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4 of my clients dropped mafless and went back to running a oem MAF... ALL 4 are on here... one is Erik, Hector is PR with A30rs, another is Ken, etc... Im not making this up... Ive been around P cars for a many years, I don't know everything but I do know what I know.... my opinion is subjective of course and everyone is entitled to it... Steve, I can give you 3 emails you can contact them, then come back and maybe tell us what they say. Mind you, they started with maf tunes, went to mafless, and then went back... have you ever run mafless on a stock ecu? I doubt it... you went from epl to proefi. I've went thru many cars... I had mafless on mine many moons ago...
It's not for everyone... some really do NOT like it... and thats a subjective opinion not a fact... yet you of all people never had mafless on a stock ecu( other then sitting in a few ) and make it sound like you know the absolute answer. I'm sorry but I disagree with you... and thats Ok too...
markski
mbgt72 on here. completely stock car zero mods. went to todd and received a mafless file. installed the file and simply unplugged the maf. at idle theres zero difference. car runs as stock. i never said mine was mafless i said i have been in others that have. this isn't the only car i have seen run mafless files, 2 cars in atl as well.talk about the pot calling the kettle black, you sit here saying mafless ruins driveablilty yet i can't say it doesn't. maybe todd is just a better tuner but thats OK too.....
My 2 cents on the MAF and MAF-less setups. I've never tuned a Porsche but I have tuned other MAP and MAF based cars and take it the concepts are similar.
When I turned my turbo Honda myself, MAF-less setup that used a MAP sensor, I had to populate a lot of tables and it took some time. Load vs RPM etc. You have to populate all the values for all the possible configurations.
Then you have to tweak and configure sub tables that take into account air temp changes because air density varies with temp as much as it does with pressure. I found myself constantly tweaking and fine tuning this setup in the 2+ years I daily drove it. Especially when the weather had huge swings in temps things would be off a little till I could adjust the tables for those temps etc.
My supercharged Mustang on the other hand is a MAF setup, also tuned myself, and it's a dream to tune by comparison. The MAF sensor takes into account air density by temperature and there's no tweaking. It simply tells you the volume of air going in period. No ifs ands or buts about it.
So I can see where a MAF setup runs very smooth in nature and a MAF-less setup requires a lot of work to have the tables just perfect and could indeed present drivability issues if not done right.
Just my experience on different cars.... same concepts so I imagine the logic is not to far off when applied here.
something to remember here is that the turbo pcar has both maf and map sensors from the factory. when i was running a s/c amg i had some friends with a 3.2 non s/c motor that they wanted to turbo. the m/b computer was very unhappy with any form of modding from maf to map. its the tuner in the end that either makes it smooth or crap.
I've ridden in one mafless car, Irish's. Car drives as stock and I think it's a Proto tune. Pretty stock so far so a modified car might be different, his boost has been raised but i think that's it. Tuning SD shouldn't be too bad aftermarket but on a stock MAF computer I don't think it's completely straight forward..
I agree with Markski on this one. I spent a number of hours driving a TT with a Proto built engine running mafless and on e85. Compared to a Maf set up it sucked. Engine had a tendency to stall from time to time and throttle response was so so at best. Car was okay at higher rpm with bursts of heavy throttle thrown in but it would be hell on a road course where partial throttle and precise throttle modulation is a must. Funny thing is the owner was thrilled with it so you have to take opinions with a grain of salt. When I inquired about maffless every tuner I spoke with said don't do it. Just my $0.02.
Question, how does the ECU precisely calculate load taking all variables into account when running mafless? It seems the only thing it can do is go off tables which is an approximation at best especially if you have large temperature and barometric pressure swings. When running Mafless, are you not giving up some safety nets normally provided by the Maf? Just curious..
changing bov's to aftermarket ones maybe would change the sound, but from my own experience and other turbocharged cars, venting would cause running rich, idle issues, nd consume more oil, not worth it.
I agree with Markski on this one. I spent a number of hours driving a TT with a Proto built engine running mafless and on e85. Compared to a Maf set up it sucked. Engine had a tendency to stall from time to time and throttle response was so so at best. Car was okay at higher rpm with bursts of heavy throttle thrown in but it would be hell on a road course where partial throttle and precise throttle modulation is a must. Funny thing is the owner was thrilled with it so you have to take opinions with a grain of salt. When I inquired about maffless every tuner I spoke with said don't do it. Just my $0.02.
Question, how does the ECU precisely calculate load taking all variables into account when running mafless? It seems the only thing it can do is go off tables which is an approximation at best especially if you have large temperature and barometric pressure swings. When running Mafless, are you not giving up some safety nets normally provided by the Maf? Just curious..
Im glad some guys are coming out sharing their experiences on mafless set ups. Its not as straight forward turn key as some assume. I've seen a couple good mafless set ups( with lots of fine tuning ) and a handful of complaints from guys that only reverted back to running a Maf. It's not for everyone but does work great when it works.
Markski
Yes, baro is compensated for by... the MAP sensor! The IAT takes care of temp compensation via a table as well, these when accurate are simply math. The tough part is having an accurate table for what amounts to VE of the engine. I'm not sure how the Bosch ecu works especially since it was designed for MAF. Having seen it work though it does work at least for some people. In my case I will only want it for emissions purposes and will be running standalone for sure.
My understanding is that MAF is easier to tune, instead of inferring you have what is hopefully an accurate direct measurement. However you also get a flow restriction and a range limit. If you're on the stock MAF you get both of these to deal with and the intake piping on these cars is awful from the factory. At some point the MAF simply runs out of measurement room...
changing bov's to aftermarket ones maybe would change the sound, but from my own experience and other turbocharged cars, venting would cause running rich, idle issues, nd consume more oil, not worth it.
Could you give more details on this? Venting to the atmosphere will cause a rich spike right as it happens due to blowing out metered air.
How does it cause idle issues? They are closed at idle. It should be irrelevant.
I'm also curious how does it consume more oil?
The only thing I can think of it doing is causing momentary rich spikes as it blows off. The ECU may throw a CEL if it keeps seeing those rich spikes but it would totally depend on the programming and logic in the 996 ECU. It's not fair to compare to another vehicle as they don't necessarily have the same logic.
I had mafless tune once. The car was good at wot but when I was cruising and at idle there was misfire all the time. And the Idle was a little high and felt very aggressive. For me the car felt much smother with the Maf tune without any power loss.
I had mafless tune once. The car was good at wot but when I was cruising and at idle there was misfire all the time. And the Idle was a little high and felt very aggressive. For me the car felt much smother with the Maf tune without any power loss.
Thats my experience with the mafless tune.
Same here - it was fine at WOT (only), but overall drivabilty was inferior to OEM. I had the same idle issues, surging at slow speeds, etc. Went back to Bosch MAF custom dyno tune at higher boost and we made even more power, while retaining perfect OEM manners. I would never do it again on a car that I wanted to behave well and enjoy in a wide variety of circumstances.
to the OP's post, some of us are running straight BOV's and as you can see some of us are running mafless. I've had both amazing and ****ty tunes being maf'd or mafless, it's all in the tune.
As far as noise, I hear the exhaust over the blow off valves. When I had the filters on the turbos I thought I heard the BOV's much louder but I believe was actually coming from the turbos. I changed BOV springs and that went away.
08-30-2015 | 06:27 AM
