ok, so i just got back from the dyno and my car made about 320hp@14psi with rc 750 injectors. Laurence (my tuner) says my injectors are starting to max out and the duty cycle was pretty high. its a 2 litre gsr motor with a 50 trim 48 AR turbo. my friend had the same injectors on his set up and made 380@14 psi with more room on the injectors for more power. he had a gsr motor with a gt35r. what caused my injectors to max out earlier than his? these are his injectors that i bought off him. both cars are at stock fuel pressure.

 

probably not 750cc injectors?

 

whats the fuel pressure?

 

i just made 424whp on 750CC. there not maxed out


platinum

 

whats the setup?
im just curious

 

https://honda-tech.com/zerothread/1622221

 

im sure they are rc 750ccs. the fuel pressure is stoc.. at about 46psi or so.

setup:
sleeved gsr block
84mm bore
9:1 pistons
stock head
skunk2 pro manifold
50 trim 48ar turbo
3 in dp
spoolin quick 4 mani
2.5 inch charge piping
spearco intercooler (not sure what size)

 

What was your A/F ratio during the run?

And what was the duty cycle?

Chris Macellaro

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DC2xSiR &raquo;</TD></TR><TR><TD CLASS="quote">the fuel pressure is stoc.. at about 46psi or so.

setup:
sleeved gsr block
84mm bore
9:1 pistons
stock head
skunk2 pro manifold
50 trim 48ar turbo
3 in dp
spoolin quick 4 mani
2.5 inch charge piping
spearco intercooler (not sure what size)</TD></TR></TABLE>
up the fuel pressure

 

there 550cc

 

i bought the injectors off my friend (null.) they are 750s for sure. plsu, laurence made a base map for 750s and it started. i didnt get a chance to ask them for a dyno sheet but i remember the richest it got on the monitor was about 12.5 or something. so around 13-12. the dudty cycle was like at 100% at 18 psi so he backed it down to 14 psi and i think it was like at 84% . i probbaly will up the pressure, or buy new injectors. i wa sjust curious why they maxed out so fast. laurence said something about different turbos will want more fuel or something. but i also hear that he tunes pretty consertivaley.

 

they arent 750 injectors 550 and 750 have pretty close pulse width so a 750 base map can work.... my freind just maxxed 750s out tonight at 531whp

 

no way you should be maxing out 750's, what engine management are you running?

 

it's not the injectors, i had these injectors on my setup which made 350hp on low boost. it even has the 750 engraved in the injectors.

 

something doesnt seem right give us some more info on ur fuel mangement. Talk to your tuner laurence about this issue if hes expierenced and has tuned many cars hell know if somethings not right.

 

is the car set up to drive low impedance injectors?

 

thats what i was thinking saturated vs peak n hold injectors, god im so drunk

 

im using hondata s200b. i questioned my tuner about it, but nothing seemed wrong to him, so kinda just forgot about and let him do his thing. im not using any kind of resistor box. they should be saturated injectors.
are there any other variables that can determine when an injector maxes out besides fuel pressure?

 

do you have a injector driver box or a resistor box set up to run 750's?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by quicksilver1689 &raquo;</TD></TR><TR><TD CLASS="quote">that's what i was thinking saturated vs peak n hold injectors, god im so drunk</TD></TR></TABLE>

lol jagermiseter will get you every time

 

the 750's are low impedance, your computer cant run them correctly, that's why they are running out. you should be able to use a resistor box or a driver box like the aem #30-2710

http://www.aempower.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prostock &raquo;</TD></TR><TR><TD CLASS="quote">do you have a injector driver box or a resistor box set up to run 750's?

lol jagermiseter will get you every time</TD></TR></TABLE>


how come they worked fine in my friends car?

 

What kind/size of fuel pump are you running?

Chris Macellaro

 

walbro 255 lph. dont know if its the high pressure one or not.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DC2xSiR &raquo;</TD></TR><TR><TD CLASS="quote">


how come they worked fine in my friends car?</TD></TR></TABLE>

every setup can vary, battery voltage can change A/f, mabye his tune is leaner, ect ect ect but 750's should support over 500whp when set up correctly

 

Sorry for all the questions.... just trying to go through the process of elimination.


What type of dyno was that output measured on?


It may sound funny but have you changed the fuel filter lately? You may want to consider a fuel flow(volume) test for the fuel pump.


Did your tuner try to push the car any farther than the observed 100% duty cycle? And if so did the A/F get leaner?

Chris Macellaro