I am a beta tester for the Stage One Tuning kit that uses the Eaton MP62 supercharger. Using Greddy Emanage Ultimate with a 5th injector (480cc Bosch) for the extra fuel requirements. Zeitronix wideband and boost gages. I have had the kit running for a couple of months.

My problem is that I am having trouble lowering the AFR to below 12 once VTEC kicks in at 7 psi boost or more. This problem is more acute now that morning temps have dropped to the 40F range. At 40F outside temp and WOT, I get an AFR spike to 13 at VTEC which drops quickly to around 12.3 from 6500 to 9000rpm. Boost peaks at 11.8 psi.

I believe I have the stock injectors and 5th injector maxed out but the AFR is still too high. I am expecting around 320 rwhp from this set up based on WLaurents dyno and almost identical installation.

Here is my question: Should the stock injectors plus the 480cc 5th injector be sufficient for 320 rwhp or should I be looking for bigger injectors?

 

what kind of FPR do you have?

The way that the SC units can run ~300rwhp without larger injectors is that they have 12:1 rising rate FPRs so the extra fuel pressure helps drop the A/F ratio. Without that, they need larger injectors.

So either get a rising rate FPR (if you don't have one) or upgrade the size of the injectors.

 

I have OEM FPR. The 5th injector provides extra fuel just like larger injectors. The issue is whether the 480cc 5th injector plus increasing the duty cycle of the OEM injectors would provide enough fuel or not.

I am looking for a calculation, rule of thumb or some good experience that would indicate if my set up should provide adequate fuel or not. If my set up is theoretically adequate, then I will look for something that is malfunctioning. If my set up is theoretically inadequate, then I will look for new hardware (bigger injectors, etc.) to increase fuel supply.

 

do you have a walbaro fuel pump, you didnt mention it or say anything about it in your sig. have you checked your fuel pressure?

 

I have the OEM fuel pump. I have read here before that the OEM fuel pump is OK up to 400HP. Have not checked the fuel pressure yet, could be the problem.

 

stock comptech supercharger kits come with a walbaro pump... Hook up a gauge to your fuel and see the pressure under boost... you might have inadequate flow... I would certainly put a pump, if anything just to be sure you have adequate flow

 

Yeah you should be running a Walbaro pump for sure.

 

 

I have gone to a few of the fuel injector sites and used their injector sizing calculators. Looks like I need more injector capacity to get 320rwhp and not go over 80% duty cycle. Considering the RC 550's.