Driving in "manual" mode 9C3

Drivetrain discussion including Transmission, Differential, Driveshaft, and related items.
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v8suprcapric
Posts: 100
Joined: Sun Mar 30, 2014 9:58 pm
Location: Seattle, WA

Driving in "manual" mode 9C3

Post by v8suprcapric »

I pretty much always drive in manual mode, and I'm wondering why (maybe I'm the only one) the transmission doesn't downshift all the way to 1st gear when I come to a stop? It automatically downshifts for me from all the other gears as I reduce speed, but only as far as 2nd gear.
And let me throw in a little side question here, how does the speedometer get it's information? My new tires are about an inch shorter than the OEM spec, and according to this online wheel comparison calculator http://rimsntires.com/specspro.jsp (which was a great help in figuring out what would fit/work) my speedometer would read 60 I'm really only doing 57. Not a big deal but I'm wondering if it's something that can be recalibrated easily, either through the bcm or something else?
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1987 Landau (383 stroker, vortec heads, 700r4, posi rear, Bilstein shocks, Eibach springs, Bassett 15x8, BFGoodrich 275/60, 9C1 speedo)
2011 9C3 (K&N CAI, Weldcraft widened 18x9 factory steelies, Bridgestone 285/35)
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kevink
Posts: 480
Joined: Sun Aug 09, 2015 12:55 pm

Re: Driving in "manual" mode 9C3

Post by kevink »

Mine 9C3 only automatically downshifts to 2nd in manual mode also. Are G8s also like this? I kind of like it, since if you don't come to a full stop, 2nd gear is low enough and 4th is 4:1, which is way too low of a ratio if you're still rolling. On the off chance that you need first, just select it manually. It's interesting that they programmed it like that, though. Maybe they knew 1st was almost useless since it's so low. I wonder if it can be tuned to downshift into first in manual mode if you come to a full stop.
2011 9C3: 11.48 @118.
CrashTestDummy
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Re: Driving in "manual" mode 9C3

Post by CrashTestDummy »

G8s will go into low in manual mode. And if you don't upshift properly, it'll stay in gear, just not accelerate anymore. Ask me how I know. :?
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Pursuit
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Re: Driving in "manual" mode 9C3

Post by Pursuit »

I know that in the HP Tuners programming there is table that allows for tire size, gear ratio etc...I think it is in the TCM not the ECM files.

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S13REMI
Posts: 123
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Re: Driving in "manual" mode 9C3

Post by S13REMI »

Very few auto cars will automatically drop down in to first when coming to a stop. From what I understand the cars are programmed that way to assist with a smoother acceleration. My 05 e55 amg didnt, my 91 Ls400 didnt, Caprice doesnt.
2012 CAPRICE 460WHP! NIGHT FURY CAM, LONG TUBES, OTR INTAKE, NEW ERA TUNE, COILOVERS, C6 Z06 WHEELS. (BIGGEST EVER ON A CAPRICE)
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v8suprcapric
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Location: Seattle, WA

Re: Driving in "manual" mode 9C3

Post by v8suprcapric »

Can the ECM be programmed to NOT downshift automatically? I would rather accidentally stall the engine than what happens to me quite often, i.e. I'll be rolling through a corner and I won't feel the automatic downshift and then I manually tap to downshift and bang all of a sudden I'm a gear lower than I wanted. Ugh.
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1987 Landau (383 stroker, vortec heads, 700r4, posi rear, Bilstein shocks, Eibach springs, Bassett 15x8, BFGoodrich 275/60, 9C1 speedo)
2011 9C3 (K&N CAI, Weldcraft widened 18x9 factory steelies, Bridgestone 285/35)
S13REMI
Posts: 123
Joined: Sun Oct 11, 2015 11:59 am

Re: Driving in "manual" mode 9C3

Post by S13REMI »

v8suprcapric wrote:Can the ECM be programmed to NOT downshift automatically? I would rather accidentally stall the engine than what happens to me quite often, i.e. I'll be rolling through a corner and I won't feel the automatic downshift and then I manually tap to downshift and bang all of a sudden I'm a gear lower than I wanted. Ugh.
Im sure theres a way but I would talk to a tuner. Not and area im super familiar with
2012 CAPRICE 460WHP! NIGHT FURY CAM, LONG TUBES, OTR INTAKE, NEW ERA TUNE, COILOVERS, C6 Z06 WHEELS. (BIGGEST EVER ON A CAPRICE)
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