2001 A4 1.8T quattro manual.

What I want:
A custom/cheap high flow exhaust with a nice tone that will be ok for a k04 upgrade later on without going to 3" pipe.

What I have uninstalled:

(2) Magnaflow mufflers with 2.25" inlets/outlets (main muff has 3" tips)
#14815 at: http://www.magnaflow.com/02product/s...ain&id=386
#12225 at: http://www.magnaflow.com/02product/s...ain&id=301

(1) ebay testpipe with 2.5"inlet/outlet
http://cgi.ebay.com/ebaymotors/New-B...spagenameZWDVW

(1) stock DownPipe/stock cat/stock exhaust/k03 turbo(still on it)

Questions:
1. what diameteris the stock downpipe? stock exhaust piping? 2.25"?

2. will going 2.5" or 2.75" in a sense "bottle neck" at the mufflers making the 2.5"/2.75" piping useless? (might as well keep 2.25" pipe?)

3. should I order piping online and bring it somewhere to have it bent? any recommendations on shops in New Jersey?
or
4. Should I bring my mufflers to a shop and have them fabricate a downpipe/piping? (I would get the appopraite sized flex pipe and bring that too)

I plan on doing the test pipe myself and possibly the down pipe if it is recommended that I get a larger one. Should I get the test pipe on there and then do exhaust? (no shops will put it on for me) or let them deal with those cat>Dp bolts and then go back and do the install.

That's all I can think of right now. I'm sure I will have more questions after everyone posts back.

I just need some advice from someone who knows exhaust and how it works because I don't.

Thanks.

 

personally I would have a stainless system made up and cat removed then tuned to the emissions required in your state then go from there

 

If youre gunna get a test pipe, its easiest to do with the exhaust disconnected from the DP back so you can move it around for easyaccess to the cat/dp bolts. Its still doable with the exhaust attatched, just more of a pita. A muffler shop should have stainless pipes on hand and fabricate them to fit easily/cheaply. The mufflers should be the most expensive part. I see no problems going from 2.5 piping to 2.25 muffler inlet. Its not going to make a big difference when its that far back in the system.

PS: Im not an expert.

 

ok so go stainless all the way.

no shops in NJ are agreeing to install the T-pipe so I'll have to do it. shouldI do it before or after I have this installed? andwould a local shop even be able to fabricate a downpipe?

thanks...

 

down pipe only needs the 02 sensors fitted and preferably with spark arrestor fitted to the last one then the cat can be removed and no need for a test pipe which only replaces the cat which isnt required when moding the exhaust so main issue is emmisions and that can be sorted with VAG

 

02 sensors are on the catalytic converter on 1.8t engines. The down pipe is after the cat (2 seperate pipes.)

 

there is no law stating there should be a visible catalyst in the exhaust system it only has to meet the emissions for where you are

 

It doesnt matter if you do the TP before or after the rest of the exhaust is donesince either way its going to stay connected. BTW the test pipe install on a manual is half the pita it is on a tip car.

 

You can do it, I would just go to an exhaust shop and have them make one for you, they have the piping and all. Thats what they did on my last car, I think it was like 215 or 185. Downside, you may want stainless if you plan to keep your car for over 5 years to prevent rust. You can go form a 2.5 to a 2.25, they have adaptors (but if you own those two already, I would try to sell them to get one that is 2.5 or 2.75. Yes.25 will bottleneck your system a bit, and especially with a k04 on the way... 2.25 from what I was "told" on my last installment is only optimum in most cars at around 180-190 hp anything after that it is going to hold your system down.

 

As long as you arent using a stock cat against a k04, you will be fine. You just want to make sure that back pressure is reduced as close to the turbo as possible, anything after that is easily expelled. Some people keep their stock exhausts and just put on a test pipe and achieve significant power gains.