Injector duty

[Guest KILLER-T]

I am trying to find out what the max safe injector duty is mine is going up to 85% @7000rpm is that safe :burnout:

[meggala]

yes that is fairly safe they say 80% but I wouldn't be running out for injectors yet if it was 95 yes Iwould be worried

cheers

how many kw now with the new motor

[Guest KILLER-T]

Hi Meggala the car has 228 kw and had the rev limiter set to 6500 rpm on the dyno because i was a bit worried about blowing the new engine but i have had it for a while and i have a bit more faith in it so i have lifted the rev limit to 7500 rpm and thats why im asking about the injectors. So 85% is ok hey would a fuel reg help me get a bit more out of it

[macka]

Hey Adam

Yeah put a adj fuel reg in then wind the boost up abit more.

Thats what im gonna do altho cant boost it much more with the standard guts maybe 16psi wid dat turbo i have.

Cheers

[25GTT]

Originally posted by macka

Hey Adam

Yeah put a adj fuel reg in then wind the boost up abit more.

Thats what im gonna do altho cant boost it much more with the standard guts maybe 16psi wid dat turbo i have.

Cheers

Heya Macka,

Isn't 16psi a bit too much without forged pistons? I know with the PSI hybrid turbo Brett was saying not too push it too much over 14psi without having forged pistons......or say bye to the engine after a while kinda thing??

[GTS-t VSPEC]

Macka/25GTT,

I have already warned Macka against running too high boost, but in his quest for more power he will push his engine to its limits. I wouldn't run more than 14psi, and I'm getting my forgies in soon, so I can tell you the total cost of pistons plus fitting.

KillerT,

I use a fuel pressure regulator, and it will extend your fuel system for a bit more power, but it is not the best way. Save up for some bigger injectors and fuel pump if your planning on more power, don't run past 90% duty cycle.

See'ya:burnout:

[macka]

Originally posted by 25GTT

Heya Macka,

Isn't 16psi a bit too much without forged pistons? I know with the PSI hybrid turbo Brett was saying not too push it too much over 14psi without having forged pistons......or say bye to the engine after a while kinda thing??

Hang on fellas.....

U cant just jump in and point the finger.

skylines high compression means that 15psi is about max for the engine...causing stress on alot of stuff with the high combustion pressures

I have a decompressed head running 8.5:1 and retarded timing.

Alot of skylines are running 18psi on standard pistons if u are looking out for them!

16psi would only be for the drags I run 12psi day to day anyway so the risk is GREATLY REDUCED!

You run 16 all day it aint gonna last long for sure..

[GTS-t VSPEC]

Hi Macka,

We're not having a go, and I know that is what you told me before, but even with lower compression there is the chance. If it was me I'd go for it, but if you do blow a piston then the results could be very expensive. We're just looking out for your wallet, which could suffer the most.

Yes 16psi could run fine for many years at the drags, or the engine could go bang, less likely but it is a possibility.

The main reason we siad not to do it is cause we don't want oil down on the track.(J/K)

Do it, run 16psi, it's the only way to prove your right.

See'ya:burnout:

[blind_elk]

Why does everyone automatically think larger injectors are required at the limits of duty cycle.

Why not increase the pressure behind the injector. Higher pressure will cause more fuel to be injected at a given duty cycle.

I've read somewhere of someone who tried larger injectors (on a Falcon, I think), and found that the fuel delivery was pretty poor because of the required shorter duty cycle. The car actually lost power. Refitted the original injectors and upped the fuel pressure and picked up power.

[macka]

Hey paul......

If shes gonna blow on 16 shes gonna blow on 14, 2psi isnt alot.

I have to wait till me head mech comes back from England before i start getting too serious If a piston blows now i just throw a cover over it for 6 months

Let us know what sort of price you get your reg for Adam id like to know..

cheers

mac

[25GTT]

Originally posted by GTS-t VSPEC

Macka/25GTT,

KillerT,

I use a fuel pressure regulator, and it will extend your fuel system for a bit more power, but it is not the best way. Save up for some bigger injectors and fuel pump if your planning on more power, don't run past 90% duty cycle.

See'ya:burnout:

How much are the fuel pressure regulators worth? and are they an effort to fit?

Macka can you notice anything bad at all with the injectors at the moment? if not just for longevity go the fuel pressure regulator? just a suggestion.. could save you some $$$$ injectors could be close to maxing out but depends on how many more mods you wanna do i guess as to whether or not go the bigger injectors??

Yeah we are just trying to help you dude.... quite sometime ago at the drags i did see a white skyline that had turbo probs and smoke coming out of it,, the owner looked upset at the $$$ he would have to spend to fix it..... if i remember right the owners name was ummm....you:uh-huh: i just don't want to see that happen again to your pride and joy...

[GTS-t VSPEC]

I have a Malpassi rise rate fuel regulator, approx. $220-240. There are more expensive ones, but for 600hp or less this is fine. They are easy to fit, most difficult bit is the mounting bracket.

The regulator will extend the amount of power your factory fuel system can support, but I'd still recommend bigger injectors and fuel pump aswell. I can get cheap 550cc injectors for you Macka, if you want.

When running higher horsepower 300+rwhp, then the pressure regulator is recommended so that there is not drop off in fuel at the rails, if this happens then bang, you engine has detonated.

See'ya:burnout:

[Steve]

GTS-t VSPEC, how many cheap (and how cheap) 550cc injectors can you get:D

[macka]

Originally posted by GTS-t VSPEC

I can get cheap 550cc injectors for you Macka, if you want.

See'ya:burnout:

Was that those bosch ones?

Ill try and push the envelope with the reg first Cheers Paul.

Dont forget the clutch isnt going to last on mine either but for now it seems to be hoilding up just a bit spongey! :burnout:

[GTS-t VSPEC]

Yeah they are bosch ones, might not be worth doing yet. I'll keep my eyes out for a better clutch, do you want twin or triple?

See'ya:burnout:

[macka]

Originally posted by GTS-t VSPEC

Yeah they are bosch ones, might not be worth doing yet. I'll keep my eyes out for a better clutch, do you want twin or triple?

See'ya:burnout:

Hehe i dont think i need a triple.........do u think i need a twin?

Thanks Paul

[GTS-t VSPEC]

I'd recommend the twin over the singles any day. They are easy to drive and will bite hard with the extra power your planning on sqeezing out. A single 5 puck might last at your current power, but in the furture it would die a lonely death.

See'ya:burnout:

[Clint32]

There is no reason that you cant run more than 16psi on an rb20, remember these run less compression than the rb25. Its all in the tuning, if there is no detonation the engine will be fine.

I am in the process of fitting a bigger turbo/intercooler/injectors and will run probably up to 18psi with it depending on the power it makes.

[Guest KILLER-T]

Ok so a Malpassi rise rate fuel regulator will help me.Are they hard to fit your self or am i going to have to put it on a dyno for a fuel remap

[meggala]

just so you guys know jms run a decompressed rb25 in their red car and that makes over 300 rwkw on stock internals the gtr runs similar compression and will hold 1.5 1.6 bar of boost the stock pistons are very similar to the rb25 ones. so 1.3 bar with a big turbo should be fine but not to drive with all day every day but when you need it. macka you knwo your stuff dr drift told me about your car I was to heard some times

cheers