r33 gtst S2 with z32 - Stutter

[matt_R33]

Hi,

Has anyone had the issue regarding tps transition solved yet?? It creates a pretty annoying stutter off idle?? They say some r33 gtst suffer from this others dont... how thats possible beats me....

i read a topic on this forum somewhere about it, been unable to find it.

cheers,
matt

[PL]

Matt mentioned this to me the other day as I was doing a Z32 ECU for a guy. I tried Matt's patched file to help with the TPS transition but it still has some issues. So I went back to a std Z32 image and it worked fine. This is on a S2 R33. He was running a Z32 AFM, otherwise all pretty much std.

I wonder if this is affected by TPS adjustement? Have you tried changing that?

PL

[Matt]

I've heard this also. Removing TPS plug removes it all together but then idle maps not used. I'm still looking into it (just trying to finish up GST for this quarter and then I can go back to code)

I'm working on a firmware update to get around this but previous versions had issues so I'm having to investigate again. HCR32 ECU was easy to modify but Z32 does some other stuff

Try adjusting the TPS location and let us know if that removes the stutter. Its because of the transition from idle to off idle is causing map accesses at the wrong accelerator pedal point which causes the stutter which after more than a few times would be annoying

[STATUS]

i have a base i use for the z32 ecu's here, ill post it. No stutter issues yet but maybe im lucky (done half a dozen or so now)

this one (V2) is for highflow, z32 and 650's i think. 270rwkw ish from memory. Please understand it is a rough base so has no knock maps and flags etc are all unfinished.

i think i have a std turbo one somewhere (V1) , but i have a feeling i saved over it with this one.

[PL]

Thanks Trent. Good man!!

PL

[steve_s13]

nice one

im gonna give this a go on an RB25det of mine when im on the dyno sat, ill let you know how i get one as this is my 1st attempt at this

been meaning to do this for ages as im keen to see how well it works

[STATUS]

nice one

im gonna give this a go on an RB25det of mine when im on the dyno sat, ill let you know how i get one as this is my 1st attempt at this

been meaning to do this for ages as im keen to see how well it works

be aware its for z32 etc. I unfortunately saved this bin over my start up bin i usually use

[steve_s13]

yep, ill be watching things closely as I load up on the dyno Trent

tomorrow ill be trying it, been to busy to give it a go last week but tomorrow morning ill try

[steve_s13]

right im on the dyno guys now so ill let you know how i go

so far only way ive got the rb25 rebbing clean is by unplugging the tps

[steve_s13]

rebbing??? meant to say revving, lol

[PL]

I actually liked rebbing!

I'll get Matt to change the wording in NIStune right away. "Reb limiter" - hmmm. I like it!

PL

[steve_s13]

hehe

[STATUS]

Does the map above i posted work ok? i have too many revisions. If it has any issues let me know and i will post a later version.

[PL]

Hey Trent,

Yep, all good. I did that RB25 with 3076 just after Xmas based on your tune and I didn't have to do a lot to it:

- tweaked fuel map to richen mixtures in boost transition area
- turned off closed loop a bit earlier to allow richer mixtures earlier
- gave K constant a nudge from 180 to 193
- pulled a bunch of timing out at high load to allow 22psi boost

So all in all very little change reqd. Car made a disappointing 271rwkw but that's gotta be a mechanical/flow type of issue - the tune was fine. It retrospect I'd have rather left it on 18psi cos cranking in more boost really didn't do much....

PL

[STATUS]

Hey Trent,

Yep, all good. I did that RB25 with 3076 just after Xmas based on your tune and I didn't have to do a lot to it:

- tweaked fuel map to richen mixtures in boost transition area
- turned off closed loop a bit earlier to allow richer mixtures earlier
- gave K constant a nudge from 180 to 193
- pulled a bunch of timing out at high load to allow 22psi boost

So all in all very little change reqd. Car made a disappointing 271rwkw but that's gotta be a mechanical/flow type of issue - the tune was fine. It retrospect I'd have rather left it on 18psi cos cranking in more boost really didn't do much....

PL

sweet good to hear, hate those troublesome cars... they suck your will to live and its hard to charge more for all the hard work as you know in your heart it should make more....