dantwomey Posted June 22, 2005 Report Share Posted June 22, 2005 I couldn't be happier. The smooth near stock light-throttle shifts keeps the Mrs. happy and the neck jerking WOT shifts keep me happy. Two-thumbs up for another happy Zippy shifter! Regards, Dan Link to comment Share on other sites More sharing options...
Dirt.boy Posted June 22, 2005 Report Share Posted June 22, 2005 Okay I'm confused. I thought the shift kit was to make shifts more firm but you say here that it is just while getting into the throttle. What exactly does Zippy's kit do the shifting of the trans. I understand and respect Zippy's desire to keep his business side low key but conversely I can't find any info to make a good decison. As long as I'm on a rave (sorry for the hijack)......I am trying to piece together the info to figure out what I need to do to add some logevity to my trans while making it a bit more fun to drive. Can someone clue me in as to how a shift kit and a custom tune work together. It seems that either can be used to firm up the trans. Thanks, Greg Link to comment Share on other sites More sharing options...
Dylan06SS Posted June 22, 2005 Report Share Posted June 22, 2005 Okay I'm confused. I thought the shift kit was to make shifts more firm but you say here that it is just while getting into the throttle. What exactly does Zippy's kit do the shifting of the trans. I understand and respect Zippy's desire to keep his business side low key but conversely I can't find any info to make a good decison. As long as I'm on a rave (sorry for the hijack)......I am trying to piece together the info to figure out what I need to do to add some logevity to my trans while making it a bit more fun to drive. Can someone clue me in as to how a shift kit and a custom tune work together. It seems that either can be used to firm up the trans. Thanks, Greg <{POST_SNAPBACK}> From what I understand a shift kit is actually the best thing you can do to lengthen the life of a trans because it reduces/eliminates slip. I think a higher stall torque converter could be greatly beneficial to the life of a trans as well. Link to comment Share on other sites More sharing options...
04CHASE Posted June 22, 2005 Report Share Posted June 22, 2005 well the zippy shif kit has servos with a larger surface area which gives them more holding power, and the shift kit which dvk pointed out reduces slip. The pcm tune will give you firmer shifts because the line pressure is bumped up. i would go the shift kit route , actually i already did and i love it, i am adding the trail blazer tc hopefully tommorrow or friday. Link to comment Share on other sites More sharing options...
dantwomey Posted June 22, 2005 Author Report Share Posted June 22, 2005 well the shif kit has servos with a larger surface area which gives them more holding power, and the shift kit which dvk pointed out reduces slip. The pcm tune will give you firmer shifts because the line pressure is bumped up. i would go the shift kit route , actually i already did and i love it, i am adding the trail blazer tc hopefully tommorrow or friday. <{POST_SNAPBACK}> Actually, Bryan at PCMforless reduced my line pressures back to stock out of the concern that too high a line pressure would make shifts too hard with a shift kit. Prior to the shift kit installation Bryan had my line pressures bumped up to simulate a shift kit. It was an improvement but it was no replacement for the real thing. Once again, if anyone is interested I can share how my truck shifts now versus how it shifted prior to the Zippy kit. Regards, Dan Link to comment Share on other sites More sharing options...
misterp Posted June 22, 2005 Report Share Posted June 22, 2005 From what I understand a shift kit is actually the best thing you can do to lengthen the life of a trans because it reduces/eliminates slip. I think a higher stall torque converter could be greatly beneficial to the life of a trans as well. <{POST_SNAPBACK}> The factory shift kit is designed by engineers to suit a wide variety of average drivers, uses, criteria (cost/ride quality constraints), and dozens of other obstacles. Like the rest of the vehicle there is more potential there. 'Shift improver/correction' kits will change how the transmission releases and grabs gears, both in timing and pressure, to deliver the most possible life from the clutches and bands - usually this results in a much faster, crisper shift because the factory made the stock pieces sloooooowly release the gear you are in before sloooooowly grabbing the next gear, the factory settings are exactly like slipping a clutch in a standard trans and that builds a lot of HEAT and WEAR. Also, increased line pressure (a firmer shift) improves durability through increasing clutch/band holding ability, in turn reducing heat buildup because there is no clutch/band slippage. With these kits you get a quick and firm-to-hard shift. 'Full Race' kits also increase speed and pressure of clutch release/engagement, but to the point where they deliver the absolutely fastest shift possible, parts survivability is a secondary concern. Full Race kits also typically remove the automatic operation of the transmission (it becomes fully manual operated). In these kits you get a 'near instantaneous' shift that is hard-to-violent. Both the Zippy kit and the TransGo kit mentioned here of the 'shift improver/correction' type and the timing of the shifts in my SS (JAG TransGo kit) is very similar to a stock Allision 6-speed in a mini-Pete, it is the best calibration/behavior for parts longevity. At part-throttle you can expect an authoritative 'bump' into second gear, at 1/2-throttle it will slop coffee in your lap, and at WOT you can feel the frame of the truck twist... Mind you that in my setup I am using a TCS 2800-rpm converter, so a lot more torque is being put into the tranny at the 2nd gear shift point. If you do run a higher-stall converter realize that it will slip a lot more than the OEM, hence making a lot more heat in the ATF, so be sure that you have adequate cooling with the installation of any aftermarker converter. Mr. P. Link to comment Share on other sites More sharing options...
