What gains with aftermarket DP/Decat

[Godzilla32]

hey guys i scored a hks equal length downpipe for a good price. To replace my old rusted stock one and open up my exhaust some more. I will also be putting in a test pipe. I have stock dumps and don't plan on changing them anytime soon, will this render my exhaust mods pointless?Should mention I have a 3" catback exhaust as well

[Dragon Humper]

Anything you do to free up flow after the turbo is a new lease on their lives....especially with the stock ceramics. The power gain will depend mostly on how plugged up your CAT was but you should see a solid 20hp with just those two mods. The exhaust temps should drop at least 50 deg C as well. Well worth it...



Jon.

[Skym]

Front pipe will make the boost level rise, I think was 0.1bar. That leans out A/F ratio and is where the extra hp comes from (leaner A/F ratio).

The hp it produces will vary from car to car as not all internal wastegates are made the same (some are higher psi, some are lower). One of the reasons why stock engines vary slightly with hp at factory (not the same).