Performance chips for 6.5

[Robyn]

Well now I am getting down to the nit picking now.

Can anyone here with a 94 or 95 6.5 that has installed a chip tell me how they like the performance of the chip as far as the tranny shifting goes.

My 4L80 in the dually does a hinky thing when it shifts from 3 to 4 under heavy load.
The tranny does the 2-3 fine then it locks up the TCC then just as the 3-4 shift initializes the TCC unlocks which gives an RPM flare that I just plain dont like.

The stockers wont really do it all that much but with the extra power the rpm flares about 350-400 when the TCC unlocks and then relocks after the 3-4 shift.

Seems that a reprogram on the chip can eleiminate this issue either by allowing the TCC to lock only in 4th and or not allowing a TCC lockup with more than 50-60 % throttle.

If I just touch the brake to keep the TCC off and let the tranny do all its shifting then allow the TCC to lock after the 3-4 shift it's perfect.

Having the TCC unlock then relock in quick sucession like that is real sucky.

There is nothing wrong with the tranny its just crappy programing.
Under the conditions I am seeing the TCC could stay locked for the 3-4 shift and it would not hurt anything at all.

Any one here with chip experience have any input????

My 94 will do this every so often too and its BONE stock. Its power level is considerably lower than the dually though and the flare during the unlock is minimal due to a lot less power.

Thanks
Robyn

[stingthieves]

For some time now when towing heavy- I move my shift selector to "3" when starting out. Once moving well and over 50 I lift off the accelerator and gently move the selector to D. If necessary I will again lift and move the selector back down to 3 - it sure would be nice to have a rocker switch to do this as I have noticed some others have - but too much to do and too little time - I use the column selector.

So you think a reflash will fix this?

if yes who is your likely vendor of choice?

Lately I have had the feeling that John would rather work with his Duramax customers than the 6.5 guys. But that opinion and a buck and a half will only get you a sip of good coffee!

[Robyn]

I am not well versed enough on the inner secrets of the 4L80 "YET" to offer much. My expertise goes back to the days of 350, 400, 700R, Ford C4, C6, FMX Chrysler 904's and 727's

I do know that a 4L80 uses many of the same parts as the 400 though

Its a shame that such a nice tranny can be knocked out of the game with a little sensor issue or one small broken wire.

Another really good deal would be if a manual contol system could be set up to run the 4L80 without any electrical power and still have full auto shift plus TCC lockup.

Would need a governor system to tell it what speed things are going and a way to control throttle pressure.

I believe a vacuum controled pressure regulator has been done but not sure.

Oh well

Robyn

[a5150nut]

Robyn,
I have a chip in my truck, but it a stick. I have had a long conversation with Heath and he tailor's his chip to what is needed and what you have for gages. I also talked with a guy in Chico that has a 4x4 shop and he was telling me he could program a chip for the 98 Blazer I had at the time to make it work just like an Allison trans. Tow mode and all. So I would figure anything is possible.

I would start with Heath and go from there.

Realy do appreciate your input arround here. Not only broad, but also deep. We can all bennefit from each other here. :D

[Robyn]

Thanks for the info and the compliments :D :D

I have had an ongoing dialogue with Heath diesel and I intend to chat more with them in the coming few days to see what can be done about this issue.

Robyn

[j_k_auto]

sent you a pm

[stingthieves]

http://blog.heathdiesel.com/2005/11/manual-operation-of-torque-converter.html

[a5150nut]

http://blog.heathdiesel.com/2005/11/manual-operation-of-torque-converter.html

I have noticed my 05 Grand Prix does this. In manual peddle mode when I let off the throttle it goes to coast mode. BUT, with her in cruise when I hit a down hill stretch of road the trans remains locked and speed constant. No costing and speed gain down hill. Must be one of those undocumented features.............;)

[stingthieves]

Robyn,
I have a chip in my truck, :D

may I ask please who was your chip vendor?

[a5150nut]

may I ask please who was your chip vendor?

I got it from Sierra Diesel in Redding, CA. in early 97. Supposed to be RV version not full race.

From what I understood at the time, there was only one guy in the country burning them for everyone. But then I talked to the owner of a 4x4 shop in Chico a few years ago and he said he could burn his own and put in any parameters you wanted. Just tried to locate 4x4 shop on Internet and couldn't find it. Anyone up around Butte county know the one on 8th ??

[JohnC]

I had a Kennedy chip in the '95 and it did not exhibit any of the flare you describe. I know he did some work to improve the shifting, but don't know the particulars.

Keeping the TCC locked during the shift wouldn't do it. There'd be nothing to absorb the speed differential other than the bands...

