What size do injectors do you guys use? and how much horsepower are you making with them?
I was on RC Engineerings website doing some calculation on proper injector size for my car, and tried playing around with some numbers... Here are some of the numbers I saw 720 cc injectors for 420 crank HP.. 1200 cc injectors for 600 crank HP and so on... these numbers seems high to me... whats your guys take on this?
550cc will get you to around 350 rwhp. You need bigger for anything over that otherwise you have to resort to high fuel rail pressures which can lead to other problems.
My housemates car was dynod yesterday, at 320rwhp injectors were at 95% duty cycle with 11.8 AFR's
550cc will get you to around 350 rwhp. You need bigger for anything over that otherwise you have to resort to high fuel rail pressures which can lead to other problems.
My housemates car was dynod yesterday, at 320rwhp injectors were at 95% duty cycle with 11.8 AFR's
well thats what I thought but look at RC engineering's website... http://www.rceng.com/technical.htm#WORKSHEET I not sure why they would mislead people... I just checked the injector size for 350 Crank HP and the site gave me 720 cc injectors... but that is with 80% duty cycle... this sound fishy to anyone?
Its not an exact science. I dont know what the brake specific value is for an SR. Id take dyno proof over an equation. If you are leaning out at 95% duty cycle then you need bigger injectors.
Its not an exact science. I dont know what the brake specific value is for an SR. Id take dyno proof over an equation. If you are leaning out at 95% duty cycle then you need bigger injectors.
thanks for the info.... what do you think is the largest injector size one can you on the SR20DET?
You start to get idle problems at 750cc but its still driveable. Ive seen 1000cc's on a sr drag car (700rwhp) but that was pretty much undriveable on the street
i run 72# injectors, as do many of my customers. perfect idle, aside from cams. 72# is like 740cc. you can't use a s-afc though as they are just too big for it to control. you need a jwt ecu, or other decent tuned ecu or device.
72# should make 500-550 whp at the upper end of the scale.
Shaun
The other option is to run a secondary fuel rail with extra injectors, I'm in the process of mounting 2 extra injectors in my inlet manifold on my new RB30/25 motor (Twin cam RB30)
These are VERY large injectors, flowing around 1000cc, but they are cold start injectors, and can't be pulsed....they only come on at high load.....
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Holden VL Commodore Calais......a domestic Aussie car thats RB Nissan powered (From the factory) and hated by Australian domestic people and Japanese import people alike, due to its mixed heritage.....*sigh* I can't win can I?
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