new T43 params

[Chris@HPTuners]

guys,

I've added a few new parameters for T43 TCMs (6 spd auto trans).

Clutch Air Purge - allows you to disbale the clutch air purge feature on startup

Skip Shift via neutral - allows you to disable all skip shifts via neutral, forcing the trans to shift each gear sequentially

Skip Downshift via neutral - allows you to disable all skip downshifts via neutral, forcing the trans to downshift each gear sequentially

The clutch air purge was requested by trans builders who are getting startup clunking problems after fitting aftermarket clutches. I'm not sure if there willl be any detrimental effects of disabling this, but the clunking will be gone.

The skip shift disables are useful for preventing neutral engine flare shift lockouts on shifts such as 4-2. This is when you have disabled torque management (or have it really low) so that the engine flares badly on a neutral skip power downshift. If this happens the trans will just sit in neutral on the rev limiter until you let off the gas, then it will slam (and i mean slam) into the lower gear. Not nice. These values allow you to force the trans to shift 4-3-2, rather than the 4-2 skip.

Chris...

[edcmat-l1]

Good stuff. Can't wait to try it out.

[DSteck]

Awesome on the air purge. I have a customer whose 6L90 does that. It'll be nice to get rid of it.

[icicleboy]

Interesting on the air purge. We did an in-house build of a 80e and had this clunk for a while which went away on it's own. We thought it was something we did wrong. This was a full rebuild with updated channel plate, pump, and alto 35R & 456 packs.

[TimC]

My 80 does the clunk a lot of times but not always. It started when I updated the stator shaft and increased the clearance on the alto 35r pack to .100.

Can't wait to try the new tables out.

[TimC]

When is this new version going to be released?

[Chris@HPTuners]

available now, email support.

[DSteck]

Chris, out of curiousity, do PIDs exist to show the learned values that the transmission uses for pressure and volume?

[ttpmatt]

This is great to hear.. Been waiting for these minor additions. I'll say though that HPT has the most available A6 parameters. I work with a few other tuning softwares daily and I rely on my HPT for any 6L80/90 calibrations!

[Chris@HPTuners]

Chris, out of curiousity, do PIDs exist to show the learned values that the transmission uses for pressure and volume?

not that i know of

[DSteck]

not that i know of

Damn. I'd love to find a way to see what it learns to.

[TimC]

Interesting on the air purge. We did an in-house build of a 80e and had this clunk for a while which went away on it's own. We thought it was something we did wrong. This was a full rebuild with updated channel plate, pump, and alto 35R & 456 packs.

What is this updated channel plate you speak of? Is it a GM part or aftermarket?

[icicleboy]

GM Part. I did a rebuild on an 06A6. Car runs a 427 and we wanted to freshen things up. Doing research, we found that GM had updated lots of parts in the trans since 06, and the replacement part #'s were superceeded. When comparing the original spacer plate with the new one it was obvious that MANY holes were smaller/larger than the original. I'm sure this changes shift feel, line pressure, etc. I don't have the #'s handy but if you have a good dealer you can hang out with the parts guy at the counter and get all the info.

[ttpmatt]

These new options are great! Tried them out on a 11 SS A6 with built trans and a 10 GS A6 stock trans, yesterday at the track and on the road. Working out great. The clutch air purge got rid of that fresh start hesitation in the SS with the built trans.

[WongBob]

How much longer does it take to do a WOT 6-2 or 6-3 with this option checked? Either way it has to be better than neutral dropping the gears.

[Waker]

Be carefull when adjusting the purge values on a built trans. The stock settings will give you the first indication if a clutch pack is too large. Eliminating this feature will lead to a hung/double shift (usually 2/3) if the packs are too tight or have expanded due to heat or fluid soak.

[CactusG8]

Be carefull when adjusting the purge values on a built trans. The stock settings will give you the first indication if a clutch pack is too large. Eliminating this feature will lead to a hung/double shift (usually 2/3) if the packs are too tight or have expanded due to heat or fluid soak.

was this in regards to turning off the clutch purge? since it has been over a year since this subject came up what is the latest consensus on turning the clutch purge off?

[topher455]

I'd like to know as well. Those who have disabled the purge what are your thoughts and experiences?