Wanted to Show everyone something interesting

[03LightningRocks]

With all of us pushing more and more air through our engines, I wanted to show everyone an example of how the stock MAS may be limiting some of us quicker than we had originally thought.

Here is a dyno from the recent tuning I had done out in Jersey with the new Pro-M MAS. I had previously recorded data using my Auto Tap during the pulls earlier. My stock 90mm MAS was hitting 5 volts at 4400-4500 RPMS. At the same time the A/F's would start to go very lean at the worst possible time. This was happening because the MAS was no longer able to tell my computer how much fuel was needed. The new MAS was hitting 4.76 volts at 5600 RPMS, well short of the 5 volt max. Notice the A/F's stay right at 11.9-12 all the way to the end of the pull. Notice how nice and flat they stay from start to finish, No big curve. The 92mm is defennitly controling the fuel curve better.

This was a race tune for 100 octane......the street tunes are set up a bit richer at 11.5. The Tining on this tune is set at 19 degrees versus the other would hit as much as 21 degrees. The power is still there. I realize this is a STD dynoes compared to a SAE. For the anal impared, just knock about 8-10 off of the newest H.P./Torque numbers and you will be there.

Newest Pull using the SCT and The 92mm MAS

http://www.svtgalleries.net/gallery/data/500/226JDM_Pull.jpg



With the stock 90mm MAS. Voltage of MAS loosing Control at 4400 RPM

http://www.svtgalleries.net/gallery/data/500/226RacePullThreeUpdatedTune.jpg

[cpeapea]

definitly good info ron, im kinda starting to hit this wall too, i might have to move to the newer 4 banks and a new maf

[r1eater]

I'm sure I'm there already.

[03LightningRocks]

I have done data logging with my auto tap before the ported eaton and before the Kenne Bell.

I ran as much as 16 lbs of boost on the stock super charger and did not run out of MAS. It would get as high as 4.9 volts at around 5600 RPM's.

The problem started showing up with the ported eaton. I would hit 5 volts at 5200 RPM'S with 17lbs of boost.

The Kenne Bell just pushed it right over the edge. At even 15 lbs of boost I was hitting 5 volts at 4800 RPM's. At 16 or above the problem just magnified itself and would peg at 4400-4600 depending on how cool it was and how much above 16 lbs I took it.

I was told that I was lucky I did not run it like this in cool weather, as the odds for serious problems go up the cooler it gets.



Rocks:hammer:

[StormShadow]

Maybe this is why my truck is running lean. This sounds like a good "next step" for me, along with headers. (if I can round up the $$)

[03LightningRocks]

Maybe this is why my truck is running lean. This sounds like a good "next step" for me, along with headers. (if I can round up the $$)
You can find out real easy. Just data log the run while on the dyno and set up the data logger to check the MAS voltage at the different RPM's.

I'll add this, most of the dyno sheets I saw with the MAS hitting 5 Volts showed a fuel curve like the one on my graph from speed works.

[cpeapea]

if you ever do heads and cams, it might even worsen the situation. id like to see where the voltage goes on an after market maf with heads and cams.

[Tex Arcana]

It looks to me that your old dyno sheet shows you going way rich as you go up in the rpm range: is that becasue the old MAF hits its limits, and the ECU reacts by dumping a shitload of fuel into the air?? IT seems to me that under cooler conditions, you should be able to run leaner because of the cooler temps, especially intake temps.

[03'svtlight]

I have done data logging with my auto tap before the ported eaton and before the Kenne Bell.

I ran as much as 16 lbs of boost on the stock super charger and did not run out of MAS. It would get as high as 4.9 volts at around 5600 RPM's.

The problem started showing up with the ported eaton. I would hit 5 volts at 5200 RPM'S with 17lbs of boost.

The Kenne Bell just pushed it right over the edge. At even 15 lbs of boost I was hitting 5 volts at 4800 RPM's. At 16 or above the problem just magnified itself and would peg at 4400-4600 depending on how cool it was and how much above 16 lbs I took it.

I was told that I was lucky I did not run it like this in cool weather, as the odds for serious problems go up the cooler it gets.



Rocks:hammer:
I TOLD YOU my truck ran ALOT better with the PRO-M Uncle Rocks. I didn't have a chance to prove it but it did feel better. :cool:

[03LightningRocks]

It looks to me that your old dyno sheet shows you going way rich as you go up in the rpm range: is that becasue the old MAF hits its limits, and the ECU reacts by dumping a shitload of fuel into the air?? IT seems to me that under cooler conditions, you should be able to run leaner because of the cooler temps, especially intake temps.
Your right about the computer suddenly increasing the fuel. The reason this happens is that the computer no longer can react to demand when the MAS hits 5 volts. What it does is go to an "emergency" table in the program. As load increases the fuel will not keep up since the computer has no way of knowing what is going on.....That is a real basic explanation from a "stupid" person, but it cuts to the chase of it all.

