HPX MAF on RB25det NEO

[vip performance]

Finally have had time to play around with are shop's R34. We have added few more parts, 20in wheels, carbon diffuser, this year and also started spending some time on the engine performances aspect. Our goal is to make around 500whp, we were making 405whp with a ebay grade turbo manifold and HX35. We have now upgraded to a precision 6266 billet wheel turbo, Tial mvs wastegates and twin scroll DOC top mount manifold (http://docrace.com/). We were running a z32 maf that as maxing 5v's at just over 400whp, over all drivabilty was also poor, even with a resuscitating bov we could never seem to get it just right. There was talk of just finding a standalone!! after looking over all the options we wanted to try one more thing, a blow through HPX slot sensor setup!! there's very little info out there ( evan on this forum!! ). We kinda just went for it, Nistune has a drop down selection for the HPX in a 3in tube, the install and wiring is very simple It took a total of 5 hours from start to finish to get the sensor installed, street tuned and running like a top!! better than its ever been with z32 MAF. We have yet to get any dyno numbers but we are happing to report we can now go all the way up to 29psi and still sitting a 4v!!!! We will report back in a few weeks with final Dyno #'s, I will also post a pic of were I placed the HPX maf.








Carbon Fiber Rear Diffuser


We had it on the dyno but were limited by the z32 MAF

[Matt]

Excellent stuff. This HPX MAF I've been trying to get going on the R34 but the 3" supplied tubing is too long for my vehicle so been trying to source another MAF insert housing from Japan (and not having much luck)

Very keen to see the photos of what housing you used with this MAF insert. How is the idle on the vehicle with this? Was there much tweaking to the VQ maps for the 3" HPX required?

[vip performance]

A lot of adjustments to VQ map were made, I just took my time and watched the A/F and adjusted as needed, I will posts some screen shots later. The idle is very good, I took a little video today to show the location and startup/idle


click here for the video:
http://www.youtube.com/watch?v=0ZHRvMQS ... ature=plcp

[Matt]

Well last night I put the R35 MAF adaptor onto my R34 and using the R35 MAF insert. We recently added the R35 VQ maps into Nistune

Basically from the autocalced values (500hp) it only needed 5% fuel pulled out and drivability is excellent. No further changes to the R35 VQ map are required as far as I can tell. There are less issues with reversion with this type of sensor compared to Z32 MAF

I had problems with the HPX insert but likely due to using the longer HPX 3" tube with no air fiilter which can cause extra turbulence

Good news is that the HPX sensor is a direct bolt in to the R35 sensor so I can use the same adaptor with this one. Having both plugs on the vehicle means an easy swapover so I will start with the latest VQ map on this 3" setup and it should in theory be running the same as R35 MAF once sorted

[djstatic]

Basically from the autocalced values (500hp) it only needed 5% fuel pulled out and drivability is excellent. No further changes to the R35 VQ map are required as far as I can tell. There are less issues with reversion with this type of sensor compared to Z32 MAF

R35 is an upgrade to a Z32... I think I might get one of those!

[skylinegtrhr]

Well last night I put the R35 MAF adaptor onto my R34 and using the R35 MAF insert. We recently added the R35 VQ maps into Nistune

So this adapter is also "offset" type like HPX should be? Any picture?

[Matt]

yes same type. same fitting

[skylinegtrhr]

so MAF is in center of tube ,not in any offset position?

[Matt]

appears so

[djstatic]

yes same type. same fitting

Hey Matt,
What's the thickness of the tube and height of the block on the R35 adapter?

[Matt]

not sure. its on the car now. We are looking to get some more. This one came from Japan

[Matt]

new thread for my stuff here
viewtopic.php?f=10&t=2428