Here are my mods, I am running a 2001 B18C5 motor with Invidia(Skunk2) exhaust, JDM 4-1 Mugen header, straight pipe, AEM CAI, Skunk2 stage 1 cams, Toda cam gears, AEM FPR, OBD1 wiring harness and OBD1 P08 computer with Skunk2 chip, VAFC.

I have been running very lean when I run at full throttle with the silencer out of the exhaust. I tried to raise the fuel with the VAFC but it goes wacko after +15%. So I put a FPR on but now am at a very high fuel pressure(over 50psi) and I am still running lean at full throttle in VTEC. I assume I must be maxing out my injectors.

My question is what injectors do I need to get enough fuel at full throttle but not too much for fuel economy on the street?

I did a search, and the options seem to be to use the Prelude injectors. I have access to some 92-96 Prelude peak and hold injectors but I think they will be too big if they are really 345cc. I think they will work with my car as my harness has the resistor box. Will 97 and up injectors work with the resistor box? Any other alternatives? Prelude SR?

Another related question, when do the stock 240cc injectors max out? I thought it was 200hp at the wheels? My last dyno before the cams and straight pipe was 181hp and I don't think the skunk2 stage 1's and straight pipe could push me past 200hp. Maybe they max out at 190hp?

Thanks,

AW

 

check the duty cycle you are running with the injectors. that will give you a ball park of what you may consider getting.

 

What do I need to read the injector duty cycle? I have been only tuning with a VAFC and the cam gears.

Thanks,

AW

 

320 CC SHOULD BE PLENTY

 

I hear ones form a a Misubishi 3000 GT (GTO) will fit on fine, really don't know the sizes though.

 

that's weird that you're running lean considering how minor your mods are.. you've got 50psi at the rail, skunk2 chip (notoriously rich) and are pumping up the fuel with the vafc and you're still lean??? something just doesn't sound right.. have you thought about getting your injectors flow tested? what's your spark plug gap set at?

 

Sparkplug gap is set to the factory spec, can't remember off hand but confirmed the setting when we put in the Denso Iridium plugs.

How much is it to flow test injectors? If it is a lot I will just put in another set of 240's to see if I get the same result.

How do you check the duty cycle of injectors? Is it a tap into one of the wires that goes into the computer?

Please keep in mind my lean problem is happening at full throttle, in VTEC, starting around 6500 rpm with the silencer out of the exhaust. With the silencer in, the problem is not there as the restriction causes the motor to run richer.

Thanks,

AW

 

how do you know its lean?
most of the time a/f meters read lean when the a/f mixture is rich off the scale.

 

Hi SGT

This is why we need you here to tune. I am using a recalibrated autometer AF meter that has been recalibrated to only work at full throttle. We confirmed the accuracy at the dyno that had another more accurate AF meter when we dynoed my car before the new cams. The AF meter in my car was very close to what it showed on the dyno.

In my car at full throttle starting around 5300 rpm when vtec comes on the meter shows rich and you can feel the slight bogging but then as the rpm's rise the meter starts to move towards the lean area with every higher rpm the car reaches.

If you could shed more light that would be great or best come here and do some tuning!

What can the stock injectors support with higher fuel pressure? I don't seem to have a clear answer on this?

Thanks,

AW