As far as running lean with cool conditions....this will cause, "boom syndrom", at this point you get to buy a built lower end and can then really get some good time slips...:D .

Remember that as the air gets cooler, it gets dense. Thus more oxygen molecules(sp). Think of it like using a shot of NOS. To run NOS you have to have a program tuned richer.

I'll let you know in October Gavin.....:D .




Trai my man...long time no see buddy. I am not surprised you ran better with your Pro-M. Especially as you increased your boost. I would definnitly recommend folks get a tune to run the after market MAS though.



Rocks:beer:

[03'svtlight]

Your right about the computer suddenly increasing the fuel. The reason this happens is that the computer no longer can react to demand when the MAS hits 5 volts. What it does is go to an "emergency" table in the program. As load increases the fuel will not keep up since the computer has no way of knowing what is going on.....That is a real basic explanation from a "stupid" person, but it cuts to the chase of it all.

As far as running lean with cool conditions....this will cause, "boom syndrom", at this point you get to buy a built lower end and can then really get some good time slips...:D .

Remember that as the air gets cooler, it gets dense. Thus more oxygen molecules(sp). Think of it like using a shot of NOS. To run NOS you have to have a program tuned richer.

I'll let you know in October Gavin.....:D .




Trai my man...long time no see buddy. I am not surprised you ran better with your Pro-M. Especially as you increased your boost. I would definnitly recommend folks get a tune to run the after market MAS though.



Rocks:beer:
It has been awhile.........I've been busy trying to start my new career. I bought a Freightliner, so now all I need is insurance, a trailer, and a few other minor details and I'm on the road. :tu:

[Tex Arcana]

I TOLD YOU my truck ran ALOT better with the PRO-M Uncle Rocks. I didn't have a chance to prove it but it did feel better. :cool:
Alright, new rule: all of your avatars must be posted in full size whenever you change them. :nono:

[Tex Arcana]

Your right about the computer suddenly increasing the fuel. The reason this happens is that the computer no longer can react to demand when the MAS hits 5 volts. What it does is go to an "emergency" table in the program. As load increases the fuel will not keep up since the computer has no way of knowing what is going on.....That is a real basic explanation from a "stupid" person, but it cuts to the chase of it all.

As far as running lean with cool conditions....this will cause, "boom syndrom", at this point you get to buy a built lower end and can then really get some good time slips...:D .

Remember that as the air gets cooler, it gets dense. Thus more oxygen molecules(sp). Think of it like using a shot of NOS. To run NOS you have to have a program tuned richer.

I'll let you know in October Gavin.....:D .




Trai my man...long time no see buddy. I am not surprised you ran better with your Pro-M. Especially as you increased your boost. I would definnitly recommend folks get a tune to run the after market MAS though.



Rocks:beer:
Yah, I see that.. I never think of cooler air like that, simply because it does help prevent detonation by virtue of the fact that the intake charge is cooler; but if the MAF is maxed, the ECU can't adjust, and BANG. :(

Is there an ECU or an add-on unit that can utilize a broadband O2 sensor for the Lightning?? One would think this would be the best thing for going beyond stock.:tu:

[03LightningRocks]

........snip.........

Is there an ECU or an add-on unit that can utilize a broadband O2 sensor for the Lightning?? One would think this would be the best thing for going beyond stock.:tu:

That is what the different tuning applications are for:D .

[03LightningRocks]

It has been awhile.........I've been busy trying to start my new career. I bought a Freightliner, so now all I need is insurance, a trailer, and a few other minor details and I'm on the road. :tu:

Kewl:d . Maybe I will see you out on the Interstates in a few weeks....:beer: .

So...are you planning on modding the new ride:cool: . I would love to see a Freightliner pull an 11 at Ennis:nana2

[03'svtlight]

Alright, new rule: all of your avatars must be posted in full size whenever you change them. :nono:
:rll: :rll:

[03'svtlight]

Kewl:d . Maybe I will see you out on the Interstates in a few weeks....:beer: .

So...are you planning on modding the new ride:cool: . I would love to see a Freightliner pull an 11 at Ennis:nana2
that would be a trip :nana2