Injectors rated different duty cycles? RC vs. Veno

[blowncivic]

Does RC and Venom rate their injectors using different duty cycles? If so, who uses which duty cycle? I'm looking for a 310 cc injector set for my D16. Thanks again everyone. Tom

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'92 Civic Si H/B (D16Z6) w/JRSC @ 6psi, J&S Safeguard, Fields SFC, Slater CAI, DC 4-2-1 header, custom 2.5" B-pipe, Tenzo-R muffler, Cartech FMU, B&M CommandFlo FPR, a grindin' 2nd gear and a bunch of knock...

[Bigkat]

I just called RC and they said all injectors are rated at 100% duty cycle. That most injectors max between 80-90% duty cycle. I don't know where I heard or read different. Oh well

Tom get the Rc 310's and dial them dawgs down. You might want to get the new Apexi SAFC.....it allows you dial in part throttle. On my Apexi(1gen - only has 5 adjusting points), I'm dialing out -30% fuel at 4000,5600,7200rpms and -10% at 800,2400rpms. You'll get a code 43 while cruising in 4th or 5th. Pain in the ass having to pull over to reset your ecu.

[sjoback]

yeah but RC's are better if you want to run high fuel pressures, right?

anyone know what the pintal style are good for as far as psi? or do they hold as well as rc's??

[This message has been edited by sjoback (edited September 13, 2000).]

[Holden]

According to the "Honda Builders Handbook", pintle injectors start to "flutter" (getting stuck between open and closed) and have poor atomization once they are pushed past 80% duty cycle while disc injectors work fine right up to 100% duty cycle.

Take that with a grain of salt, since the "Honda Builders Handbook" is not held in the highest regard by everyone.

rjaffey has said in the past that he's observed that OE Honda injectors don't squirt much more additional fuel once the PSI goes past 90psi. I don't know if this is the case for all pintle injectors.

Greg

[rjaffey]

Both RC and Venom rate their injectors at 100% (wide open).

RC rates theirs with 43psi reference pressure while Venom rates theirs with 40psi reference pressure.

I have yet to see an actual "Honda OE" rating at any duty cycle. I've seen ratings from 225 to 245 for GSR injectors, but have no idea where these numbers come from. According to Venom, they're around 265 at 100% and 40psi.

I posted some info at the end of:

http://www.hostboard.com/ubb/Forum40/HTML/003725.html

As to high pressure operation, the RCs are reported to work better. The Venoms (and probably OEs) are probably only good for 75 to 80psi pressure differential max. For example if you're running 10psi of boost, then you shouldn't run more than 85 to 90psi of fuel pressure. I certainly found with OE and Venom 280 injectors with 6psi JRSC, that fuel delivery didn't seem to change much above 85psi of fuel pressure.

[This message has been edited by rjaffey (edited September 14, 2000).]

[blowncivic]

Woa, woa, woa...Bigkat, you mean to tell me that my CEL light will come on everytime I curise at part throttle?! Why? What the hell! I haven't installed my Fields VTEC-SFC yet, but will it do what I want or should I get rid of it? Thanks. Tom

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'92 Civic Si H/B (D16Z6) w/JRSC @ 6psi, J&S Safeguard, Fields SFC, Slater CAI, DC 4-2-1 header, custom 2.5" B-pipe, Tenzo-R muffler, Cartech FMU, B&M CommandFlo FPR, a grindin' 2nd gear and a bunch of knock...

[MDA]

I;m not sure about taping out the duty cyle (100%) on the venom's... but as noted by Holden, i would expect the pintal style to not work as well at high fuel pressures... But that lends me to ask why you're using high fuel pressures with big injectors ?

Currently I still run my stock injector with a fuel pressure riser so it hits 80psi... just to ram some more gas in there.... but that's only temporary ... Till i put in some Venom 500's or 550's (just have to got pick'em up, Holden, BTW: found a place around my area that has them in stock) ... with an injector of that size and a Super AFC, the high fuel pressure is NOT needed... It makes for an easier and smoother idle...

[rjaffey]

MDA,

The 100% wide open rating is intended for measuring flow capacity and provides a common basis for comparison. It's not for real world operation.

As to why the high pressures, it's a means to an end. Assuming the fuel demands aren't too far from stock, it's possible to have great idle, overall NA performance, and fuel economy, while meeting the fuel demands by manipulating pressure alone. It's highly dependant on the range of pressures over which the injectors will flow reliably and predictably. Varying fuel pressure effectively makes the injectors have variable flow ratings.

[This message has been edited by rjaffey (edited September 13, 2000).]

[Bigkat]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by blowncivic:
Woa, woa, woa...Bigkat, you mean to tell me that my CEL light will come on everytime I curise at part throttle?! Why? What the hell! I haven't installed my Fields VTEC-SFC yet, but will it do what I want or should I get rid of it? Thanks. Tom
<HR></BLOCKQUOTE>

I don't know anything about the Fields unit. Doesn't it have just 5 rpm adjustable points? In the simplest terms, the ecu(fuel maps) is keeping the injectors open, in turn dumping extra fuel. With OEM injectors this is not a problem, but with the 310's there is a rediculous amount of fuel be dumped into the combustion chambers. The new Apexi SAFC looks looks like it can allow us to dial that fuel out at more rpm points and dial more fuel in where it is needed(@ WOT).

[SteveW]

Is there anywhere that would flowtest your injectors to check that they are all the same? Obviously a third party doing this would be best, so that would knock out RC or Venom checking the flow. I think it might be worth checking them after buying the injectors to double check quality.

Steve