Fuel Injectors

[Shaneo]

it's time for me to upgrade my injectors, the factory ones are now at max flow. So what i am after is some first hand experience with aftermarket injectors... What's worked? What's failed? What should i steer clear of?

Current mods that you may need to know are:

T3/T4 turbo

PowerFC

Malpassi Fuel Reg

FMIC

running 15psi boost

[nizmokid]

it's time for me to upgrade my injectors, the factory ones are now at max flow. So what i am after is some first hand experience with aftermarket injectors... What's worked? What's failed? What should i steer clear of?

Current mods that you may need to know are:

T3/T4 turbo

PowerFC

Malpassi Fuel Reg

FMIC

running 15psi boost

I dropped in a set of nismo 555cc injectors into my car, and the Sard ones were cheaper but needed collars to fit, which took the price up to the same as the nismo ones!.....the nismo one drop straight in with no problems!....easy!

[r33_racer]

not only that the sards require a plug rewire. Nismos would be much better as they are a true drop in replacement. The only thing that i think they dont come with is new o rings, and its highly recomended to change them while their out so you dont get a leaky injector down the track.

[R31Nismoid]

Nismo 555 or 550, whatever the RB25 bolt in ones.

Definately the way to go.

When you do get the injectors, sell the Fuel Reg and put the stock one back on. Will get some cash back

[satanic]

Why would you sell the fuel reg, I'm sorry I don't understand...

[r33_racer]

because you dont need to control the fuel pressure with an aftermarket pump on, cause you have a/m management needed to control the injectors. Does that make sense. I think it does.

I kept mine on just for the ability to keep monitoring fuel pressure....im lazy though.

[race_snooze]

slight side track, I have had a quick search, but what is the difference between long and short injectors by sard, which say they are a drop in?? They would be for a rb25det

[Shaneo]

not only that the sards require a plug rewire. Nismos would be much better as they are a true drop in replacement. The only thing that i think they dont come with is new o rings, and its highly recomended to change them while their out so you dont get a leaky injector down the track.

what injectors are you using on your cars michael? i was think of going the Nismo 740cc injectors, talking with a few people, we think the 555cc wouldn't allow for enough future growth.

[Shaneo]

I dropped in a set of nismo 555cc injectors into my car, and the Sard ones were cheaper but needed collars to fit, which took the price up to the same as the nismo ones!.....the nismo one drop straight in with no problems!....easy!

i've also heard that the Sard injectors aren't the best nozzle

[mickr33]

Hi Shane. I know it's a bit of topic, but could i ask at what power did the stockies run out at.

Im upgrading the turbo and just wondering what roughly the 370cc will do.

[r33_racer]

Shane in my r33 I have 550cc SARDS and in the race car we got 850cc SARDS. I think the basic equation is that its 1HP to every 1cc, so going on that 550hp @ the fly is the max, call it 500hp to be safe. Thats about 420hp @ the wheels.

I think the price difference is almost nothing for the 740cc nismo items, might as well go them if you think your going to come up short with the 555cc ones.

Whats the t3/t4 you have rated at? Unless your changing turbos in the future that will tell you how much you should allow for.

[R31Nismoid]

Why would you sell the fuel reg, I'm sorry I don't understand...

r33_racer beat me

See his response, no requirement for it at all.

[Shaneo]

Hi Shane. I know it's a bit of topic, but could i ask at what power did the stockies run out at.

Im upgrading the turbo and just wondering what roughly the 370cc will do.

i had it tuned to 225rwkw, then we downtuned it to 215rwkw to try stop the pinging. they are still maxing out...

from my googling during the week, i found that 370cc is probably only good for 210rwkw.

[AzzurrA]

you didn't mention an upgraded fuel pump in your list of mods... have you looked at that?

[Sydneykid]

As usual it's all in the numbers...................

210 rwkw + 65 rwkw for losses = 275 rwkw

27 rwkw x 1.34 = 368.5 bhp

Pretty close to 370 cc = 370 bhp.

550 cc = 550 bhp

550 bhp / 1.34 = 410 rwkw

410 rwkw – 65 rwkw losses = 345 rwkw

That’s at standard fuel pressure (34-36 psi)

You could use the adjustable FPR to raise the pressure to 47 psi and you are looking at just over 625 cc of flow

625 cc = 625 bhp

625 bhp / 1.34 = 466 rwkw

466 rwkw – 65 rwkw losses = 401 rwkw

47 psi fuel pressure + boost, say 25 psi = 72 psi

Which is well within the range of a Bosch fuel pump (044 for example).

I wouldn’t use a Walbro though. Plus I would STRONGLY suggest using new fuel hoses and clamps for that level of fuel pressure.

cheers

Edited August 16, 2006 by Sydneykid

[Shaneo]

you didn't mention an upgraded fuel pump in your list of mods... have you looked at that?

Which is well within the range of a Bosch fuel pump (044 for example).

I wouldn’t use a Walbro though. Plus I would STRONGLY suggest using new fuel hoses and clamps for that level of fuel pressure.

cheers

i currently have a Walbro pump on, i'm on my 2nd one in under 12 months. the latest one has been on for 3 months and has already started to shit itself... a Bosch 040 will be going in ASAP.

[Kaido_RR]

go the nismo 740cc, they only work out to be $50 more (will it was in my case), that is like $8.30cent more pre injector

[Shaneo]

go the nismo 740cc, they only work out to be $50 more (will it was in my case), that is like $8.30cent more pre injector

what ECU are you running? someone mentioned to me that PowerFC doesn't really support big injectors all that well

[r33_racer]

Thats a lie...shoot whoever told you that If there is a problem its more then likely the tuner, remember a good tradesman never blames his tools.

And the powerfc in the race car is running the 850's perfectly fine

[R31Nismoid]

what ECU are you running? someone mentioned to me that PowerFC doesn't really support big injectors all that well

Thats pure bullshit dude

As stated, shoot the person that told you that

I ran 740's with a PowerFC, idle was as good as when the factory injectors were in there