exhaust

[Drift m0nkey]

forgive me if im wrong but ur input would help..... I hear that if u run a 2.5 inch catback with a 3inch test pipe on a NA engine u get a bigger gain over a 2.5 inch exhuast with a factory cat and a bigger gain than a 2.5 exhaust with a 2.5 inch test pipe??????????

[Drift m0nkey]

bump?!?!?!?! help

[the head]

results would vary depending on motor but as long as the path is no more restrictive (i.e. factory cat to test pipe) and the exaust is the same in all tests i believe that 2.5 to 2.5 would make the same power as 3 to 2.5 it might make more because you will deal with a non tapered reduction (.5" lip at teh change in the pipe) which would cause some eddying and reversion in the airflow as opposed to the clean flow of equal diameter

If you were going to change sizes you need to get larger as the piping gets to the rear of the car allowing for expansion of cooling exaust gasses (i.e. tuned exaust systems used for high performance vehicle from factory)

This is what i have learned on cars in general and is not nissan or even import specific but in exaust there is little difference that i know of

[AJ]

what a nice response, i read the first post and was thinking 'ahhh i hope he put on his flame suit'.... durr... i'll shutup..

i think the best results would be 2.5" all the way back...