Hey all,

After searching on the forum, I didn’t really find the answer I was looking for so figured I would just ask.

I just purchased a 2017 Z with 8K miles. The previous owner had ported heads / cam / headers/ pulley / flex fuel & a few other things. However, after always owning manual sports cars, I decide I wanted to give an auto a shot, after driving a friends trackhawk. Long story short, I’m disappointed (read many people are). The car shifts great as long as you’re heavy on the throttle, 1-2 paddle shift otherwise has a huge delay. The downshifts are pretty sloppy unless decently high RPM’s and recently just started holding 1st gear then shifting hard into 2nd when left in D. Car always like to lunge right before coming to a complete stop, not
positive if thats a tcm issue or tuning issue with the cam though.

I love the car and it’s blast to drive when putting it through it’s paces, but cruising in it is terrible. What’s the best course of action to get trans tuned? Is it something I can get done remotely without affecting my current ECM tune? Who has proven tcm tunes? I live in Indiana and really don’t have any shops close that I have used in the last year or two.

Thanks

 

You need HP Tuners & get someone that has done this for sure sounds like it need more line pressure. Give Billy in here a call really nice guy & the shop has put out some really fast cars. They are a vendor in here he just posted one of the cars he has worked on with stock converter putting down a 1.3 60 ft Vendor is Billy @ MTI in here...Robert

 

Thanks for the info, I’ll check him out.

 

How much rwhp is behind that 1.3 sixty foot..just curious ?
thx
Pitt

 

I'm working with phil@pdhtuning, I'm pretty sure the 17s must have the TCM unlocked by HP Tuners. He's done wonders with my C7 trans, love the way it shifts now and looking to get into the 10s next time out.

 

Thanks for the info. The previous owner told me it was unlocked but he just never had the tune done.

 

Brent that just saved you a bunch of bucks. I've only had a 16 C7 and a 16 Camaro SS and those didn't need unlocking, it wasn't till 17 that GM changed that. It sure does make a difference when you have a good tuner cause he can free up some performance on the shifts by making them shift harder and quicker either on the up or down shift. I just keep thinking back that my old Camaro with 2650 Magnuson never had the trans tuned, the only change was the shifter pressure. If I'd then had Phil to tune the trans that car probably would have run 9.20s or maybe even in the teens.

 

Billy Said it was on the 900 hp kit that they sell, It had to be one nice tune set up & track prep for it to hit that 60ft on a stock converter, I know that A8 had to also have a trans tune also. Robert

 

My Camaro made 850 plus and I consistently cut 1.35 to 1.39 short times and ran 9.40 to 9.45s at 146 to 148, however that car weighed 3900 with driver including a six point cage. There would be at least a 400 lb difference between a lighter C7 and a Camaro with a Magnuson 2650 SC

 

Is the trans tunes something they can just do remotely and without affecting my ecm tune? Always used a Ngauge in the S550 to make changes. Is there something similar?

 

You'll have to have HP Tuners for any tuner to help you. They will need to email your current tune so they can modify it and return it to you so you can load it into your TCM and ECU. Its possible to tune just the TCM but the tuner may see something in the ECU that may need to be slightly changed also. If you don't have HP Tuners you'll need to purchase it. I use the MPVi2 for and send logs to Phil for his trans tuning.