downshifting on A4
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From: Miami, FL
downshifting on A4 Alright, I'm no expert, but unless you used the numbers right after D on the PRND will it jsut happen automatically if you gun it at a certain speed? And What speed(s) do you have to be at?
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Leave it in "D" and it will downshift on its own when the PCM sees the proper parameters are met (via TPS [Throttle Position Sensor], VSS [Vehicle Speed Sensor], and probably many other sensors.). Which gear it chooses depends also on VSS and TPS readings (how far you push the gas pedal down [TPS], and how fast you are going at that time [VSS]) in addition to other sensor input.
The trans also automatically downshifts as you come to a stop.
The trans also automatically downshifts as you come to a stop.
that makes sense now i was confused about that to. i noticed if im cruising and i slowly put my foot to the floor it would just stay in fourth and accelerate, but if i just step on it when im cruising it hesitates for a second then kicks in and i was wondering why it would do that, now i realize that its downshifting when it hesitates. thanks for the input RPM WS6. i kinda thought thats what it was doing but i wasnt completley sure.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Originally Posted by ls1charged
that makes sense now i was confused about that to. i noticed if im cruising and i slowly put my foot to the floor it would just stay in fourth and accelerate, but if i just step on it when im cruising it hesitates for a second then kicks in and i was wondering why it would do that, now i realize that its downshifting when it hesitates. thanks for the input RPM WS6. i kinda thought thats what it was doing but i wasnt completley sure.
Glad to help.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Originally Posted by mpe488
so for roll racing what is the best speed to start at for as A4?
2.73 (RPO GU2) cars will downshift back to 1st at up to ~37mph. Punching it in the 25-35mph range is pretty strong. From 38 to 45-50 is a pretty dead spot to hit it at. Above 50 is better, and up to ~75mph you'll go back to 2nd. 70-75 is another good spot to hit it at.
3.23 (RPO GU5) cars will downshift back to 1st at up to ~30mph. 20-29mph is a good strong spot. 31-45 is not so great, 45+ is better. Up to ~70mph you'll go back to second. 65-70 is pretty strong.
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Originally Posted by RPM WS6
That depends a lot on what gears you have.
2.73 (RPO GU2) cars will downshift back to 1st at up to ~37mph. Punching it in the 25-35mph range is pretty strong. From 38 to 45-50 is a pretty dead spot to hit it at. Above 50 is better, and up to ~75mph you'll go back to 2nd. 70-75 is another good spot to hit it at.
3.23 (RPO GU5) cars will downshift back to 1st at up to ~30mph. 20-29mph is a good strong spot. 31-45 is not so great, 45+ is better. Up to ~70mph you'll go back to second. 65-70 is pretty strong.
2.73 (RPO GU2) cars will downshift back to 1st at up to ~37mph. Punching it in the 25-35mph range is pretty strong. From 38 to 45-50 is a pretty dead spot to hit it at. Above 50 is better, and up to ~75mph you'll go back to 2nd. 70-75 is another good spot to hit it at.
3.23 (RPO GU5) cars will downshift back to 1st at up to ~30mph. 20-29mph is a good strong spot. 31-45 is not so great, 45+ is better. Up to ~70mph you'll go back to second. 65-70 is pretty strong.
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Also, another thing to think about... It is better to down shift to 3rd before mashing the peddle. There is a planetary gear that undergoes a lot of extra stress when you do a WOT downshift from overdrive...
Ryan
Ryan
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Originally Posted by Ryan K
Also, another thing to think about... It is better to down shift to 3rd before mashing the peddle. There is a planetary gear that undergoes a lot of extra stress when you do a WOT downshift from overdrive...
Ryan
Ryan
All I know is, the first "built" 4L60E in my WS6 gave out after about 3K miles. I used to always shift back to 3rd before going WOT. The second "built" 4L60E was from a different (better) builder and I always just left that one in OD before going WOT and that trans never gave me any issues. Hard to compare though, because the quality of the first trans was questionable.
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From: Schiller Park, ILL Member: #317
Originally Posted by BOBA_VETT
that's the question I'd like answered; DO you shift to 3rd and punch it or leave it in OD and punch it?
I personally shift to 3rd, but I'm curious if I'm doing more damage than leaving it in OD.
I personally shift to 3rd, but I'm curious if I'm doing more damage than leaving it in OD.
One thing you can ask yourself though, if you've been doing what you're doing now for lots of miles without any problems, then you have to take that into account as well.
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From: Santa Clarita, CA
At the end of the day think it is 'safest' just to leave it in OD, if there was an issue with that imagine GM would have addressed it or put something in the owners manual about spirted driving or something. Don't think GM would allow a weakness associated with downshifts from overdrive with all of those transmissions out there under waranty.
I say if the tranny is stock leave it in OD but once you get an aftermarket stall, leave it in 3rd if you plan on roll racing. The downshifts from an aftermarket stall are more harsh than the stock one. That's my personal opinion of course.
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From: Schiller Park, ILL Member: #317
Originally Posted by ArcticFormula
At the end of the day think it is 'safest' just to leave it in OD, if there was an issue with that imagine GM would have addressed it or put something in the owners manual about spirted driving or something. Don't think GM would allow a weakness associated with downshifts from overdrive with all of those transmissions out there under waranty.
Originally Posted by Roarin_8
I say if the tranny is stock leave it in OD but once you get an aftermarket stall, leave it in 3rd if you plan on roll racing. The downshifts from an aftermarket stall are more harsh than the stock one. That's my personal opinion of course.
This is the pattern I have been following as well. With my stock stall/stock 4L60E Camaro I just leave it in OD. With my high stall/modified 4L60E WS6 I tried both 3rd and OD and never really decided what I should stick with. But these days I've been using OD for everything.
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From: Schiller Park, ILL Member: #317
Originally Posted by Sgt. Spuds
I usually down shift manually 
lol
lol
Look, we all get it....you love the manuals. Glad you're happy with your car.
But beleive it or not, many of us actually like the autos for various reasons. Neither trans is better than the other, just a matter of preferance. 
I was under the impression that the 1-3 gears in a 4L60E come from the planetary gear set and OD is a drum/band not the planetary gear set.
In that case, would it be better to not be in OD before going to WOT? I am sure the factory parameters protect the trans either way.
There are a couple of diff ways to do planetary gears though. I forget which transmision is which type.
Also, I do manually downshift, also. I do miss the days I drove a TH350 though.
In that case, would it be better to not be in OD before going to WOT? I am sure the factory parameters protect the trans either way.
There are a couple of diff ways to do planetary gears though. I forget which transmision is which type.
Also, I do manually downshift, also.
I do miss the days I drove a TH350 though.