Ok so help. supercharged v8 nistune, pmas hpx maf, vq table?

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gsracer
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Ok so help. supercharged v8 nistune, pmas hpx maf, vq table?

Post by gsracer »

Ok guys.. I'm posting here because I'm at my wits end.

I have a vh45de with a vortech supercharger.

It has been running nistune successfully for the last 2 years. Recentltly i changed the intake manifold to a porsche cayenne manifold with custom adapters top feed seimens deka 60lb injectors and a pmas hpx maf in a 3.5 inch tube blow through.

Once i changed the manifold, i put the 60lb injectors and left the stock maf, got it to run and drive decently. Then i changed the maf, and thats when the **** hit the fan.

Using the nistune vq table for the hpx 3.5 the car wouldn't drive at all let alone start, I made some radical changed to the vq map and it drives now but theres no sense or reason to what the car is doing. Lean on throttle inputs, lean on cruising.. etc.

The stock k value was 198 and after the injector change and maf change mistune gave me something in the 260 range, then i adjusted as low as 150 and as high as 400. Nothing gives rhyme or reason to what the car is doing. It seems to me that the vq table in mistune for the 3.5 inch maf is way off. The latency on the injectors is set at .500 milliseconds.

Any help, give me a run down on building a vq table or a bin for a 3.5 hpx maf would be appreciated, or just talk to me and tell me I'm stupid.

pics for those that are interested...
before

Image


after porsche intake, injectors, and maf

Image
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turbonola
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Post by turbonola »

so effin sexy!!!!!
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car6on14
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Post by car6on14 »

nice swap! sorry I cant help you as im not familar w/ vq but free bump... What rad did you use that fit moved up like that?
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gsracer
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Post by gsracer »

thanks guys its a griffin 26221x radiator.

heres what I've been playing with, throughout just sheer trial and error.


This is a sheer guess on my part based on observed a/f against maf voltage and raising and vq look ups.

This got the car drivable n/a not on boost with the a/f all over the place from 12.3 to 16.1

voltage- vq
0.08 ----0
0.16 ----500
0.24 ----587
0.32 ----684
0.4 ----871
0.48 ----1768
0.56 ----2036
0.64 ----2058
0.72 ----2680
0.8 ----2814
0.88 ----2974
0.96 ----3380
1.04 ----3449
1.12 ----3965
1.2 ----4460
1.28 ----4670
1.36 ----4870
1.44 ----5048
1.52 ----5075
1.6 ----5198
1.68 ----5333
1.76 ----5520
1.84 ----5706
1.92 ----5937
2 ----6134
2.08 ----6350
2.16 ----6841
2.24 ----7070
2.32 ----7530
2.4 ----7875
2.48 ----8286
2.56 ----8551
2.64 ----9000
2.72 ----9498
2.8 ----10271
2.88 ----10903
2.96 ----11308
3.04 ----12262
3.12 ----13285
3.2 ----14354
3.28 ----15588
3.36 ----16823
3.44 ----18088
3.52 ----19504
3.6 ----21068
3.68 ----22831
3.76 ----24359
3.84 ----26056
3.92 ----27681
4 ----29417
4.08 ----31592
4.16 ----33690
4.24 ----35844
4.32 ----37650
4.4 ----40167
4.48 ----42907
4.56 ----45637
4.64 ----48368
4.72 ----51234
4.8 ----54674
4.88 ----57832
4.96 ----61525
5.04 ----65235
5.12 ----65535
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emo_tactical9
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Post by emo_tactical9 »

Have you tried emailing the Nistune guys to see if they had an updated vq table? if it was running fine before the mafs change, I would say the vq table is just not right.
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Post by gsracer »

yea.. i emailed them... he says the vq table is not correct, but he doesn't have an updated one for it.
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Post by Freise »

I'm sorry I don't have advise for you, but do you have a build thread out there somewhere? I love custom work like this.
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emo_tactical9
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Post by emo_tactical9 »

I'm not sure then.
Did you see this?
http://www.eccs-tech.info/viewtopic.php?f=55&t=2024
There is a VQ table a guy created for. 3.5 in tube in there
Just call me Adam.
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Post by gsracer »

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Post by gsracer »

emo-tactical... i looked at that, its the vq table for the 3 inch that he apparently figured out. Very similar to the 3 inch vq table i started out with.
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Post by gsracer »

just to update, i removed the hpx maf and installed a 90mm lightning maf, car is up and running like a champ. Thanks for the help guys.
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emo_tactical9
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Post by emo_tactical9 »

It really sucks you couldn't get any help on it.
That is exactly why I switched from a Nissan ecu to a MegaSquirt. There is a lot more support and development for them.
Just call me Adam.
95 240: DIYPNP and T28.
08 Honda Fit
84 200sx: Sold after almost 10 years.
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