Showing my ignorance

[2tall]

I want a 3" exhaust.

I think that means I need to either:

a) Get 3"/3" high-flows
or
b) Weld a do-it-yourself adapter.

If a) then I have to either:

a) Get 3" headers
or
b) Weld together an adapter

Wrong or right?

I would imagine that unless I go all the way from the get go, I'll be in trouble...

 

[Gerald]

I think most headers will be 1 5/8 or 1 7/8. Could you imagine the size of the collector if all the tubes were 3"?

I think depending on brand, they will use those sizes above, but for catback, it's the 2 1/2" or 3" that everyone uses, depending on budget and header choice.. But I"m not much of a mechanic what not, but just what I think I"ve learned from doing my exhaust, but with any technical ?, I' usually wrong

.


Gerald

 

[red98GTS]

If you have the bug for a three inch exhaust, as you say, you may want to consider some of these options you have: You may keep your stock headers and cats and buy the CORSA 3" catback system and just have that. Nice sound change from dead stock. Or, you can keep your stock header setup and put hi-flow cats on in 2 1/2 inch or 3 inch sizes and use the CORSA in back of that. OR, you can choose to go with new headers and do it all at once, but if you do this, remember your choice of cats (stock or h-flow) and catback system will determine how the car sounds both INSIDE and outside. Something to keep in mind. pete the ex glass guy......98GTS w/ Belanger headers, stock cats cut to 3", CORSA catback, etc.

 

[BWoodbury]

Any of the major 3" cat back systems will be a big improvement in sound over the stock ssytem and all should just bolt right up to the stock converters. They all narrow down to 2 1/2" to do so.

I would strongly recomend changing out the cats for low restriction at the same time. It does not cost much more and would be worth it just for the cooler side sills. You can get these with 2 1/2" for simple connections or 3" for max performance. The 3" will require a bit of cutting and welding. Once you see how much these systems cost the cutting and welding does not seem like a big deal.

For maximum HP you want the tripple play. Headers, cats, cat back. If you are cheap like me look in the classifieds. There are several used systems there...

 

[2tall]

Gerald; When I said 3", I meant where the header connects to the cats (which I'm still probably wrong about). That make more sense?

Thanks for the info guys. Just to clairify then, here's what I think happens under the car stock (haven't actually seen it yet):

Headers->2.5"<-Cats->2.5"->Exhaust

And the "ultimate goal" is:

Headers->3.0"<-hi-flow->3.0"->Exhaust

But if the 3" corsa goes down to 2.5" anyway I'll have to chop/roll my own/weld no matter what...

Is it worth getting a 3" exhaust if, say, I keep the cats at 2.5"? (assuming the 3" corsa goes down to 2.5")

(in case you were wondering why I'm concerned, I'm would like to keep the stock headers, cats and exhaust in "mint-ish" condition (no chopping/welds) if possible, for resale later -- ie revert and sell the car and mods separate)

 

[Anthony - 98 GTS]

2Tall,

You have 2 options, while keeping your stock system intact:

1. Go full 3" from the headers to the exhaust tips. Maximum performance but headers are pricey.

2. Get a catback system which bolts to the stock system right after the cat in the side sill. I would go with a 3" in case you decide to upgrade your cats and headers in the future. The 3" will also be easier to sell if you return to stock later.