I finally paid off my 370 Nismo so started acquiring parts looking forward to a dyno day. unfortunately my dyno dreams were not met by the output numbers.
let me start off with the mods i have.
Z1 cold air intake, Z1 high flow cats, Z1 upper and lower ported plenum, JWT C1 camshaft, DC sports stainless headers, 2 piece front and rear Akebono rotors.
some of these i installed myself (CAI, plenums, rotors) but had the shop install the headers and camshafts, and high flow cats. i am located in salt lake city where we only have 91 octane and the elevation is around 4,500ft.
the above parts only put down 305whp and 237wtq. the base run was 276whp and 236wtq.
these numbers suck! for the money i would have been much better off running a nitrous kit and keeping everything else stock. so here are my questions.
1) does anyone else have experience with NA motors at higher elevations? from what i have read for NA motors there is around a 3% power loss for every 1000ft. theoretically this would have put down around 347whp (not sure if torque loss is the same) at sea level still on 91 octane. ive read you can pull another 8-10hp from using 93 octane so that would have put me around 355whp (assuming 15% drive loss this would be just over 400hp at the crank). this makes sense because the parts i have pretty much match Z1 400hp package (test pipes, headers, ported upper).
2) how much will running E85 instead of 91 help? i see around 14whp gains and lots of low end torque on the forum but i think that is mostly compared to users who were on 93 octane.
3) similar to running E85 i think my next step is a nitrous kit as i want to put down at least 400whp. the shop is expecting a 35shot (which is really 70 shot since dual intakes mean two 35shots will spray at the same time) to put out more than 70hp due to the mods i have and the air density. any thoughts there?
4) i have searched and searched on this forum for aftermarket exhaust compared to the nismo exhaust. i cannot find any dyno numbers supporting a change from nismo to aftermarket, only base model to aftermarket. part of the nismo package was supposed to be the better exhaust. swapping to the nismo R tune at this point i think would net maybe another 11-15 hp but its about the same cost as a nitrous kit...could the stock nismo exhaust be a large restrictive factor?
i almost sold my car after i got the dyno numbers back. forced induction does not have the same issues since it compresses the air. i came from the southeast where it was flat so i did not even consider the elevation when i started planning my build. big mistake.
i can provide the dyno sheet, i will have to pull some data logs this weekend as well. any advice here would be much appreciated.