The deal with MAFs

[Kirk_dsm]

Alright here we go. It is known that our DSM MAF are very restrictive. So with that what are some of the other benefits to upgrading your stock MAF to maybe a GM MAF or the like? Plus, on that note what about your ECU when you modify this? Can I still run with a piggyback system or do I need to go with a standalone unit? I have plans on upgrading my intake pipe to the turbo and was just wondering what the deal is with the MAF.

 

[GVR4592]

It's not as restrictive as most people make it out to be. If you aren't maxing it out then there's no reason to upgrade it.

 

[420a-t]

Is there a certian hp that it becomes restrictive? I am also looking into this and had questions as to what is all needed when switching over to a new maf or maf-t.

 

[rabenne]

I believe it will vary a bit but I hear around 400 hp for a 1st gen maf and around 500 hp for a 2g maf. I was running 28 psi on a 50 trim garrett with no problems with maf overrun... if your trying to go over 500 then get dsmlink and it will provide a function of simulating maf flow signal after the actual unit has been overrun.

dont pull out the little honeycombs inside the maf either, it will destroy the way your maf was designed to meter the air. Since fuel is based almost soley on the maf signal during WOT it is important to make sure that your maf is dead on. Dsmlink also has a function for calibrating your maf.

 

[DRated]

DSMLink won't meter the MAF enough to vent a BOV though...

 

[rass1313]

http://www.orldsm.com/forum/showthread.php?t=10380

about half way down the page

"Once upon a time there were 1g Mafs....those sucked. Limited to reading airflow to ~30lbs/min.

Next up were the 2g Mafs....much better. Limited to reading airflow to ~52lbs/min.

Finally we have the end all be all Evo Maf. Limited to reading airflow to ~62lbs/min."

 

[wvturbo2]

GM Maf is good for blow through for venting, but really not needed and I think I'd rather just have a 2g, 3g, evo maf. GM maf requires the translator and I think you'll find that not alot of people are to fond of the translator. Mine sits untouched I just went straight to dsmlink to avoid tuning with that thing. I absolutely love dsmlink. Also if you are going to get standalone just run a map sensor and don't mess with mafs at all.

 

[Quasimondo]

My personal belief is that if you're flowing enough air to overrun a 2G or even an Evo mas, then it's time to step up to speed density. If you do switch to a GM mas, I'd rather install it in draw-thru then as a blow-thru setup. I used to have the maf and translator and I could never get a consistent tune as a blow thru, meanwhile I've known folks who installed as a draw-thru and never had any issues with it.

 

[absolute_DSM]

My personal belief is that if you're flowing enough air to overrun a 2G or even an Evo mas, then it's time to step up to speed density. If you do switch to a GM mas, I'd rather install it in draw-thru then as a blow-thru setup. I used to have the maf and translator and I could never get a consistent tune as a blow thru, meanwhile I've known folks who installed as a draw-thru and never had any issues with it.

You would install the draw thru with the BOV recirculating, correct?

 

[scottsee]

Correct..

 

[nightspeed87]

what are the 3g mafs rated at as far as max air flow.
I actually was planning on getting an evo mass though.

 

[snowborder714]

Is there a certian hp that it becomes restrictive? I am also looking into this and had questions as to what is all needed when switching over to a new maf or maf-t.

If you're still looking into doing a MAF-T setup, here is a great link that will tell you what all you'll need.

http://www.dsmtuners.com/forums/showthread.php?t=213196

Also, if you currently have hard upper intercooler piping, you can just modify it to put the GM MAS in and not have to buy new pipes.

 

[nightspeed87]

and weres the best place to find an evo8 mass thats the one i want to run with, i have a friend that might sell his to me but in case he doesnt i was wondering the best place to get them besides mitsubishi.

 

[Kirk_dsm]

Is there anything you need besides the EVO MAF to install that? That sounds like the best way to go.

 

[Quasimondo]

If you can't find an Evo mas, you can also use one from a 3rd gen V6 eclipse. I posted a chart on here a while back that shows the compensation differences between the 1G, 2G, and 3G/Evo mas. If you have a 2G, you can get away with installing it and using a SAFC to correct the airflow differences, but with a 1G, you'll need a Keydiver chip to get it to work properly since the correction required would be more than 50%.

 

[oldman]

If you can't find an Evo mas, you can also use one from a 3rd gen V6 eclipse. I posted a chart on here a while back that shows the compensation differences between the 1G, 2G, and 3G/Evo mas. If you have a 2G, you can get away with installing it and using a SAFC to correct the airflow differences, but with a 1G, you'll need a Keydiver chip to get it to work properly since the correction required would be more than 50%.

It's actually a pretty good option for people who wish to run larger than 680s on a piggyback system.

 

[Quasimondo]

I thought about that, but I think trying to use that mas with 650cc+ injectors will result in the same problems you'll run into with trying to use those same injectors with a SAFC. The only difference is that the airflow signal is altered from the mas instead of the SAFC, but you're still fooling the ecu and will probably still have timing issues to deal with.

 

[oldman]

Three things you can manipulate without the ECU knowing, mas, injector size and fuel pressure, the key to piggy back tuning is to minimize altering of the air flow signal which will allow the ECU to run stock fuel and timing maps. Let's use a real example.

750 injectors : 40% more fuel, requires -40 on safc throwing off your timing.

EVO mas and 750 : 40% more fuel and 50% more air, requires +10 on the SAFC.

EVO mas, 750 and AFPR : 40% more fuel and 50% more air, raise fuel pressure to 46psi (injectors flowing 833cc), requires 0 adjustments on the SAFC, SAFC will be used for fine tuning and dealing with injector dead time.

 

[rabenne]

People seem to only want to focus on the negative effects of vent to atmosphere... but on the other hand you have to remember that all that air that you bleed off to the atmosphere was designed to recirc for a reason.... Your turbo goes to all the trouble of creating a pressurized intake charge, and then you go and waste it by blowing it off to the atmosphere... When it goes back through the intake pipe, that pressurized air is a benefit because it keeps your turbo spinning nice and fast during the shift. If you have dsmlink with no lift to shift this is a moot point.