School me on C5/6 Autos
- Thread starter Oneball
- Start date
Stingray
CCCUK Member
4-speed in C5 covered the entire generation. Decent enough transmission although kickdown can unsettle the car when it jumps from 4th to 2nd. I used to change down manually to suppress this effect. It's a tough, basic transmission used extensively by GM across a wide range of vehicles.
4-speed from C5 was strengthened to carry over into the first year or so of C6 production, dealing with the additional torque of LS2.
Most C6 auto's will have later 6-speed transmission. The one time I drove a 6-speed it seemed significantly more sophisticated than my old 4-speed. Presumably more economical motorway driving too with the extended ratios.
I'm not aware of any of these transmissions being unusually troublesome, although in view of the torque sensitivity of autos I'd be cautious of cars with engine mods. I'd also be cautious of transmission mods for "firmer shifts" etc.
4-speed from C5 was strengthened to carry over into the first year or so of C6 production, dealing with the additional torque of LS2.
Most C6 auto's will have later 6-speed transmission. The one time I drove a 6-speed it seemed significantly more sophisticated than my old 4-speed. Presumably more economical motorway driving too with the extended ratios.
I'm not aware of any of these transmissions being unusually troublesome, although in view of the torque sensitivity of autos I'd be cautious of cars with engine mods. I'd also be cautious of transmission mods for "firmer shifts" etc.
teamzr1
Supporting vendor
Starting with the C5 used a A4 tranny
It is computer controlled, which is part of the engine controller (PCM)
I have tuned these with 11 plus pounds of boost with little issues
First 2 years of the C6 also used the A4 and then switched to the A6
Far more electronic controlled and required to have its own controller (TCM) that is located into the tranny
In both cases how they function can be changed by me via tuning the controllers
Any changes such as rear end gear ratio, tire or wheel size changes require than tuning of the tranny controls
along with changes to torque converter, etc
It is computer controlled, which is part of the engine controller (PCM)
I have tuned these with 11 plus pounds of boost with little issues
First 2 years of the C6 also used the A4 and then switched to the A6
Far more electronic controlled and required to have its own controller (TCM) that is located into the tranny
In both cases how they function can be changed by me via tuning the controllers
Any changes such as rear end gear ratio, tire or wheel size changes require than tuning of the tranny controls
along with changes to torque converter, etc
Oneball
CCCUK Member
Thanks both. This will be a standard road car doing normal road car stuff. I really miss my old Alpina B3s Convertible and want something to use as a proper car. I went through a load of manuals after that, never gelled with any of them and realised one of the reasons was I actually want an auto.
Did I read something about the later autos being a bit indecisive as to which gear they wanted or was that the C7?
Did I read something about the later autos being a bit indecisive as to which gear they wanted or was that the C7?
teamzr1
Supporting vendor
Keep in mind, GM uses an adaptive strategy in controller
Its job is to adjust the way the tranny functions to the drivers, drive pattern
So if they always use top gear and low cruise speeds, the controller then adjusts for that and
Then out-of-the-blue drivers stomps on gas pedal, the tranny is still adjusting as to what it long termed learned
So always better is to mix up RPMs, MPH, drive style to relearn/adjust for better shifting process
GM tunes the auto tranny to drive like a Caddy, for waxers and not the best performance as to shift points, up or down shifting
delays between shifts
With the A6 due to more gears and more involved controls it is more apt to fall into the waxer mode.
All of this though can be totally changed with tuning the controller, which really wakes up all shifting and allows higher torque output
and cause faster shifts and less latency between shift points
Oneball
CCCUK Member
After the auto Alpina I had a manual TVR Tuscan, then a manual Maserati, then a manual BMW M3 and came to the conclusion I don’t really want a manual despite the whole “analog” gumpf journos pedal.
Invetterate
CCCUK Member
Can't comment directly on the C6, but very likely to have similar effect to C5 in that the damping is, politely, not much good for UK [i.e.] bumpy roads. Changing dampers to Bilsteins will transform it. I also have C6 Z51 anti-roll/say bars on my C5 with metal end links which are significantly stiffer than standard. I also fitted Michelin Pilot Sport Non Run Flat tyres which also helped greatly.