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rb20det 270cc Injector Lag Timing

yogi000

By yogi000,
in Engines & Forced Induction

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Targa Tom Proficient

Targa Tom

Posted
Posted
Targa Tom, any joy with interfacing a GTR air temp sensor? I heard with FClogit, there is air temp correction, which would be bloody useful if you could interface a air temp sensor

Chris

Not yet mate... in Pattaya Thailand working and wont be back in Oz till Early March. What I did do though is buy a bosch sensor, welded a lug on the manifold and got that far. Was trying to do two things at once, ie circuit config and Targa Config. As Targa rules are very restrictive I have halted any playing till after TT05. I do however run a WO2 setup through my datalogit and that has already paid for itself in saved dyno time. Sorry for "offthread" Will keep you posted

TT

Targa Tom Proficient

Targa Tom

Posted
Posted
thanks targa for the info.....so at base pressure if i put the injecotors in and use 61% injector compensation on all six injectors and change the lag to -0.15 , it should be ok to crank over and idel half decent??

So is it fair to say, that the rb20 270 cc injectors have a lag of 0.922ms campared to the gtr 440 injectors which have 0.772ms at base pressure???

Cheers

No not 61% but a factor of 0.579 (58%), and set the lag relevant to your fuel pressure reg (RB20DET std = 2.55bar) Reset your computor via the etc screen to factory PFC default, adjust only the above two for all six injectors and the car should run well enough to get you cross town.

However, if you are leaving the 270's in till you get to the workshop - leave on default.

You may want to scroll thru and log all your screens before reset for a reference file.

Good Luck.

TT

Cubes Grand Master

Cubes

Posted
Posted

Why 61%?

270/440 = .61?

Or are you suggesting the GTR injectors are 466cc?

270/.579 = 466.

I really don't have much of an idea how to determine the lag time by using a oscilloscope for the given setup/base pressure. Any tips?

:)

yogi000 Mentor

yogi000

Posted
  • Author
Posted

Got it all running....initialised the pfc and it ran beautifully, change the 80+ cranking timings to help it kick over when hot.

Took it for a drive, found that my injectors are maxing out(stockers) at 5500rpm.......AFM voltage hit 4.9V, knock was tops of 21. Accelerator response had increased 150%. So crisp, and all this on r32 stock actuator boost, ~10-12psi on the 2530. Starting to wonder how people get 190rwkw with stock injectors.

The way i worked out the compensation for the injectors was how the pfc manuals says, basically 270/440, then i guess you reduce it abit more, maybe for safety??? Anyways i'm off to the tuner the following week to see how it goes. Once its tuned i'm happy to share any settings to help anyone.

Hey cubes, there used to be a website with a huge list of injectors....from OEM to aftermarked that had base pressures and lag times, i cant remember it tho, maybe that could he u.

Cheers

Targa Tom Proficient

Targa Tom

Posted
Posted
................Starting to wonder how people get 190rwkw with stock injectors.  

.......................

They crank up the fuel pressure, and live with it. Go to menu and turn off alarm...

The AFR is still safe.

That Page is on Apexi site and there are some links scattered though forums...

Good Luck TT

Targa Tom Proficient

Targa Tom

Posted
Posted
where is a good sorce to find detailed info on injector correction, inj lag time and setting up injector's??

Normally at your local dyno @ about $100/hr... Other than that is is covered in the preceeding posts.

TT

  • 4 weeks later...
Targa Tom Proficient

Targa Tom

Posted
Posted
Why 61%?

270/440 = .61?

 

Or are you suggesting the GTR injectors are 466cc?

270/.579 = 466.

 

I really don't have much of an idea how to determine the lag time by using a oscilloscope for the given setup/base pressure. Any tips?

 

:rofl:

No, I'm suggesting at 2.55 bar AP engineering rates "260" injectors @ 255 cc/min.

The "444" GT-R type are rated 440 cc/min.... therefore 255/440= .579

AP have ratings based on 3 different fuel pressures. The Manufacturer "Rating" is more like a model number - ie (Purple) "550"s only rated 530 cc/min @ 2.55bar

Thats where I was coming from.

TT

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