straight pipe with headers?

[jdmjimenez]

Im gonna get some headers for my f22a6 (all stock) and my car is straight piped with 2 3/4" piping all the way through. So my question is, when i get my headers should i put a cat converter on to have some back pressure? Or just leave it like that and have no back pressure at all??

[MrMagnificent]

Im gonna get some headers for my f22a6 (all stock) and my car is straight piped with 2 3/4" piping all the way through. So my question is, when i get my headers should i put a cat converter on to have some back pressure? Or just leave it like that and have no back pressure at all??

I suggest having a resonator to avoid raspy exhaust.

Also a cat, most states it's illegal to not have one. Where I live we don't have emission laws, but stick to a hi flow cat and don't go bigger then 2.25 piping unless your heavily modified. I think our cats are pretty free flowing to begin with.

Back pressure is a big no no, you don't want any of it. If your motors not heavily modified the large diameter piping you have will turn your exhaust gas into turbulence or back pressure. Killing your low end power.

As for headers, it's not something you want to buy off of ebay unless you know it's a quality part.

The same physics applied into flow velocity of an exhaust I explained above are applied but are also more complex, stick to oem a6 headers until you can get one custom made or buy one well designed.

[jdmjimenez]

Never mind i ment 2 1/4 piping lol sorry and as for the headers i wont even touch cheap ebay headers. I was thinking about magen headers.

[steelbluesleepR]

back pressure=torque is a myth, but you are describing it incorrectly anyway.

Our cars only have 1 header.

also, ebay headers are still ok to use, especially considering the almost complete lack of anything else on the market. a Megan or DC header is onlybetter in workmanship, Bisi headers are the only ones that have been shown to make any real power.

You should run a cat. I didn't before I took my car off the road, and even with my greddy cat-back, I hated the sound and how loud it was.

[jdmjimenez]

I thought u needed SOME back pressure

[steelbluesleepR]

I thought u needed SOME back pressure

you need velocity, not backpressure.

[jdmjimenez]

Then ill stick with the straight pipe. I just dont like how loud it is. How would i shut it up?

[steelbluesleepR]

Then ill stick with the straight pipe. I just dont like how loud it is. How would i shut it up?

a cat, a resonator, and a muffler.

edit: or a turbo

[jdmjimenez]

Thats a future plan also but i gotta take cate of other things first.

[tm123]

dont do it!
i straight piped my car 2.25 with gutted cat
1 year later....burnt piston rings and compression is 130psi and keeps going down

i suggest at LEAST 2.5" with a cat AND a resonator where the muffler would go and/or a muffler period.

[sonikaccord]

dont do it!
i straight piped my car 2.25 with gutted cat
1 year later....burnt piston rings and compression is 130psi and keeps going down

i suggest at LEAST 2.5" with a cat AND a resonator where the muffler would go and/or a muffler period.

That's weird...

You don't "need" backpressure. That's a myth, rather a less understood topic. You are looking for good scavenging, not backpressure.

[Born2RoLL]

Then ill stick with the straight pipe. I just dont like how loud it is. How would i shut it up?

Dude a word of friendly advice... "Don't do it" Unless you want the Police up in your business.

[JDMConcepts]

That's weird...

You don't "need" backpressure. That's a myth, rather a less understood topic. You are looking for good scavenging, not backpressure.

dead nuts explanation there. people often mistake the concept of flow and velocity in regards to exhaust, with the need for back pressure. Exhaust exits the ports in a uncontrolled rate this is where flow and velocity of the exhaust system comes in . If your exhaust is to big you will lose control of the velocity which creates a disruptive pulse that can even go as far as creating a reversion pulse.

[bobbycos]

Dude a word of friendly advice... "Don't do it" Unless you want the Police up in your business.

exactly

if you want to know how loud it will be just disconnect you down pipe from the cat and start the car, you will have your answer there

[jdmjimenez]

Im just gonna get a cat converter when i get my headers n call it a day. When its time for smog ill just swith out the headers and put on my exhaust manifold.