Avert Thine Eyes (OR: Andyman S/C Build Thread) ***FINISHED!!!***

[gamiller]

Andy, like you, I was running lean at idle when I first uploaded my tune for the 90mm MAF. Below are the recommendations Warmonger gave me. I hope they help...

Originally Posted by warmonger

Gary,

You just illustrated the reason why I do not like to locate the maf in the middle of the pipe. It is not turbulence that is ruining your MAF readings, it is the laminar flow that occurs in a pipe of a certain length.

I am a proponent of placing the maf into the fender with the filter bolted directly to it. This works much better due to the air being straightened out by the filter gauze and running at a lower velocity. One other thing you can do is use a larger piece of pipe leading to the MAF and place a MAF Screen in front of it like the ones used in the SVT airbox and MAF.

The reason your MAF was reading funny is that any pipe leading to the turbo will have varying velocities across the cross-section with the pipe center, having the fastest flow down to zero at the pipe wall. These are measured with a velocity profile or cross section of the pipe. The fast flowing air in the center will create more draw through the sampling tube than is truly representative across the whole pipe. Fluctuations in engine rpm will affect this, as simple a thing as intake reversion from valve opening events will cause stuttering in the MAF signal.

Also Any bends in the pipe will shift that velocity profile towards the outside radius of the turn. Even in a blow-thu configuration a screen must be used to spoil the laminar flow of the air going through the pipe.

Never mount your maf close to a pipe bend if you can help it.

Originally Posted by warmonger

As long as there are no bends within about 5" of the MAF, and the pipe is expanded to the MAF inlet diameter the last couple of inches before the MAF, then it should work. The screen should help with this. A screen will still help for very low speed air but you won't necessarily need it. If it is in the middle of pipe I think you almost have to add a screen.

[Blackcoog]

That's a good point gamiller.

Andyman try rotating your MAF or adding a MAF screen to help smooth out the air flow. The current MAF orienation may not be ideal and you may have air turbulence. I had stalling issues after installing my GMK intake a few years back. After I rotated it everything went back to normal. The bend and the reducer coupler could make this setup a little picky but honestly my tune was relatively uneventful and I haven't had any issues.

I posted a question on the SCT forums asking what needs to be done to tune for a MAF setup for blow through. If I get any good responses I'll post them here.

I had contemplated running a 3.5" 90 degree coupler off the compressor inlet down into the fender on the passenger side so I could run a larger filter. The current filter has been discontinued and is not exactly a high flow unit, but it works. If the filter was run into the fender then the MAF could be moved over there and you could run a suck through setup without venting the valve cover vents. You'd have to run a bypass instead of a blow off though. Of course that would mean another large hole in the car near the windshield washer tank hole.

[gamiller]

Originally Posted by Blackcoog

I had contemplated running a 3.5" 90 degree coupler off the compressor inlet down into the fender on the passenger side so I could run a larger filter. The current filter has been discontinued and is not exactly a high flow unit, but it works. If the filter was run into the fender then the MAF could be moved over there and you could run a suck through setup without venting the valve cover vents. Of course that would mean another large hole in the car near the windshield washer tank hole.

GMTA... That's what I recommended to Andy last night. Just seems to make too much sense to use the MAF sensor as it was intended. At least that would eliminate one significant variable in the equation.

[Blackcoog]

Try the stock MAF in the stock orientation. The pictures you have up show the lightning MAF upside down. Were you already trying different orientations? You saw the video of the Contour running with this exact kit on it. That was without any tune and it idled perfectly fine. Here is the picture of the MAF when it was on that car.

BTW ignore the valve cover vents. They were not hooked up this way when it was running. The intake ports were capped off and the vents were run to a breather as you have in your setup.

[gamiller]

Originally Posted by Blackcoog

Try the stock MAF in the stock orientation. The pictures you have up show the lightning MAF upside down. Were you already trying different orientations?

We tried the stock MAF as well with a tune for the stock MAF. No dice. By disconnecting everything ahead of the MAF, we pretty much demonstrated that the piping was not the main issue. If it was me, I would confirm that the tune was for both the MAF and injectors I was running. In Andy's case, he's got the 90mm Ford MAF and 38# returnless injectors.

[Blackcoog]

Then he may want to disconnect the supercharger belt and run the car NA until the tune is nailed down. Leave the piping as it is and the valve cover vents hooked up to the breather. Then the only change after the tune is perfect will be the pressurized air.

[fordrule]

andy do u have the xcal2 and the prp? i see u have a widband 02. did u get a LM-1?

[gamiller]

I thought of two other things to try while troubleshooting:

1. Confirm that the new, SVT Focus fuel pump is operating correctly.
2. Remove the belt from the supercharger and see if the engine will idle happier. The supercharger may have increases load beyond what the tuner anticipated.

[AndyMan]

Well i made it back to NC... sadly i had to leave to cougar behide... but i will return i promise. Just need a weekend i can go back up and get it and tune it more.

the only reason we turnedthe MAF upside down was because it couldn't close the hood clearance...
I do have a fuel pressure gauge thats hooked already on the motor, i just need the wires hooked in and i am out of room cause the boost and wideband gauge is on the piliar already.

-fordrule, yes i have the Xcal2 i got from Joey and TIm.

[Badazzcougar]

The 90mm maf is what I am running and I to have very poor drivability under 1500rpms It will not idle nice and sometimes stalls. I disconnect it and it idles just fine. I have been to my tuner twice already for this. I am going to try someone else.