hi i heard a lot of people telling me that sti's dont need uppipes because the stock is already straight.....my question is i have a gt-spec uppipe and want to know if i should go through the trouble in putting it in or just selling it

 

Many WRX owners replace the factory uppipe because it contains a pre-catalyst for cold-start emissions. Over time, the catalytic converter can disintegrate, causing damage to the turbo. It is also restrictive to exhaust flow.

The STi does not use a pre-cat in the factory uppipe and therefore flows much better than the WRX uppipe. Replacing it with an aftermarket uppipe would not yield much benefit unless you have some sort of special application.

--
0==WW==0
"…axles of evil…" - george w. bush

 

just curious... whats the special application?

 

Big aftermarket turbos which don't bolt to the factory uppipe or downpipe. There is a fair selection of bolt-on turbos for the WRX and STi but for race applications or built engines, those turbos can be marginal for all-out performance.

--
0==WW==0
"…axles of evil…" - george w. bush

 

gotcha, thanks!

 

A bit off-topic, but here's one example of a Garrett GT30R turbo kit from Gruppe-S. There's a pic showing the custom uppipe with external wastegate flange for this turbo.

--
0==WW==0
"…axles of evil…" - george w. bush

 

Does this apply to the 06 WRX?

 

'06 WRX does not have a pre-cat in the uppipe. Money is better spent somewhere else.

--
0==WW==0
"…axles of evil…" - george w. bush