Altering Auto-Trans Shift Points

[Moto-Mojo]

I use to work for a company that made transmission dyno's. I left shortly after the newer electronic shifted units, we all drive, took over. I have a 2015 2SS RS and I'm not really happy with how fast it gets to 5th and 6th gear. You might be in either gear at 35MPH or less. It just creates an engine lugging sound and feel. I get that it's done for fuel mileage reasons but how efficient is a 6.2L V8 running at 900RPM lugging at 30MPH?

I'm pretty sure shift points can be re-programmed through the ECM and/or via a hand held "tuner" plugged into the tranny data port. I was just wondering if anyone here has done that?

[jeffrsho]

My tuner adjusted my shift points when he tuned the car. I'm pretty sure every tuner who tunes an auto adjusts these points.

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[2010reddevil]

Yeah , will have to be done via a tune.

[ucHuskies]

Originally Posted by Moto-Mojo

I use to work for a company that made transmission dyno's. I left shortly after the newer electronic shifted units, we all drive, took over. I have a 2015 2SS RS and I'm not really happy with how fast it gets to 5th and 6th gear. You might be in either gear at 35MPH or less. It just creates an engine lugging sound and feel. I get that it's done for fuel mileage reasons but how efficient is a 6.2L V8 running at 900RPM lugging at 30MPH?

I'm pretty sure shift points can be re-programmed through the ECM and/or via a hand held "tuner" plugged into the tranny data port. I was just wondering if anyone here has done that?

I've noticed this too, quite a bit. To me, it's most annoying when you take a turn from a stop onto a main road and attempt to accelerate, but you're already in 4th gear because you weren't stomping on the gas from the get-go.

[ChocoTaco369]

You can raise your shift points at any shop that'll dynotune your car. It isn't a big deal, but this is one of the tradeoffs of an automatic transmission. You're never going to have complete control of where your car shifts unless you buy a manual transmission, or run around in paddle shift mode all the time.

[Ice-Forever]

a Manual-Transmission swap will fix that problem for ya ;P

[SlingShot]

Originally Posted by Moto-Mojo

I use to work for a company that made transmission dyno's. I left shortly after the newer electronic shifted units, we all drive, took over. I have a 2015 2SS RS and I'm not really happy with how fast it gets to 5th and 6th gear. You might be in either gear at 35MPH or less. It just creates an engine lugging sound and feel. I get that it's done for fuel mileage reasons but how efficient is a 6.2L V8 running at 900RPM lugging at 30MPH?

I'm pretty sure shift points can be re-programmed through the ECM and/or via a hand held "tuner" plugged into the tranny data port. I was just wondering if anyone here has done that?

It only does that when you are driving it too easy. Put it in sport mode, and put your foot in it. If you drive it more aggressive, the trans will go into more of a performance mode and run the gears out and hold gears at a higher RPM.

There are also trans tunes, that you can tune just the Sport side and leave the normal Drive side alone.

[Sandman1969]

Tune and/or control via the paddles.

I got my car JRE tuned recently with the SCT X4 and it shifts so much faster and firmer now. Chirps second without really trying. Love the difference the tune made.

[deltatango]

Either let it reprogram by a tuning shop or if you want to do it yourself, get a Diablo Intune. Having your own handheld tuner (the size of a very small smartphone) alows you to fiddle with the parameters until you're satisfied.
(But please stay away from fiddling with the fuel injection parameters on the Intune unless you do EXACTLY what you're doing!)

[Moto-Mojo]

I do use the paddles quite a bit. I used to work for Superflow and talked to an old workmate yesterday. He said there's a remote chance these "stacked shifts" could be a valve body problem but more than likely, it's designed that way so GM can report better numbers for their 'gas guzzler' status.

That's the upside to an electronically shifted tranny, (as opposed to the old governor shift) that it can be tuned. He also said any reduced fuel mileage would be negligible.

Thanks, folks.

[Vick415]

aka 'slush box' - you will be much happier once transmission is finely tuned.

[Moto-Mojo]

Originally Posted by Vick415

aka 'slush box' - you will be much happier once transmission is finely tuned.

Yeah, I find it kind of annoying listening to it lug at 900RPM. You can't have yer foot in it all the time! BEAUTIFUL ZL1, Vick415.

[PalmerGA]

Originally Posted by Moto-Mojo

Yeah, I find it kind of annoying listening to it lug at 900RPM. You can't have yer foot in it all the time! BEAUTIFUL ZL1, Vick415.

Sounds like you have AFM issues. Yes, you can tune it out OR you can get a plug-in Range device, run it in Sport Mode, and be happy as a clam.

[Moto-Mojo]

Originally Posted by Comrando

Why do you think your L99 is "lugging" at 900 RPM? Does it rattle? Shake and buck?

My LS3 at 600 RPM doesn't have any of that.

Yes, more a shake than buck. I'll admit, it's more of a sound than a feel, but still a minor shake. I can't quote the exact gear ratios but 6th gear at 35MPH would seem to want to lug any V8 engine, based on my old school experience with 3 and 4 speed tranny's at low speeds.