Thread: RC 750cc injectors duty cycle to high ?

Hello !
I Have some problems with RC 750cc injectors what have duty cycle of 90% i think that in my tune is something wrong because this injectors should support about 500hp easy but i dont have so much power !
What you think what i need to change ?
Spec:
Nismotronic SA
SR20det
Z32Maf blow trought.
RC 750cc inj. latency is 13,5v@ 0,88ms 14v@0.88ms
Reg. FPR 1:1 fuel pressure is 3 bar at idle with vacum
Holset HX35 1,2bar boost.
Walbro 255 fuel pump , stock fuel system , new fuel filter.
Using 98 octane fuel.

you may need a resistor box, if you have peak and hold injectors, which are low impediance (low ohm value/resistance)
where did you get latency values ? from RC ? When you scroll down list for saturated RC 750cc 0.18 or 0.63 @ 14V or P&H 0.24@ 14V
Fuel Injector Lag Time

Yes its a a low impediance injectors denso style and i have resistor box for them ! This injectors is on my Nissan Pulsar GTiR on stock fuel rail.
RC say that latency need to be about 0,24 at 14v and 0.31 at 13v but if i put this number car run very lean 19-18 afr and wery bad idle or it dies and wont start.
Or i need put that latency and then try adjust idle afr with maf load value ?

Keep the latency to where they recommend. If you are way lean, change the injector size to a bigger value until you are close. Then adjust the fuel map from there.

That latency seems rather low and I wouldn't suggest using that as some of the RC latency values are WAAYYYY off, specifically the low impedance values.

The RC 750cc injectors are NOT good to 500hp at the wheels.. I am not sure if you are mistaking the crank HP for your actual HP rating for those injectors.

Most RC 750cc injectors will make anywhere from 400-450whp at max duty cycle and relatively low base pressure.

John what i can make to change to lower my duty cycle ? Lowering latency ? setting bigger injector value ?

I would think you need to do this, yes.

Edit: Well, maybe not based on what has been said above about RC's specs being off.

That website is totally inaccurate. I would *NOT* recommend it!! People should stop linking it.



That's quite rich. First off, your fuel pressure should be 3 bar at idle WITHOUT vacuum. Also, what are your AFR's? What are your MAF voltages at max power?

-G

Straight from aem rc injector 750 cc 12ohm 13v is 760 uSec and 14v is 630 now for the 3ohm it's 13v 320 14v is 180 uSec. I would trust these values because I have seen them work great on the Ems

Sent from my GT-I9300 using Tapatalk 2

AFR is at WOT 12 , maf v is 4,53v , inject duty 92%
I will try play with latency (lower it) and see what it will change !