i am currently running a h22a4 tuned with a p28 on crome. after a tuning session today, we discovered that my puny 290cc injectors are running at about 94% DC. this only occurs up around 8k however. can i get away with using the h22a1 345cc injectors even though they are peak and hold? or should i upgrade to something bigger? will the 290's be ok for now ?? suggestions welcome. thanx

 

I would go to 450 just for room to grow

EDITED** 450 not 440


Modified by MadCityLude at 12:15 AM 9/19/2006

 

i dont see the need of going bigger than 345cc unless you plan on building the bottom end anytime soon. 94% is pretty dangerous to run at 8k rpms. If anything goes wrong you can say goodbye to a cylinder or two. If you have a fuel pressure regulator, you can raise the psi to lower the DC.

how are you formulating duty cycle? Are you going by what crome says?

 

yeah based on crome. i understand that is a slighty inaccurate DC reading no?

 

the 440s are peak and hold or saturated or does it matter?

 

I was speaking of the DSM 450cc earlier

They also use the resistor box I believe.

 

if you have everything setup, it can give you an idea of what DC you are running.

you have to make sure your fuel multipliers, displacement and fuel pressure data are all correct in Crome or the formula will be off. Although i dont know how much i trust the values even with everything is inputted correctly.

you got skunk2 cams right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91preyludesi &raquo;</TD></TR><TR><TD CLASS="quote">the 440s are peak and hold or saturated or does it matter?</TD></TR></TABLE>

you would need a resistor box to run the JDM OBDI injectors which are 345cc as well with the DSM injectors and most RC injetors

 

http://cgi.ebay.com/ebaymotors...wItem

 

or
http://cgi.ebay.com/ebaymotors...wItem

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98vtec &raquo;</TD></TR><TR><TD CLASS="quote">if you have everything setup, it can give you an idea of what DC you are running.

you have to make sure your fuel multipliers, displacement and fuel pressure data are all correct in Crome or the formula will be off. Although i dont know how much i trust the values even with everything is inputted correctly.

you got skunk2 cams right?</TD></TR></TABLE>
nope game time decsion and i went with crower stage2's.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98vtec &raquo;</TD></TR><TR><TD CLASS="quote">you would need a resistor box to run the JDM OBDI injectors which are 345cc as well with the DSM injectors and most RC injetors</TD></TR></TABLE> damn i thought so. oh well whats money anyway.

madcitylude: thanks for the links

 

no problem, anytime, hopefully everything works out for you

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91preyludesi &raquo;</TD></TR><TR><TD CLASS="quote">nope game time decsion and i went with crower stage2's.
damn i thought so. oh well whats money anyway.

madcitylude: thanks for the links </TD></TR></TABLE>

well then yea, i can see your car running around that duty cycle. With that header, cams and tuning your really gonna be putting some stress on those injectors.

 

yea that sux i shoulda just gotten bigger injectors to begin with. now i gotta buy injectors and pay for a retune. i didnt think i would be putting down enough power to stress them past 85% or so. think they will be ok for a lil bit. i am rarely going to rev up to 8k anyway. i've only done it once since the tune and it backfired from the 3rd to 4th shift.... whatever that means

 

I needed 57psi or so (giving me low 80s duty cycle) out of my stockers for boltons + crower 2's.

 

hmmm maybe i'll just get a fpr. you are running 290's right??. BTW im gonna try and get you my bin to see if that helps you out at all with your tune. im hitting the dyno in a couple weeks so i will keep you updated

 

You aren't running a FPR? Why? Thats a must when your tuning man. For sure get one.

 

to be honest i didnt think i'd need one. i never expected to come that close to maxing out the injectors. i also thought of the fpr as kind of a hack. ya know? why not get bigger injectors and tune for them if you got the program.

gotta admit though a fpr sounds a lot more tempting then buy new injectors and wiring up a resistor box

 

FYI the resister box is pretty easy to wire in actually. Don't let that scare you away. Honestly I would do both rather than one now and then end up doing the other later. Then you know your good to go for a long time.

 

why buy a resistor box when you can get RC injectors that are saturated?

 

^^ i didnt know you could. the last time i had to deal with bigger injectors was when i turboed my 3rd gen. but i already had a resistor box so i all i had to do was throw in some 450 dsm blue tops and i was good to go.

 

I'd suggest you get bigger injectors before you jack up the FP. I only went the way I did because the bigger injectors I was going to get turned out to be...290 Prelude injectors, and I didn't really have any more time to kill. Nearly 60psi is definitely unkind to the injectors and is also pretty much the limit of the stock pump.

Unless you're going no farther with your engine, and have a pressing interest in the OBD2 computer running the car at times (state inspection, w/e)


Modified by A Blue Lude at 10:48 AM 9/19/2006

 

Cause the DSM 450s are 1/3 the cost. Thats why.

 

DSMs also suck in comparison.

Thats why i dont use em anymore and bought new RC's, they work a hell of a lot better. Much more stable AFR's

 

^^^ I have never heard anyone talk down on the DSMs before. Everyone I have spoken with has been very happy with them.