because vortech doesnt think someone would waste their money on bigger injectors and a 6:1 disk at 7psi, when a 12:1 on stock injectors would suffice for the low boost. you only need to raise pressure when you have small flow rating injectors trying to dump a lot more fuel than they are rated for (high boost+smaller injectors). you could use bigger injectors and never have to raise the fuel pressure at all. so for your injectors to flow the fuel needed for only 7psi in achieved by raising the fuel pressure to only 42psi.
I know it does seem like you'd lean out since its almost like running 310's no fmu at 7psi so maybe 310's arent meant to be used with a 6:1, isnt a 8:1 safer for 310's anyways?

 

I disagree. does anyone on this board have any experience with this? what psi do 310s max out at w/no fmu, stock pressure?

 

Please elaborate a little. what do you mean by maxing out with no fmu at stock pressure?

 

[quote]vortech doesnt think someone would waste their money on bigger injectors and a 6:1 disk at 7psi, when a 12:1 on stock injectors would suffice for the low boost.

it has to do with flow pattern and quality.....really high pressure = poor automization..


You would still need to use some sort of piggyback fuel computer with injectors that large.your probably thinking of the common set-up that involves dsm 440cc injectors and a v-afc or sfc.You then use the piggyback fuel computer to add more fuel under boost and lean it out at idle since the stock honda ecu will not idle 440's.[QUOTE]]

 

at what boost pressure do 310cc injectors max out at with no help from a rising rate fuel regulator meaning at the stock honda set fuel pressure?

edit: yes i realize you would need a piggyback or standalone to control any bigger than stock injector. you also need it to control 310's


[Modified by TurboedGSR, 3:52 AM 11/22/2002]

 

oh, i'm the wrong person to answer that one then ( i know you werent asking me anyway).......my answer is going to be 1psi of boost....................anybody else have any comments to add.......?

 

honda does not make stock injectors to be at 100% duty cycle even at the highest rpm. so stock injectors can handle a little boost. stocks are 240cc's so the extra 70cc's from the 310's im sure could handle more than 1psi

 

true.Stock injectors max out at about 75psi (before perfomance takes a nose dive) aftermarket injectors like rc max out at about 90psi before taking a turn for the worse.
the stock honda fuel system is not designed to support forced induction so therfore it will provide no additional fuel under boost.Where would the extra fuel come from once boost starts? the map sensor cannot see boost (unless your using hondata) so it will not add more fuel once you start boosting...if you try boosting with no form of fuel management you are guaranteed to detonate.you need more fuel to mix with boost in order to maintain a good air/fuel ratio and to make power.
The ecu is mapped for atmospheric pressure (14.7) so it's preprogrmed to add x amount of fuel to mix with x amount of air.once you start messing with the amount of air entering the engine and not doing anything to provide more fuel your looking for trouble...You cant just throw 3psi of boost at an engine with only enough fuel for atmospheric pressure (14.7 or 0 psi of boost).
the only way to make honda injectors perform at a higher duty cycle is to raise the pressure or use a piggyback fuel computer to tailor the fuel curve by widening the injector pulse.....
stock they perform at about 55% duty cycle under full throttle it jumps to about 70% duty raise the pressure 10 more psi your at 80% 10 more psi your at about 95&...i don't feel like doing math so they are rough estimates......

 

Actually, I've read that Hondas run at about 80% duty cycle stock. With an fmu you are not changing the duty cycle, you are forcing more fuel through the injector while it is open, at the same duty cycle.

 

I stand corrected.That i did not know, but it makes sense.

 

I am a going turbo in the near future and i am little confused, Could i use the aem fpr and 310's with a Vafc and no fmu for my turbo set up.