GM Drivetrain & Suspension Chassis | Transmission| Driveshaft | Gears/Rear End/Differential | Traction Aids

Transgo Shift Firmness...

Old Aug 5, 2013 | 10:32 PM
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Mine are a .086 but I wish I had .096 instead. The shifts are firm and not bad at all during normal driving but I wish I had the bigger size drilled for the hard launches. It feels like I could use just a little more pressure on those. If only I had remembered to tell him that. I also went with the firmest springs.
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Old Aug 5, 2013 | 10:55 PM
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On mine i went inbetween the soft and average on the 1-2 and average on the 2-3. I have slightly up the shift pressures from stock and slightly lowered the force motor current table. I live my shifts now. Very quick and not jarring at all.
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Old Aug 5, 2013 | 11:58 PM
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If I go firm on 2-3 and 3-4 then .086 on the 1-2 shift then everything should look good I presume? This will be a street truck so I do not necessarily want to chirp every time I take off WOT or not. I wonder how the shift from 1-2 will feel in relation to the TC or will it even matter?
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Old Aug 6, 2013 | 12:28 AM
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I'd go biggest on all gears to get the volume and then adjust firmness via pressure in the tune for each gear. We have that advantage, thankfully.
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Old Aug 6, 2013 | 12:56 AM
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Originally Posted by swift700
I'd go biggest on all gears to get the volume and then adjust firmness via pressure in the tune for each gear. We have that advantage, thankfully.
Yeah I suppose if it becomes unruly I can tame it down. Did not want to enlarge the holes and wish I didn't.

What does the ACCUM firmness have to do with the overall firmness within the shifts? Since it can be adjusted seperately what role does it play?
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Old Aug 6, 2013 | 01:29 AM
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Originally Posted by Hivelocit
Yeah I suppose if it becomes unruly I can tame it down. Did not want to enlarge the holes and wish I didn't.

What does the ACCUM firmness have to do with the overall firmness within the shifts? Since it can be adjusted seperately what role does it play?
In a nutshell, the accumulator controls apply piston speed. With a softer spring in the accumulators, they will fill up with transmission fluid while compressing the spring. The piston being applied is in parallel with this accumulator, so since the accumulator has a certain volume to fill, it effectively slows the piston down so it doesn't just slam the clutches. Firmer springs make the accumulators basically have more resistance to filling, so the piston moves faster and applies the gear sooner and sometimes harsher. I use the firm accumulator springs and the .096 holes in the transmissions that i build.
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Old Aug 6, 2013 | 01:50 AM
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Originally Posted by smokeshow
In a nutshell, the accumulator controls apply piston speed. With a softer spring in the accumulators, they will fill up with transmission fluid while compressing the spring. The piston being applied is in parallel with this accumulator, so since the accumulator has a certain volume to fill, it effectively slows the piston down so it doesn't just slam the clutches. Firmer springs make the accumulators basically have more resistance to filling, so the piston moves faster and applies the gear sooner and sometimes harsher. I use the firm accumulator springs and the .096 holes in the transmissions that i build.
Thank you Smoke you broke that down perfectly! And thank you everyone for your input.

If anyone else has anything to add like using the average shift holes or different combination feel free to talk about your experience. Just like seeing an array of thoughts on how everyone's ride performs. Thanks!
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Old Aug 6, 2013 | 11:22 AM
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Originally Posted by swift700
I'd go biggest on all gears to get the volume and then adjust firmness via pressure in the tune for each gear. We have that advantage, thankfully.
If you go firmest everything in the shift kit, how much softening can be done in the tune? Or could you go average firmness in the shift kit, and then soften/firm up what you want in the tune?
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Old Aug 6, 2013 | 11:56 AM
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Drilling out the holes adds flow volume. Adjusting pressure in the tune adjusts the pressure of the flow. They both add energy to the apply pistons but in different ways. It's like a big block engine at low rpm (volume) vs a smallblock at high rpm (pressure). If you spin a big block faster you get the best of both worlds. The right combination of both makes for the perfect shift but I think flow volume is more gentle on parts and is also more effective.

The accumulator is a hydraulic shock absorber. It also provides stored hydraulic energy. A stronger spring will make for faster shifts but will reduce its shock absorbing qualities. If you have good parts in your transmission then firming this up will improve your shifts.
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Old Aug 6, 2013 | 12:59 PM
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What would you do for an 80E with 100% stock internals?
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