trans tuning.

[mustang_gt_350]

IS there anyway you can keep the 4r100 from downshifting after it hits 3rd gear and loses rpms? Meaning that start in manual 2nd, shift into drive and not have it downshift when it starts losing rpm's.

[Jackpine]

Originally Posted by mustang_gt_350

IS there anyway you can keep the 4r100 from downshifting after it hits 3rd gear and loses rpms? Meaning that start in manual 2nd, shift into drive and not have it downshift when it starts losing rpm's.

You're asking an odd question here in my mind. Why are you starting in 2nd? Is it because you are on a slippery surface and you want to limit the torque to the wheels? Then, after you're rolling, you put it into drive so that it will shift into 3rd, right? (I assume you have the O/D off so it stays out of 4th). But now you don't want it to go back down to 2nd unless it REALLY has to, is that what you're asking?

So anyway, ignoring the part about starting in 2nd, which keeps you in 2nd till the cows come home, regardless of load or speed, you are wanting the same behavior in 3rd gear I think.

As far as I know, the answer is NO. Once in Drive, you have a fully automatic transmission that's going to shift according to throttle position and speed. I felt I was able to delay the onset of shifting a bit by reducing the part throttle downshifts for all gears by the max amount and by doing the same to the TC unlock points. But, the change was really pretty minor. If I'm reading you right, you think the downshift is happening too quickly, when there's still plenty of pulling power left.

Bill may be able to adjust things to make the downshift/unlock behavior less aggressive, but I don't know if that's true or not.

And now that I've noticed where you've posted this, are you asking is it possible to adjust things in Minotaur to "lock" it in 3rd? If that is the question, I would suspect there is a way to de-sensitize this.

- Jack

[John Anderson]

Mustang, I suspect you are sled pulling. There is definately a way to do what you want. Bill should be able to hook you up.

If you do have the Minotaur software, let us know what you are doing that you want to be like that. For example, towing, daily driving, or sled pulling. We can go from there.

[mustang_gt_350]

Originally Posted by John Anderson

Mustang, I suspect you are sled pulling. There is definately a way to do what you want. Bill should be able to hook you up.

If you do have the Minotaur software, let us know what you are doing that you want to be like that. For example, towing, daily driving, or sled pulling. We can go from there.

It would be for sled pulling. Basically i want to try it for a speed sled. I think if i start in 2nd like normal and manualy change it to drive and let it shift into 3rd with doing this and not having the downshift even if i drop below the turbo and loose power the speed that is first generated will be a better gain than pulling in 2nd only. Just an idea, it will be a while until i can hook to a speed sled to find out.

[John Anderson]

What you want to do will work. If you have the Minotaur software, this is very easy to do. If you look through the scalars, you should see the ones to adjust for the downshift vs throttle position. Just set it up so that it won't ever down shift until the vehicle speed is zero.

Bill might have a better way to do this, but thats what I can see.

[mustang_gt_350]

Ok i had thought about doing it that way but i wasn't sure and wanted so see what somone else thought.

[soutthpaw]

John is correct, you can definitely do what you want to do. also you are going to need look at your torque converter settings as to if and when u want it to lock up.
Hope you have a built tranny

[mustang_gt_350]

I have a manual lock switch for the T/C so thats not a problem, however the built trans is lol

[Power Hungry]

There are 2 switches which control the trans and converter states.

Switch 1 will turn on or off the ability to lock the trans into a specific gear. There is a values that is used in conjunction with this to select the gear in which to stay locked (1, 2, 3, or 4).

Switch 2 will turn on or off the ability to lock the converter. On 94-97 this is simply an on or off state. On 99 and later, it is used in conjunction with with a value that determines the pulsewidth in which to lock the converter. Normally, this would be set to 100%, but if you're really curious as to how fast you can fry your converter clutch you could set this to 25% or 50%.

We frequently do "sled-pull" applications on a chip that goes something like this...

Pos 1: 2nd Gear, Converter Unlocked, Fuel Curve modified to spool and light turbos
Pos 2: 2nd Gear, Converter Unlocked, Pulling Fuel Curve
Pos 3: 2nd Gear, Converter Locked, Pulling Fuel Curve
Pos 4: 3rd Gear, Converter Locked, Pulling Fuel Curve
Pos 5: 4th Gear, Converter Locked, Pulling Fuel Curve
Pos 6: Normal Operation, Light Fuel Curve

Instead of 1st gear, we can also set up to start in 1st gear.

These types of strategies work really well because they completely bypass most of the delay circuits in the shift strategies and just grab the gear desired. The only drawback is that you have to be very careful when switching or you could accidentally skip a position and jump 2 gears instead of 1. In a bouncy truck it's quite easy.

Anyway, just some thoughts.

[cleatus12r]

Oh my God, the Mad Doctor LIVES!!!






Just giving ya a hard time, Bill!