Can this be done? I know that an SD tune makes life easier with cams, but can it be done with FI or so we need the MAF?

Sorry if it's a stupid question..

 

Here is a thread with the info you're looking for.

http://www.cz28.com/forums/showthread.php?t=560089

I've been running an SD tune with moderate boost for a few months now with good success.

EDIT: Oops, this link applies to the LT1, and it looks like you've got an LS1. From what I've heard, it's even easier on an LS1.

 

Yes. It's worth it too. My TT 99 Vette is absolutely flawless and I can turn up the boost a couple of lbs when I want and will be covered. Plus, unlike the MAF tune, a SD tune will adapt to temp/density/altitude changes.

 

Huh? This is the main reason NOT to use an SD tune. It won't adapt to temp/density/altitude as well as MAF tune will.

 

It has been my understanding that SD lacks the ability to adapt to temp, presure, etc as Pilot stated.

I have a second gen car w/ an LT1 running SD and I have always wanted to put a SC on the car. Although I have decide to go N/A with a 383 because living here in Colorado I thought that an SC SD car would not adapt well if I drove the car into the mountains or out to coast.

Not meaning to hijack Bayer but I have not had the cam ground yet maybe SC is still an option?

 

What are you smoking man? MAF. Mass Air Flow. Measures airflow of incoming air through the MAF sensor. It has a limited capability to adapt to changes. Speed Density uses MAP and air temperature as it's primary source to calculate it's fueling. Speed Density can and will react and adapt better to altitude and temperature changes better than a MAF car will.

 

I've done several different SD tunes on several different cars and they are great when they leave the shop but always come back needing to be tweaked. Check around and ask some of the mail order tuners which is more consistent. Why do you think GM went to MAF systems? It certainly wasn't because of cost. They were trying to get the a/f ratio as close to perfect as possible to meet the continually tougher emission standards. Only downfall of the MAF is that it maxes out and has to be cleaned. Oh and just for the record mine is descreened. LOL.

 

Ok, consistency has nothing to do with SD or MAF. It has to do with the quality of and how accurate the tune is. If the car is coming back for tweaking, the tune wasn't good enough to begin with then. The MAF is much easier to tune, thus is easier to get dialed in quicker, and less frequently returns. You're trying to say that because a SD tune car comes back for tweaking means that SD doesn't adapt as well or better than a MAF car and thus MAF is the better tune. If you're tuning peoples cars on that knowledge (or lack thereof) then I feel sorry for the people who are paying for it.

Ask any good tuner how long it takes them to nail down a SD tune. Don Kinder A.K.A. Slowhawk had my vette for 5 days working on the tune before he was completely satisfied. A long time yes, but my car is absolutely flawless on the tune. I haven't had so much as a hiccup out of the car. Tuning in SD is not an easy process, but when done correctly, you'll have a more stable tune, a more adaptive tune, and one less part (MAF) to crap out and leave you high and dry.

I have seen examples of the smaller tuning shops out there that will tune a MAF car and leave the VE tables completely untouched. What do you think happens to those guys running huge head/cam packages or FI when their MAF takes a dump?? A completely undriveable car at that point. Why do they do that? Because it's easier.

Look at it logically. Speed Density uses primarily two things for fueling: MAP (manifold air pressure), and IAT (intake air temperature). MAP is directly related to the density of the air based on altitude and temperature (humidity affects this too obviously). How the hell can you sit there and say that a SD tune won't adapt to temperature and altitude changes then?

 

The MAF measures air mass. If the air becomes less dense, like it is at a higher altitude, it has less mass, so the MAF reports that and you should get less fuel. So in that regard, the MAF cars are better. But in WOT, if the MAF tops out, and most of them do, then it isn't doing you much good and you're stuck with whatever fuel you are dumping in from your PE tables, unless you were lean when you went into PE, in which case you might have some added fuel correction.

 

You don't have a good understanding of how a Maf works or you would know it corrects for temp and density. Have you ever even done an SD tune? Do you have a wideband on your car to know how good your "flawless" tune really is? I know your a pretty knowledgeable guy but you are showing your as_ here.

 

I never claimed to have an innate understanding of a MAF system. I haven't messed with them all that much. I do know that MAF systems have the ability to compensate; That wasn't questioned and I don't recall saying that it doesn't correct. I am simply saying that a SD tune does correct in regards to the statement that you made saying it doesn't.

Yes, I have done an SD tune. No, I didn't use a wide band because I was only tweaking certain things. I never claimed to have done a flawless tune either. However, the car I did say was flawless, my vette, DOES have a wide band and I see zero problems, and trust me, I carefully watch that car when I'm driving it. Flawless isn't the right word though. Nothing is perfect, be it a SD or a MAF tune.

All I was trying to point out is that yes, a SD tune has the capability to adapt to changes.

 

This is the statement I have a problem with. You said a MAF tune doesn't adapt to temp/density/altitude. It not only adapts but it adapts better than an SD tune. I don't really disagree with anything else you said except that my SD tunes aren't done right. LOL

 

Don't take offense to that, just a poke at ya all in good fun. Admittedly, I was a bit preemptive in that above statement and you're right, the MAF will adjust to it. I happen to think that the SD would adapt better than the MAF, but in most cases, the differences are going to be too small for the general driver to even know about.

Good stuff.