MAF questions

[Wills7MGTE]

I've heard that the stock MAF can be replaced with a GM housing to allow more air in and still use the stock sensor itself without changing things, I was curious if this were true and what GM sensor must be purchased? how much it costs? will it make the car hit fuel cut (I have a HKS MBC set to 10spi)? and if there is anything else neccessary to get the car running with a larger MAF?

Thanks for any and all help on this, I'm looking to get my intake tract cleaned up, an aluminum accordian and this sensor would help a lot since I already have the K&N Intake.

 

[GrimJack]

Yes, absolutely true.

You need a GM MAF - pretty much any one, personally I used one from the Impala SS. These can be had on eBay for pretty cheap every so often, usually under $50.

Then you need a MAFT from Full Throttle Motorsports. I seem to recall the price for these being ~$200, but google to their sales page and check.

You could also step up to a MAFT Pro, which gives you a lot more options and flexibility, DrJonez is selling them here, check the misc. vendors section or simply PM him.

Chances are you'll start running into fuel cut with this setup, but some decent tuning at a local shop will make that go away.

 

[Nick M]

What Grim said. Because they are not interchangable. You need to have those items with the GM sensor. We do not have a MAF sensor, it is a volume sensor that sends a different signal. So if you change the housing only, just make sure the KV device fits perfectly.

 

[Wills7MGTE]

Cool, so I saw 200 for the MAF T and then 50 to whatever depending on where and what GM sensor you get, I'm sure it'll raise the boost like the Lexus AFM does on my buds car, If I turn the Boost controller down from the 10psi its set to run will I be able to keep the boost down at 10 or will it not allow that period? I just been looking at doing this and other mods to help until I have money for a complete head job and fuel upgrade, as you know being stuck at low boosts like I am due to the engine just plain sucks.

Thanks for the info so far, I'm doing research on this still, it's kinda confusing sometimes but this has helped quite a bit, not sure if I'll do it or not but for 200 plus a sensor it may work well, I may be able to get a sensor fairly cheap I don't know.

 

[Doward]

Well, technically, it outputs in frequency (the stock KV meter) - from about 30-1400, from what I've seen.

The GM MAFs also put out a frequency (well, some do - some put out a 0-5v signal) - but the range is different.

The MAF-Translator does just what its name implies - it translates the incoming MAF signal to a signal the stock TCCS (ECU) can understand and make use of.

 

[GrimJack]

FYI, boost controllers allow you to turn UP the boost. I've yet to see one that lets you turn it down.

 

[Wills7MGTE]

I realize that Grim, but stock it was boosting 5 to 6 psi, so it's turned up right now to 10psi, I was meaning if I turn it back down to stock setting will it be around 10 due to the MAF or will it just hit fuel cut every time it spools, sorry for the confusion.

 

[GrimJack]

Ah, no worries. If you turn it down chances are it will drop some, but not all the way back to stock.

Even so, most people need to use a boost controller to hit fuel cut, so chances are your FC level will be higher than what you would get with just this installed.

 

[gsx750r93]

Grim nose way more then me by far... But My understanding on that is replacing the AFM housing and sensor with a larger one will not increase your boost. Well maybe a little bit. My understanding is by changing the afm to a lrager one will alow you to raise your boost higher then where ever fuel cut is. For instance fuel cut is at 13 plus or minus, now it will be at a higher rate. Your wastegate or boost controller is what controlls your boost not the AFM.

With old and stock HG U should be a little conserned about pushing over 10 psi anywho. Well Unless....

P.S. basically what he just said but i revised it so slow people like ME can understand a little better. But hey please correct me if im wrong..

 

[bigaaron]

Dan's Cressida made 350whp/360tq at 14psi with the original Maft (draw-thru, 3" gm maf in the accordian pipe where the stock afm was), and my 7m made 370whp and 395tq with one too. The only drawback is that it's not boost or throttle referenced (it only knows when to go from low to mid to high by air flow), and the 4 band afc is VERY basic. The best setup was the maft with a safcII, that let us dial it in very well on both cars, and gave it a tps reference. It was scary sometimes to see 14psi at part throttle with the afr still at 14.7/1! I think the new Maft ver.II has more of the important features you would want.

 

[Wills7MGTE]

Thanks for all the info, and I wasn't saying the afm controlled the boost, but I was ocncerned because my friend put the lexus afm on his 7M supra and it kept boosting to high even though his boost controller was set at 11psi, it just went up to around 14 or 15 psi. Now it makes a lot more sense, thanks for all the help guys. I'm probably gonna do my suspension and brake upgrade this coming month then I'll start looking for a GM sensor and eventually install that, I'll let you guys know how that goes for me.

Thanks again to all who posted.

 

[TurboStreetCar]

you might want to look into the maft GEN2, its only a little more money but gives MUCH more controlled and flexible tuning, im running one with a 3.5 inch GM maf, and it runs great. you can also use the same variety of MAF's.

changing to the maft setup with the gm maf shouldnt affect boost level. it wont affect fuel cut either untill you tune it. when you swap to the maft setup, it will/should run exactly like stock.

it simply converts the GM frequency/grams per second chart to the factory AFM/grams per second chart. based on how many grams per second the GM MAF is reading it outputs the coresponding frequency based on the stock AFM chart. so it is only a conversion. basicly it sends the same airflow signal to the computer as the new MAF is reading.

you change fuel cut and Air Fuel mixture by altering the conversion frequency/grams per second tables so it reports less/more airflow then measured by the new MAF. since stock program of the TCCS is horribly rich at about 10.5-10.0 (at least im my experiance) you can reduce fuel a decent amount. i havnt looked at how much im currently reducing but its enough to raise fuel cut by about 3-4 psi while still on stock fuel with the only mods bieng the Gen2 and GM maf of your choice.

when you put bigger injectors in you can further raise fuel cut by adjusting the main scale. using the hypothetical assumption that your stock injectors are still flow ballanced and flowing 440cc's, moving to 550's would net you 25% more flow, a change to the mainscale of 25% reduction would compensate for the larger injectors and in a perfect world still maintain the good tune you previously established with the stock injectors. ofcourse thats not how it works and you would most likely have to retune but the 25% reduction in the mainscale still holds strong.

its also all digital and has more options, tuning parameters and i beleive more range then the origional maf-t.

 

[Nick M]

The main reason I will neve use the MAF-Translator is GM's history with making mass air flow sensors is not exactly quality. I would consider the MAFT-Pro which converts to speed density.