how can i choose the piping size for my exhaust?

Question

i have an acura rsx base and planning to put in a custom exhaust. I removed the catalytic converter and the modifications i have are a 4-1 stainless headers with a short ram intake and wanted to know what my piping size should be.

Answer 1

I have a really great idea. Why don't you save yourself a bunch of money and stick with the factory recommended spec.

All you are going to do is create a vehicle that will make more noise, pollute the environment more, and will be an advertisement to anyone who sees your car that you are a sad boy racer trying to make his car into something it is not.

When you come to sell the car, they will arrive at the same conclusion and you will get less money for the car because it is now not standard spec.

If you want to go fast, buy a motorbike, or save up for a vehicle that is fast like the TL or TL Type S. These juvenile modifications are not good for the car, your wallet, the environment, or other people who have to listen to the stupid loud noise your car makes.

Answer 2

Pipe size varies greatly depending on your specific engine, the mods already done, and what you intend on using it for (week-ender, pro racing, daily driver, etc.) Kits can be OK, but they don't know what your engine has, so they are almost never correct. Use a reputable speeed shop or an exhaust expert (not your local muffler shop.) And beware of going too large - it may sound faster, but can make the car significantly slower if there's not enough back pressure. You want the pipe to flow well for the volume of gass that the engine can pump, but any bigger and you lose power. A basic rule of thumb is to never exceed 2 inches in diameter without a turbo, or unless using a full-race engine. And you might want to put the converter back. They're not really a problem these days, and it's no fun having a fast car if it keeps failing the emissions inspection.

Answer 3

First, I wouldn't advise you to remove the converter, converters these days offer less resistance to airflow than you may think. The new honey comb designs are transparent when you look through the opening.

I second the mandrel bent kit. I also advocate thermal barrier coatings, as keeping the heat in the pipes will help exhaust scavenging, this means a clean intake charge thus more power.

I would also not exceed the 2 inch pipe diameter as you will need to keep exhaust gas velocities high in order to enjoy the
exhaust scavenging 2.25 inch pipe is pushing it. Too large of pipe and this benefit suffers. Plus noise levels get nasty at the engine's resonant freqs. and your 4 cyl engine can only pump so much air.

Answer 4

Don't let some muffler shop build you an exhaust system. If your think about doing it yourself don't. Buy a kit. Kits are usally tested and they are mendrel bent. Most kits for that RSX will be stainless steel and fit perfect. I would recommend 2 1/2 inch, unless you have serious plans to get a turbo. If thats the case I would go for 3 inch.

Answer 5

Choose pipe sizeby determining plans for the car. All motor N/A 2.25 is good 2.5 may be overkill.

Turbo 3.0 is usually good. If going all motor buy an aftermarket catback exhaust.

I would suggest these aftermarket brands:
HKS hiPower... Great kit that sounds killer, not too loud untill you mash the throttle

any apexi kit is good too!

Konrad