Nistune Forums

Anyone have any luck with the VQ bin in nistune? having a hell of a time getting my car to start or idle. Not 100% sure it's the maf yet or the 800cc injectors.

which did you modify first? change maf or injectors in nistune?

It works, I was having some problems getting the car started at the time. I did injectors 1st then maf. My problem turned out to be my stock FPR.

800cc injectors and a lightning MAF?
I wanna drive your car when its tuned.

Me too lol. Here is a test start vid I did the other day don't mind the smartass chatter behind me.

http://www.youtube.com/watch?v=z3FSWRsPtL0

This is just a base map with the injectors and maf corrected on the factory bin. I have some buttoning up to do before I get it on the dyno prob next week.

it's a blow through setup here is the location of the maf

looks good.
the pipe also looks very good TIG welded
by the way, is it stainless steel or just steel ?

The intercooler piping and the adapter are just mild steel. It's getting painted blk along with the front of the intercooler before the bumper goes back on.

That IC piping looks very nicely done - those welds!!

A couple of questions: what kind of changes to tune are required to make it work in blow through mode? What injectors - brand and impedance? I was a bit worried about fuelling of 800cc injectors at idle - at low pulse widths on small engines like RB. Now I see your rb20 works smoothly - so injectors are able to provide necessary short pulse precision.

Good luck with the car!

Petros.

Legionnaire wrote:That IC piping looks very nicely done - those welds!!

A couple of questions: what kind of changes to tune are required to make it work in blow through mode? What injectors - brand and impedance? I was a bit worried about fuelling of 800cc injectors at idle - at low pulse widths on small engines like RB. Now I see your rb20 works smoothly - so injectors are able to provide necessary short pulse precision.

Good luck with the car!

Petros.

Nothing really since the car doesn't know the maf is where it's at. All it cares about it that the air going into the motor is getting metered. I'm sure I'll have to play with the K-value to get it smooth but I also have large cams so it prob won't be perfect. I'm running Sard aka Denso 800cc low impedance injectors. They sell them in high impedance now but when I placed my order many years ago they didn't have it.

Thanks.
I've read somewhere Dr.Drift's post that moving MAF to cold intercooler pipe requires a lot of retune, that's why i asked.

Low impedance injectors definitely have better short pulsewidth behaviour than high-imp. Thanks for info.

High impedance on a low impedance ECU will not activate as nicely since it hasnt got a matched current draw with the drivers

I have the Z32 MAF plumped in on the R31 and seems to work okay currently. Had a problem with the element getting dirty so had to pull it out and clean it. Not sure if its because of being after the turbo, the previous MAF looked like water had got to it (rusty?!)

However I have had to do some messing around with cold start tables to get it running smoothly. Something I'm gonig to investigate further, since changing the MAF shouldnt require that or doubling the K like we do on RB30/VG30

Was thinking of using siemens 80lb/min low imp injectors with GTR resistor pack on RB25 Neo. Is this possible electrical wise?

Regarding MAF in IC piping - you really need an oil catch can or some form of oil separator as under above-atmospheric pressure crankcase gasses, consisting partly of fine oil mist, partly of piston ring blow-by are ventilated to turbo entry, and amount of oil and soot in these gasses is not small. I have seen an intercooler off a 2000km-old R34 GTR - oil was not dripping, it was flowing form it. That's why factory mounts MAF immediately after air filter and before BOV recirc/crankcase vent hoses.

RB25DET Neo injectors are 15 ohm (just measured them) and GTR injectors are 4 ohm

You would need dropping resistance of 9 ohm

Assuming GTR resistor packs are about this then you should be able to use them. Any idea of the resistance of these?

I'm not too worried about oil since I'm not routing back the BOV back and I have a oil catch can hooked up.

I'm pretty certain I've read about someone's measurements of GTR resistors and they are 6.7 ohm. Looks like it is enough current drop to not burn out ECU injector drivers and to control peak and hold injectors.

On the other hand I can buy 6 10 ohm 10 watt resistors and use them instead of GTR resistors.

Or just buy high-resistance injectors... And face low PW problems at idle.