I've got a quick question here, I'm looking at purchasing/upgrading an air filter intake system and I was wondering if I would need to upgrade my exhaust as well since I would be bringing in more air into my engine? My thought is that it will not be expelled as quick as it is being brought in, which would not be a smooth flow of air through my system.

Please send me your thoughts and let me know if this is a valid question.

 

You don't have to upgrade your exhaust for an intake.

 

No, you don't have to upgrade the exhaust but engine airflow is a system. The more you allow in, the more volumn is available to expel. So, if you increase your input, it has to go somewhere. Making the intake more efficient does nothing for the exhaust, it still has to use those skinny OEM pipes. Headers, downpipe, cat, and exhaust, or catback are all part of the engine system after the intake (with model variations). Allowing for more flow will make your engine more efficient and provide more horsepower. Start at one end and work your way down. Biggest bang for the buck bolt-ons are Intake, Headers, and Catback exhaust....in my humble opinion.

 

change your intake don't require u to ungrade your exhaust. But since you are starting to mods your car, it is a good idea to go through the whole exhaust system, like the header and exhaust for better performance gain.

 

Where should I start. Some credentials may help.

I have worked on drag cars of mine and my friends for the past for 20 years, drag raced my 69 camara at the track for 14 years (10.4sec in the 1/4), owned a mustang gt heavily modded and I have a degree in molecular engineering.

Ok I'm not bragging just trying to qualify my next comments so that you understand I'm not BS'ing.

Let's assume (I know assuming is bad but we must start somewhere), that honda has built your car correctly. What I mean is they have balanced the intake and exhaust so that the proper air flow has been acheived. If you put an aftermarket CAI on that ACTUALLY allows more air into the intake(throttle body) then you have changed this balance. Therefore you need to "re balance" this air flow. To do this you would need to increase air flow out of the exhaust. Air readings in the exhaust should be taken stock and then again after each mod to the intake or exhaust especially if you n02 or turbo. otherwise you will not know if you are to0 lean. It is very important to do this if you are spraying or turbo charging slightly less important if you do headers and a complete exhaust and not very important for a cat back and cai only. There is little to no risk of running to lean and detonating by changing to a CAI and cat back exhaust. Most not all manufacturers of cai and bolt on cat backs test their products on the actual vehicle and will provde dyno charts with their results. Some manufacturers will only bench test(on a calculator) and give you estimated not proven results.

So lets take it the other way. Let's sa Honda did not create the best intake and the exhaust can put out more air than the intake can provide. You install a quality CAI that has been dyno tested on you car. You should see improvements in throttle respnse fuel economy and hp/tq.

So the answer is not as simple as no you do not need to swap out the exhaust to put a CAI on or yes you need to put a cat back exhaust on.

The best answer I can give you is either to talk to people here who have dyno'd a similar vehicle before and after each mod to show what gains if any the mods have given or do it yourself.

here are some recommendations if you choose to do it yourself assuming you are not going to spray or turbo otherwise you wold need to do different steps:

1) dyno you vehicle before you do any mods(usually 60-75 dollars for 3 pulls)

2) purchase an air meter and check the reading before any mods I believe 14 is a good number on a stock vehicle)

3) choose the CAI first ( less expanse(200 dollars) and less invasive to break into modding( no permanant changes are made and you can return to stock easily)

4) re-dyno your car (compare graphs and hp/tq gains if any, be sure to note where in the curve the gains occured i.e higher or lower rpm's)

5) proceed to replace the exhaust next. there are 2 basics options 1) cat back only. advantages: less expensive than replacing headers and switching to high flow cats and less likely to interfere with emissions. Also much easier to do it yourself. If you have never swapped out a manifold for headers before it can be tricky and be sure to have some experienced help.Again choose a system that has been dyno tested on you vehicle. Your gains wil be decent if you do both(cai and cat back) maybe 15hp/tq. 2) the other option is to replace the entire exhaust system from the headers back. This is more expensive and time consuming and rather permanant. The gains are greater though and this would allow you to add n02 or a turbo without needing to change exhaust again. expect 20 to 25hp/tq depending on the system you buy. Follow the guidelines I gave you and you should do fine.


Choose a CAI that pulls air from down in front to get the coldest air be aware of water being pulled in to the pipe. Ensure that there is at least 5-6 inches of vertical pipe so water will not be pulled into the engine, A functional hood scoop works the best because you will get a ram air affect.
Also the CAI should have the least bends as possible with smooth walls on the inside no accordion type piping. The diameter of the piping should be the same as the throttle body or only slightly bigger. Too big of a pipe and you will actually slow the air down with turblance or eddy flow. The bends in the pipe should be of a long radius(no sharp turns). The material the piping is made out of is important as well. Some plastics provide great insulation form the heat n the engine compartment buy may not look as shiny as aluminium or stainless steal. The problem with some CAI is that they are not insulated. A metal only pipe will actually heat the air so if you like the chrome look buy one that is insulated.

Follow similar guidelines for the exhaust. Mandrel bent pipes are the best because there aren't any strictures at the bends. Stainless will last longer and look nicer. Headers that are polished or with ceramic coating are the best.

 

Buy a K&N air filter

 

Thanks for all the input. That was pretty indepth, but you pretty much proved my thoughts.

Thanks again for taking the time to write that!!!!!

 

It's not mandatory that you get an exhaust along with an intake, but to get the best performance, it's helpful.

As previously stated (But I'll say much shorter ) the more air you car can take in and the faster it can be pushed out the better.
Of course if you're getting more air in, more fuel has to be mixed thus, creating more power.
For example

Imagine your stock intake is one of those little stirrer straws you use to stir your coffee. Imagine drinking from that straw, Pretty restrictive right.

Now Imagine an aftermarket intake is a Mcdonalds straw. Drinking through that straw is much easier

The same with an exhaust system (header(s)..pipes..muffler)
Try blowing through that stirrer (which is your stock exhaust) and then blow through a Mcdonalds straw (aftermarket exhaust)