Lightning 90mm

[Lupo]

I just switched to a Lightning 90mm MAF, from a Lightning 80mm.
It runs fine, but the idle is not as steady as it was with the 80mm. This is after driving around all day. Of course I used the proper MAF curve for the 90, versus the 80.
It doesn't hunt, or stall, but still jumps around a bit where it didn't before. Has anyone else had this problem?

Lets assume nothing is wrong with the MAF...
I'm thinking a coupe reasons might apply. First of all, this is a MAF for a much bigger engine, and at idle, my 3.2 does not draw enough air to read consistantly. In this case, maybe upping the idle a tad will fix the problem.(I'm at 1000RPM right now)

Or maybe because the piping path has a different transition? The 80 has a 3.5 inlet, that quickly goes to 3.0" where the sampler is, then the MAF goes to my 3" connecting pipe.
On the 90mm, it has a 3.5 inlet as well, but does not transition down. It exits as 3.5, and I had to use a reducer on the connecting pipe, which is 3".

Anybody have experience with 90mm?

 

[Ishodu]

What do you get for a max air flow. If your not using the whole 1741 kg/h you can take some of the higher reference points on the scale and put more lower ones in. For example My 80mm lightning maf was good for 1550 kg But I will never see more than 900 with it being NA. So I took the 30 points and spread them over the 0-900 kg/h rather than having them spread out to 1550. It makes the area between the reference points loads closer and makes the maf more accurate for its application. So maybe this will help you for your very low end between 0-1 volt if your not using the very top points.

 

[Lupo]

What do you get for a max air flow. If your not using the whole 1741 kg/h you can take some of the higher reference points on the scale and put more lower ones in. For example My 80mm lightning maf was good for 1550 kg But I will never see more than 900 with it being NA. So I took the 30 points and spread them over the 0-900 kg/h rather than having them spread out to 1550. It makes the area between the reference points loads closer and makes the maf more accurate for its application. So maybe this will help you for your very low end between 0-1 volt if your not using the very top points.

My application is S/C, and I have gotten up to 4.73 volts on my old 80mm, limited to 13psi. I used the 90mm to give me a little more leeway.

That is a really good idea however to redistribute the spread (slightly) , especially at low RPMs for driveability. I think I'll give htat try.

 

[sho_sc]

I just switched to a Lightning 90mm MAF, from a Lightning 80mm.
It runs fine, but the idle is not as steady as it was with the 80mm. This is after driving around all day. Of course I used the proper MAF curve for the 90, versus the 80.
It doesn't hunt, or stall, but still jumps around a bit where it didn't before. Has anyone else had this problem?

Lets assume nothing is wrong with the MAF...
I'm thinking a coupe reasons might apply. First of all, this is a MAF for a much bigger engine, and at idle, my 3.2 does not draw enough air to read consistantly. In this case, maybe upping the idle a tad will fix the problem.(I'm at 1000RPM right now)

Or maybe because the piping path has a different transition? The 80 has a 3.5 inlet, that quickly goes to 3.0" where the sampler is, then the MAF goes to my 3" connecting pipe.
On the 90mm, it has a 3.5 inlet as well, but does not transition down. It exits as 3.5, and I had to use a reducer on the connecting pipe, which is 3".

Anybody have experience with 90mm?

The bigger the MAF (or MAF curve), the more tweaking you have to do with the curve at low speeds (idle).

 

[Lupo]

The bigger the MAF (or MAF curve), the more tweaking you have to do with the curve at low speeds (idle).

Yea, that makes sense. If I have 30 points to work with, maybe I can give a couple more points of resolution down low, because I don't think I'll be hitting 1740+ CFM, and if I do, I'll just do the Vadim way, and dump in fuel from the WOT function.

 

[Ishodu]

My application is S/C, and I have gotten up to 4.73 volts on my old 80mm, limited to 13psi. I used the 90mm to give me a little more leeway.

That is a really good idea however to redistribute the spread (slightly) , especially at low RPMs for driveability. I think I'll give htat try.

4.8v on the 80 is just below 1400. So you likely getting around 1350-1375. And on the 90 you could leave 4.64v point that is 1475. This is a fair bit above what you have hit before. That will leave 2 extra points you could take down to the low end and tune for better drive ability. You can also just make a custom curve with some of the mid and high range points a tiny little bit farther apart and it will give you some extra ones for the bottom end. Bad part is the high end accuracy will be effected a little. But it just might be worth it. Looking at the 90 curve it appears to have really no point until its gets t0 .56v. I think it would really help to put a point below this. FYI I start mine at .39v but its also NA. You would have to see what your getting for a voltage at your lowest idle or driving speed.

 

[Lupo]

4.8v on the 80 is just below 1400. So you likely getting around 1350-1375. And on the 90 you could leave 4.64v point that is 1475. This is a fair bit above what you have hit before. That will leave 2 extra points you could take down to the low end and tune for better drive ability. You can also just make a custom curve with some of the mid and high range points a tiny little bit farther apart and it will give you some extra ones for the bottom end. Bad part is the high end accuracy will be effected a little. But it just might be worth it. Looking at the 90 curve it appears to have really no point until its gets t0 .56v. I think it would really help to put a point below this. FYI I start mine at .39v but its also NA. You would have to see what your getting for a voltage at your lowest idle or driving speed.

Good ideas. Also, you could give a value to the first number 0, which is what the stock one does. In this case 8.196

 

[luigisho]

Post back with results please. Always good to have info available.

 

[Lupo]

Post back with results please. Always good to have info available.

Looking at my datalogs, and using Calcon in real time, it looks as though at idle, the MAF is in the .8-1.2 volt range.
So this is the range that I will add a couple points to, to give extra resolution.
Then we will see what happens.