On cars with mid/big cams, stock cubes/bigger cubes, ported/aftermarket heads.

I have been seeing more and more people going SD. My car has been tuned in SD for 3 years now and i love it! Rides and drives like stock. I have put 35k miles on my cam only ls1 and i love it and think all modded cars should be tune in SD. There have been few people here local that have went to shops and got Maff tunes and for DD use they suck! Surge when you crank them up and take a few sec to find idle. Then they get there car tuned by local board member in SD and it rides like a stock car again.

What your thoughts! I dont see what people are scared of SD tunes! My car was tuned in Hawaii and i now live in Missouri and have been on road trips all over! As far south a florida! Temps from -10degs to 105degs everything is good.

 

You know my thoughts

Really depends on how the person doing the tune does it. The stock tune uses SD down low for a reason. It is a mix of SD/MAF and then going to maf only above 4000rpm from the factory. Most people doing tunes only make adjustments for WOT. Some tuners even just play with the PE table until the WOT is right. They might end up with a PE of 11.0 just to get a 12.8 AFR. Yes, in the end you get the same WOT results. But if the VE table was right in the first place you could have the PE mode set to 12.8 and it would produce the same AFR. Imagine how far off the rest of the VE table is if the WOT needed to be fooled with the 11.0 AFR in the PE mode.


OK I have said to much

 

I think it all depends. On a stock car with a few bolt-ons, I can't see any reason to get rid of the maf. Now, with a Big cam and FI, it might make life easy by switching to SD.

 

I have great improvements with everyday and spirited driving by going to SD, even on stock cars.

 

Had mine done SD last week, cars runs great and feels good.

 

really? I'll have to try that out then. My car already drives amazing though I can't imagine it getting any better.

 

My 2000 Z28 has a lid/filter/cold air and air and EGR are deleted...other than that it's basically a stock car. I did the speed density tune myself, and I am still tweaking it (I'm down to very very minor changes now because I'm a perfectionist) and I can't explain how nice it is to drive...you have to drive it to understand.

 

Im going to have my 35th LE APS SD (2 bar) tuned after everthing ive heard about it so far !Now, I just got to find the BEST SD tunner there is thats closest to me ? Im 10 minutes north of (SIX)BURGE, PA. I mean Pittsburge ,PA LOL Yea,Im a die hard STEELER and F body fan till the day I die!! LOL Anybody got any ideas for me? I definatly want someone thats been doing it for quit some time ,beings ive got so much cash tied up into this TT build, Im kinda scared to just go to anybody The cars just about done.Ive allready put the 300 break in miles on my forged 6.0, APS setup and will be installing 60 lb injectors at the time of the tune. Everything else is done including the fuel , tranny and rear end moods
Shes readyI cant wait for spring to get this thing tuned!!I want someone thats gonna gaurentee their not gonna hurt my **** with a bad tune!!!LOL
Thanks guys

 

hmm, I'm gonna try that when I break the vette out for the summer. What kind of A/F do you run? Just 14.7 during idle, cruise and light throttle, then taper progressively to PE?

 

If the tuner knows what they are doing, you will be hard pressed to notice a difference from a MAF tune versus an SD tune. One example I always reference is a customer that had a 2000 Camaro convertible. It had a 224/230 cam and heads. I tuned the VE tables and MAF table. A couple of months later he returns with a check engine light, but he had no idea what it was as the car drove just as I tuned it. I scanned it and low and behold he had a low frequency MAF code. I verified if the MAF was reporting a signal and nothing from the MAF. He bought a new one and was on his way.

Throttle transients are handled by the VE table, while steady state cruising is handled by the MAF for all conditions under 4000rpms. Over 4000rpms under WOT is MAF exclusively. This is for a stock OE calibration. Although you can run strictly off of the MAF by changing the dynamic airflow disable parameter to say 1000rpms.

A good way to figure out if you have a good tuner is how long he invests in your tune. If it is just an hour or less, you will have issues. If he rides along with you and spends hours on it finely tuning things (and explaining what he is doing), then you have a great tuner. Also, to get an idle tune just right, the car will need to sit over night to verify cold start up to warmed up conditions. I always do at least two cold starts on M6s and four on A4s (because of the park/neutral and drive tables).

I will tune it how ever the customer wants, but don't give me this bullshit of SD > MAF or MAF > SD driveability. I will go SD-only on cars with over 5psi (MAF gets pegged) or if the overlap causes to much reverse air flow over the MAF.

 

SD is easier to tune and usually gives better throttle response. There was one case where I had a car that surged with SD only, but didn't surge with MAF. Dont know if it was a sensor issue or something else.

 

This question has so many answers it's impossible to answer and shouldn't be answered by a "poll". Therefore I won't vote.

 

12secSS is right. Most of the time when people say one sucks, it's because it ain't tuned right. Even some renowned sponsors here tune like ****. GM used a mix of SD and MAF for a reason, best of both worlds. (when it's right)
"It's easier to do it this way" is NOT a good answer to me at least. I want it RIGHT and don't give a damn if it's "hard".

That's right, and the good tuners know it.

EDIT: I am referring to mild N/A builds or near stock. Wild heads/cams and high boost is a different story. Then I would toss the maf.

 

with the edit, agreed

 

I do agree with 12secSS and troopercar...I should have qualified my own post better, I specifically decided to go for speed density because A my MAF was failing, and B, I have HPTuners, so I decided "why not take the MAF restriction right out of the intake, and tune SD well?" I know that the MAF is VERY VERY VERY little restriction...but it's still more than no restriction. I had it tuned on the MAF prior to the sensor faling, and it ran great then too...lots of people give SD a bad rap though because they don't know how to tune it properly...when it's tuned properly there's no downsides to it...however if my MAF hadn't been failing, I wouldn't have bothered to switch.

 

WTF, I thought that was how you were supposed to do it!

 

lots of good info in here guys. i have been debating the maf/sd thing lately as i just got my car running and will be needing a tune very soon.

 

What do you guys consider a agressive H/C setup? I'd like to make the switch as I think the 85mm MAF might be a small restriction at 500whp. Any thoughts to when the MAF is hindering performance?

 

Hey George, you and I have had this exact conversation before haven't we? I'm a firm believer in this practice. If it's tuned right, you shouldn't be able to tell the difference. Even most big cam motors can run a MAF. Some motors don't like MAFs, but most are ok running them.

As for the power levels, I've seen many over 500 rwhp on stock MAFs.

 

Looks like I'm on the endangered species list. I still run a MAF, though I considered switching to SD.