UK Pre-Cat Vs Jap Stock DP

[Jim_rx7]

My car is a UK car with a pre-cat. I bought a Jap stock downpipe from someone. (not gonna fit until I get a PFC).

My question is, is there much difference between them? Is the stock UK/US Pre-cat quite restrictive??

Should I just not bother with putting the stock Jap one on at all, or get a decent aftermarket one?


cheers

[m4drx]

if you\'re changing it then you can put aftermarket but depends on what your after and how far you want to go with the car.

jap one is less restrictive as without a cat is just empty pipe with a large bore.

[Jim_rx7]

Want to get about 350ish bhp out of her to start with. Dooable on stock jap downpipe?

[m4drx]

i\'m going between 350-380 and not doin the downpipe so not a problem.