The car will drive much smoother when transitioning to boost w/ the SD tune. Done both.....recommend the SD. 
MAF or SD tune? which is right for me?
MAF or SD tune? which is right for me? 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??
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.
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
Joined: Jun 2004
Posts: 1,501
Likes: 7
From: Ft. Irwin, California (But Virginia is home)
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I have been poking around lately trying to learn about FI. I am looking at the APS TT kit. It uses the MAF, as far as I know. Should I ditch the MAF and go SD when I install it? I am planning on a cam at the same time to complement the turbo's.
Any advice?
Any advice?
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APS sells an intercooler to TB silicone coupler. I'll be installing a highly polished connector instead and keeping both couplers. I need to tap my meth in somewhere anyhow....
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
CLSD Problems 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; Jul 15, 2008 at 01:24 PM.
Do you have a W/B installed in the car? I do and I can watch every lean transition. If I didn't have the gauge in the car I would think everything was OK because it doesn't drive all that bad. If anyone else has any constructive advice please join in...
Teching In
Joined: Jul 2007
Posts: 29
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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%???
TECH Senior Member
iTrader: (10)
Joined: May 2005
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From: Bossier city,LA barksdale AFB
SD SD SD SD all the way 
Mine has been tuned in SD for 2 years and rides and drives like stock. From Hawaii to Missouri to Florida traveled all over you name it! Its still good! My car dosnt surge or anything with the big cam! Startup vid
Mine has been tuned in SD for 2 years and rides and drives like stock. From Hawaii to Missouri to Florida traveled all over you name it! Its still good! My car dosnt surge or anything with the big cam! Startup vid 
FormerVendor
Joined: Mar 2006
Posts: 1,540
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From: Hell AFB
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.
