I have a wrx Sti hatchback, I had it mapped up to 312bhp a couple of months back, I'm now wanting to get a cat back exhaust for it to give it more of that burble..

Will I need the map tweaking if I stick to a 2.5inch non res system?

Picture here of the RR figures if anyone is interested

Final run was 312bhp

 

Id think you would be fine with the same size cat back. But for peace of mind your mapper should only charge about £150 give or take for a map tweak/health check once fitted.

 

I was told that with just cat back you shouldn't need a tweak, if you have boost gauge see if boost has changed with new exhaust, if not then you're ok. If it's changed then you can go for a tweak.

 

Cheers lads, I'm hoping it won't because it just adds expense.. But it's got to be right, don't want to break it lol... Will get it next month and see how it goes.. Don't have a boost gauge but hoping I will notice a difference in How it drives.

 

It shouldnt drive any different. Might seem quicker due to more noise but wont be. If you want to notice a difference go down the full decat route but this will 100% need/benifit from a map tweak.

 

I know I keep thinking about it but again it's more expense, where I live I can't even use the power it's got, so no point in having more..lol..

Will stick to a cat back, I only want it to sound like you expect a scooby to sound like..