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R32 GTST rb25 neo rebuild


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Updates!

Car has completed its run-in tune but had more hiccups.
Was hoping the Walbro 460Lph pump could operate with the standard FPCM wiring but unfortunately was unable to provide enough fuel pressure at high-revs.

Unfortunately the power tune had to be stopped & will be retuned once my 1000km run-in is complete.
Managed to half-attempt a 270kw @ 10psi with failing fuel pressure on e85. However signs are pointing to much more once fuel pump re-wired.

So far, a lot more torque and power downlow in comparison to my old rb20 setup which was running 20psi

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So the next few weeks will be racking up 1000km and visiting Unitied for some sweet e85 juice. No boost & no revs beyond 4000rpm until the run-in is complete :)

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  • 4 weeks later...

1000km run-in complete!

Wired in a Fuel pump relay to provide a nice 13.5v to the Walbro pump. Tucked away behind the boot carpet & spliced into Fuel pump harness.
Should suffice until I can work out how to directly replace the wires attached to the fuel tank lid.

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Reinstalled the radiator shroud, refit the undertray & fitted the Neo engine cover. Looking pretty standard with the airbox and all.
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Now back to the Tuner for a touch-up of the aborted E85 run & an e-flex tune on 98 petrol.
Unfortunately ran into another issue where we weren't able to hold any boost beyond 16psi. Tried free-boosting and would only hit 19psi, no luck! 
Our assumption is the stock NEO bov is leaking? Any suggestions on a stealth/recirc option? GTR Bov able to handle 25psi? Or should I be looking at the Turbosmart Kompact?

Chequered Tuning also managed to wire in a MAC valve to run off Nistune - providing rpm/tps boost control. Still in testing by Nistune themselves....exciting stuff.
Unfortunately we werent able to complete the eflex tune as there was a Nistune firmware issue with the cold crank table. Parked until there is a fix...

Managed to grab a couple screenshots of the latest dyno result - we are now up to 282kw @ 16psi // to be continued...

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Looks like it's getting there. Shit luck with the slight issues but the potential is Def there. I'm running a gfb response series bov, bolts straight on, switches between plumb back an atmo. Got it real cheap. You could try just blocking yours to see if that in fact is the problem.

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1 hour ago, admS15 said:

Looks like it's getting there. Shit luck with the slight issues but the potential is Def there. I'm running a gfb response series bov, bolts straight on, switches between plumb back an atmo. Got it real cheap. You could try just blocking yours to see if that in fact is the problem.

Thanks, i just bought a GFB Mach 2 - it states:
"The Mach 2 solves all of these issues. It can effectively hold unlimited boost (unlimited in that no turbo could ever produce enough pressure to damage it), and the TMS technology ensures maximum throttle response."

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Sorry if Im stating the obvious but regardless of the turbo not wanting to hit over 16psi, shouldnt it be hitting 16psi on that turbo under 4000RPM as opposed to 5000Rpm. Looking at the boost curve too it seems the boost ramp rate is actually being hindered around 8-9 psi, it should continue building boost as quickly if not faster between 9-16psi as it does for 0-9 psi. Theres got to be some sort of leak somewhere or something bleeding air when it isnt supposed too ?

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1 hour ago, 30640 said:

Sorry if Im stating the obvious but regardless of the turbo not wanting to hit over 16psi, shouldnt it be hitting 16psi on that turbo under 4000RPM as opposed to 5000Rpm. Looking at the boost curve too it seems the boost ramp rate is actually being hindered around 8-9 psi, it should continue building boost as quickly if not faster between 9-16psi as it does for 0-9 psi. Theres got to be some sort of leak somewhere or something bleeding air when it isnt supposed too ?

yeah you're right - I will start with a new bov & pressurize the system to hear for any leaks.

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  • 2 weeks later...

minor update - 

new GFB Mach 2 blow-off valve fitted & set to hardest spring rate to prevent any leaks.

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What I think is happening now, is wastegate flutter as I build boost.
A quick test-run shows I can boost to 21psi+ but as I build boost I start to hear wastegate flutter. I've adjusted the actuator another turn to tighten the preload but still hear it...
Worth pre-loading anymore than the picture below? Ive been told half a hole is the recommendation & any more can lead to further dramas?

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Seeing as the above tune was for 16psi, and im now hitting 20psi+, I might lay-off the boost until I go back in for a touch-up after I sort out this wastegate flutter issue...

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wastegate flutter?

The boost leak may have caused the tuner to add more duty cycle to the solenoid to reach the targetted boost. Now the boost leak is solved, being an open loop boost table in Nistune it still is commanding the same duty cycle thus you're getting more boost.

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wastegate flutter?

The boost leak may have caused the tuner to add more duty cycle to the solenoid to reach the targetted boost. Now the boost leak is solved, being an open loop boost table in Nistune it still is commanding the same duty cycle thus you're getting more boost.

Good call, I'll bypass the Mac valve and run direct to actuator to see if wastegate flutter still there.

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On 9/20/2017 at 12:40 PM, Dose Pipe Sutututu said:

wastegate flutter?

The boost leak may have caused the tuner to add more duty cycle to the solenoid to reach the targetted boost. Now the boost leak is solved, being an open loop boost table in Nistune it still is commanding the same duty cycle thus you're getting more boost.

You were right - disconnect the MAC valve & no more wastegate flutter sound.
However at 4000rpm boosts to 15psi and then holds for a second and starts to creep towards 19psi. Doesnt seem to be wanting to hit 19psi with ease (actuator rating)
Still looks similar to the the previous boost-graph above, just sitting a couple of psi higher now...will report back after a boost-leak check on the intercooler piping.

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  • 3 months later...

Ended up booking the car in to my trusty performance workshop RevZone to investigate the boost buildup issue. 
Seeing as it could have been anything from electrical to mechanical issues, thought I would leave it to the experts to troubleshoot, repair & dyno.

Success!!! the boost-creep issue had been resolved, with the turbo now coming on strong, quickly & holding. Issue was a combination of intake/intercooler piping leaks, actuator boost-feed placement & customising the actuator-arm for better wastegate range.

Before & After of boost-pressure:
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Unfortunately not enough time for a full-retune, RevZone did stay back till late at night to make the car safe to drive. This yielded in a rough retune of 300kw atw.

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Followed with a nice picture of my r32 going through its dyno troubleshooting at RevZone.

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With RevZone's calendar booked-out for the rest of the year, the only option was to wait for a drop-out to fit me in for a proper retune with some serious boost ;)

Shout out to Justin & the team at RevZone (http://www.revzone.com.au/) for their continual support over the past 8 years I have been going there.


What felt like death-by-thousand cuts would have taken me months to sort out, whereas they turned around the fix & tune touch-up within a day (& night!)

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Waiting for a tune window to open-up at RevZone, I decided to open a couple of presents from Nissan Japan. Some new window moulding, door-latches, air-vents & p/s piping.

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The difference between old vs. new is night and day! In addition, the new window moulding had fresh window guides which now stopped the windows rattling when down (bonus!!)
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To give the car the best chance for its final tune, cut a cheeky air-hole in the airbox, because physics...?
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Still continue to wait for a dropout to squeeze in before Christmas...

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