The 04-07 Subaru STI GrimmSpeed 44/45mm EWG Up-Pipe is CNC machined from 304 stainless steel with thick 12mm flanges that will not warp. A flex section has been added for ease of install and to extend the life of the up-pipe (allows expansion/contraction of pipe without cracking). With the added heat that comes with running an EWG, Grimmspeed offers an optional ceramic coated version to help reduce underhood temps.
An external wastegate allows exhaust gases to be diverted prior to entering the turbo; thus creating a quicker turbo spool. Moving the wastegate out of the turbo relieves the turbo from the massive amounts of turbulence that the stock internal wastegate creates, this allows the exhaust gas to be released faster, which improves boost control, maintains maximum boost longer in the rpm range, and extends the life of the turbo. Users should also expect gains in the 15-40hp range when tuned for the EWG set-up.
Required with the EWG up-pipe and wastegate is a bracket to hold the stock internal wastegate shut. This bracket is helpful because the turbo door does not need to be welded shut, decreasing the chance for leaks and allowing for easy removal if necessary. Availabe for many popular turbos.
(Adjustable IWG bracket : #010019 / VF Series IWG bracket : #010001)
Follow this link to see all available & compatible External Wastegate options.
- 04-07 Subaru STI GrimmSpeed 44/45mm EWG Up-Pipe
- Improve boost control & reduce lag
- 2.0mm pipe thickness
- CNC machined 304 stainless steel
- 12mm stainless steel flanges
- Includes flex joint for easier fitment
- Optional ceramic coating