You would not believe the number of questions that I get regarding more horsepower from the car. And the most common question that I get is: What should I do with the fuel injection system or the intake manifold or the mass airflow sensor? Well, the reality is that’s not where you start. See, no matter how much more fuel and air you put into the engine, it doesn’t do you any good unless you can get exhaust out of the engine. So that means that the exhaust system is your first area to modify.
But then comes the question: How about a cat-back system? Will I gain a lot of horsepower there? Maybe, but probably not. So then comes the question: headers. Well, if I put headers on it, that’s certainly going to do it. Well, again, probably not. And the reason is very simple. The catalytic converter, mounted right in the middle of all of this stuff, it is not a high-performance converter, it is not free flow, and it has some age on it. So the interior of it may be partially melted, which restricts exhaust flow. So you always do it as a complete package from beginning to end. And the catalytic converter is critically important. Also, install new oxygen sensors while you’re doing it.
Now, then comes the question of legality. And everybody looks at the box or the statements that come with the product, and it says 50-states legal and, hey, I’m good to go. Well, maybe, maybe not. You have to check your local regulations because sometimes there are going to be noise limits, there may be restrictions on these systems and so on. So you have to do your homework. That way you don’t throw a lot of money away.
All right, now, you get all of that done. Here’s another common question. I want to put a high-performance air filter in my car. Can I expect 20 or 30 horsepower from it? Probably not. You see, high-performance air filters on most cars are going to have little or no benefit except at full throttle. That means if you’re towing a trailer or doing some other kind of heavy work or you’re racing the car, yeah, you’re going to get some benefit from it. But for day-to-day driving, you may not notice anything at all. So study what you’re going to do, follow your plan, and you can gain horsepower.