forgive me if this is one of them "duh !" mods. that everyone knows about. this is the first time i've played with a computer controlled engine. i've noticed that the MAF has an air diffusor aligned north to south. behind the maf is the throttle body with an axis going east to west. what would happen if the maf was rotated 90 degrees ? would aligning the flow direction send the computer into fail safe ? would the sudden increase in air flow across the half that it would sense the increase and flood ? or is this one of them things that everyone already knows that you would never want to do this ?

 

I think you mean 90*, I've never heard of anyone doing this, and frankly I don't see that this could have any impact on HP. It will not affect the computer because the MAF is what measures the air, so changing it's alignment would only affect flow after the maf.

I supposed it's tied up in the question of whether the 90* rotation of hte diffuser and the TB axis results in any pertubation of the airflow...

My gut says you don't stand much to gain, but I'm no expert.

 

ok, you pass... it was 90 degree. but next time don't use words i gotta look up. , ok, thanks. whew that was close. :bb .

yes, it will effect the air flow behind the maf, which should result in a smoother flow allowing a stronger vacuum to be created in front of the maf. problem is i don't know what the resistors do for each side. if the maf was rotated so it lined up with the tb then there would be two resistors on top and one on the bottom, or vice-versa (depends upon which way it was rotated. the resistor (now) aligned across the bottom of the flow (as the throttle plate opens) would receive more air while the top would receive less to a point then it would flow the same as the lower. initially, the top of the butterfly would block air (as it rotates forward) and direct it down and forward, then once it passes a point the flow would equalize between the two halfs. the flow should be more streamlined as a result of the diffusor, as air speed increases the better the stream should get. if the resistors serve a different purpose for each side of the diffusor it may confuse the computer, or would it allow us to tune the computer without getting into it. based upon the flow across the maf, it will cause different fuel mixtures but i understand you gotta be very careful. if it receives to much (of the wrong type ?) of air it goes into a "fail safe" mode and floods the fuel.

it's my understanding that the stock computer will too a certian degree make adjustments to compensate for automospheric differences, loads, etc. if one knew what the thresholds were that made specific changes in the computer you could tune the computer by making it react to your changes. ppsstt.... that's what bolt-ons try to do. the secret is finding the right combination that retunes the computer the way you want it, without taping into it. i'm not quite sure how i feel about reprogramming the computer, i'm sure it's as easy as adding additional hard drive space to your tivo, but, i just don't know. it's kinda like asking for directions, it takes all the fun out of looking. reprogramming should only, imho, be needed on the strip. when you start pushing 900+, when you cart it from meet to meet, etc., etc.

 

changed original value of 45 degrees, that was a mistake is was supporsed to be as written, 90 degrees.

 

On the Ls1's, we removed those defusers. They take up a fair amount of volume and the results were quite good. On the LS2, I've heard some folks say it will set off a code until you get it reprogramed. This seems to indicate my earlier point.

 

The diffuser in the middle of the MAF simply splits the air so that half of the air goes to the side with one resistor and half to the other side with two resistors. Using relatively simple equations, the MAF can get a better reading on the amount of air flowing through the system by comparing how much cooling effect is seen by passing the same amount of air across one resistor versus two resistors. It also gives the MAF a way to check itself because if it gets fouled, the fouling on the single resistor will have a different effect than the same fouling on the two resistor side, making their readings diverge. Too much divergence and you get a MAF error.

My initial reaction is that rotating the MAF won't have any noticeable effect on power because the MAF and the TB are separated too far, but it would be an interesting thing to test.

Mike

 

maybe try a 8x4 (or 6x3 - haven't looked at it yet) empty airbox inline. would the empty airbox act as a 'air reserve' for immediate response to the vacuum.

polish the maf (CAREFULLY), rotate it so the diffusor aims the air where you want, probably not worth much without an air duct (hint, hint), if the air is smooth enough you should be able to send it through the bottom of the butterfly on the tb, but it's the air resistance heat difference calibration on the maf that may create interesting results.

 

Hey Zig. Don't forget that the purpose of most mods is to increase the airflow through the motor. Adding aditional fuel (and spark) is the easy part.

 

i may have a way to get more air, just need to try it but i don't want to have the same issue that halltech did.

 

Yeah, it looks like we may have to revise programming if air intake is increased substantially. That's o.k. - it will result in a nice HP increase. But I still wonder if Haltecs problem is turbulence at the MAF as Chrisbquick mentioned.

 

that's what i suspect, wrong type of air, too turbulent. i can't remember if he ever said he tested it with the maf in the stock location.

 

from what i can tell rotating the maf may cause a decrease in power. you've got four wires (two resistors) on one side and two wires (one resistor) on the other. the maf uses the variance between the two sides. if the maf is rotated into a position so that the majority of the air is directed to one set of wires it will cause too much of a variance. this appears to cause an overly rich condition. do the maf and the map compare numbers ? if so, then the distance between the two may also cause different results. removing the diffusor would be someting to try (imo) but just haven't worked up the courage to start chopping on my maf.