4R100 tuning, and engine braking...

[Colt]

I've been messing with Minotaur, loving it so far, not too difficult..

I like the way the standard tunes control the tranny, there is very little I'd change, but there are a few things. A few of them I'm not sure what the effects would be to the tranny, or if they could be done..

The 5R110 has spoiled me a bit when in tow/haul mode, and I'd like to do something similar with the 4R100..

The first thing I noticed with the 80 HP towing tune, the way it keeps the converter locked when coasting. I'd like to toss in some down shifts.. I think I've figured out how to change that, just change the shift schedule to a higher MPH at 0 TPS, should do the trick. For example, your in 4th, 70 MPH, you start coasting down and at 55 MPH the trans down shifts into 3rd, and so on. I'm curious to know what the effects to the tranny would be though.. I know that a stock tranny with a exhaust brake dont get along very well.. Since your basicly doing the same thing keeping the converter locked, and down shifting, wouldnt the result be the same? My trans is stock, but as soon as money allows I'll have it rebuilt, and I'm going to throw everything at it.. So that wont be a issue, but what about for right now?

The other stuff I want to change is letting the converter unlock for a short time during the 2 to 3 shift, and the 3 to 4 shift.. The loads I tow are heavy, and I'm worried that not letting the converter unlock for a short time after those shifts that it will lug the engine. I'm not sure right now if that will be a issue since I haven't had to tow anything since I got the PHP stuff. I just know how it was with the factory tuning, hauling 15K LBS plus, shifting into 4th gear converter locked at 45 MPH, the engine hated that, so I'd have to keep the trans out of 4th until 55 or so. Which is right where it's shifting now, so it may not be a issue.. Thats how the 5R110 acts in tow/haul, and it works well, so I figured I could do the same with the 4R100.. I dont recall ever seeing the ECM unlock the converter in 4th, is there a reason for that?

The other thing I'd like to try is torque reduction before a shift.. I'm a bit of a lead foot, so those hard shifts while the engine is putting out large amounts of power make me cringe as to what it's doing to the drivetrain. Even more so when I'm hauling livestock, they dont need to be jolted around at every shift, thats probably the only time I like a mushy shift. Torque reduction would still allow firm quick shifts from the tranny, without the shock through the drivetrain.. It's like power shifting a manual trans while towing, you just dont do it.. I want the trans to shift quick and hard, but allow the engine output to be reduced during those shifts without letting out of the throttle. Once you start doing that, then depending on the tune, you may end up increasing the scheduled shift RPM because of the reduced TPS. Both of my 6.0's do this with the help of their programers ( Edge Platinum's ), and I really like it..

Anyone see any issues with doing this stuff? A tune such as that is something I'd only use while towing, no need when empty, but I tow a lot, I'd bet that 50% of this truck's life has been spent towing ( almost 228K miles on the odo ). Deep down I'm a manual trans guy, so my knowledge on auto's is limited as far as what effects certain operations have on them.. I know that quicker firmer shifts are better for the clutches and things like that ( I cant stand those mushy shifts anyways ), but when you start down shifting similar to what you'd be doing when driving a truck with a manual tranny, I dont know what the effects will be.. I think I have it figured out as to how I'm going to do all of this, on paper anyways, real world is always different. I dont mind tinkering until I get it right, but I dont want to waste my time if it cant be done the way I want it, or it eats a tranny shortly after getting it right.

Thoughts?