3s VR-4 Injectors in 1g:MAFT Setup

[codym]

I got a few things for the dsm with tax return

I've been having some issues with my 1g n/t MAF, so I went ahead and ordered a MAF-Translator, and picked up a GM MAF from a 2003 Impala at the local salvage yard.
Along with a wideband so I can use my SAFC more effectively.


I am working on a 91 3000gt VR-4 as a side project, these have 360cc Injectors from the factory vs 240cc in the n/t 1g's. I'll be putting 1250's in the VR4 for e85 setup, so I have these 360's as spare.

After reading how to set up your base injector size on the MAFT, I see the lowest value for base and aux is 0,0 - equalling the factory turbo dsm injector size of 450cc.

I assume you can not go below these values, for example Base: -9 Aux:0 (360cc)

How would I go about setting up the MAFT to function properly with these injectors?
I'll be setting up the Translator in cab, I will be using it for base tune, and the SAFC for fine tuning.

Thanks for any help/feedback!

 

[92AWDHX40]

DOWNLOAD USER MANUALS HERE! - Full Throttle Speed Tech Support

 

[EGLTAWLN]

is it running? have you tried it?
you cant go lower but you can stay at 450 and tune down the fuel knobs and hope it evens out.
or put in 450s and dumb them down as well.
i say try it it might work. probably want a datalogger and a wideband though.

 

[okm12346]

you have 240cc at 48psi pressure

3kgt has 360cc at 43 psi pressure

The 360cc will flow as 380cc at 48psi

the formula is (old inj/new inj)-1 = 240/380 -1 = -37%

You have to lean things out with the BASE knob by 37%.

Thats setting 7or8 on BASE knob

 

[codym]

I have read that along with multiple threads on the fullthrottle website.

Just got my wideband installed, I have yet to get a datalogger. I'll get that when I'm closer to getting a turbo on, but for now I'm tuning for ideal AFR's. The GM MAF or the MAFT isn't on the car yet, I want to get my injector size settled before I put it on.

Thank you for that info okm, I read that the base knob is oposite of other knobs, so to match 360cc(380 @48psi) I would turn it clockwise 8 times, correct? & then I can fine tune with SAFC.


I got my idle set to roughly 14.7

Did some cruising(Less than 30% Throttle) around with the settings I had, and she was running at over 17:1.
Using the SAFC I richened up a hair and got cruising AFR's to around 15.
I took it up to about 50% throttle, AFRs went to roughly 13.3, and the car started to bog and sputter like it was rich. Noted.

That is where I left off, and I won't even step into WOT until I get cruising nailed.

I'll have to do some more research on what AFRs I should target , but I know turbo vehicles will require a richer mixture than a n/a car. 13.3 seemed too rich at 50% throttle, while 13.3 would be about perfect for WOT.

 

[okm12346]

IDK if its at the 8th click, but you can set exactly at 7 or 8. Look closer at the BASE knob. If you get the base setting right, car should idle and cruise w/o tinkering with the SAFC

 

[codym]

Alright thanks again.

I just read a few threads about ideal AFRs for us N/A guys, the common ratios I am seeing are...


Idle:14.7
Cruise:15-16
WOT: roughly 13



I'll play around with everything tomorrow and see if I can get her running good & strong.

 

[EGLTAWLN]

did you order the dsm maftranslator or the 3000gt maftranslator?