can u use a ls1 maf in a LT1 car

 

A while back the part numbers were merged, so I would say yes.

 

That is an interesting question (and answer). I went looking around, and some places indicate that the same MAF fits both engines. Why then, do the aftermarket guys (i.e. Granatelli) offer different part numbers (and presumably different parts) for each engine? IDK, I would just like to find out the answer.

 

Don't use any of those aftermarket MAF's, they are junk. And in high hp applications, many opt for a speed density tune.

 

IDK, but after a period of time GM merged the replacement MAF for LT1 and LS1 to the same part number. So now, there is only one for both engines.

 

That is truly useful information. I kept poking around at the stock ones, they seem to be 75 mm bodies, the wires, screens chip and connector appeared to be the same. So Good, although there are still some companys selling them as separate parts. And we unwashed who do't know any better have to scrape by.

So, if the stock MAFs are the same from the LT1 to the LS1, I have a couple of questions.
First, why did they start out different, or did they? Did they just have different part numbers but behaved the very same? I think you answered part of that already, they may have dedided they were "close enough".
I am pretty sure the LT1 and LS1 MAFs function in the following way: air flowing through the cylinder causes the wires to vibrate which causes the chip to send out frequencies to the PCM. Different volumes, different frequencies. The PCM manipulates that info, along with other info, and makes decision on things like timing, fuel flow, etc. Keeping in mind that this is all strickly time based, with our PCM the keeper of the clock.
If this is the case, and an LT1 MAF can be interchanged with an LS1 MAF, this indicates that the frequency patterns are the same between the two types.

Second, if this is the case, why haven't the aftermarket manufacturers followed suit and combined their products? The economies of scale dictate that if they can minimize packaging differences, covering multiple product lines, they can cut costs. Or are they trying to make each model seem unique? Or have they found different ways to tweak the response of the LS1 to make it perform better, so its MAF remains unique? After all they start with the same basics; a tube, some wires, and a sensor. They make the diameter of the tube larger. They probably make the wires resonated differently so the chip feeds altered freuquencies to the PCM. Does the PCM then have to be tuned for this different data? That is how I would do it, and I have been in the computer business for almost 20 years, spanning the military, the government, and the automobile/truck industry. So rather than make a blanket statement that they are junk, I suggest that they are not currently understood. I ran one when I first got my turbo, it achieved the numbers others were seeing, and I had no problems with it at all. But when I dug into what had been done I found It was by someone who clearly did not know what he was doing. it was a miracle it ran. Having seen that good of performance from a horrible attempt, I am certain that a well executed effort will yield excellent results. But it make take more time and effort that most would care to spend.

Thanks for the info.

SD tuning is a whole nuther subject, a.k.a. shoot the MAF. I like it, I intend to use it (it is especially useful in 2 bar and 3 bar applications), and its discussion should be another thread, IMHO.

 

my friends 98 ls1 came with an lt1 maf from the factory so i would say yes

 

So I think we have enough affirmatives to take the next step, they can be interchanged, stock for stock.
For me, that opens up a much larger field of MAFs that I can pick up and make changes to, Not big on descreening due to the bugs out here in the country, but those blades down the center have always bugged me. Of course there are PCM tables that will have to be rewritten, but so what. And the 85mm ends from an LS1 maf should fit an LT1 as well...or perhaps practice with my dremel a bit...

 

My testing has shown that they are not exactly the same, but are within 5% or so. I was not aware of the merging of the part numbers. So your BLM's will adjust a little, but it should run fine.

I have both kinds kicking around here, so once the weather clears, I may swap them.

Bob

 

This is also good information. Would you consider this 5% to be manufacturer's tolerances, or did one model consistently perform above the other? And I take it the connector is the same?
IIRC, BLMs are analogous to fuel trims?