Supercharged peeps please come in
Thread Starter
Joined: Oct 2007
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From: Gainesville FL
Supercharged peeps please come in My build is a 408 lsa heads 9.8 - 1 Cr with a Novi 2200 supercharger. My question is shood I use a mass air meter , or go speed density? What are the disadvantage,and the advantages. I was thinking of using the 100mm mass air meter . 
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You are not the first to ask, so try a search and you'll find a lot more discussion on the topic.
It can be done either way, and there are advantages and disadvantages by both.
SD is easier to tune. So from a tuners standpoint, he will have less time in it. But you have to realize that your car will be tuned for the exact atmospheric conditions for that day, that elevation, and that time. So as things change (which it will even being in the same location as the weather changes) your tune will not compensate for the differences at all. Where as a MAF tune will.
IMO, the MAF tune is better and more accurate. It makes adjustments for atmospheric changes in your tune and is more accurate. Some people will argue their .02 cents on why SD is better, but again from the research that is out there on this very topic, I have found that the MAF tune is better.
Here are a few good threads to read;
https://ls1tech.com/forums/generatio...-maf-tune.html
https://ls1tech.com/forums/pcm-diagn...-maf-tune.html
https://ls1tech.com/forums/pcm-diagn...ng-debate.html
It can be done either way, and there are advantages and disadvantages by both.
SD is easier to tune. So from a tuners standpoint, he will have less time in it. But you have to realize that your car will be tuned for the exact atmospheric conditions for that day, that elevation, and that time. So as things change (which it will even being in the same location as the weather changes) your tune will not compensate for the differences at all. Where as a MAF tune will.
IMO, the MAF tune is better and more accurate. It makes adjustments for atmospheric changes in your tune and is more accurate. Some people will argue their .02 cents on why SD is better, but again from the research that is out there on this very topic, I have found that the MAF tune is better.
Here are a few good threads to read;
https://ls1tech.com/forums/generatio...-maf-tune.html
https://ls1tech.com/forums/pcm-diagn...-maf-tune.html
https://ls1tech.com/forums/pcm-diagn...ng-debate.html
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Joined: Oct 2014
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Check out the above linked threads.
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SD is easier to tune. So from a tuners standpoint, he will have less time in it. But you have to realize that your car will be tuned for the exact atmospheric conditions for that day, that elevation, and that time. So as things change (which it will even being in the same location as the weather changes) your tune will not compensate for the differences at all. Where as a MAF tune will.
IMO, the MAF tune is better and more accurate. It makes adjustments for atmospheric changes in your tune and is more accurate. Some people will argue their .02 cents on why SD is better, but again from the research that is out there on this very topic, I have found that the MAF tune is better.
Here are a few good threads to read;
https://ls1tech.com/forums/generatio...-maf-tune.html
https://ls1tech.com/forums/pcm-diagn...-maf-tune.html
https://ls1tech.com/forums/pcm-diagn...ng-debate.html
Here's one of the things that's flawed in your logic, is that when it comes to FI, you are generating and changing atmosphere conditions as boost changes. So at higher elevations, the amount of boost will change, but as long as it's tuned in those areas, you'll be fine.
I have had my car in a 2/3 bar SD tune for 3+ years now, and I don't see much of any difference between summer and winter, and we're talking about a good 80 degree swing in temperature.
So sure, you can go in and modify tables, and divide them in half, to get more range out of the maf, but then you lose resolution down low where it really is critical.
I am on SD, and had my car driving almost like it was box stock. Idled at 700rpm, and I was able to lug around at 1400rpm in parking lots with no issues. I got 25mpg on the highway, and 15 around town, well, depending on how much boost I got into.
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Joined: Jun 2002
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It's not the maf that gets maxed out, it's the factory operating system that has a set value for maximum airflow that gets maxed out.
So sure, you can go in and modify tables, and divide them in half, to get more range out of the maf, but then you lose resolution down low where it really is critical.
I am on SD, and had my car driving almost like it was box stock. Idled at 700rpm, and I was able to lug around at 1400rpm in parking lots with no issues. I got 25mpg on the highway, and 15 around town, well, depending on how much boost I got into.
So sure, you can go in and modify tables, and divide them in half, to get more range out of the maf, but then you lose resolution down low where it really is critical.
I am on SD, and had my car driving almost like it was box stock. Idled at 700rpm, and I was able to lug around at 1400rpm in parking lots with no issues. I got 25mpg on the highway, and 15 around town, well, depending on how much boost I got into.
TECH Regular
Joined: Oct 2014
Posts: 415
Likes: 2
Here's one of the things that's flawed in your logic, is that when it comes to FI, you are generating and changing atmosphere conditions as boost changes. So at higher elevations, the amount of boost will change, but as long as it's tuned in those areas, you'll be fine.
I have had my car in a 2/3 bar SD tune for 3+ years now, and I don't see much of any difference between summer and winter, and we're talking about a good 80 degree swing in temperature.
I have had my car in a 2/3 bar SD tune for 3+ years now, and I don't see much of any difference between summer and winter, and we're talking about a good 80 degree swing in temperature.
It's not the maf that gets maxed out, it's the factory operating system that has a set value for maximum airflow that gets maxed out.
So sure, you can go in and modify tables, and divide them in half, to get more range out of the maf, but then you lose resolution down low where it really is critical.
I am on SD, and had my car driving almost like it was box stock. Idled at 700rpm, and I was able to lug around at 1400rpm in parking lots with no issues. I got 25mpg on the highway, and 15 around town, well, depending on how much boost I got into.
So sure, you can go in and modify tables, and divide them in half, to get more range out of the maf, but then you lose resolution down low where it really is critical.
I am on SD, and had my car driving almost like it was box stock. Idled at 700rpm, and I was able to lug around at 1400rpm in parking lots with no issues. I got 25mpg on the highway, and 15 around town, well, depending on how much boost I got into.
I do not doubt his experience. He has been on the forum a lot, and had a lot of different combos. At the same time, if you look in the linked threads I had, you have far greater experienced people like Ed Wright who has probably tuned more than most others arguing that a MAF tune is better.
I'd do speed density. We do them OLSD and the weather doesn't affect them.
Even my personal Race car runs the stock computer tuned OLSD. It's a high 7 second car. Have never logged it after the initial tune and raced all year on that tune. Street driving was always 14.5-1 where I set it.11.5-1 at WOT. 45-95 degree's out.
Even my personal Race car runs the stock computer tuned OLSD. It's a high 7 second car. Have never logged it after the initial tune and raced all year on that tune. Street driving was always 14.5-1 where I set it.11.5-1 at WOT. 45-95 degree's out.
I'm not saying I know it all, far from it, but once you exceed the max values for the flow rate in the computer, you need to get creative if you want to stay using a maf.
To me, there's more than can go wrong in doing that than simply going to a 2 or 3 bar speed density tune.
If you want to stay MAF, I would read a LOT, and talk to some pretty smart people, and get a clear understanding of how you want to proceed.
To me, there's more than can go wrong in doing that than simply going to a 2 or 3 bar speed density tune.
If you want to stay MAF, I would read a LOT, and talk to some pretty smart people, and get a clear understanding of how you want to proceed.