shift pressure modifier tables

[moregrip]

what are the typical settings for performance oriented setups? and is it really needed to lower/raise shift pressures based on tranny oil temp when used in conjunction with a shift kit?

[Russ K]

I don't touch those tables, just change the base shift press. vs torque on normal & performance and lower the force motor table at 100 psi to 0 ma. Also raise the max press box to 96.

Russ Kemp

[moregrip]

I don't touch those tables, just change the base shift press. vs torque on normal & performance and lower the force motor table at 100 psi to 0 ma. Also raise the max press box to 96.

Russ Kemp

what does lowering the force motor table to 0ma @ 100psi do for me?

[Russ K]

So in case that if your shift pressure whent over 96 psi, the force motor table wouldn't go to 1245 ma ( full pressure blow off) This is just a safety setting so there isn't any change of losing line pressure. Just raise the base shift pressure tables to firm the shifts.

Russ Kemp

[moregrip]

So in case that if your shift pressure whent over 96 psi, the force motor table wouldn't go to 1245 ma ( full pressure blow off) This is just a safety setting so there isn't any change of losing line pressure. Just raise the base shift pressure tables to firm the shifts.

Russ Kemp

will do. Since I have a shift kit and my 1-2 shift has softened since the install I'm also thinking the torque converter may be slipping more now or its wearing out. But with a 4l80e a 27k that seems a little premature with only 425ftlbs to the wheels. Would you recommend the TCC table set a min/max of 90 and 100?

[Russ K]

Yes, set the min TCC table to 90 and the max table to 100. This gets rid of the TCC duty cycle/slip.

Russ Kemp

[moregrip]

Yes, set the min TCC table to 90 and the max table to 100. This gets rid of the TCC duty cycle/slip.

Russ Kemp

thanks again Russ, are there any downsides to doing this?

[Russ K]

thanks again Russ, are there any downsides to doing this?

None what so ever, it just makes the TCC apply like the 700R4 trans did.
The TCC is either applied or released fully. GM did the duty cycle thing to
make the TCC apply "smoother". The trans shops like this feature = more
trans rebuilds.

Russ Kemp

[moregrip]

None what so ever, it just makes the TCC apply like the 700R4 trans did.
The TCC is either applied or released fully. GM did the duty cycle thing to
make the TCC apply "smoother". The trans shops like this feature = more
trans rebuilds.

Russ Kemp

fantastic, I'll apply our conversation to a new tune and report back

[98A4LS1]

Would 100% TCC max duty cycle and 90% TCC min duty cycle be ok to use on a '98 Z28?

[moregrip]

None what so ever, it just makes the TCC apply like the 700R4 trans did.
The TCC is either applied or released fully. GM did the duty cycle thing to
make the TCC apply "smoother". The trans shops like this feature = more
trans rebuilds.

Russ Kemp

so it should look like this?

[Russ K]

moregrip,

Yes you have the TCC min & max tables set right.

98A4LS1,

You can set your TCC min & max tables the same.

Russ Kemp

[PurplePiss]

Would it be wise to set the min to 90 and max to 100 on a "stock" car? Is it ok to mult the pos and neg motor tables by .95 to firm up the shifts? I left max line pressure at 90.

How do these tables affect each other?

[EC_Tune]

PP- You still want to play with the Shift Pressure tables more than the calibrated Force Motor tables. If you do play with the FM Tables make sure they match the stockers in the amount you offset things.

Remember you want the "minimum" linepressure needed to do the job otherwise your just dragging the front pump around and wasting energy doing it.

I don't however advocate putting shift pressures to zero.
EC

[PurplePiss]

Can you explain more? What is the differance between the force motor tables and base shift pressure and TCC DC line pressure?

So you think on a stock car its better to leave the force tables alone and up the shift pressures to ?? in 1st and 2nd from like 300 ft lbs on up?

Seems strange because I dulled TM, now I'm trying to stiffen up the shift. LOL.

[EC_Tune]

Base shift pressure is a lookup to the Force Motor table. As the shift pressure request rises, the FM current goes down. The X axis of the FM table is the shift pressure table.

EC

[PurplePiss]

Wha wha what? I must be dense.

Should Max line pressure be left alone on a stock car at 90?

[jimmyblue]

You want to be sure that, if you bump up max pressure,
that it does not then index a bad-news value in the
force motor table (like can be seen in F-body stock
tunes).

0% line does not result in zero pressure but does take
you down to maybe half max; the force motor table
for my model*year began at 900mA (max current is
higher, and max current still produces some line).

I agree that you want as little line as needed to get
the job done. But finding out exactly how much is too
little, is tedious and probably life-shortening for the
trans. Now that we have the general pressure stuff
there appears to be no need to go off-cal for the
force motor table anymore.

[PurplePiss]

So on a stock GTO, I should put the Force motor tables back to stock, leave the max line pressure at 90, but modify the "Base shift pressure vs. torque vs. gear - normal" table to beef up the 325 ft lb - 472 ft. lb 1-3 gears? How does the TCC DC Max and min vs line pressure vs trans temp play into this? And... if you have TM turned on, is all of this out the window?

[EC_Tune]

Stock FM tables for stock vehicles. I would put the 100 line the same as the 96 line though. Then log Delivered Transmission Torque PID to determine where you are at on the Shift Pressure table. Adjust, rinse, repeat as necessary.

EC