MAF or SD tune? which is right for me?
#1
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Ive done some research on this subject and it seems SD is preferred over a MAF. But Heres where I stand. I do not know how to tune so i will be having someone tune this for me. A local guy that does good work reccomends running the MAF. The other shops ive been looking at ( 5-6 hours away) like the SD tune. Im shooting for 625-650rwhp with my setup. Im planning on leaving the boost alone, where ever it is set at when tuned. I read SD tuning takes alot of time to get dialed in. So my question is, would the rewards be worth driving the 6 hours one way for the SD tune for what im doing??
#2
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Try PM'ing Turbo LS1 SS on the board. He's up in Buffalo, NY and him/the shop he deals with seem to know their stuff. I'm not sure the name, but they tuned his last setup (I bought his old turbo kit) with a SD tune and it made great power. Mine will be tuned SD this weekend for it as well. Just make sure that the tuner knows what they're doing and actually edits the VE tables, thats where the tune/power is made.
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Yea.. maf maxes out @ 512 g/s i think. Could be wrong, anyways usually it maxes out 500ish, maybe a little more. this is something you cannot fix by a bigger maf. It is actually a max in the ecu it can see.
That being said, they can still tune off the afr and get it close, but they are guessing and the maf isn't really correcting for anything at that point because its maxed out. If you were going blower not a big deal cause boost is very predictable and you get a tuner that has done a couple can do a great tune, not so easy on turbo car.
I have a maf but am 500 ish. Wen i build a motor for more boost it will be sd for sure. Chris
That being said, they can still tune off the afr and get it close, but they are guessing and the maf isn't really correcting for anything at that point because its maxed out. If you were going blower not a big deal cause boost is very predictable and you get a tuner that has done a couple can do a great tune, not so easy on turbo car.
I have a maf but am 500 ish. Wen i build a motor for more boost it will be sd for sure. Chris
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#11
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We keep the maf's quite often with the ProCharger kits, it has not been a problem on the higher horsepower builds. Here is one that is at 740 rwhp that we kept the maf on. This car still gets 28 mpg to boot! http://www.exoticperformanceplus.com...Car.php?car=40 Bob
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I've been running CLSD for about a month now and thinking about putting the MAF back in. I'm encountering problems like temporary leaning out when the A/C kicks on and leaning out from the additional drag from the alternator when the fans kicked on. The O2s will eventually pull it back down to 14.7, but it's fairly lean for 10 seconds or so as comes down from 16.4.
Other problems I've seen are lean spikes when I stab the throttle and leaning out when coasting to a stop with the clutch pushed in.
I'm thinking that a good MAF tune would fix all these problems.
The big question is how do you overcome the problem when the MAF pegs at 511 g/s?
Other problems I've seen are lean spikes when I stab the throttle and leaning out when coasting to a stop with the clutch pushed in.
I'm thinking that a good MAF tune would fix all these problems.
The big question is how do you overcome the problem when the MAF pegs at 511 g/s?
Last edited by white01ss; 07-15-2008 at 01:24 PM.
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what is a 2 bar, 3 bar map? is that like 2 and 3 different speed density tunes? and lets say we speed tune the car in ohio in the winter with IATs at 10 deg F, what will happen to the car when its in FL with IATs at 120 F and humidity at 100%???
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As i posted in another thread,
I dont care your making as far as rwhp, over 500ish rwhp the maf is pegged out, aka no more then 512g/s. The tuning is then done by PE modifier, this is not the correct way to tune.
Ex, you hit 512 g/s at 4500rpm, maf is done reading anymore, so you add more in by your PE table, well its done in 1000rpm or so increments so your commanding more fuel by rpm, not airflow, not boost.
What happens when the wastegate sticks and he over boosts? The pcm will not know what happened and you WILL go lean and bad things happen.
Also, with PE the tune changes with climate and altitude. Tune it in warm summer, well in the fall with some nice dense air you go lean.
PE is incorrect, why risk a motor when you can pick up a $60 2bar map sensor and run a OS where the PCM knows the boost lingo, fuel by boost, instead of guessing by rpm.
PE vs RPM, does work, and is usualy used by tuners that do not want to put the entire effort into a full VE + 2bar map tune.
I see no reason to chance it by running a cop out way to tuning when there is a perfect way of tuning, you 04-05 guys, EFI has you covered, the 06 HPT is on its way i belive.
We are doing a f1c blower car on a 06, and there was no tuning avalible for SD at the time, so on stock engine it used a MAF, it made 540 or so, and it did use PE at the top end, but its not maxing out in the mid range. Now that were upping boost numbers we swapped out to a standalone Bigstuff 3 computer that uses a 3bar map, the correct way of tuning big boost.
I dont care your making as far as rwhp, over 500ish rwhp the maf is pegged out, aka no more then 512g/s. The tuning is then done by PE modifier, this is not the correct way to tune.
Ex, you hit 512 g/s at 4500rpm, maf is done reading anymore, so you add more in by your PE table, well its done in 1000rpm or so increments so your commanding more fuel by rpm, not airflow, not boost.
What happens when the wastegate sticks and he over boosts? The pcm will not know what happened and you WILL go lean and bad things happen.
Also, with PE the tune changes with climate and altitude. Tune it in warm summer, well in the fall with some nice dense air you go lean.
PE is incorrect, why risk a motor when you can pick up a $60 2bar map sensor and run a OS where the PCM knows the boost lingo, fuel by boost, instead of guessing by rpm.
PE vs RPM, does work, and is usualy used by tuners that do not want to put the entire effort into a full VE + 2bar map tune.
I see no reason to chance it by running a cop out way to tuning when there is a perfect way of tuning, you 04-05 guys, EFI has you covered, the 06 HPT is on its way i belive.
We are doing a f1c blower car on a 06, and there was no tuning avalible for SD at the time, so on stock engine it used a MAF, it made 540 or so, and it did use PE at the top end, but its not maxing out in the mid range. Now that were upping boost numbers we swapped out to a standalone Bigstuff 3 computer that uses a 3bar map, the correct way of tuning big boost.