I am finishing up my vortech/superram setup on ym '85 vette soon.
I do not have enough space between the TB and the Supercharger Discharge side to mount my MAF, so I'm thinking of putting it on the intake side of the supercharger. Anyone doing something like this?
Ohh and no I do NOT want to switch to SD. I like the 'tunability' of MAF, and don't want to keep buring and experimenting with chips..



[Modified by MrNuke, 11:28 PM 2/22/2003]

 

I have never tried that but it should work. There is the same amout of air going into the supercharger as what is going out however the time delay between the time you moved the throtle and the air speed changed at the maf may cause some minor problems. Let us know how it works.

 

ATI uses a pull through on their LT1 kits....the bypass needs to recirculate downstream of the MAF (between the maf meter and the supercharger) to ensure you don't start changing metered air volumes in the system...good luck.

 

Huh? I think you got that backwards some. :) No matter what you'll be experimenting with chips.

 

Most S/C kits are draw through on the MAF - as is my '95. You WILL have to tune the computer, though, to make maximum, reliable horsepower, unless you are going with very low boost. MAF position will have no effect on this nor will SD v MAF, although tuning may be easier with MAF

 

With MAF you don't have to mess with the stock chips' settings much. With SD you have to get a custom chip automatically. I just wanna save myself that step. I have not seen a sueprcharger setup with the MAF mounted in front of the supercharger as in a 'draw-through' setup. Anyone have pics of this? How it is mounted, and the filter or air intake routing form there? There is very little room there.

 

Misinformed. :) A buddy of mine with S/D runs a cheapo PROM and goes 12.1x in his car.

 

MAP vs MAF depends on the car and the hp goals.

The stock 1 bar MAP systems stop reading when 0 psi. The stock MAF stops reading about 375hp. For a moderate boost on a stock motor I would prefer MAF car. You can swap to 2 bar or even 3 bar 749 ECM but their is a lot tuning to get it to work properly.

 

BTW an 85 ECM is going to be pretty hard to get any useful tuning data out of ...


[Modified by dgoodhue, 2:19 PM 2/27/2003]

 

Yea but still I don't have to start burning different PRoms left and right.. Out of the box it is still 'easier' to use with a stock chip than SD. :D

 

We were in the same boat. Its been a long long learing road too. I made special mandrel bent pipe that is 2 piece. It turns out of the blower, thru the MAF, and then snakes up to the TB. 7 different madrel bent pieces with welds grinded as I went. Painted it black too... I'll post a pic soon.

WARNING – Since you have the '85 you use the Bosch hotwire type MAF. Guess what, it works better in-between the SC and the TB. I could break loose the tires at any given rpm in 2nd gear... 1st gear was useless. I have stock 3.07 gearing too. ALTHOUGH - I also burned up 2 Bosch meters since doing so. If you put it inline, you will too. The hot air out of the blower just kills the little diamond wire that is strung around the inside of the Bosch meter.

Whats the fix? Still working on it. You can easily put the MAF before the blower... and driveability is actually better. BUT, throttle response SUCKS. Its terribley dissappointing the adverse affects of it being before the blower. Even with a bypass... lugging at 1000 rpm and nailing it in 2st will barely turn my tires where as before it'd get crazy sideways.

Crusing down the road at 3,000 RPMs you don't notice it as much... because everything is moving the air so fast.

I went so far as to install a wells MAF in it. BEWARE of this too. It has a foil strip that is only "taped" down to the panel board. The first time I romped it, it almost ripped it off the board. So, I used some "potting" material to encase it to the board, but the plastic casing has been catching heck because of some super tight hose clamps.

Also, I even took a C&L 73mm MAF (vortech) from a Mustang setup. The guy that designed the meter, Lee of (C&L) lives in Huntsville also. I used some MAF voltage/airflow data to supply him my Bosch readings so he could match up a sampling tube that was interchangeable in the 73mm meter. Was a breakthrough… he had a tube that matched perfectly .5 – 4.7v (plotted airflow and voltage)

Which brought on yet another problem. If you don’t use a factory MAF (Wells or Bosch) the ECU doesn’t see one at all, and the input line to the ECU from the MAF is held “high” being tied to +5 volts by a resistor. So… the 73mm meter posed a problem… so I removed the pull-up resistor. Wah Lah ! Worked like a charm. Bigger flow hole, adjustable sampling tubes, etc etc etc. I can say that I am still working out driveability issues with it, but I believe it is do to the placement of the bypass valve.

Oh, the reason for using the Ford MAF (vortech 73mm) was the design of the sensor. It has 2 small resistive wires in it also, but they are extremely heavy duty. I just put it all back together about 2 weeks ago… but I’ll keep you informed on how it goes.




[Modified by 85Procharged383, 10:13 PM 3/18/2003]

 

Ohh defenately keep me posted please. Also any pics you have of this setup would be great. I am having custom tubing done too. ordering them this week, where I'll be putting the MAF inbetween the TB and the supercharger outlet. Hopefully it won't start eating MAF sensors on me too.. :(

Thanks for the info. this is exactly what I was looking for..