Tweaking with HPTuners

[G8-4-Speed]

Can you explain this? The Initial and Final are listed as Percentages...not time.

You are correct, they are percentages. I can only guess that they reference of a seperate value that is not shown and if you adjust the base time without initial and final that they don't match and can cause a flare or just be diappointing. Just like turning off DOD with COT disabled, there is no direct link but one affects the other. Same with shift points and trying to adjust them by RPM. OR even changing MPH shift points without making a difference. Shift points seem be changed by more than the last cell values. If the last three cells are the same it seems to want to MPH past the shift point or shift early if there is a big difference befoer the last cell. Sorry to ramble but it just brings up that some adjustments don't have direct link or reasoning that are easy to see unless you stumble across them. I don't have a clear answer for you on it.

The only example I have was the 09 I just started tuning on. With my 09, I made "group" changes before I installed the tune and never had any flares or weird shifting. Last week when I was at the track, there was a 09 G8 that showed up which I ended up messing with. There wasn't much time so I only did some basic changes to timing and trans setting. I only adjusted shift MPH, BASE Time, TQ Management, PE table, and timing. With a quick return road run, it had weak shifts. Even when I was more aggressive with time and TQ Management it was weak and even flared. When the rest of the trans shift properties were matched to mine, it was flat out EVIL with the more aggressive BASE SHIFT times, and .3 on TQ Management. If you look at the 09 Vette trans setting they are 0 for shift times.....see attached file.....Yes, it is an auto a6 vette..

Thanks on the DOD/COT. I turned it off at the track once and never turned it back on. ops....

[shane]

good thread. ill be getting my Tuners tuners very soon..


timing and VE tables and all that are old news and pretty easy, its this tranny stuff i gotta learn..

[PerfectD3]

good thread. ill be getting my Tuners tuners very soon..


timing and VE tables and all that are old news and pretty easy, its this tranny stuff i gotta learn..

There aren't any VE tables with the G8, it's all coefficient based now.

[shane]

Really... thats new too..i was used to me 04 gto

[johnh]

Thanks, yep this ECM/TCM combo definitely has its quirks....

[PerfectD3]

Hey Johnh and g8-4-speed, thanks for posting up your TCM tune. I ran around with johnh's for a few days and gotta say it is very nice. I have changed the TM values to .6 and made Pattern A shift just as fast as g8-4-speed and I gotta say that this hybrid between y'alls and the middle ground for the TM is awesome. Normal is nice and quick without being intrusive, Pttrn A is nasty, and 0 flares w00t!

[shane]

post it up?

i got mine yesterday and im looking around in it!

[shane]

u guys getting a TCM u101 error once in awhile that goes away? this is just from flashing the stock tune in and out>?

[PerfectD3]

I don't know the error code, but when you read the ecm/tcm it does pull a tcm error code. Just pull the TCM fuse under the hood for a minute and you will be good to go.

I left my netbook at work, but when I pick it up I'll post up my Johnh/g8-4-speed hybrid tune.

[MtbDoc]

Guys, thank you for sharing all of your knowledge and experience. This is TRULY valuable. And the neat thing is that it is so easy to compare different tranny tunes and try them out. Now, if I could figure out what needs to be done w/ HPT when I go to headers and a smaller pulley on the maggie!

One SPECIFIC question: what about throttle tip-in stuff? This is in the TCM and I have been very displeased with this since installing the blower. Brian @ Magnuson has a guy looking at it, but it is annoying. Delay when stepping on the gas is NOT RIGHT!