sr20det injector size for tuning question
sr20det injector size for tuning question
I am wondering if I will need to buy a new set of injectors before I get my car tuned. I have an S15 sr20 motor with stock 480cc injectors. I am installing a new GT2871R turbo with a Z32 MAF and also a set of HKS stage 2 cams all at the same time. I have an SAFC II for tuning purposes. To maxamize horsepower, will the 480's keep up or should I upgrade to 550's. I hate to spend $400 just for 60cc's, but I will if I have to.
injector size is all about what hp numbers you want ... what hp are you trying to run with then decide based on the math... the 480 are about good for 253hp then 550 will do about 290hp... at a 90% dutie cycle for both
http://www.z31.com/software/injector.pl this is a handy dandy tool to figure it all out
http://www.z31.com/software/injector.pl this is a handy dandy tool to figure it all out
Re: (USsil80)
I believe that you are talking about crank HP, because the S15 stock is around 250, and im sure that it wouldn't come from the factory maxed out, and that's factory at 8psi. With the new turbo, cams, Z32, and at 17psi, I wouldn't think 350 would be hard to reach number. I'm just not sure what percentage the 480cc run at stock. If they only run at 60%, I can get close. If the are at 80%, then no. I'm just not sure about that one.
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:: orion ::
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Those numbers are WAY too low.
I've seen 350rwhp from 525cc injectors (50#), safe A/F, ~95% duty cycle.
Empirical evidence is better than any math guestimation...but the math here supports my claim.
(injectors size) X (# of injectors) X (duty cylce) DIVIDED by BSFC
Assume 50lb'ers, 4 injectors, 95% duty cycle,...and .55 BSFC
(50*4*.95) / .55 = ~345 as a safe max.
...
370cc injectors are commonly known to do ~240rwhp safely...S13 SR guys do it all the time (T25 @ 15psi or so).
370/10.5 = 35.2lbs/hr
(35.2*4*.95) / .55 = 243rwhp as a SAFE max.
...
So...do that math for your 480cc injectors:
480/10.5 = 45.7lbs/hr
(45.7*4*.95) / .55 = 316rwhp as the SAFE MAX.
Hope that helps - Brian
I've seen 350rwhp from 525cc injectors (50#), safe A/F, ~95% duty cycle.
Empirical evidence is better than any math guestimation...but the math here supports my claim.
(injectors size) X (# of injectors) X (duty cylce) DIVIDED by BSFC
Assume 50lb'ers, 4 injectors, 95% duty cycle,...and .55 BSFC
(50*4*.95) / .55 = ~345 as a safe max.
...
370cc injectors are commonly known to do ~240rwhp safely...S13 SR guys do it all the time (T25 @ 15psi or so).
370/10.5 = 35.2lbs/hr
(35.2*4*.95) / .55 = 243rwhp as a SAFE max.
...
So...do that math for your 480cc injectors:
480/10.5 = 45.7lbs/hr
(45.7*4*.95) / .55 = 316rwhp as the SAFE MAX.
Hope that helps - Brian
