Currently have a PPP sports cat and 2.5" system non res and I'm looking to get a 3" open mouth downpipe to go with some other mods. My question is is there really much performance gain in a full 3" system compared to a 3" reducing to 2.5" after the downpipe? Prefer not to replace it all unless there is a real need.

Thanks

 

Unless you've got the mods to go with it the full 3" system could even reduce power. I ran 2.5" all the way to 425bhp and there's plenty of higher power cars still on 2.5".

 

I'll be fitting new injectors, turbo etc to get close to 400 hopefully and need to get the decat just wasn't sure if to get a full 3" and have to replace it all or get a reducing one and save some expense if not reduced.

Cheers

 

Interesting. I'm in the same boat I am going 450bhp I have a 3" from turbo down to a 2.5" centre then to a 3" back box. Have been advised to change the centre to 3". So any more info on this would be great.