Car is bone stock other than apexi exhaust. Just ordered a 3' downpipe, does that make much of a difference and what next mod should I do??? Thanks

 

That's a big *** downpipe(3 feet)! The rest of us mortals only have 3"(inch) downpipes. Just messing with ya... Here you go, read this: http://robrobinette.com/mod_pro_con.htm

The generally accepted rule of thumb in modding an FD is:

Three "Flow Mods"(i.e.: Intake, DP, Cat Back) = Need a new ECU to add more fuel to the mixture, or else... You may "lean out" and "pop" your motor.

 

lol.

I recommend checking out http://turborx7.com/recomend.htm