polo 9n3 downpipe query

[clicht]

hi all,
i am doing some research on downpipes for the polo 9n3 gti.
firstly, i am looking for some information on the differances between a 2.5" and a 3" downpipe.
secondly, i though i would ask if anyone could give me a few comments on what they are running, and their views. i am a huge fan of apr, but before looking at the downpipe, i would like to do some investigations....
appreciate your asisstance all
thanks
Clint

[Bflat]

Hi Clint,

I'm running the APR downpipe which is 2.5" through to the highflow cat.
I've found it's allowed the turbo to spool up quicker and sounds better under load.
At idle you wouldn't even know it's there.
Whichever route you go down, you'll have to invest in an o2 spacer to eliminate the likely Check Engine Light that will appear due to the increased airflow.
If you want I can happily show you my car of you're interested.
Cheers,
Ryan

[Smead]

Hi mate, running the same as Bflat. No problems whatsoever and it works as described in the above post

[clicht]

Thanks BFlat, I may indeed take youp on your offer .
I am just debating onthe 2.5" vs 3" diamater , and what difference this will make to sound / performance.

[jamesatfish]

Thanks BFlat, I may indeed take youp on your offer .
I am just debating onthe 2.5" vs 3" diamater , and what difference this will make to sound / performance.

I originally installed the APR 2.5" down pipe, which included the appropriate adjustments to my APR tune to prevent (or ignore) the CEL issues. The exhaust note did change slightly but it was still quite subtle.

I'm now running a 3" custom exhaust from turbo back, and that's a whole different story. The burble on overrun is fantastic, and the rumble at idle is very enjoyable, but it's absolutely horrid at highway speeds with a drone that will drown out everything and give you a headache after a few kms.

I don't think things would be so bad running just a larger down pipe without changing the rest of the exhaust system, but if I was looking for a compromise between performance and retaining drivability I'd go with the 2.5" down pipe.

[geoff_gti]

http://www.vwwatercooled.org.au/foru...ues-69394.html