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GCtech Motorsports
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1,666 Posts
Discussion Starter #1
who will know were i can get this information of how is possible to combine two MAF signals into one ...
any web sites?

thanks
Gilbert
GCT automechanic
Racing Engineerig
 

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20 yr owner
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1,867 Posts
That is very simple...I was going to go that
route.

Use a apexi S-AFC.:)
 

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You break em, we fix em
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1,266 Posts
An interesting idea is to not use 2 MAF, but 1 MAF and one open pipe to feed your air intake. This combined with an AFC or other fuel computer should work. It is actually how the stock MAF on the DSMs for sure and I believe on the Stealths work anyway. The factory couldn't get MAFs big enough to flow enough air when the cars were designed. The factory MAF really consists of 2 chambers - upper and lower. The upper is the only one that actually measures airflow, the lower is similar size but just a honeycombed tube with no measurement. What they do is assume roughly the same amount of air is going through the upper and lower so they just take the upper signal and double the reading. What DSM guys do is "hack" the lower portion out, remove the honeycomb, port it out so it flows more air and the car runs leaner and they can get more air before hitting fuel cut.

So if you were to run an unmetered air tube just throwing out say a quarterthe size as the factory maf, then correct the fuel mixture + 25% with and AFC that should int theory work. It would take some experimentation and tuning obviously.

Or you can do what I did and just get a VPC and toss the MAF entirely, run a HUGE K&N.
 

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GCtech Motorsports
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1,666 Posts
Discussion Starter #4
uhm..

well i already have the VPC runnig open turbos, but i can not run mo re than 15psi before i get fuel cut with the vpc now if i can manage to run two mafs one per turbo , i'll hae more than enough air for each turbo....
now the question is how to do it ,, u said u got rid of your MAF , do u still have t ? i'll buy it from u ...\
later
 

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You break em, we fix em
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1,266 Posts
ummm if you have a VPC you should NEVER get fuel cut. It eliminates it by "capping" the Karmann signal it sends to the ECU. Also I assume you have bigger injectors, etc so it is sending a smaller Karmann signal to begin with.

Check for a boost leak, that will seem like fuel cut. It was happening on my DSM when I hit around 12 psi it would buck, etc. like fuel cut. turned out I was leaking at higher boost levels - pinholes in the IC outlet - and it would suddenly go real rich, causing misfires.
 

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GCtech Motorsports
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1,666 Posts
Discussion Starter #6
no

naw man , im still using the 360c injecor chip , i dont have bigger injectors , would that be the cause/.??
if it is, why only it happened wih teh VPC i can boost 1 bar no problem,but when i put my MAF back i can boost 1.20bar and use my 125 shot nitrous no problem,\


late
 

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You break em, we fix em
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1,266 Posts
Thats your problem, get a bigger chip and injectors!! The VPC is notoriously programmed RICH. You may also have it adjusted RICH. All other things being the same, injector size, etc. your VPC is most likely for one or both of the causes i just gave you tgiving the ECU HIGHER airflow readings than the MAF because it is trying to get the ECU to run more fuel. This is why you get your fuel cut sooner.
 
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