Topic: GDA Chassis exaust/downpipe fitment questions

[Reid183]

Hey guys, I am planning on getting a dyno tune really soon for my 2000 GDA wrx and thought while i'm at it I might as well install/ buy a downpipe while i'm at it because if I plan on getting one further down the road then I would need to re tune it again on a dyno so I might as well save some money on something I was kind of planning on doing in the future.

I'm just wondering because I really don't have any idea; Do JDM Gd's have the same issue as JDM Gc's have where USDM and JDM spec exhaust systems have different specs? Like, in my situation, I have the OEM JDM catback bolted to a Blitz aftermarket catback, if I was to buy a normal usdm catless downpipe, would it bolt right up to the rest of my exhaust system?

Just to clarify, I have a GDA so just a WRX with the ej205, not a ej207 but it is still an import.

[AirbornBugeye]

IIRC When my car came here it had a JDM stock down pipe to a aftermarket jdm catback.
When I swapped out the exhaust to a full usdm setup it bolted up no problem but I swapped out everything(Dp all the way back). When I sold the aftermarket exhaust to someone on here it did not bolt up to his USDM downpipe. It seemed like they were different lengths, I just gave him my stock dp and never heard of it again.

My car is a ej207 but for the most part subaru used the same exhaust housing on these two engines. For my car the GDB it has been really good for match parts to the 02 wrx but only for some parts.

You might be a little late to do a dyno tune unless you already have it booked, as I dont think they tune when its below 0 degrees.

Also my car may have some boost creep now that there is no restriction in the exhaust. Not sure if this is exhaust problem or not having a tune yet problem.
And if you get the sweet ti tipped exhaust the silencer they give you to put in the end will rattle upon use(Only the end not the whole exhaust). So you want to hear the exhaust volume before swapping everything out.

[jellynuts]

He lives on the Island, so, a) I have no idea who he's tuning with and b) they don't get winter.

[AirbornBugeye]

Oh! Thats very true! I didnt even notice that. My guess is if I get boost creep it would be really bad at sea level.

[NuTypeR]

The downpipe lengths for JDM and USDM are different, so You would have to find a USDM catback to match your new downpipe. If the piping diameter differs between the dp and the catback, grimmspeed sells adaptors to compensate for the difference. You can find them at rallysportdirect

[FresH599]

Aftermarket dp is a tight squeeze on these cars.. well invidia is.
First you have to cut and weld the mid pipe for length
Then once it’s installed you’ll find it makes contact with your steering column.
It barbaric but I think I’ll have to bang it out to make it work...