macca_779

No that's not what Dale was getting at. Weather changes and so does the tune to compensate in a correctly performed SD tune.. We know BARO is compensated for automatically and MAP is measures so that leaves Temp for the Density Calculation.. What do you think the D stands for in SD. Temp is applied to calculate g/cyl in the SD forumla.. This is very basic stuff and it amazes me that so many people come up with this fallacy that SD doesn't compensate for the conditions.

CALL911

iTrader: (17)

It does not compensate for it in the same way that MAF cars do. If Bryan Herter from PCM's for less, one of the best tuners in the country, who Mario Andretti himself only trusts to do a tune on his Corvette's feels that MAF is the only way to tune to a point he won't even do SD tunes, it is good enough to back MAF tunes IMO.

Josh@KY-Turbo

iTrader: (120)

Everyone has thier own opinion about the SD vs MAF debate.

I have done both with HPT and EFI Live. I have done both on Boosted engines and N/A engines.

I liked the SD tunes better hands down. It required more work to get it tuned in. That was the fun of it. It made for a more responsive feeling car. It is all a matter of opinion.

I guess the fastest cars in the country run SD tunes via AEM, FAST, BS3, ect.... for a reason. That should stir this up

JL ws-6

iTrader: (50)

Maf is a crutch, and should be looked at as that.

Now, I just need to get mine off the car.

macca_779

If someone can't/wont do SD tuning that shows a huge short fall in their ability. MAF tuning is so easy in comparison if an accurate VE Map is not bothered with. So perhaps this guy is a good tuner.. Just a lazy one.

Mike454SS

iTrader: (4)

No offense...but you REALLY need to stop swinging from Bryan's nuts. If he's refusing to do SD tunes (especially on forced induction), it's because he wants to get your car out fast and he doesn't want to spend the time to tune it fully , and as for your argument, if you can't backup an argument with any facts other than "oh yeah...well this guy does this"...you should step away from it.

Why don't you call him and ask him to tell you the story on how he got started in the tuning business? I doubt he'll be honest, if he even remembers...some of us still do though, was only 7 or 8 years ago...MAYBE 9 (wow...I'm 26 and suddenly I feel old).

A speed desity tune requires more work...really it's a LOT LESS work than some people think. GM used to run only speed density as well (92-93 LT1's were SD, who here remembers the old 730/749 ECM's in the late 3rd gen's and Syclone's/Typhoons?)...the MAF is an excellent sensor too, but it has it's limits, and a speed density tune doesn't (provided you've got the right MAP sensor). It certainly is more with SD than a MAF tune, but it's also a more rewarding car to drive when the work is done...and whats a few hours spent behind the wheel of your own car getting the tune right on a few different days on some back roads? Those hours are fun for me. I learn more about the car and more about what the tune wants to have in it for numbers that will result in it running better.

Mike454SS

iTrader: (4)

Just to throw more fuel on the fire...when I tune a car with a MAF, my first step is disabling the MAF and getting the speed density and VE tuning dead nuts accurate...then I plug the MAF back in and make sure it's still right...MAF tables are for calibrating a sensor...not for tuning the engine behind the sensor.

CALL911

iTrader: (17)

Everyones got their own opinion on SD vs MAF. I'm not wrong or right on my side, both have their pro's and cons, not everyone sees the other side the same. Both sides if done correctly can lead to well tuned cars. You don't have to jump on me just because I happen to be the only one reading and posting on this thread that doesn't side with SD.

BTW Mike, PCM's for less and Bryan Herter is well known all around the country. They have probably tuned more cars than you I am guessing. From Mario Andretti going with Bryan only for his tunes, I am guessing he is doing something right.

CALL911

iTrader: (17)

There are plenty of other good facts and arguments to both sides here;

https://ls1tech.com/forums/showthrea...ight=vs+maf+sd

and here;

https://ls1tech.com/forums/showthrea...ight=vs+maf+sd

Mike454SS

iTrader: (4)

Trust me, I know how well known he is...read what I wrote in my post (between the lines)...you're not telling me anything new, but there is something you don't know, and like I said, he might not be honest about it if he does remember it...and no it doesn't have anything to do with me, and your argument is still "well this guy does this do it's gotta be the best method", it sounds to me like you've probably never tuned a car yourself, or if you have, it's been completely guess and check with numbers in the tables in the PCM and not based on any math or any chemistry, or anything at all really, and thats why you insist SD isn't as good, or won't work well in changing climates...I live in new england, weather here changes every dam day, and my car runs fantastic without the MAF regardless...

