Supercharger FAQ - MAF vs. MAFless discussion

[cadguy77 0]

Here's a chance for all of us to discuss the pros and cons and technical issues of each setup when it comes to superchargering our beloved VR's.

I'm absolutely clueless on the subject so I leave the floor open to you more experienced amongst us.

[ingham 5]

i think it down to each car ,some cars work better with some without.

[jon@vagworx 0]

Totally dissagree with ^^^^^ (sorry) but it has the same overall effect on every car/engine.

No doubt in my mind, if i was to do it again it would be with a MAF, Lambda just doesn't react quickly enough and isn't anywhere near reliable enough.

My 2p

[cadguy77 0]

i think it down to each car ' date='some cars work better with some without.

[/quote']

and your reasoning behind your statment is?

[lee060 3]

MAF is needed , ECU has to know whats going on to be able to make the most of the setup . just doesnt seem right sacking it off , it is there for a reason .

just my opinion .

Liam

[rodney 17]

Well I chatted to a few people and it seems MAFless is the option when MAF doesn't work.. I don't know if that means the same as Quick fix and I also understand if OBD1 & 2 react differently.

I do not understand why etc but pass these observations on for the point of discussion!

I know you CADGUY have a slot just before me at Stealth So am keen to understand this and learn from your experience!

My view from my conversatons is MAF all the way as it works as it should - designed to and all that... I am going to push for that!

Interested to see what comes of this.

Do stealth log on to this site???????

[jon@vagworx 0]

Has anyone actually tried solving the problem of the maf going out of its parameters?????

Surely you could just increase the size of the maf housing to 4", which is exactly how the yanks run 400hp turbo'd vr's still running stock management and the stock maf sensor.

[VR6Pete 1,455]

From what i've heard and read on the forums the maffless map responded better on obd2 cars.

[cadguy77 0]

So does anyone know how the ecu reads airflow on a MAFless setup?

Anyone know of a source for a 4" MAF housing?

[VR6Rich 3]

Thought C2 Motorsport did an enlarged MAF housing.

[cadguy77 0]

Thought C2 Motorsport did an enlarged MAF housing.

Email I received from C2:

[blockquote]WE are discontinuing the SC program' date=' and going forward with our software and our Turbo systems

Chris

C2

Chris Collier

C2Motorsports, LLC

[/blockquote']

[VR6Rich 3]

Do they not do the enlarged MAF housing for turbo applications then?

[VR6Rich 3]

And theyve still not updated their website if that is the case!

[jaysVR6 2]

I covered this whole issue when I first had my VR charged. The whole idea of running the engine without the MAF seemed dodgy to me anyway.

As soon as Vince pulled the VR off the dyno and I drove it, it was down on power and had flat spots all over the rev range and his excuse was 'The timing is out'!!

Well complete waist of time and money that map was. The guy who built my engine was absolutely stunned that someone could even consider removing the MAF as the ECU will just be completely confused. Hense why it completely retarded my ignition and dropped all the fueling off as it couldn't read the airflow.

After riding/driving Oaky and a couple of other charged VR's they all had some funny characteristics with odd flat spots and idle issues.

Not a fan

[FishWick 21]

Bill Schimmel does 4" MAF housings, and indeed I have a spare one. I'll give it to Vince to experiment with on some customers cars. It's OBD2 only though. OBD1 MAFs need custom housings made up and takes a bit of chopping up of the MAF to remove the sensor. OBD2 sensors just unscrew. 4" MAFs should give up to 17psi support, but the MAF tables need remapping to suit.

You guys speak like the MAF is the all seeing power and the cure to all your problems. I'm afraid it isn't. What sensors do you think the ECU falls back on when the MAF fails, which is frequently on forced induced engines? Yep, lambda and TPS. MAFs cause problems on standard engines, let alone S/C'd ones.

Which ever way you look at it, the main problem is not the MAF, but rather the ECU's inability to deal with boost. A standalone with a MAP sensor and boost compensation map would solve all of these problems.

Consider the cost of endless remaps chasing small problems against a standalone. It makes sense.

What ever Vince does (and he's doing a lot on this behind the scenes) seems to be met with sceptism and ungratefulness. He didn't design the ECU or the S/C kits, he's trying his best on a workaround. He's the good guy and was the only person willing to do the maps. The other companies were too worried about their reputations and refused to get involved. Some of you won't remember the GIAC chips that came with the kits originally. It's a shame you can't compare a GIAC map to one of Vince's to get an idea!!! Chalk and cheese.

And before anyone says it, 1.8T ECUs were designed to run boost from day one, but even so, if a MAF goes on a 1.8T, you can say goodbye to piston 3.

So the choices are, a workaround, or the real deal. A proper ECU with MAP and boost compensation, or flogging the dead horse stock ECU. It's up to you. VR6 S/Cs will never be 100% using the stock management.

