Tech Recommended Against MAFless Tune...why?

BoostedE21 · 20th August 2012, 02:57

One of my friends, who also happens to be a BMW Master Tech did some work on my M5 for me lately. He mentioned that I could use some new MAFs, because my car doesn't really accelerate smoothly with steady throttle under 2.1k rpm in lower gears. I said "oh, no worries, I have a MAFless tune that I just need to load in, and that'll be job avoided."

He reacted like "uh, what? why would you want to run without mass air flow sensors? that's more dangerous than the benefits you'd get." I don't know enough to know if he's over-reacting...thoughts?

rao · 20th August 2012, 03:04

Oh boy.

Giving the benefit of the doubt assume he is thinking of just unplugging the mafs, not changing the tune.

Diny · 20th August 2012, 03:09

The way you worded it might've sound as if you would just unplug the MAFs and run a tune that would disable the SES. That's certainly not what Alpha-N does. You need to show your friend a link and show him what you plan on doing in more detail.

bimmerule · 20th August 2012, 03:19

Why don't you ask your friend straight up WHY it's dangerous? Now what exactly makes someone a BMW master tech? I see that word thrown around a lot, does it carry any value when it comes to servicing our cars?

BoostedE21 · 20th August 2012, 03:36

Quote:

Originally Posted by bimmerule

Why don't you ask your friend straight up WHY it's dangerous? Now what exactly makes someone a BMW master tech? I see that word thrown around a lot, does it carry any value when it comes to servicing our cars?

He's lead tech at a major bmw dealership in town. He's not a dumb guy, has had a few M5s in the past, and has a super slick 700 hp E36 M3. He really does know his stuff...which is why I take his opinion seriously. I think his belief is that without the MAFs, the car can't compensate for barometric pressures and other conditions.

Sailor24 · 20th August 2012, 03:45

Give him the evolve sales pitch and see if he changes his mind. I doubt he will. If he really knows his stuff he will probably explain to you what they have done to create this tune.

JDMM5 · 20th August 2012, 10:06

I would assume that most techs employed directly by BMW would give the same response as it is politically correct for them to do so. Those same people will have you believe (whether or not they believe themselves) that no outside tuning company can produce equal or better results than the company that manufactured the car in the first place. It's quite possible he knows that it can be done but maybe he's not familiar with Evolve or, as Sailor says, what was involved in producing this tune and the amount of R&D and trial testing that went into it.

sikessr · 20th August 2012, 12:28

See my thread "$7k in repairs." My car has been at a major BMW dealership for 8 weeks now being worked on by a BMW "M" certified master tech who "really knows his stuff." I would put the link if I wasn't on my iPhone right now. It's not in that thread, but he said the same thing when i asked about it, having never heard of Evolve. I'm currently running stock tune.

Hey, do me a favor, if you don't mind. Next time you talk to him, ask if a VANOS solenoid went bad if that could cause the timing to jump and valves to be bent. That is what my M certified tech is saying. It's been hashed out in my thread, but I would love to here his response. This is for the E39 M5 S62 motor.

Dan Kelly · 20th August 2012, 12:38

I'm no expert by a long way so I don't know but I'm puzzled as to why BMW decided to use MAF's in their flagship M car if an Alpha N tune is so much better. There must be some advantage other than being able to sell us new MAF's every X000 miles?

Sailor24 · 20th August 2012, 14:51

Frankly I don't think Alpha-n is better than MAFS. I would never run it for extended periods although I do unplug my MAFs for tracking and spirited driving. Alpha-n is already programed into the DME. BMW put it in as a fail safe. Certainly Alpha-n is better than running with bad Mafs. Here is a brief explanation of Alpha-n Alpha-N Elplanation just to get everyone on the same page.
The major concern I have is what happens when the vanos goes a bit out of place and the air/ exhaust ratio goes out of whack. I see this symptom frequently on the board. The nature of Alpha-n will then screw up the air/fuel. Again though bad Mafs will do more damage.

For those that don't want to struggle with maintenance it might be the best for them. Personally I watch every detail of the engine and often replace sensors on suspicion so Alpha-n is of no interest I am happy to buy Mafs.

And before Matt has the chance to ask again yes I have now driven a Evolve Alpha-n car. It was no better than my car with the Mafs simply unplugged, mine I think is a bit better. The car I drove was one for sale and I think the tune went in to skip maintenance so possibly mine is better maintained, this would likely be the difference. My car with the Mafs plugged in runs better in its DD roll, but when things get competitive it runs better with them unplugged.