Gtr Dyno Tune [email protected]

[Travis Trayhern]

Have just had my car tunned 98 GTR

list of mod

steel wheel turbos

HKS evc boost controller

Hard intake and cooler piping

cooling pro fmic 80mm

tomei fuel reg

std injectors

std afm

std fuel pump

manifolds

std dumps

3" fronts

3" exhaust straight threw atm

lightened flywheel 12lbs

pfc

cam gears

after tune got 260awkw with injectors at 96% duty and didnt want to push them any harder had fuel pressure bumped up to 70psi running 1.25bar have included dyno sheet.

is this a good tune? have read others dyno resaults and some getting 300awkw on std injectors why are mine maxed out?

[The Dan]

Have just had my car tunned 98 GTR

list of mod

steel wheel turbos

HKS evc boost controller

Hard intake and cooler piping

cooling pro fmic 80mm

tomei fuel reg

std injectors

std afm

std fuel pump

manifolds

std dumps

3" fronts

3" exhaust straight threw atm

lightened flywheel 12lbs

pfc

cam gears

after tune got 260awkw with injectors at 96% duty and didnt want to push them any harder had fuel pressure bumped up to 70psi running 1.25bar have included dyno sheet.

is this a good tune? have read others dyno resaults and some getting 300awkw on std injectors why are mine maxed out?

Try running less boost and more timing. And are you sure the tuner wasn't just winding in the fuel to compensate for a dying pump? Maybe a new pump might help to keep things in order. But without seeing the car, it's anyones guess really.

[Bonsai]

Dam thats pretty good IMO.

How does it feel to drive now? ...before and after?

IMO I think i would want the safe tune and tune the car for 250kw.

[Bumblebee]

yer dude... i hit nearly 300awkw with a lil headroom left inthe injectors n pump for a lil more...

260 doesnt seem right.. maybe 3lit3 is right.. dying fuel pump?

[Bonsai]

is this a good tune? have read others dyno resaults and some getting 300awkw on std injectors why are mine maxed out?

I did not read this before.. but I agree your fuel pump needs upgrading.

I would also replace injectors with new 550-700cc depends what you want to achive and headroom.

Replacing old parts for new is a good thing and a safe thing to do.

[CSNet]

Seems a little low..

Stock turbos, injectors, no gears, just exhaust/dumps & power FC made me 250kw at 12 psi.

[saliya]

std fuel pump

after tune got 260awkw with injectors at 96% duty and didnt want to push them any harder had fuel pressure bumped up to 70psi running 1.25bar have included dyno sheet.

is this a good tune? have read others dyno resaults and some getting 300awkw on std injectors why are mine maxed out?

Hey,

It should be easy to figure out whether the pump's not up to the task - get a graph of

fuel pressure on one of those runs (or have someone watch a gauge if it's in the engine bay),

if it falls off at maximum flow your pump needs help.

Regards,

Saliya

[R31Nismoid]

I also think dying fuel pump.

Silly to bump the rail pressure without checking the pump is ok first.

Very dangerous infact as in a few weeks the pump could be in even worse state then you'll really have more drama's

Seems a little low..

Stock turbos, injectors, no gears, just exhaust/dumps & power FC made me 250kw at 12 psi.

That’s actually a little high… 250rwkw is generally a result of 1bar.

[CSNet]

Yeah my tuner commented that the engine seemed very healthy (creatd). But anyway. Was 246rwkw to be exact... also have pods on there.

I say check the fuel pump also. Don't the pumps max out at 260-280 anyway?

[-Stokesy-]

That looks low to me especially running 1.25 bar. I got 260awkw on std turbos running about 12 psi...

[Travis Trayhern]

fuel pump seemed fine i watched the gauge and held pressure strong but at 85psi its was bouncey on the gauge so that why we wound it back to 70 and when on a dyno run it woundnt drop back down or the neddle wounldnt go bouncey at all. but i have just bought a 044 im setting up a swell pot in the boot because i do hill climbs but really dont wanna drive 400km to get another tune on it already have already drop $1000 into tuning it.

[R31Nismoid]

Injectors really shouldnt be maxed @ that power though.

Maybe fuel filter is blocked up slightly?

Injectors maybe not the best condition?

[Travis Trayhern]

when put this new fuel pump in will it stuff up all the a/f ratios?

[Strik3r]

no, as long as your fuel pressure regulator can handle the flow from the new pump (which im sure it will), it will be fine.

[R31Nismoid]

when put this new fuel pump in will it stuff up all the a/f ratios?

Very much a potential yes.

If your running a higher than stock fuel pressure to counteract a dying pump

And then put the new pump in, you could find that its running even more pressure = bad.

[Bumblebee]

especially runnin @ 96%... god, imagine all that extra fuel lol

[bnr#@]

Whats the deal with the graph? Looks like the run is going from 80 to 140kph, what gear was that done in? I would take a guess at 3rd but that goes to 175kph at 8000 rpm

[femno]

Ha, yeah they need to learn how to scale their graphs a little better...

Did you run a flow test on it? No point having pressure if you got no flow.

Of course the a/f will be affected, if people are running 280 maxxing the injectors out, and if yours are on 96% then you technically should have almost 280kw worth of fuel going into it with a decent pump.

and theres no way you get 260AWkw running standard turbos and under a bar HAHA.

[Duncan]

well he said "steel wheel turbos" not standard turbos. (or did you mean someone else?) certainly my 32 n1s give me about the same at 0.8 bar which is all we are allowed to run.

travis we make very similar power in our targa car at 0.8 bar using standard injectors, standard fuel pump, standard afms etc. we are also running over 90% duty cycle which is high enough for me considering how the car is used (no point pushing it to a dangerous level when fuel quality and temperature can vary so much). Not sure where these 280 or 300kw numbers are coming from standard injectors unless maybe they mean rwkw not 4wkw?

definately check the fuel pump is OK to be safe but we don't get any more than you do with new pump, clean and tested injectors and nismo adjustable fpr. easy to check since it sounds like you have a fuel pressure gauge - pressure should climb with boost right to the top of the rev range...if it drops off up high you have fuel pump or fuel pump wiring problems

[Travis Trayhern]

yes i noticed it to that it only goes to 140kph, the tunner said something that it wasnt getting traction would this be the case and he said his rollers where warn? i will be putting a swell pot in and a 044 pump and i re-run the wiring aswell.