max hp on 240cc injectors

[fredtoast]

I have an ITR with stock 240cc injectors. I know about the problems with high fuel pressure (up to 90), but I need to know the maximum hp these injectors will support.

[CROM]

Running skyhigh fuel pressures is not a good way to run things, but with all of the aftermarket kits like ours(turbo or super) that is what is relied upon for extra fuel.

Engine configuration and safety should also be included in your question. You can run a maximum X amount of horsepower but you will blow up much sooner. There are several important tolerances to take into account.

There have been some with the GSR (B18C1) that have used stock injectors and 8-9psi. This in my opinion is like playing with fire. With your car and its .5-.6 higher compression, this is not recommended.

So to answer your question: The 240cc injectors can support up to roughly 220whp maybe even 230whp, but that is a stretch. At 9psi you would be raising fuel pressure 5.5 x 9 = 49.9psi over static pressure. And given that JR Recommend static pressure to be between 55-60psi, you are running SKY HIGH pressures at that point(105-110psi). If you are wondering, I am getting the 5.5 from the rise rate that the JR FMU is configured for. I am assuming you are trying to establish this figure for a car with a JR Kit, so I use the JR info as a reference.

[fredtoast]

Thanks guys. That's about what I was thinking. (5:1 at 8 psi = 40 + 55 psi = 95 max) I know about the safty problems as well as the strain on the fuel pump, but I'm on a real tight budget. My car is not for racing, so it is rarely pushed to its limits and never for any extended period. But on the other hand I want something reliable. I don't want to ruin a nice car because I tried to save a few bucks on one part.

[grand600intercooled]

I went to RC engineering website and put in these factors and this is what I got back. crank HP 300,4 injectors, brake specific 40, 80%duty cycle, and 125 psi fuel pressure. and it calculated it to be 233cc injectors. so it is possible but wow that really pushing it

<font color="#a62a2a" size="1">[ April 25, 2003 09:56 AM: Message edited by: grand600intercooled ]</font>

[fredtoast]

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by grand600intercooled:
[QB]I went to RC engineering website and put in these factors and this is what I got back. crank HP 300,4 injectors, brake specific 40, 80%duty cycle, and 125 psi fuel pressure. and it calculated it to be 233cc injectors. so it is possible but wow that really pushing it.</font></td></tr></table></td></tr></table></BLOCKQUOTE>

I think I have seen that worksheet, but I couldn't figure it out. I'm on a real tight budget so I'm trying to find the cheapest injectors that would support 250 whp at max fuel pressure of 75 psi. How much could the prelude 290's produce?

[JRCivic]

You are just about it !!!
I have seen injector duty cycles of over 96% on a STOCK N/A ITR !!! The really high fuel pressures are the only option to eek out more power...

[Batoutahell]

Fred, see my comments in your H-T thread. My 240cc injectors made 218whp, but they were maxed out and running around 95psi. That's way too much pressure for my taste. I installed prelude injectors recently and they should be good to 230whp or so with more reasonable fuel pressures. I'll be selling my prelude injectors soon as I'm moving up to 440cc for hondata use. Let me know if you're looking for a set.

[CROM]

Prelude injectors are gonna be good for 250whp or so. Many guys are making 240whp on prelude injectors.

Ive seen 250whp on 270cc injectors in a GSR before.

[JRCivic]

The brake specific fuel consumption is MUCH higher than .40 when referring to a Supercharged or Turbocharged engine... be careful not to skew the values in the equation because this creates series consequences when searching for REAL results.