Downpipe done !

[shaneth]

this is all well and good but from what i heard guy telling me, although the car will run fine it can change where you get your gains i could be wrong but i think the 3" gave more noticable gains on the upper end of the rev range where the 2.5" was more mid rev range. I also pretty sure he tried both 3" and 2.5" inch and the total power gain was minimal if at all. Hopefully he will come on and add his 2 cents.

[mitch_gti]

I said A CERTAIN amount of back pressure.



If this is not correct then why didnt APR make the GTI polo Exhaust 3'inch or 3.5'

Most likely because 3-3.5 would make no significant gains over using 2.5 (when doing the whole exhaust)

As shanneth said, '' '3" gave more noticable gains on the upper end of the rev range where the 2.5" was more mid rev range. ''

Our cars have a tiny inzy wintzy turbo, if you upgrade the whole exhaust surely 2.5 would be better, to keep exhaust gas velocity up, creating faster spool up and more low/mid range.