How much improvement can i expect from completeing my I/H/E i have a cold air intake now just wondering what I would get from puting on dc headers and a 2.5 custom exost dont know what muffler im going to get or if i will get a hi flow cat or not????

 

you won't see any considerable gains, it will sound nice though. Really, the only benefit of I/H/E is after you've done a decent amount of internal and fuel modifications. For the money you are gonna spend, it's really just for show.....maybe about another 6-8 hp.

 

you'll notice the difference in the High rpms for sure. And on a cold night, you'll feel the difference also...

 

you lookin at probably a gain of no more than 10 hp for all the basic boltons. thats almost about $1000 youre spending on it too. you can always save your money and go turbo later down the line or build your motor. try slappin on a skunk2 intake manifold in addition to the i/h/e.

 

skunk2 manifold will harm u more than help u unless u've got some good cams in there to flow more air thru. and up the compression w some new pistons too...cuz w/o it u'll lose hella low end. but yes unelss ur doing turbo...i/h/e is a start to any NA or SC build up

 

I just read a post about an ITR gaining 20whp from just JDM 4-1, 2.5" cat (or test pipe, forgot which), and 2.5" SMSP exhaust, all that OVER the Spoon N1 axel back. Granted, that is an ITR, if you try full 2.5" exhaust uncorking, I think you could gain more than the basic bolt on 10hp call. I don't know, I could be wrong though...

-Andrew