Will this cause damage to my transmission?
#1
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Will this cause damage to my transmission?
I am thinking of having the shift points stiffened, and changing the %'s and mph at which it switches gears in my A4 with a mild tune.
My question is, will this cause excessive wear and damage to the tranny?
Mabey we can adjust it a just a little with next to no negative side effects???
Thanks for your expert advise,
Paul.
My question is, will this cause excessive wear and damage to the tranny?
Mabey we can adjust it a just a little with next to no negative side effects???
Thanks for your expert advise,
Paul.
#2
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Paul,
Making the shifts firmer than stock is good, it won't have any negative side effects, won't cause more wear (will cause less), and won't damage anything ("firm" not "harsh/hard".
You increase firmness by editing the following:
- increasing the shift pressure tables,
- decreasing the shift times tables,
- decreasing the shift torque reduction tables.
If you're also tuning the motor, keep in mind these 2 things:
- those tables are indexed by calculated engine torque,
- the base/running pressure is calculated based on calculated engine torque ;
the PCM calculates engine torque (GM.TRQENG) from cylinder airmass which it computes from either of MAF or VE;
if your tuning the VE/MAF tables, keep an eye on the PCM's calculated engine torque and the various air pids (g/cyl and g/s);
if these go low (because the VE/MAF is heading downward by error), then the running/shift pressures will be low and the trans will slip which will cause damage.
Making the shifts firmer than stock is good, it won't have any negative side effects, won't cause more wear (will cause less), and won't damage anything ("firm" not "harsh/hard".
You increase firmness by editing the following:
- increasing the shift pressure tables,
- decreasing the shift times tables,
- decreasing the shift torque reduction tables.
If you're also tuning the motor, keep in mind these 2 things:
- those tables are indexed by calculated engine torque,
- the base/running pressure is calculated based on calculated engine torque ;
the PCM calculates engine torque (GM.TRQENG) from cylinder airmass which it computes from either of MAF or VE;
if your tuning the VE/MAF tables, keep an eye on the PCM's calculated engine torque and the various air pids (g/cyl and g/s);
if these go low (because the VE/MAF is heading downward by error), then the running/shift pressures will be low and the trans will slip which will cause damage.
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Thank you for your reply joecar.
That's great, the answer I wanted to be true also!
I read something else that said it would, but your explanation and reasons are a much more insigtfull answer.
Many thanks for straightening this out for me,
Kind regards,
Paul.
That's great, the answer I wanted to be true also!
I read something else that said it would, but your explanation and reasons are a much more insigtfull answer.
Many thanks for straightening this out for me,
Kind regards,
Paul.
#4
TECH Senior Member
Oh, if your shifts get harsh/hard/jerking (instead of just firm), then reduce the Torque Reduction tables by a lesser amount
(i.e. if you went from 20% to 0%, then try in between, 10%).
What software are you using...?
(i.e. if you went from 20% to 0%, then try in between, 10%).
What software are you using...?
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Thanks for the tips.
I have a friend who has about £6K worth of tuning software (garage), so he's going to play with the settings for me, not sure what he's got.
I'm sure he knows what he's doing, I just like to know I'm getting better performance without added wear and tear.
I read another post about possable damage to the transmission, and it got me worrying!
I have a friend who has about £6K worth of tuning software (garage), so he's going to play with the settings for me, not sure what he's got.
I'm sure he knows what he's doing, I just like to know I'm getting better performance without added wear and tear.
I read another post about possable damage to the transmission, and it got me worrying!