Chillinit

Sup all,

In the process of installing my 18g kit onto my b18c1. For the time being, I plan on using the strawlike downpipe( ) that come with the kit along with my current 2 1/4" exhaust piping(funds are low). However, I do plan on getting a 3" downpipe along with a 3" exhaust in the near future. My question is...if I install the 3" exhaust after tuning with the smaller exhuast.....will I have to re-tune my ride?

Boostfed

Yes because boost will come in sooner in the RPM band with the 3" downpipe and also will make more power or FREE up more power.


EDIT:Real world #s my car was tuned WITHOUT exhaust on, then later went to a dyno contest the car made 503whp 28psi through a 3" Thermal R&D exhaust, dropped exhaust and later the car made 573whp no exhaust. Also the flex pipe was only a 2.5inch that was dropped off also, so I am sure a 3" flex pipe would've been different. But with and without exhaust and or bigger downpipe is going to be a pretty good difference.

Chillinit

so is it best to get the car tuned without exhaust initially?? then u can slap on any exhaust u want and know that the car is running safely?....ofcourse ur performance will suffer by doing this but this would be a tempory thing until I can afford to go back to the dyno...

psi420

Get yur car tuned when you are running everything you intend to run.

With a free flowing exhaust, you will tend to run leaner somewhere in your band.