R33 injector limit??

[ABuSD]

Any1 know how much power the stock R33 GTS-t injectors can flow?

And whats a good set of more powerful aftermarket injectors?

How much u looking @ spending for a set?

Cheers

[Sydneykid]

Hi ABuSD, R33 RB25DET uses side feed, high impedance injectors @ 340cc and that's enough for around 340 BHP, 253 kw, 190 rwkw or 255 rwhp. Do a search and you will find heaps of posts on this subject.

[ABuSD]

Thank u very much, well i know i need some new injectors!!!

Any recommendations Sydneykid??

[ABuSD]

and when will i have to upgrade my fuel pump, is it when ive got over 240+rwkw??

Thanks heaps for the advice!

[lukits01]

hey while we're on the fuel delivery subject

I was wondering when would you require fuel pressure regulators? and why?

[Busky2k]

You'd need one if you wanna bump up the fuel pressures because you want more fuel flow. Its really more of a bandaid to try and avoid getting bigger injectors, but if set up properly, it works quite well.

[muffas 180]

I have a RB25 power fc, high flow turbo, front mount, malpassi reg, exhaust, dump pipe with standard injectors my car made 229.2 kws at wheels @1 bar boost with fuel pressure @ 90 psi @ 1 bar boost my air flow ratios were 11.5. Couldnt tune for more boost because no. 3 coil pack was breaking down.

Michael...

[Busky2k]

Your injectors still fired at 90psi? Pretty good I think, but just watch out.. What fuel pump are you using?

[GTS-t VSPEC]

I've got over 400rwhp from a set of standard R33 GTS-t injectors, running 45psi of fuel pressure with a Malpassi rise rate regulator. It has alot of do with engine management:D

[ABuSD]

Swoit, whats that equate to in rwkw?

see what happens the 33's goin into Race Pace in a day or so for a dyno tune, see what they say!

Cheers fellas!

[VIPERGTSR01]

400rwhp = roughly 308rwkws'

[ABuSD]

DAAAAAMN i tell ya some tuners are absolute magicians!!

[R31Nismoid]

Yeah... but GTS-t VSPEC dont care if his motor goes.

there is a difference

[Sydneykid]

Ok GTS-t VSPEC, here we go again.

"It has alot of do with engine management"

Explain this to me, if I have an engine that shows an A/F ratio of 12 to 1 at 6,000 rpm at 1 bar using X brand ECU. How will it make any difference to the amount of fuel used if I have Y Brand ECU on that same engine that shows an A/F ratio of 12 to 1 at 6,000 rpm at 1 bar?

Same rpm, same boost, same engine, same injectors, same everything, how can one ECU use less fuel over another ECU if they both produce the same A/F ratio?

Now if you can't get the same A/F ratio with Y brand ECU because it has limitations, then that's a different story. But the A/F ratio won't be 12 to 1 and the dyno lambda sensor will show that.

I had a very long conversation (cost me many beers) with a couple of Motec and Autronic engineers at Bathurst and this was one of the subjects. As long as your A/F readings are consistent (they don't have to be correct, just consistent) then there is no way they could see where one ECU would use less fuel than another.

Maybe I've missed something, I am here to learn........

[RBVS]

gts-t vspec what colour is your car, im know iv seen those plates befor

[caminperth]

Hi ABuSD, R33 RB25DET uses side feed, high impedance injectors @ 340cc and that's enough for around 340 BHP, 253 kw, 190 rwkw or 255 rwhp.  Do a search and you will find heaps of posts on this subject.

I had my standard R33 series 1 injectors flowtested and they all flowed between 500 and 550cc? Or are you just saying that with the standard regulator they will only flow 340cc?

Also - I think GTST-VSPEC was just alluding to the fact that different tuners and different engine management can produce very different results. The engine management is like any other piece of equipment - it's only as good as the operator.

[Sydneykid]

Hi caminperth, at 38 psi the R33 GTST RB25DET injectors are rated at 340 cc's per minute. I have cleaned and tested over 20 sets and they have all actually flow around 350 to 365 cc's at 38 psi. This is normal tolerance. If you increase the fuel pressure they will flow more, but at 38 psi they should only flow to their rating.

So if your injectors flowed between 500 and 550 cc's, then I would say they are either not standard R33 GTST RB25DET injectors or the fuel pressure was a lot higher than 38 psi.

In addition a 50 cc variation (from 500 to 550) is far greater than I have even seen, and would result in the cylinder with the 550 cc injector running 10% richer (and that's a lot) than the cylinder with 500 cc injector. The most I tolerate is 3% and I carefully select which cylinder each injector goes in ie; I put the highest flowing injector in #6.

Hope that clarifies

[benm]

and when will i have to upgrade my fuel pump, is it when ive got over 240+rwkw??

On an R33 GTS-t i'd be doing this around 180-190rwkw. The standard R33 GTS-t pump is rated at 300bhp which is approx 180rwkw.

400rwhp = roughly 308rwkws'

400 x 0.746 = 298.4rwkw

But lets not get down to the nitty gritty

[benm]

Is an aftermarket ECU "required" in order to use aftermarket Injectors? (ie; 550cc's instead of the standard 340cc's). Or will the standard ECU just continue on its way and pump more fuel in "if possible" ?

[Busky2k]

Nah you'll definitely need an aftermarket ECU as the ECU will just pulse your new injectors like before and and you'll be overfueling BIG TIME.