Observations on the tranny after chip install

[SMOKNZ]

First off I want to say I love my DP chip. I just have some observations that I'd like to bring up and see if this is normal. When I take off at low speed, or any speed before the converter locks the rpm's come up and stay up while the truck is accelerating. They stay pretty constant while you can feel the tranny shift. It has the feeling like it has a real loose (high stall) converter in it. While I have no idea what converter is in the truck, I know the tranny was rebuilt by it's previous owner, so it may or may not be stock. The truck feels like it has a 5 speed auto (I know it's a 4 speed). I take off while normally driving and the revs come up to around 2100 or so, I feel the 1-2 shift, revs stay the same, 2-3 shift revs still the same, get to around 45 and the converter locks kinda hard, and the revs fall to around 1650 or so, keep accelerating and the revs will now follow the speed of the truck all the way to overdrive and above. I guess what I'm trying to ask is is the stock converter sloppy with the additional power of a chip? it didn't act like this stock, and immediately did it after the chip. The trans doesn't feel like it slips at all, and really pulls fine when loaded. With more throttle the rpm's really just go higher and stay the same when accelerating, unless I stomp it down and then it will climb with the gears. Just wondering if this is common. Sorry if the rambling is confusing, just trying to explain in words

Bill

 

[Tbar]

Early 99 F350

Part of the your problem. My 99.5 revs like that too. Thats why I put in a t/c lock switch. One of these days I will do some upgrades.


Tbar

 

[CSIPSD]

Did you get XLE tunes on the chip? I know jody is the man, but I would have had PMT1 or PMT3 burns on there, the tranny stratages are soooo much better, the TC stays locked when you brake, locks quicker...

Call him, that sounds like the lock up is too high, I lock my TC at about 28-35 depending on what I am doing...

 

[SeeYa]

Did you get XLE tunes on the chip? I know jody is the man, but I would have had PMT1 or PMT3 burns on there, the tranny stratages are soooo much better, the TC stays locked when you brake, locks quicker...

Call him, that sounds like the lock up is too high, I lock my TC at about 28-35 depending on what I am doing...

Since his truck is an early '99 his original PCM is a DPC-402 he can't do PMT on there. I can check if he has changed out his PCM for the newer DPC-422 PCM. Just PM me your name and I'll check it out for you. He would need a newer PCM (DPC-422) for PMT to work.

Agreed that PMT has better trans parameters. All around it is better code.

SMOKNZ,

It sounds like you have the stock shifting parameters. Jody uses XLE8 stock shift parameters for the Early '99, but he can adjust that for you if you wish. Give him a call when you get a chance.

 

[CSIPSD]

I hated my XLE... Had a PMT fuel 7 on my 99... Maybe thats why it stalled everytime I changed... LOL

 

[SMOKNZ]

Did you get XLE tunes on the chip? I know jody is the man, but I would have had PMT1 or PMT3 burns on there, the tranny stratages are soooo much better, the TC stays locked when you brake, locks quicker...

Call him, that sounds like the lock up is too high, I lock my TC at about 28-35 depending on what I am doing...

I did get a new PMT1 computer with the flip chip to replace the early 99 pcm. The converter does lock at lower speeds with a little less throttle. I'm not saying I dislike it. With the stock 99 pcm the converter would lock at the 1-2 shift and dropped the revs way low and made the truck doggy. I like it that the converter now locks over 40 with moderate throttle. Makes the truck really move and funner to drive. I was just wondering about the loose converter, and if others experienced it.

Bill

 

[SeeYa]

Cool, you got the upgraded DPC-422 PCM. What you are descrbing as the shift patterns is the stock shifting characteristc's of PMT1. T/c lock up around 28 mph and goes into over drve around 40ish mph. Jody will suggest that you use some kind of scan tool to gather data at the intreval in which the converter feels loose. This will help greatly in trying to diagnosis what could be going on. If you can do that and let us know what you find.

 

[SMOKNZ]

I have no such scan tool all I can say is it's loose as long as the converter is not locked.

 

[CSIPSD]

Might be time to install a new TC, or tranny... The HP of the chip might be overwelming the stocker with that many miles...

 

[SMOKNZ]

The tranny only has 80K on it. I'm only running a 80 Hp Econo tune. Tranny doesn't get over 190 when pulling.

Bill