Test pipe and downpipe? Difference?

**ksatan** · 01-29-2010 03:18 PM

Hi.
Guys, I've tried to search but haven't found. Can anyone explain what's the difference between test pipe and downpipe?

**AudiA4Turbo22** · 01-29-2010 03:24 PM

testpipe replaces your catalytic converter with a straight pipe.

The downpipe is the pipe that goes from the cat down to the exhaust.

**tdn** · 01-29-2010 04:10 PM

Some places sell replacement/aftermarket downpipes which replaces the cat as well, to make a downpipe-testpipe combo, which is listed as just a downpipe.

**DasValet** · 01-29-2010 04:37 PM

I've having mine set up with a turbo-back set of pipes, with a resonator. The thing is, I'm not real sure what a resonator is. Anyone clear that up for my dumb ass?

**ocod** · 01-29-2010 04:43 PM

Originally Posted by DasValet

I've having mine set up with a turbo-back set of pipes, with a resonator. The thing is, I'm not real sure what a resonator is. Anyone clear that up for my dumb ass?

http://www.magnaflow.com/02product/u...sp?shape=Round

Resonator
The muffler alone cannot always quiet all of the engine noise. Many car exhaust systems also include a resonator which is like a mini muffler. They are usually straight pipes filled with sound muffling materials. The resonator can be either before of after the muffler in the exhaust system

**Audi Skate Snow** · 01-29-2010 04:44 PM

to help more... the test pipe replaces the stock cat converter. It is a straight pipe that deletes the cat. Helps the turbo breath more, spool faster.

Downpipe also helps turbo breath more... it is the part that is attached after the cat or testpipe that goes down to the exhaust.

**hercfe** · 01-29-2010 04:44 PM

a resonator is a muffler. it is usually packed with fiberglass wick rather than baffled like a standard muffler. it will quiet the sound usually 1-15Db, depending on how much and the quality of the wick. Ebay mufflers for example have cheap wick that isn't packed very well, so after a while you get a tinny rattle from the resonator. dynomax or cherrybomb or apexi, although a big difference in price, are all equal in quality and will last a LONG time without the wick coming apart and ruining the effect of the resonator.