My stock 2000 C5 tune from GM has values of 30 in the 0 to 40 torque columns in the upshift pressure modifier tables. What was the purpose for this ? I have a Rossler built trans and my 1st to 2nd shift was so hard under low throttle conditions that I changed the modifier table to zero which has made a huge difference. I was thinking about zeroing out the 2nd to 3rd and 3rd to 4th shift tables as well. Does this sound reasonable or am I asking for trouble ?
Thanks >>>>> INTHERED
LINGENFELTER MAGNACHARGED 2000 A4 Torch Red Z51 Vert, Smoothline HT, LPE IC Magnacharger, Z06 cam, LPE CNC heads, CC RPM kit, LPE hood, Yank 2800, Rossler trans, Z06 rear w/300Ms, Chrome C6 Z06 rims w/PS2s, Z06 calipers w/PF carbon metallics , Eradispeeds, WCC screens, BBK 80mm TB, TB bypass, 160 TS, GM Z06 MAF, Blackwing, Corsa Pace, AR headers X-pipe & Hiflow Cats, GM HP wires, NGK TR6s, Hptuned by INTHERED with a best 1/4 mile of 10.87 @ 128.90 mph on BFG DRs
Yep. Those tables add/subtract to the base pressure tables. I think it is used so that the pressure is increased only during the shift so the line pressure isn't so high during "normal" driving in a non-shift mode.
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Yea but having a value of 30 when the torque is between 0 and 40 does not make sense when the value is 1 to 3 between torque values 80 and 140Originally Posted by EC_Tune
LINGENFELTER MAGNACHARGED 2000 A4 Torch Red Z51 Vert, Smoothline HT, LPE IC Magnacharger, Z06 cam, LPE CNC heads, CC RPM kit, LPE hood, Yank 2800, Rossler trans, Z06 rear w/300Ms, Chrome C6 Z06 rims w/PS2s, Z06 calipers w/PF carbon metallics , Eradispeeds, WCC screens, BBK 80mm TB, TB bypass, 160 TS, GM Z06 MAF, Blackwing, Corsa Pace, AR headers X-pipe & Hiflow Cats, GM HP wires, NGK TR6s, Hptuned by INTHERED with a best 1/4 mile of 10.87 @ 128.90 mph on BFG DRs
Well, yes it does.At those low torque values, the transmission pump is not pumping out a large amount of pressure, so for the durability of the clutches and bands GM added more pressure via those modifiers. This help keep the shift at a certain pressure to ensure proper shift change with the required fluid pressure. otherwise you would have low fluid pressure and wear out the bands/clutches prematurely. It is just enough (modifier) to help with the internal parts' longevity (during low pressure situations).
On a built transmission like a Rossler would the ATF pump beefed up so that those added modifier numbers are not necessary at the low torque values ?
My car just creeping out of my driveway shifts from 1st to 2nd pretty hard.
LINGENFELTER MAGNACHARGED 2000 A4 Torch Red Z51 Vert, Smoothline HT, LPE IC Magnacharger, Z06 cam, LPE CNC heads, CC RPM kit, LPE hood, Yank 2800, Rossler trans, Z06 rear w/300Ms, Chrome C6 Z06 rims w/PS2s, Z06 calipers w/PF carbon metallics , Eradispeeds, WCC screens, BBK 80mm TB, TB bypass, 160 TS, GM Z06 MAF, Blackwing, Corsa Pace, AR headers X-pipe & Hiflow Cats, GM HP wires, NGK TR6s, Hptuned by INTHERED with a best 1/4 mile of 10.87 @ 128.90 mph on BFG DRs
Could be, although I haven't heard of any trans companies "porting" the trans fluid pump. But it is possible. I would ask your trans builder (Rossler) what they recommend as far as pressure modifiers. They would be the ones best to answer your questions, since they should know what modifications they made to the hydraulic circuits/channels in the trans.
The transmission guy did not seem to know about pressure modifiers.Could be, although I haven't heard of any trans companies "porting" the trans fluid pump. But it is possible. I would ask your trans builder (Rossler) what they recommend as far as pressure modifiers. They would be the ones best to answer your questions, since they should know what modifications they made to the hydraulic circuits/channels in the trans.
One last question: In the pressure modifier table assume I have a value of 30 in the 0 to 40 torque column and 30 in the 640 torque column would the ATF pump be outputing fluid at the same pressure under those two conditions ?
