Chris'stransam

iTrader: (7)

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 .

stmz28

iTrader: (9)

speed density

Detoxx03

iTrader: (14)

I switched to speed density in August and wish I would have done it sooner.

Mike 02T/A

iTrader: (28)

Speed Density here also.

conan

iTrader: (5)

One more with SD, don't miss the MAF at all.

SpeedJunkee

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

Blown06

iTrader: (32)

SD for sure on something like that. You'll likely surpass the flow of the maf around 4500 rpm anyway.

SpeedJunkee

There are MAFs that it would not come close to maxing out, plus there are ways to tune past a MAF when it is maxed if you have a knowledgable enough tuner.

Check out the above linked threads.

The Alchemist

iTrader: (19)

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.

The Alchemist

iTrader: (19)

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.

scottywheels

Preaching knowledge buddy!!!!

SpeedJunkee

You are not just tuning for boost, but the MAF compensates in ways SD can't. At the same time, I'm not saying that a tune cannot be completed in SD and not be fine (otherwise this would not be nearly as debatable and there would be one clear answer).

That's great, but for your setup in your car there are many others who have very successful MAF tunes. Take my 19 year old ancient LT1 car for example. I ran the stock PCM and stock MAF with it tuned perfectly after the MAF was maxed out. It also ran flawless for years both at idle, normal driving as well as WOT, no hesitation at all in the tune. Still got 24 MPG on the highway with over 600 RWHP. This was done for years on a PCM that is far inferior compared to how easily an LS1 PCM like yours is to tune. So, it's not that it can't be done.

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.

01boydws6

iTrader: (19)

go sd, my maf is maxed and you can tell the driveability suffers a bit from it.

Slowhawk

iTrader: (12)

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.

The Alchemist

iTrader: (19)

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.