Is it possible to tune the trany for a 3rd gear start for sled pulling??

[Dragbear]

A lot of pullers use this but they buy a 2nd tcm and have it tuned then switch it out at the track.
Is it possible the tune it with the V2 so you can just flash it at the track when you get there then flash it back after.
This 3rd shift defueling is a killer!!!!.
Rick

[WisconsinHick1]

You can adjust your defueling so it's not as much of a killer. Only recommended if you have a built tranny though. Otherwise yes you can tune the TCM to start in 3rd gear. I did that in all my 4low tables. I never had to reflash my tcm or switch tcm's.

[Dragbear]

Thanks!!! That is what I was hoping to hear.
It is a $600 deal to get the 3rd gear start. You have to buy a new TCM then take to a GM dealer to get it flashed to match your truck then send it away to get the 3rd gear start tuned into it then switch it back and forth when you want to use it. That sounds insane!!
So you say I can plug in at the track and lower the shifts live and not have to build a file and take the risk of reflashing each time.

Rick

[WisconsinHick1]

Post up your TCM file and I will take a look at it.

[hog]

Just set your 4lo tables so that you get the 3rd gear start, these will be enabled every time you shift into 4LO. Then once done pulling just shift into 4HI or 2HI for noirmal daily driving and youu will be using those tables with more normal settings.
No flashing
peace
Hog

[Dragbear]

Cool!!!!!!!!!
How far do you lower 2nd and 3rd? Do you lower MPH or RPM or both?
I have not looked into the TCM so I am not sure what I will be looking at. I will check it out tomorrow for sure.
Thanks, guys!!
I will try and post the file tomorrow so you can check it out for me.

[Dragbear]

trany factory read.tun
This is my factory trany tune
I looked through it but didn't find the settings I need to change. I will look some more later on but I have to head for work for now.

Thanks, Rick

[Dragbear]

Ok I found everything
Hog I have a few questions?
This will only work in 4low, Drive. (Not 4low, m3, towhaul)
Using Drive I will need to raise 3-4 shift to keep it in 3rd?
Do you need to lower both rpm and MPh? how low did you set them?
Did you set your converter to lock?

Thanks for the help everyone!! Rick

[WisconsinHick1]

So I understand this right you want to start and stay in 3rd gear?

Make sure you do full throttle and part throttle tables with both RPM and MPH tables.

Are you not able to run manual shifting mode in 4low with your 6 speed?

[JoshH]

Ok I found everything
Hog I have a few questions?
This will only work in 4low, Drive. (Not 4low, m3, towhaul)
Using Drive I will need to raise 3-4 shift to keep it in 3rd?
Do you need to lower both rpm and MPh? how low did you set them?
Did you set your converter to lock?

Thanks for the help everyone!! Rick

You can put it in M3 and it will start in 3rd if you lower all the part throttle and full throttle MPH and RPM shift points for 1-2 and 2-3. If you want to run it in D, you will need to raise the 3-4 shift speed and RPM. The MPH for 1-2 and 2-3 needs to be set at 0, and I set RPM at 200. I don't modify converter lockup.