Not Quite There Yet!

[b8r]

I had may car at the mechanics late last week for a remap to suit the new turbo combo, much to my dissapointment there wasnt a whole lot of improvment in max power.

The current set up is an emanage ultimate, gt30/vg30, with a blitz sbc controlling boost.

While i am quite happy with the way the car drives i would still like to squeeze a little more out of it.

The suporting mods ive been told should see me around the 200 awkw mark, but the best so far was

176 on boost setting 4, 1.1 bar.

my problem is this, beyond this level, vehicle boost cuts. the mechanics have scoped and data logged to determine injector and air flow meter ranges but neither were the cause of boost cut, also inspected for boost sensing devices for factory ecu, none were evident.

They seem to think that the internal mapping of the factory ecu offers fuel cut at certain rpm when boost causes specific injector demand.

has any one else had this problem I know there are a quite a few s1 out there that have 200awk and above,

any ideas or advice would be appreciated.

[STAGE-A]

yeah id also like to know as i cant adjust my boost at all without the boost cut ... 100% factory boost spec with the annoying dual stage boost control. I tried doing the boost solenoid trick and it jus hit the boost cut (can run it standard tho and no probs??? weird)

So now i have a hi flow turbo and im back to fully stock boost ... feels tha same as a stock turbo runnin about 11-12 pounds ... very annoying especially when i got smoked badly by someone on this forum the other day when they werent even in a Nissan you know who u are!!

cmon guys an girls any help??

Lee

[wolverine]

there is no boost cut, the ECU goes into rich and retard based on AFM voltage ie airflow.

there are numerous threads in forced induction on the same issue.

[fergo308]

again,people keep denying the boost cut exists,when it does. rich and retard does NOT put your head through the windscreen in the same way the boost cut does.

1.1bar is just over a kg/cm2,which is where my series 2 oes the same thing - it CUTS the ignition. it doesn't retard it a few degrees,it stops it.

a retard gives you a dull feeling,a cut stops the party entirely,which is what happens. again,do people want a demo? I'm still happy to be proven wrong in person on this.

Justin...

[mr manfringinsen]

I think the series 2 does monitor the boost at the ECU but the series 1 doesn't. They both run an R34 style of ECU but the series 1 is the only one to run the older RB25DET with this ECU. This means a few changes such as no facility for oil temp monitoring etc. I would follow wolverines advice.

[STAGE-A]

  fergo308 said:

again,people keep denying the boost cut exists,when it does. rich and retard does NOT put your head through the windscreen in the same way the boost cut does.

1.1bar is just over a kg/cm2,which is where my series 2 oes the same thing - it CUTS the ignition. it doesn't retard it a few degrees,it stops it.

a retard gives you a dull feeling,a cut stops the party entirely,which is what happens. again,do people want a demo? I'm still happy to be proven wrong in person on this.

Justin...

had mine on the dyno by a well respected tuner in Perth and he was the one that said it was the boost cut. confusing

[Tangles]

  fergo308 said:

again,people keep denying the boost cut exists,when it does. rich and retard does NOT put your head through the windscreen in the same way the boost cut does.

1.1bar is just over a kg/cm2,which is where my series 2 oes the same thing - it CUTS the ignition. it doesn't retard it a few degrees,it stops it.

a retard gives you a dull feeling,a cut stops the party entirely,which is what happens. again,do people want a demo? I'm still happy to be proven wrong in person on this.

Justin...

Yup, I know exactly what you are feeling there. With the SAFC and SITC you can tune around these, use a Z32 air flow meter too for better resolution for the tune. Make sure you have a good fuel pump and maybe a nismo fuel reg, then get it tuned on the dyno. Obviously a good exhaust & cool air supply is a necessity.

You'll get around that BAM into the windscreen feeling

Ive got that problem now, had everything tuned nicely with the stnd turbo but with the highflow now on, winding the boost to 14psi results in "head-2-windscreen" sydrome - as you describe, its like the ecu just shuts up shop, a feeling very similar to when you hit the revlimiter in 4th gear on a sportsbike = over the front you go!

ggrrr need a retune! need funds lol