Quote:
Originally Posted by fisherman
So according to Bills info, I should be able to safely run the WOT shifts at 5300?? And shift firmness at 25? WOW, the shifting at 14 felt pretty harsh. The change in my ashtray would rattle when it shifted!
Anyways, I'll probably leave those parameters alone for a while cause I'll be terified of destroying the transmission again!!  |
Fisherman, I'm going to try to explain this very carefully, so please pay attention!
You bought a pickup truck, not a funny car. Don't drive it like a funny car unless you make some major mods!
When Bill put nitrous in the truck he was testing, he moved the HP and torque peak outputs to the right in the graphs. And, we really don't know how often he ran the thing at WOT, do we?
In your truck, the torque and HP are falling off at 5000 RPM. There's no benefit whatsoever to setting a shift point higher than that (unless you just like to hear the engine scream and the transmission self-destruct). The Torque Converter starts to balloon (distort) at 5400 RPM. Give you any clue why your TC got toasted?
To get the transmission to shift properly at WOT, the max RPM needs to be at least 400 above any of the WOT shift points. From personal experience, it needs to be even higher for the 3-4 upshift. However, notice that Bill had the 3-4 upshift on his truck set 500 below the other shifts. Bill has mentioned that this shift is somewhat harder on the drivetrain than the others, so it's best to keep it at a lower point.
Here are my numbers, for my tow tune, just to give you a reference point:
1-2 Upshift: 4975
2-3 Upshift: 4975
3-4 Upshift: 4400
Max RPM: 5400
The tow tune is designed to keep the engine in the power band as long as possible during WOT acceleration.
Bluejay, in the f150Online forum, set his shift firmness at about +12, +12, +9 when he had the "canned" tunes - he likes "very firm" shifts. But remember, the canned tunes have already "firmed up" the shifts some! Don't get carried away here! Once Bluejay got his custom tunes, he left the firmness settings at 0, which is where I have them. On a WOT shift, it's quick enough to cause my serpentine belt to "squeak". I don't really want it any harsher than that. A strong "jolt" is putting stress on things. No "feel" at all, is wearing out the bands, due to prolonged slippage. Cleatus12r talked about this in his post, and I'd pay attention to what he said. He knows what he's talking about.
OK, I've probably lectured you enough. The programmer did not destroy your transmission. You should not hesitate to use it again - just use it sensibly!
- Jack