[john8662]

Chips and the 4L80E.

I've done both, the 94-95 and the 96 OBD-II performance upgrade on my personal 6.5's and in both cases the tranny was affected.

The short story here is that the line psi in the transmission is changed by programming in nearly all the aftermarket tunes.

Heath's tune does indeed do this, but as I was told not by much, and not enough to even be able to tell the difference from stock to the increased line psi.

The truth of the matter here is that the only thing that the increased line pressure does in sharpen up shifts by making them quicker, the TCC lock is also more agressive.

Can you tell the difference? Certainly, and it does shift harder, but I'm picky.

Most 4L80E's with some miles on them don't enjoy the sudden change in pressure, and will start to exibit some odd characteristics when used with the new combination, even if perfectly normal all of it's life beforhand.

One of which is a form of limp mode, where just because you were being mean to the truck (hot rodding) that the trans will decide that (for some reason, code reader not running at time) to default to harsh shifting. Restarting cures this, no hard codes set.

Other times, it just seems to shift harder.

So, Robyn. With your flare, the increased line psi will likely mask this.

If the tranny is already acting odd, I'd recommend dropping the pan and replacing ALL the noids, the two shift solenoids and the Pressure Control Solenoid.

Out of 5 Members with the Heath's tune I have talked to, all of them have agreed that at times the transmission has done different things. Some like it, like a gentleman I talk to here locally who pulls stock trailers and races a 10 second car at the dragstrip. Some don't (me).

But, this transmission abnormality isn't just limited to certain tunes, it's the practice of increasing line psi that is the cause.

Clear as Mud?

J

[stingthieves]

Well now I am getting down to the nit picking now.

Any one here with chip experience have any input????

Thanks
Robyn

My boost command has failed from my ECM. Programmer explained via email that his chip will correct this fault so I am ordering my Websters chip this week. most likely the 30 hp safe chip but I do covet the 60 hp hot chip.

[damork]

Been using the BD Race chip for 200k with no complaints. Shifts have always been firm, boost went to 12 psi or so, exhaust temps have stayed reasonable and it made a huge difference in overall driveability.

Understand BD now has a different supplier with more power capability at the wheels. I also have the RV chip from BD which I'd like to get reprogrammed to a newer version - it was a little better than stock, but a waste of time otherwise.

[Robyn]

I have spent a bunch of time with the truck now and the "flare" is not component slippage but instead the result of the extra torque and it manifests itself quite well when the tranny unlocks just before the 4th gear engagement under heavy boot running. (Stalll is up a bunch)

I cant stall the convertor totally. The truck will smoke the duals at 2100 with the brakes on and if I use 4x4 it will smoke the duals plus one front.
That crap is gonna end up breaking something. :eek:

My stock 94 Burb will do the flare just a little but not nearly as much.

Its just part of the way this thing is going to work I guess.
I am not happy about it.
It could be avoided if the programing is changed to allow 3rd lockup only in manual 3rd position and or allowing lockup only in 4th gear.

I will yack at Bill Heath and John Kennedy here when I get ready to do something and see what we can do.
The lovely thing about software is, that if you dont like the way it works, rewrite it :D

To do this stuff mechanically/hydraulically would take far more work to get a good reliable auto operation.

Another little thing comes to mind. Speaking of limp mode.
Back in 95 we had a 95 Burb with 6.5 and one eavening I was waiting for the family to get in the rig and I was sitting there with the rngine idleing and repeatedly "Poking" the throttle out of boredom.
When we took off the thing shifted like a ton of bricks. Shutting it off then a restart fixed it. The messing around must have made it mad.:eek:

It would do that same thing any time you poked the throttle repeatedly for more than a few times.

Just some interesting info

Robyn

[stingthieves]

I
Another little thing comes to mind. Speaking of limp mode.
Back in 95 we had a 95 Burb with 6.5 and one eavening I was waiting for the family to get in the rig and I was sitting there with the rngine idleing and repeatedly "Poking" the throttle out of boredom.
When we took off the thing shifted like a ton of bricks. Shutting it off then a restart fixed it. The messing around must have made it mad.:eek:

It would do that same thing any time you poked the throttle repeatedly for more than a few times.

Just some interesting info

Robyn


Did you ever only have one forward speed when you first started out in the 95- again solved with a KO-KO restart sequence?
Happened a lot till I changed out my ignition switch - and it still appearers in winter.

[javadog]

Has anybody used any of the SSDiesel chips? I was thinking about getting one of the +40HP
upgrades to stay out of trouble. They also have a +80HP unit.