exhuast size question

I'm going in next weekend to get a quote to put in a custom exhaust(and also check my brake rotors, see if I need to change, if so I'm gettin A8 front rotors). My plans for the future will be either K04, gt2x, gtrs elim, and no bigger then that!!!

Should I get a 2.75 inch exhaust, or is it still better to go a full 3 inches? Turbo back or catback? (I know turbo is better, but is catback good enough, I'm not looking for a 1/4 rocket, just a faster daily driver)

Would it be better to buy a muffler and cat then just get the shop to do the piping, or would I get a better deal ordering muffler and cat through the same shop I get my custom piping done?

Thanks

2.75 will be big enough for your plans.  No reason to go bigger unless you want it louder.  You want a full turboback.  The cat section and dp is the most important area to change, so skipping that is bad.  If possible, get that stuff 3" and 2.75" the rest of the way back.
 
As for parts, have them increase the inlet/outlet of the stock cat and add in a borla or magnaflow strait thourough muffler.  It would be cheaper if you get it yourself, but less hassle if you dont.  ALso if you want it quieter and more tame on the highway, i would also get a resinator

Only thing against 2.75" is the piping is harder to come by.  Most shops carry 2.25, 2.5, and 3" so call up a shop and get a quote for it and they will mention if it's a problem.

quote:

Only thing against 2.75" is the piping is harder to come by.

exactly! i was told they would have to order it and i would have to wait about a week and pay for it upfront and it was going to be about $100 more then just getting the 3'' but def put a muffler on it

i'm getting gt28rs elim kit and 3" catless downpipe+exhaust.

If 3" is easier and cheaper it sounds good to me. So long as I can find a classy muffler that is REALLY REALLY quiet but doesn't impact performance 2 much. (quietest not restrictive muffler???)

dha514, I can't go catless, I'm limited here in Vancouver, B.C. for that. It's not as tough as Califonia, but we have emissions testing and can be pulled over for a loud exhuast, etc.

Exhaust, brakes, cheapo intake, fmic and ebc are on the list of hopeful "soon todo's".

Since you will be running a cat, it will be quieter, but you will need to run a resinator and a large muffler (still strait through) for it to work its best.  Chambered mufflers do not belong on a turbo car.

APR designed their exhaust to work with all thier products, which I have, and they only use 2.5" tubing on their B5 exhaust system.

I have their;

APR stage III kit
APR high flow cat and
APR cat back exhaust

It works, sounds and performs great, without being to loud. As a matter of fact, APR has a reputation for being one of the more quiter exhausts on the market. I'm no trying to sell you an APR exhaust but just to inform you that bigger is not always better and that 2.5 would work just fine, depending on your needs. Mike Hood only runs a 3" exhaust and is putting down 600whp, so you don't want to put yourself in a position where you are not moving enough air to justify a 3" exhaust as it can hurt your performance as well.  

well then the question becomes can I(more like should I) run 2.5 inch for a gtrs elim? (since that's about the max turbo I want)

You can run a 2.5", but it could rob you of 5-10whp in the upper rpms and not let the turbo spool as fast.  Honestly, 2.5" is fine, but 2.75 or 3" will be better. 

A 2.5 would be perfect for the size turbo you are planning to run. IMO I would not go any bigger.

robbing 5-10hp is not a big deal to me, but spooling quicker is a huge deal for me.

I guess I'll see if I can easily get 2.75 done at the shop, if not, I'll check pricing on 2.5 and 3

I great compromise would be getting a 3" cat section and downpipe and then either a 2.75 or 2.5" catback.  This works much better than 2.5" turboback and still offers a quiter ride and better performance/spool up

quote:

ORIGINAL: dr_zoidberg

If 3" is easier and cheaper it sounds good to me. So long as I can find a classy muffler that is REALLY REALLY quiet but doesn't impact performance 2 much. (quietest not restrictive muffler???)
 
I heard borlas are pretty quiet.

dha514, I can't go catless, I'm limited here in Vancouver, B.C. for that. It's not as tough as Califonia, but we have emissions testing and can be pulled over for a loud exhuast, etc.
 
Haha... I live in Southern California. But I am still getting a 3" turboback exhaust. :)

if you use both mufflers, borla is pretty quiet until you step on it. i like the way it sounds better with just 1 muffler tho, but dont get the borla system, its only 2.25. techtonics is 2.5 w/ borla mufflers, or you can custom make your own pipes and buy the mufflers from borla (what i would do)

custom pipes is the plan, just waiting on a shop I like so I can actually get a quote first. I go in Sat morning.