Featured Articles

Five Bolt Ons That Will Make Your Car Slower

Posted in Car Accessories, Car Tech, Cars, General, Horsepower, How To, Maintenance, Repair, Tips, Tires by Kurt Ernst | August 25th, 2010 | 12 Responses |
2009 Chevy Camaro

Wouldn't a chrome boat anchor be cool, too?

I’ve always been about function over form, and can’t think of very many upgrades I’ve done on cars or bikes that haven’t added either straight line speed, improved braking or enhanced grip in corners. Before I change a part, I try to find out exactly what it’s going to do for me; if the benefit is just enhanced appearance, chances are good I won’t spend my money. If it enhances appearance but slows the car down, I definitely won’t be spending my hard earned dollars on it.

Here are five common bolt on items that will make your car slower if you don’t shop carefully. The common theme with all of them is that there’s no such thing as a free lunch; bolt ons that add horsepower have significant R&D behind them, which is usually reflected in the price. Knock off parts don’t have much R&D, hence the reason they cost a lot less. If you’re going to make an upgrade, spend the time and money to do it right; otherwise, you’re just throwing cash away.

Bigger Wheels

Satan rolls on 26ers...

These days, even crossovers come from the factory with 22” wheels. Aside from some enhanced grip in the corners (thanks to the tire’s reduced shoulder height), what are you getting for your money? Slower acceleration, longer braking distances, more expensive tires, premature suspension component failure and bent rims if you roll in the land of potholes. Other than good looks, is there a valid reason to go with oversized wheels?

The answer is, “it depends on what you want from your car”. If you’re taking it to the dragstrip, leave the factory 18s on instead of the chromed 22s you just spent a month’s salary on. Ditto for track days; going up a few sizes will net you slightly more grip, but at the expense of slower acceleration out of corners and longer braking distances into corners. Unless, of course, your new wheel and tire combo is lighter than the stock setup.

If you’re in the market for a set of track day wheels, look for the lightest ones you can find from a manufacturer you’ve actually heard of. If you’re looking for street wheels, light is also important, but strong is equally important. Nothing sucks more than pretzeling a new $500 wheel on the first pothole of the season, especially if it leaves you stuck by the side of the road.

Cheap Tires

Can you believe I only paid $50 per tire?

Tires are big business, and cheap imports from China can be had in nearly every size you can think of. Tires are what get you moving, give you grip in corners and stop you, so in my mind they’re the most critical component of any vehicle. There are plenty of places to save money (eating ramen, sneaking into movies, pirating your neighbor’s internet), but tires aren’t one of them.

The major tire manufacturers put huge amounts of money into racing, R&D and testing. Do you really think that “Lucky Dragon Manufacturing” does the same, or do you think that they just reverse engineer a tire from another company? Wouldn’t you rather have a tire built by a company that specializes in tires, instead of one that builds everything from bicycles to battery powered adult novelties?

I’m not saying you need to stick to Goodyear, Bridgestone, Michelin or Pirelli, either. If you’re on a budget, Yokohama, Kumho, Falken and Toyo (to name just a few) build good tires, and I’d run them on anything I own. Do a little research on marque specific websites and see what members are using, then use the internet to compare pricing before you buy.

“Brand X” Cold Air Intakes

But it was half the price of an AEM system...

Everyone knows that a cold air intake can add instant horsepower, right? Not exactly. In the real world, you’d need to have a fairly restrictive intake to see serious gains from just a cold air intake. The best kits will probably get you anywhere from a few extra horses to a max of 15 or so. Chances are good you won’t even feel the difference on your “butt dyno”, so adding a cold air intake is just one step in getting the most out of a stock motor.

Ebay is chock full of cold air intakes made to look pretty, but with no science behind them. If K&N, Comptech, Mugen, etc. can only get you a few ponies, do you really think that the “Cheng Shin Fireball” intake, with a buy-it-now price of $49.95, is going to deliver the 40 extra horsepower they claim? I’m going to go with “no” as an answer to that question.

“Brand X” Exhausts

Yeah, that'll add some serious horsepower...

I don’t want to open up the whole “backpressure versus open exhaust” argument here, but I’ll say this: adding a high flow exhaust that isn’t specifically designed for your car can rob you of horsepower on all but top end. The gains you make on top end are likely to be very small, so if your car gets slower from 40 to 65, does it matter if it’s a hair quicker from 70 to 73? Probably not.

As with every other bolt on performance part, quality costs money and an aftermarket exhaust should be just one of your bolt on upgrades. Try to match it with an intake and header that others have documented experience with. Dyno results are much more valid that personal claims, since you can see the net result of mods across all RPMs.

If you opt to go for an exhaust only, make sure you listen to it first. What sounds cool as an audio file on a website may just be grating in real life, especially if you spend an hour a day in the car commuting.

Junk Science

It was a fraction of the cost of the Cosworth blower...


Over the years I’ve seen just about every gimmick you can think of to “squeeze more power out of your engine” or “boost your car’s mileage”. Aligning your car’s fuel molecules won’t have any effect on your mileage, there is no pill you can add to your fuel tank to boost performance, adding fins to “turbulate” the air in your intake tract won’t boost power and a small electric fan is not a “bolt on electric turbocharger”.

The best you can hope for with any product that makes ridiculous claims is that it won’t damage your car. There is no chance that it will actually produce the results described by the manufacturer, which is why so many of these companies pop up and then quickly disappear.

Part of tuning any car or bike is the development work you do before you even begin ordering parts. It’s researching what parts work and what parts don’t, then planning the upgrades in a sequential order as your budget allows. There is no easy or cheap way to make your ride significantly faster, but if you set goals for mods along the way, the build process can be as enjoyable as the end result.

Our Best Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

12 Responses

  1. ds440 says:

    And everyone knows that vinyl carbon fiber decals are worth AT LEAST half a second in the quarter mile…..

  2. Kurt says:

    No joke – my Voodoo shift knob is good for 10 horsepower…

  3. Taylor says:

    Turning whitewall tires inside gains you horsepower and traction.

  4. Kurt says:

    Taylor, not sure about that but it does gain you respect.

  5. 68SportFury says:

    Y’know, I try not to rag on other people’s cars, I really do, but when I came across that Camaro on 26’s, my first thought was “You-gee-ell-WHY???”

  6. DaveMofo says:

    D00d! Are you trying to tell me that sweet HUGE wing I spent 6 grand on and just mounted on the rear lid of my (front wheel drive) Honda won’t give me an extra 20 mph top end?

    Fuck that! I’m sick of these car sites and their know it all writers trying to tell me I’M NOT THE MAN.

    • Kurt says:

      You should have gone for the carbon fiber JATO rocket package instead. Wouldn’t help with downforce, but it would definitely add to top end…

  7. DaveMofo says:

    Does it have V-Tec (yo)?

  8. Kurt says:

    And NOS!

  9. Camp says:

    Lol Ricers.

  10. Ross says:

    Double Over Head Pinstripes will add hp to each cylinder bank (hence only one stripe needed for 4cyl) but only if they’ve got the “Silicone Chrome 2000″ finish. And my car runs on water. Yeah, of course it does.