Topic: Auto trans, firmer shifts

[TC-GXP]

My GXP is an automatic and I'd like it to shift firmer. I know with these computer operated transmissions you can do the necessary changes in the programming rather than install a shift improver kit like in the old days. A friend of mine has a chassis dyno shop and is quite well versed in HP Tuners and he said he could modify the transmission to shift firmer if I wanted him to. He said it costs about $200 to license the vehicle (I think that was the term he used anyway) from HP Tuners and he didn't think GM would be able to tell that the transmission was modified if I had to go in for warranty work on it someday.

So my question is has anyone else modified their automatic trans to shift firmer? Have you had any issues from modifying it and have you regretted doing it? If you had a problem and went to the dealer for warranty consideration did they give you any trouble regarding the computer programming alteration? Just wanted to check with my peers before I go down this road.

[spicy3480]

Westers has a tune for the transmission in the turbo Sky and Solstice.  I had my TCM tuned by him and he turned the "L" gear into "performance shift mode."  The shifts are all at redline and super firm. 

[J_Bond]

I did this to my Sky, and it worked great!!!!  was going to do a modified valve-body and upgraded torque-converter, but HPtuner made the shifts firm and raised the redline a tiny bit.

[TC-GXP]

Thanks for the responses guys! So have either of you had any transmission problems attributable to making it shift harder? How many miles since your change? Did your tuner happen to mention if it was an "invisible" change or not?

[tazz]

I did this to my Sky, and it worked great!!!!  was going to do a modified valve-body and upgraded torque-converter, but HPtuner made the shifts firm and raised the redline a tiny bit.

Huh???
Im lost.
Hptuners can not program the transmission module on the LNF just the ECM.
Now if you had Lyndon program the Transmission module that a different story.

[J_Bond]

uhh.... TAZZ, I drive an LE5. (as seen in my long list of mods in my Sig.     )    I payed extra to have it done, turned out great, don't know who or what a 'Lyndon' is, but it turned out great.

Huh???
Im lost.
Hptuners can not program the transmission module on the LNF just the ECM.
Now if you had Lyndon program the Transmission module that a different story.

[Sly Bob]

uhh.... TAZZ, I drive an LE5. (as seen in my long list of mods in my Sig.     )    I payed extra to have it done, turned out great, don't know who or what a 'Lyndon' is, but it turned out great.

Lyndon is Lyndon Wester of Wester's Garage.

http://westersgarage.eidnet.org/index2.html

Glad that the tranny tune worked out well for you. DickW was the first to get the transmission done by Wester's and he drove half way across the country and into Canada to get it done. You can read about people's experiences with his TCM tune here.

http://www.kappaperformance.com/forum/index.php/topic,4669.0.html

[J_Bond]

Lyndon is Lyndon Wester of Wester's Garage.

http://westersgarage.eidnet.org/index2.html

Glad that the tranny tune worked out well for you. DickW was the first to get the transmission done by Wester's and he drove half way across the country and into Canada to get it done. You can read about people's experiences with his TCM tune here.

http://www.kappaperformance.com/forum/index.php/topic,4669.0.html

Great info!  Thanks SlyBob!!!!

[tazz]

I really didnt look since I assumed that only a person with a LNF would post a answer in regards to his question.
Been wanting to do this but my car falls apart just with a tune let alone the tranny.  Get that done and the DS would probably be laying on the road.

[Sly Bob]

I really didnt look since I assumed that only a person with a LNF would post a answer in regards to his question.

Yeah I sometimes make that mistake as well. I just assume sometimes that everyone has the LNF.

[JimmyBaja]

So which way is it... who or what can program the LNF TCM and who or what can program the LE5 TCM???

[tazz]

LNF TCM Lyndon and you need to send him your stock TCM or a NEW Used TCM of the same code as your stock TCM so he can program it.

LE5 I guess HPT has the parameters unlocked that you need to change the settings of the TCM.  I don't know since I've never really follow the LE5 tuning.

[JimmyBaja]

Thanks tazz.