firmer shifts

Zmav5 · 02-06-2003, 05:22 PM

Hey guys just wanted to ask you if any one knows of a good way to get firmer shifts from my automatic transmission in my 94 Z28??? any good cheap easy way?? or what are my options?

Mordant · 02-06-2003, 05:34 PM

I felt an improvement in firmness from my Hypertech programming (not huge, but it's better). The other choice is a TransGo shift improvement kit, just don't get the cheap TransGo unit get the full kit.

RamAir95TA · 02-06-2003, 05:34 PM

Using any kind of aftermarket electronic shift improver is very popular, but is not the best choice. They simply increase line pressure and can prematurely blow out seals.

The only real substitute is a Transgo. Mechanical versus electric, there's no comparison. Transgo plus install should cost you around $250 to $300 depending on shop install costs.

kjlvilla · 02-08-2003, 11:27 PM

Pull your #8 check ball for a firm 1-2. It prevents the fluid from being orificed down. Drill out the 3rd clutch feed hole in the spacer plate, this sends more fluid to the 3-4 clutches. These will not damage your trans. because it's only giving your clutches/servos more fluid faster. If you really want to bang gears, pull your accumulator springs and put a piece of pipe in place of the spring. This will lock the piston in the bore and defeat the accumulator. I did this on the 1-2 and could't get the trans. from not chirping 2nd, even at 1/4 throttle. These are the free mods. A more realistic trick for a firm 2nd is replacing your servo piston with a Corvette piston, it makes it more streetable. This can be done in the car and is accessed on the side of the trans. The computer will not be affected by any of these because it isn't able to calculate shift time, so no SES light or codes should store. Hope this helps.

c5formetoo · 02-08-2003, 11:46 PM

another free mod is to turn up your force motor 1/4 of a turn.you must remove the pan and use a torx screwdriver

shoebox · 02-09-2003, 12:00 AM

Quote:

Originally posted by c5formetoo
another free mod is to turn up your force motor 1/4 of a turn.you must remove the pan and use a torx screwdriver

That sounds like the same effect as the electronic shift improvers (like Shiftplus). If so, it is not a good idea for the same reasons. Simply turning up the pressure does not sit well with everyone's tranny. Perhaps a finer adjustment could be made with the method you presented, but would be a lot of trouble to go back and change it.

c5formetoo · 02-09-2003, 12:26 AM

it is the same as the electronic shift improvers.some like it some dont and you can turn it as much as you want but it is a pain to drop the pan.i installed a supierior shift kit and turning it up was an option with the kit.they said some like it some dont.i turned it up and have had no problems yet but who knows?it is just a free way to do it if you want.i dont think it increases the line pressure i think it just decreases the amount of time it takes to shift.making it shift faster and harder,but i am not sure

shoebox · 02-09-2003, 12:32 AM

Quote:

Originally posted by c5formetoo
it is the same as the electronic shift improvers.some like it some dont and you can turn it as much as you want but it is a pain to drop the pan.i installed a supierior shift kit and turning it up was an option with the kit.they said some like it some dont.i turned it up and have had no problems yet but who knows?it is just a free way to do it if you want.i dont think it increases the line pressure i think it just decreases the amount of time it takes to shift.making it shift faster and harder,but i am not sure

AFAIK, the force motor is otherwise known as the pressure control solenoid. So yeah, it would control the pressure. More pressure=shifts faster, harder. You can tell that with the Shiftplus when is is on the "2" setting. Even when you shift from park or neutral to a drive gear, the change is almost immediate instead of the nice, soft engagement.

c5formetoo · 02-09-2003, 12:47 AM

thanks for the heads up shoebox

psychocabbage · 02-09-2003, 01:36 AM

for me.. I liked the shift kit option.. Used a transgo.. shifts were super hard. think head snap...
0-60 in 4.6 with 3.73 and only 270rwhp... in a 3700 car... tranny was setup good with shift kit.. too bad it didnt last.. 6 times..
hehe

Pro Built Automatics · 02-09-2003, 05:33 AM

Remember, you are wanting to control the firmness of the shift at different throttle openings. Trans-Go addresses this in their Performance Shift kit, allowing you to keep nice light throttle shifts and gradually firmer shifts with more throttle opening. When I build these units with the 9.5" lockup torque converter, I use the Trans-Go Performance Shift kit, Corvette servo, 8 Borg Warner Hi-Energy clutches in the 3-4 pack, and a Borg Warner Hi-Energy 2-4 band, etc., and I modify the hole sizes on the valve body plate to Trans-Go's earlier version of the performance shift kit, and have found that these modifications to give very good driveability, and durability. These earlier plate modifications are .096 for 2nd gear, .155 for 3rd & 4th gear. The later plate Trans-Go Performance Shift kit hole sizes have not worked very well for me and some others that I know who build these units, to harsh 1-2 part throttle shifts and to soft 2-3 WOT shifts, along with a short 3-4 clutch life. Remember, you want the tires to break loose from "horsepower", and not from how hard you can make the transmission shift, as it will only shorten transmission life. If you have any questions about this, let me know?

James3219 · 02-09-2003, 10:27 AM

I have a 94 T/A with the performance transmition button and I always turn mine on whenever I am driving. Is that bad on the tranny? I had 125k miles when I bought it, it now has 145k. The tranny is starting to leak now, could that have caused the leak?

shoebox · 02-09-2003, 10:34 AM

Quote:

Originally posted by James3219
I have a 94 T/A with the performance transmition button and I always turn mine on whenever I am driving. Is that bad on the tranny? I had 125k miles when I bought it, it now has 145k. The tranny is starting to leak now, could that have caused the leak?

I highly doubt it. The performance button does increase line pressure in part throttle just a little, but does it in a linear fashion controlled by the pcm. Plus, I don't think GM would have made it so it would hurt the tranny. The biggest benefit/difference with the performance shift is the shift timing, IMO. I use mine nearly all the time, now.
You might be due for a new filter and pan gasket.

RamAir95TA · 02-09-2003, 10:44 AM

Quote:

Originally posted by shoebox
I highly doubt it. The performance button does increase line pressure in part throttle just a little, but does it in a linear fashion controlled by the pcm. Plus, I don't think GM would have made it so it would hurt the tranny. The biggest benefit/difference with the performance shift is the shift timing, IMO. I use mine nearly all the time, now.
You might be due for a new filter and pan gasket.

Just to add to that on another note, using the factory performance shift option and an aftermarket shift improver in conjunction is NOT a good idea. Doubling line pressure can do some pretty devastating things.

Brad122470 · 02-09-2003, 11:55 AM

Just out of curiosity why hasn't someone mentioned wiring the factory performance shift button in his car? I agree with shoebox that the shifts points especially the down shifts at interstate speeds are way better and the shift firmness is noticeable at part throttle. Plus it is an easy free mod if your 94 didn't come with the button. One more thing, it is also probably the least stressful to old high mile transmissions.
Just my .02
Brad