Just a suggestion, but have you considered approaching DTA for a group buy? They've just launced the all new S series ECUs, which have tonnes of features and tuning scope.

I used to be very pro standard management, but trust me, standalones knock them into the middle of next week.

[cadguy77 0]

Just a suggestion' date=' but have you considered approaching DTA for a group buy? They've just launced the all new S series ECUs, which have tonnes of features and tuning scope.

[/quote']

I have been playing with the idea of standalone, doubt there would be enough interest to justify a group buy tho!!! :-(

[rodney 17]

There are a few of us doing chargers at the moment so whilst cash is not readily available there are a few of us who may be interested in a few months. How much do they retail at???

[jon@vagworx 0]

Lol, yeah standalone is allways going to be the best option (which is why i've got one) but for people who want a bolt on upgrade its obviously not a feasable option, plus 2k for a charger then atleast another 1k for ecu pushes the cost out of a hell of a lot of peoples reaches.

Btw obd2 mafs are easy to change to 4", but obd1's are a bit more involved because of the way they work, you have to be careful about how the air passes through them, so you need a good length of pipe before them so the air can stabilise etc.

As kev says, you struggle to get the stock ecu to be anywhere near perfect, but having said that the z charger on my old car ran spot on with a maf. I then changed it to the vortech stage 2 and went mafless and it was seriously flawed, in many ways, but most effected was throttle responce. It made it impossible to roll on and off the throttle, which especially in a fwd car is rubbish.

Not slating Vince at all, he maped both chargers btw.

[FishWick 21]

Yeah standalones aren't cheap and some of them have issues and limitations, but in terms of bolting one in, doing a map for it and off you go, I've had good luck with the DTA P8Pro.

I still think a larger MAF is the way to go on the Standard ECU. I don't know enough about what's involved in getting it to work though.

Vince has said he's cured the MAF clipping problem with the standard bore one, but I think the main problem that remains is the cold starting. Partly due to the red tops being too big and partly because it's not clear in the map where the cold start settings are as it's all raw binary data.

That is one area that GIAC were spot on with. Idle speed and cold starting were both excellent. God knows what software they used to code these areas.

Maybe with 4" MAF, which has 33% more air flow, will give a corresponding 33% reduction in fuelling at idle against the reduced air mass, which with the red tops might just work out. Not sure, but I'm happy for Stealth to have my maf housing to experiment with. It can't hurt to try :-)

[jon@vagworx 0]

Yeah standalones aren't cheap and some of them have issues and limitations' date=' but in terms of bolting one in, doing a map for it and off you go, I've had good luck with the DTA P8Pro.

I still think a larger MAF is the way to go on the Standard ECU. I don't know enough about what's involved in getting it to work though.

Vince has said he's cured the MAF clipping problem with the standard bore one, but I think the main problem that remains is the cold starting. Partly due to the red tops being too big and partly because it's not clear in the map where the cold start settings are as it's all raw binary data.

That is one area that GIAC were spot on with. Idle speed and cold starting were both excellent. God knows what software they used to code these areas.

Maybe with 4" MAF, which has 33% more air flow, will give a corresponding 33% reduction in fuelling at idle against the reduced air mass, which with the red tops might just work out. Not sure, but I'm happy for Stealth to have my maf housing to experiment with. It can't hurt to try :-)

[/quote']

My thoughts exactly.

[antera309 3]

That is one area that GIAC were spot on with. Idle speed and cold starting were both excellent. God knows what software they used to code these areas.

Maybe with 4" MAF' date=' which has 33% more air flow, will give a corresponding 33% reduction in fuelling at idle against the reduced air mass, which with the red tops might just work out. Not sure, but I'm happy for Stealth to have my maf housing to experiment with. It can't hurt to try :-)

[/quote']

I had to take my stage 2 VF-E kit (Stealth map, MAF connected) off the car due to the cold overfuelling problem - it coked up a brand new set of spark plugs, rendering them inoperable, after just 2 weeks of VERY light use.

This is not a trivial problem - continuing to run this setup would have carbon-fouled my valves and may even have resulted in hot-spots & preignition, causing untold damage to the engine.

All the evidence is pointing at the Redtop injectors just being too big for an 8-10PSi setup. Vince said he was going to experiment with smaller G60 injectors. Did he ever get around to this?

[FishWick 21]

I think he's found the cold starting maps now, so the injector size is no longer an issue. My mate is leaving his OBD1 Stage 2 Corrado with Vince to play with until the cold running has been sorted. Vince WILL sort it, he just needs time.

[cadguy77 0]

hope he gets it spot on by the time i arrive on the 3rd April

[antera309 3]

Let us know how it goes, cadguy!

[cadguy77 0]

Let us know how it goes' date=' cadguy!

[/quote']

will do