning-one is a depreciated, late-model car like the E92 BMW 335i, Infiniti G35, Focus ST, Subaru WRX, or something like that. You could pick one up for $15,000-$20,000 and for another $10,000, be as quick as a brand new 335i-a $50,000 car. So there is some value to that level of tuning. The other is, believe it or not, exotic cars, which, for enough money spent in the aftermarket, are able to go way faster than basically any car available new off the showroom floor. We're talking twin-turbo Lamborghini's, big-boost Porsche Turbo's, Supercharged Audi R8's, and crazy Nissan GTR's. If you're rolling in that kind of cash and you want to shame people at your local runway race, a $300,000 Heffner Twin-Turbo Huracan will embarrass a $2 million Veyron Super Sport in a drag race every day of the week. That's value, just with more zeroes on the end of it. Once you're outside of those sweet spots though, it's tough to make a tuning value argument. Case-in-point, the modified M4's and modified Caddy ATS-V I tested recently. Each of these projects began as a very fast and well-rounded $80,000 sport coupe; each of these projects featured at least an additional $30,000 in power, suspension, wheel, and brake modifications. One, the M4, had as much as $50,000 in parts installed, on top of the car. All of these cars made big power, but none in a particularly pleasant way; like they were either making too much or not enough power at various points on the power band. They all had expensive, track-ready suspension setups and fucking horrible ride quality. They were all so loud, so stiff, so jerky and darty, that the refinement for which you paid extra by getting a BMW rather than a Mustang, is now gone. And all that work to maybe be as fast as a bone stock Porsche GT3, Corvette Z06, or Shelby GT350R? What happened is, these cars were all tuned into the next price bracket, right alongside my stupid Project Mustang, which has crossed deep into Porsche 997 territory. I know car guys don't like to do math, because then we have to face how much we've spent on our cars, but if you even consider for a minute that you might have the inkling to tune yourself into the next price bracket, maybe, just maybe, you're looking at the wrong car. You should always start with the best car you can afford from the factory. There is no substitute for factory development, so if you want to go faster, consider starting with a better car before modifying your cheaper car into that price bracket anyway.
- Not Modifying the Driver - Last, but not least, the Driver Mod. Neither you nor I can drive our cars as fast as they can go. I know this because I've raced the same car with other team members who have gone faster than me, and you've demonstrated this to me in person by being batshit terrified in the right seat while I'm going six-tenths in your modified car. A racing instructor's favorite activity is showing students what's possible in the most basic of cars. In my early driving days at Skip Barber at Lime Rock, instructor Bruce MacInnes shepherded a lead/follow group in an old, used Mazda3 at a pace I could not sustain in a Formula Ford. I'd like to think I've gotten better, but if I went with my Focus RS up to Lime Rock to visit old Bruce, I'd be shocked if he still couldn't put a second a lap on me-in my own fucking car. Having some humility with your own driving ability, recognizing where to improve, and practicing at the track with instruction; that's the driver mod. If you truly are faster than your own car, then you should have no problem addressing the parts of your car which are ripe for modification. But I dare you: go to a track day and let an instructor run 5 laps in your car. If you're not faster than the instructor, it's not the car that requires modification: it's the driver.