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Max Power From Stock R34 Neo Injectors

ZXY

By ZXY,
in Western Australia

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ZXY Mentor

ZXY

Posted
Posted

hi guys,

i got my car tuned today, its a r34 gtt with stock injectors. I am running a hi flow turbo with a gt30 rear housing and sweet wheels. I got 270rwhp at 13.5psi. my tuner told me the reason i couldnt get more is that my injectors are at 97% duty cycle. I was sure there are people running more power with stock injectors. can anyone confirm?

Thanks

Terence

BoostBitz JDM Explorer

BoostBitz JDM

Posted
Posted
  ZXY said:
hi guys,

i got my car tuned today, its a r34 gtt with stock injectors. I am running a hi flow turbo with a gt30 rear housing and sweet wheels. I got 270rwhp at 13.5psi. my tuner told me the reason i couldnt get more is that my injectors are at 97% duty cycle. I was sure there are people running more power with stock injectors. can anyone confirm?

Thanks

Terence

An adjustable fuel pressure reg can give you a bit more out of stock injectors.

Hope that helps :banana:

ZXY Mentor

ZXY

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  • Author
Posted (edited)

im going to upgrade the injectors, but i was wondering if it is normal for this power with the stock fuel system.

attached is the dyno graph. i feel the end of the power curve is abit dodgy, so maybe its time to do the fuel system

post-54969-1286966741_thumb.jpg

Edited by ZXY
monga Experienced

monga

Posted
Posted (edited)

Thats about spot on without f**king around with fuel pressure, I've seen around 300hp but it's all about the same with different conditions and dyno's, especially if you are running the stock afm. Also, stockers are not huge been rated to 440 or 450cc. Curves pretty normal, if it was scaled out the line would appear much straighter, also Andy is pretty mint when it comes to tuning at Hypers so I would not be concerned.

Edited by monga
ZXY Mentor

ZXY

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Posted

yea i trust andy too monga which is why i go back to get the work done...still looks like plenty more power to come from the turbo. still got the stock afm..will start collecting parts and do everything at once...at least the hard part is done and paid for.

bubba Grand Master

bubba

Posted
Posted

I reckon your fuel pump is dying and that's why you're running out of fuel up top..

I'm running 15psi through my highflow, my duty cycle doesn't go over 90% and that's still rich as hell, no idea what power it is making though, somewhere around 300rwhp at a guess.

Will be ripping the Haltech out real soon and fitting the NIStune board I have sitting here, will have a better idea then.

P.S. +1 for Andrew :ninja:

bubba Grand Master

bubba

Posted
Posted (edited)

Everything I've seen in regards to Neos is that stock injectors should be good for ~240wkw.. I'd like to go as far as I can without changing injectors (rather spend those $_$ on the 32).

I've maxed the stock afm already and have wired in a z32 ready for the ECU swap.

But yeah, do the fuel pump at the same time as the afm and injectors then go back for a tune :P

What ECU are you using?

Edited by bubba
ZXY Mentor

ZXY

Posted
  • Author
Posted
  bubba said:
Everything I've seen in regards to Neos is that stock injectors should be good for ~240wkw.. I'd like to go as far as I can without changing injectors (rather spend those $_$ on the 32).

I've maxed the stock afm already and have wired in a z32 ready for the ECU swap.

But yeah, do the fuel pump at the same time as the afm and injectors then go back for a tune :P

What ECU are you using?

Im using a Power FC

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Posted
  ZXY said:
thanks bubba for that.

andrew told me my pump is still good :S

ive got a bosch 040 that ill do soon. he said should see 350 when fuel is sorted out

Easy way to tell if its failing, fit a fuel pressure gauge just before the rail and watch it when on the dyno. If the pressure drops off at high rpm there is an issue.

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