(assuming of course that the base table was set to all zeros)
LINGENFELTER MAGNACHARGED 2000 A4 Torch Red Z51 Vert, Smoothline HT, LPE IC Magnacharger, Z06 cam, LPE CNC heads, CC RPM kit, LPE hood, Yank 2800, Rossler trans, Z06 rear w/300Ms, Chrome C6 Z06 rims w/PS2s, Z06 calipers w/PF carbon metallics , Eradispeeds, WCC screens, BBK 80mm TB, TB bypass, 160 TS, GM Z06 MAF, Blackwing, Corsa Pace, AR headers X-pipe & Hiflow Cats, GM HP wires, NGK TR6s, Hptuned by INTHERED with a best 1/4 mile of 10.87 @ 128.90 mph on BFG DRs
Correct, they add to the base table. Which is then a lookup to the force motor table.
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Do you know the answer to the question ?
LINGENFELTER MAGNACHARGED 2000 A4 Torch Red Z51 Vert, Smoothline HT, LPE IC Magnacharger, Z06 cam, LPE CNC heads, CC RPM kit, LPE hood, Yank 2800, Rossler trans, Z06 rear w/300Ms, Chrome C6 Z06 rims w/PS2s, Z06 calipers w/PF carbon metallics , Eradispeeds, WCC screens, BBK 80mm TB, TB bypass, 160 TS, GM Z06 MAF, Blackwing, Corsa Pace, AR headers X-pipe & Hiflow Cats, GM HP wires, NGK TR6s, Hptuned by INTHERED with a best 1/4 mile of 10.87 @ 128.90 mph on BFG DRs
^^^ See above. If base is 0 and the PM tables have 30 then the output will be 30.
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If I understand this stuff, 30 is just an index into the FMC table which corresponds to a current value in miliamps that controls a relief valve in the transmission. But would an index of 30 at 0 lbs of torque produce the same ATF pump output pressure that an index of 30 at 640 lbs of torque ?
LINGENFELTER MAGNACHARGED 2000 A4 Torch Red Z51 Vert, Smoothline HT, LPE IC Magnacharger, Z06 cam, LPE CNC heads, CC RPM kit, LPE hood, Yank 2800, Rossler trans, Z06 rear w/300Ms, Chrome C6 Z06 rims w/PS2s, Z06 calipers w/PF carbon metallics , Eradispeeds, WCC screens, BBK 80mm TB, TB bypass, 160 TS, GM Z06 MAF, Blackwing, Corsa Pace, AR headers X-pipe & Hiflow Cats, GM HP wires, NGK TR6s, Hptuned by INTHERED with a best 1/4 mile of 10.87 @ 128.90 mph on BFG DRs
I have yet to measure the transmission pressures with a gauge and verify all these tables and their interactions. But the 30 at 0 (zero) TQ is not the same ATF pressure as 30 at 640 tq. The 30 is an index (milliamps) for percentage of desired fluid pressure added to the FMC.
I guess I better fess up. I have been running my A4 Rossler trans with the shift pressure modifier tables completed zeroed out for the past 10K miles. I put all of my changes in my base table. The base table has the 1st to 2nd shift set to 0 from 0 to 120 lbs of torque, the 2nd to 3rd shift is set to 5 from 0 to 120 lbs of torque, the 3rd to 4th shift is set to 10 from 0 to 120 lbs of torque and all shifts are set to 96 from 400 to 640 lbs of torque. It seems to work fine with no problems on the street or the strip. Does this seem reasonable or am I flirting with diaster ?
INTHERED
LINGENFELTER MAGNACHARGED 2000 A4 Torch Red Z51 Vert, Smoothline HT, LPE IC Magnacharger, Z06 cam, LPE CNC heads, CC RPM kit, LPE hood, Yank 2800, Rossler trans, Z06 rear w/300Ms, Chrome C6 Z06 rims w/PS2s, Z06 calipers w/PF carbon metallics , Eradispeeds, WCC screens, BBK 80mm TB, TB bypass, 160 TS, GM Z06 MAF, Blackwing, Corsa Pace, AR headers X-pipe & Hiflow Cats, GM HP wires, NGK TR6s, Hptuned by INTHERED with a best 1/4 mile of 10.87 @ 128.90 mph on BFG DRs
Thats close to how mine is set up and so far its been decently shifting.
99Z A4 w/ SS LT's, h/f cats, magnaflow catback, port/polish t/b, egr deleted, ls6 intake, lid, 3.73's, hpt, performabuilt level 1 tranny, 3600 stall, Stage 2.5 (5.3 heads), Torquer 2 cam, 42# reworked injectors, TR6 plugs.
2007 Avalanche LTZ - Catback and Eibach springs
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