I noticed that when I have my tune loaded that the throttle is super sensitive. Meaning that when I hit a bump (not that large) the tranny will kick out of OD. I just wanted to see if anyone else had this issue.

 

Details please.

Programmer type.


If custom:

- Who provided the tune files?

- Have you discussed with yer custom tuner feller?

If canned:

- have you called tech support?

General - have you made any end-user adjustements? If so - what?


Could be a simple tweak - all the way to a fundamental incompatability or other issue with yer specific strategy.

MGD

 

If this is with a custom tune call your tuner.
If this is with canned/generic tunes call the company who manufactured it.

 

bumps shouldn't cause any deviation in the tranny performance.

 

tuner is an X3 tuned by VMP, Justin said he never heard of such a thing
it has to deal with the sentivity of my foot on the throttle when hitting a bump, thats what I think, I don't feel my foot move at all, and on cruise it won't do it

 

I know my throttle response is super touchy and I too notice the rpm's increase while riding over bumps, but that is normal since the tuner gets rid of a lot of the throttle lag on the "drive by wire" systems.

But the trans kicking down is strange...maybe someone will have ideas for you, sometimes all it takes is the right person to read the post.

 

The right people ARE reading the post

OP - I seem to recall a thread dealing with this before - it had to do with the torque converter unlock schedules interacting with small throttle movement, cause by foot movment, which in turn was caused by bumps.

What you are feeling is likely that, NOT dropping out of OD - an unlock feels like a shift ...

Sorry -too lazy to Search fer it - but good 'ol Jack was involved

MGD

 

You know what I meant......someone who had that same hiccup!

I'll be mindful of how I word my phrases next time aight!

 

Good. See that you do

And - it's aight, eh!





MGD

 

^^Stop your making me thirsty....

Actually for the past few years I've been drinking:

 

Oh Gawd!!!! That's a tad LARGE!!!

Sorry! :o

 

Good post, good info.

I wonder if you can go into the custom settings on the xcal and adjust the shift pressure?

 

yah, I know it's the torque converter kicking out, I figured it had something to do with the throttle by wire set-up. Sounds as if there is a solution out there ?????

Thanks for all the replies

 

You originally said in yer first post that it was the OD kicking out. Now you say you know it's the TC. Make up yer mind !

Here are the available end-user adjustments on yer VMP-tunes device:



Given that, I think you will need to get Justin to mod the tune to defer/delay TC unlock under those conditions - there is nothing above that will help. He does something similar in his tow tunes to help keep it locked, reducing slip, hence keeping the tranny cooler.

MGD

 

I've always wondered if the tuners make the throttle open more when the gas pedal is pressed a little (say 10% more for the first half of the pedal travel) to make the truck seem like it has a bigger power increase than it really does.