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Discussion Starter #1
I was wondering if stock MAF is enough for 400+rwhp supras?
if MAF maxed out (engine takes in more air than MAf can measure), engine will run lean.
 

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Zerosoul said:
I was wondering if stock MAF is enough for 400+rwhp supras?
if MAF maxed out (engine takes in more air than MAf can measure), engine will run lean.
Common wisdom says 500+rwhp before the MAF runs out of room. I think Steve Jarvis made 526 rwhp using the stock MAF.

The MAF is not your problem, unless it is somehow defective.
 
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Discussion Starter #3
Ya MAF is proven to be safe @ 500 and can be done up near 550+.
 
Z

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Discussion Starter #4
Re: Re: MAF question on BPU supras

Lagtime said:


Common wisdom says 500+rwhp before the MAF runs out of room. I think Steve Jarvis made 526 rwhp using the stock MAF.

The MAF is not your problem, unless it is somehow defective.
I will double check my MAF again.
however, seems like my symptom could be MAF/air related.
because 1-3 gears, especially at 3rd gear my A/F is rich at 11:1
and once in 4th gear myA/F jumps to 13:1 at same boost (18psi)
and the higher the gear goes, the higher my A/F. in 5th gear my A/F goes as high as 15:1. (thats when I let ogg cuz EGT goes pass 750C)
I just got my new fuel pump, will throw that in and see if it helps. but after the new fuel pump is in, I will have brand new stock fuel system in my car so fuel supply shouldnt be a probable cause for my lean condition.

Chip, does your car have VPC? whats your EGT running 91octan on high end pulls with engine heat soaked?

sorry for the long post..

thanx!
Jonas
 

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Jonas, no VPC.

I never use 91 octane. :)

I don't use an EGT gauge either. :)

But, on the dyno using the wideband O2 my car goes from 13.5:1 at 5000 to 12.5: at 5700 dropping down to 10:1 at 6800. This is with 100 octane.
 
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Discussion Starter #6
Lagtime said:
Jonas, no VPC.

I never use 91 octane. :)

I don't use an EGT gauge either. :)

But, on the dyno using the wideband O2 my car goes from 13.5:1 at 5000 to 12.5: at 5700 dropping down to 10:1 at 6800. This is with 100 octane.
Chip,
Time for a fuel controller! :D I smell few more horsies in your future...:p
 

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Monkeyman said:
Chip,
Time for a fuel controller! :D I smell few more horsies in your future...:p
Brian, I've been thinking about it. I think if I tuned for 12.5:1 (I run 100 octane 24/7 and rarely, if ever, do 5th gear freeway pulls) I would lose a little power around 5k, but I could pick up quite a bit (20+) from 5700 to 6800.

It's in my plans. :)
 

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You will probably be in the 550rwhp range before you max out the MAF. On the dyno I was at 97% when I ran 526rwhp. I have seen 99.9% on the street. Have you swapped ECU's with someone? I know you are still running the orginal ECU, but your problem seems to be very similar to the problem Andi and I had.

Later, Steve
 
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Discussion Starter #10
Steve,
I have swapped 2 ECU (1 from my friends BPU and another was brand new ECU) into my car and the car ran the same.
my originalMAF was also swapped out with another (K&N cleaner oil got all over it...oversprayed)

may I ask what electronic you used to monitor MAF %?
 

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I used my Apexi S-AFC. It does seem to be fairly reliable.

Later, Steve
 
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