How much would your stock hp increase if you have the following:

Intake, y-pipe, cat converter, b-pipe, exhaust

 

Assuming alot of things, you can probably see around 10-20 HP.

The biggest one would be that the air/fuel ratios wouldn't be messed up. Mine were when I put on the cat/y/b/exhaust. Once I coarsely re-tuned the car using my Greddy E-Manage (similar to APEXi S-AFC), I got closer to 20 HP.

I was at 198 HP stock. Then I went to 218 HP the last time I dyno'd. The E-Manage has yet to be finely tuned as I am awaiting dyno time.

 

Are you driving a Honda? Our cars are 255 hp (235, rather) at stock.


~limsandy

 

Not to disagree but my best dyno stock results on my 02 6 speed SAE corrected was 208 HP. The range of #'s I got was 205.2, 206.2, and 208.4. That was within 10HP of your stated high. Seems like that everything you've done has only amounted to 10HP increase and even that is somewhat debatable as there is always room for error. Even 2% would mean +/- 4HP. Just something to consider before doing a lot.

 

WHP! not flywheel HP.

 

The stock dyno was 198. I took the car to the Nissan dealer and had them re-flash the ECU. After that flash, I got 204 the next time I dyno'd, but I had already installed the exhaust. Once I got going, it varied from run to run, so it was hard tell what the actual gains were.

Like I said... expect between 10 and 20 HP. Probably closer to 10, but some have seen more.