Frost

iTrader: (45)

Your argument hinges around you thinking that climate seriously affects SD tuning; let me tell you something that you won't like to hear. You made 614rwhp? Your MAF was most likely maxed out before 5K RPMs. After that, with no extended VE (SD!), you are limited to a single static fuel table (PE). It's true, fuel can be 'cheated in' through that table, but do you really think you need the same fueling at 100degF at WOT as you do at 40degF at WOT? Well that's what you are getting. A pegged MAF car has WOT fueling that swings pretty drastically with outside temps past the point where the MAF maxes out... I have a buddy with a way maxed MAF stock bottom end that made just over 600, and he sees well over a half point AFR swing with a good outside temp change.

SO I guess what I am trying to say, is that if you are still running a MAF, there is certainly some irony to your debate.

Reject

iTrader: (24)

BlackNiteWS6

iTrader: (2)

Well now that the temps have dropped around here the last few days the car feels like it has alittle more pop from a dead stop, but the SD tuning the car had that pop but even stronger...I've always been a pro MAF person, but now after feeling SD on my car and if it can be tuned right to start in all weather conditions i think i like the SD tuning alittle better...i cant' believe i'm saying this...lol. I just always ran my MAF on all my cars so i didn't know better...And just think back in the day GM had some fast cars that were SD. I think the GN was SD tuned and some L98 Vettes, and the '93 LT1 Z28 was SD with batch fire injection. So SD definately works well. I would like to feel it on a FI setup

10sec_rx7

every forced induction car we do is SD, every NA car we do is SD,

we are the only people in australia running a forced induction IRS Commodore into the 8's and it is SD using HPT 3bar OS.

Frost is 100% correct in what he is saying about the maf maxing out.. it is worse than a SD tune for AFR drift... a good tuner will have the tune dialed in so it is not effected by temp.

BlackNiteWS6

iTrader: (2)

Thats really cool...i was driving around today and still wished i had my SD tuning still
in my pcm. My buddy has HPT and he has my SD file saved. I'm gonna work with him to get the cold idle tuning fixed then put the SD tuning back in. Now when tuned SD for FI setups
how do you tuned for part throttle and WOT? Do you use a A/F meter or do you just use your scanner and look at the LTFT's and PE tables?

10sec_rx7

if you dont have a cam you should have no problems with cold idle and the stock settings should work 100% if you have the VE table dialed in.

i have a Dyno Dynamics 450ds dyno we use for all tuning, so we use the wideband for all WOT tuning and light throttle tuning,
if you dont have a wideband your going to struggle. you can use the LTFT and STFT for light throttle but will be stuffed for WOT with out one

DaveX

I have heard this before but am going to ask a dumb question. Why is it more work to tune SD vs MAF? Spending more time on the VE table? Or is it something else? Just wondering if I've missed something. I have mine tuned in SD (assuming I've done it correctly) and in general it seems to run better other than a minor transitional issue I've recently picked up.

BlackNiteWS6

iTrader: (2)

My car was tuned to SD when it still had it's stock lid and filter but when i
swapped in a SLP lid and Holley filter the SD file most likely only needs a tweak
so it idles. I would like to just get the car retuned using SD with my SLP lid and filter. I would bet it runs great....ever since i bought this car i knew it felt too quick for a stock SS A4..lol. I wish i would have had my WS6 tuned to SD i bet i could have shaved atleast a tenth and 1 mph, maybe even more...Other than having to be on the dyno and a wideband i would use SD from now on.

macca_779

Its more work because for an SD tune you MUST tune the VE. On a MAF tuned car its desirable to tune in SD first then re-enable the MAF and tune that too.

But the simple fact is that the majority of tuners neglect to spend any time on the SD part of a MAF tune as the majority of the time the stock MAF cal which is the primary measurement is close enough.

BlackNiteWS6

iTrader: (2)

^^Now when you decide to switch to SD there's already a Main VE table in the pcm that i guess the pcm uses incase the MAF craps out correct? So after you disable the MAF you have a good starting point with the stock VE table...Like in my case my car only has a lid and filter..so making a few small adjustments should be all i need i'm guessing. I used LS1-Edit for like 3 years and got really good with it but after playing with EFILive and HPT they are both great tools. I would have a hard time choosing though. Cause i think i want to go back to SD tuning. The tip in throttle responds faster to me in SD mode.