I currently have RC 550 injectors and a Walbro 255 hp fuel pump. I am about to sell my super charger and go turbo. I am going to be shooting for a little over 400 whp, are these injectors going to be able to flow enough fuel? I hope they will, as I am not looking forward to buying another set of injectors. Do you know of any sites that I can calculate injector size with?

edit: this is on a H22 with an H23 crank and 89 mm pistons. Probably going to do a GT35 turbo or something along those lines.

 

too small, go with some 750's at least

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wantboost &raquo;</TD></TR><TR><TD CLASS="quote">too small, go with some 750's at least</TD></TR></TABLE>

ugghhh not looking forward to spending more money.

 

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

ugghhh not looking forward to spending more money.</TD></TR></TABLE>

The price difference of selling your old ones and get RC750's isn't that bad.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 11psiTurboSI &raquo;</TD></TR><TR><TD CLASS="quote">

The price difference of selling your old ones and get RC750's isn't that bad.</TD></TR></TABLE>

Yeah you want to buy some 550's

 

I do how much?

 

yeah man you will max out your 550's around 320 give or take depending on the rail pressure and duty cycle.

here is a calculator to help you out:
http://www.rceng.com/technical.htm

 

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

Yeah you want to buy some 550's </TD></TR></TABLE>

I sold my RC440's for $200 and bought a brand new set of RC750's for $260

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 11psiTurboSI &raquo;</TD></TR><TR><TD CLASS="quote">I sold my RC440's for $200 and bought a brand new set of RC750's for $260 </TD></TR></TABLE>

Where did you find 770's for $260?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adseguy &raquo;</TD></TR><TR><TD CLASS="quote">I do how much? </TD></TR></TABLE>

They are coming out of the car in a week and a half.. make me an offer.

 

Dont mean to thread jack; check sig. 650's are more than enough for your hp goals...trust me.

 

Precision 680, 780, and 880 injectors all sell for about $300 on ebay.

 

Flow rate vs. supported WHP. (Approximations!)

310cc 200~220whp
370cc 220~280whp
440cc 280~330whp
550cc 330whp~380whp
660cc 380whp~425whp
720cc 425whp~475whp
880cc 475whp~525whp
980cc 525whp~600whp

 

you need to take into consideration that you can also upp the fuel pressure to get more out of your injectors...

and how do people idle with injectors that are like 1000cc..

I just dont get it...

550cc is fine for what you need. just up the fuel pressure a bit.

 

the 380 number is with the fuel pressure turned up. and 1000cc injectors idle just fine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wantboost &raquo;</TD></TR><TR><TD CLASS="quote">the 380 number is with the fuel pressure turned up. and 1000cc injectors idle just fine.

</TD></TR></TABLE>

whats idle? like 2500 rpms?

 

my friends have cars that idle like normal. i'll be idling 1600cc injectors with the aem ems

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wantboost &raquo;</TD></TR><TR><TD CLASS="quote">my friends have cars that idle like normal. i'll be idling 1600cc injectors with the aem ems</TD></TR></TABLE>

whats normal?

and tell me this.. how can you get a 1600cc injector to idle at stock when its flowing 1360cc at the same 700rpms when idling?

even if you can get the injector pulse to be the smallest as possible to the point of almost completly shutting off, i dont see it idling at 700rpms...

 

I don't know about no 1000cc+ injectors, but Mase got my RC750cc's idling perfect with no problems

 

yea 750ccs i think is a little on the bigger side but i cna see them idling like stock, but what i dont get is the bigger 880+cc injectors.

 

if you run 1600cc on a stock ecu, then yes it s gonna be dumping that much fuel. with the aem i can run as small a pulsewidht as i see fit. i might idle my motor around 1000.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wantboost &raquo;</TD></TR><TR><TD CLASS="quote">if you run 1600cc on a stock ecu, then yes it s gonna be dumping that much fuel. with the aem i can run as small a pulsewidht as i see fit. i might idle my motor around 1000.</TD></TR></TABLE>

true you can run a small pulsewidth, but you can only run soo small until the injector completly shuts off... so how do you get around making it soo small without the injector shutting off and still having it idle at around 1000rpms.

the only way i can see you can idle such large injectors is upping the idle to around 1500 or so. if its that high, then to me thats not idle. Idle to me is around 700-900rpms (1000max)

 

i get what you are saying. I guess i'll find out in a few weeks, exactly how low i can get the idle.

 

So reading the previous few posts it makes it sound like 750's will idle just fine?

 

id get the 750cc's.