04CHASE Posted June 22, 2005 Report Share Posted June 22, 2005 thanks p i did not know that about converters Link to comment Share on other sites More sharing options...
WEEZARR1&SS Posted June 22, 2005 Report Share Posted June 22, 2005 A lot of good info Link to comment Share on other sites More sharing options...
Maximus Posted June 26, 2005 Report Share Posted June 26, 2005 Damn you boys are good!! Link to comment Share on other sites More sharing options...
TBSS Posted June 26, 2005 Report Share Posted June 26, 2005 ...at 1/2-throttle it will slop coffee in your lap, and at WOT you can feel the frame of the truck twist...<{POST_SNAPBACK}> When I install my shift kit, if this is the result, then I know I will have done it wrong. A shift kit should make shifts firmer and quicker (with emphasis on the quicker), not harder. If the shift is extremely hard, then this is not good on parts. This is especially true at higher throttle, when lots more torque is applied. Certainly a 'frame-twisting' shift cannot be good for either the transmission or rear end, and if this is the case, your transmission's days will be numbered. Link to comment Share on other sites More sharing options...
Posi12Bolt Posted June 26, 2005 Report Share Posted June 26, 2005 I sent Zippy a PM for more info so I could get my SS up to part with ya'll BUT... no reply yet. Where you at bro!?!?! P.S. I may have sounded a little "tranny stupid" in my email and that could be the reason he didnt respond... thats just cause I am when it comes the these computer controlled tranny's... i dunno ~Brian Link to comment Share on other sites More sharing options...
zippy Posted June 27, 2005 Report Share Posted June 27, 2005 i probably just missed it. i get alot of pm's through the day and i occasionally miss one. sorry about that. i'll look for it and respond. Link to comment Share on other sites More sharing options...
misterp Posted June 27, 2005 Report Share Posted June 27, 2005 ...at 1/2-throttle it will slop coffee in your lap, and at WOT you can feel the frame of the truck twist...<{POST_SNAPBACK}> When I install my shift kit, if this is the result, then I know I will have done it wrong. A shift kit should make shifts firmer and quicker (with emphasis on the quicker), not harder. If the shift is extremely hard, then this is not good on parts. This is especially true at higher throttle, when lots more torque is applied. Certainly a 'frame-twisting' shift cannot be good for either the transmission or rear end, and if this is the case, your transmission's days will be numbered. <{POST_SNAPBACK}> Yeah, well we'll see... I kind of had the same worry, I called Joe Guttierez (JAG Performance) and discussed the shift behavior in depth with him and he said just drive it, it's acting as he expects and he personally guaranteed the transmission to 650 lb-ft in this truck (and a towing capacity of well over 30K-lbs). Only the 2nd-gear upshift is brutal, I am thinking that one could probably domesticate it easily through PCM programming and/or accumulator washers... The scary part is that I am using Mobil 1 ATF, can't even imagine what the shift would be like using Dexron III! I have not given any thought to differential issues only because several other FI guys here have not shared that they had the need to. But I would certainly not mind improving the diffs in the future, the rear is certainly seeing more load on the second-gear upshift. This trans grabs second in an earth-shaking way, if the truck is not tracking *dead straight* it does funny things on the WOT second upshift . I have had the right-front scratch once (frame/body bushing deflection), barked the rears twice, scratched the rears on a few occasions, and jumped the entire truck sideways a 1/2-inch once as well (AWD scratch)... I've gotten into the habit of pulling my foot out of the throttle now to get the truck to short-shift. Link to comment Share on other sites More sharing options...
zippy Posted June 27, 2005 Report Share Posted June 27, 2005 part of that is in the programming, but not all of it. i agree with joe about the shift feel. if you expect the clutches and band to hold up to power they need to apply quickly. applying the clutches quick makes for a solid feel just as it would a manual trans car when you just drop the clutch vs. easing it out. anytime you're expecting to put donw alot of power to an automatic you get the choice of how you want it done. you can replace the clutches/band more often and go for a smoother shift or build it to make the clutches/band to hold up and hope nothing breaks. to get the trans to not slip under power this is needed. it's either that or bigger parts which come in the form of a bigger trans. could a 4L65E hold up to a stock 8.1L, yes in properly built form. it would shift too hard to make it hold up and not slip. could gm have used the 4L85E behind the duramax, yes, but again it would have had to shift too hard. there comes a point where you're only trying to find the happy medium between shifting hard enough to prevent slippage and breaking parts. if you want the quick shift without the harsh feel there is only one way to get it and that's to run a higher stall converter. if you have a trans that has the quick shift feel but doesn't shift hard, you don't have a real quick shifting trans. run it hard and put it on the scan tool/log. from there you'll see that the shifts aren't as quick as you'd have guessed... Link to comment Share on other sites More sharing options...
TBSS Posted June 27, 2005 Report Share Posted June 27, 2005 part of that is in the programming, but not all of it. i agree with joe about the shift feel. if you expect the clutches and band to hold up to power they need to apply quickly. applying the clutches quick makes for a solid feel just as it would a manual trans car when you just drop the clutch vs. easing it out. anytime you're expecting to put donw alot of power to an automatic you get the choice of how you want it done. you can replace the clutches/band more often and go for a smoother shift or build it to make the clutches/band to hold up and hope nothing breaks. to get the trans to not slip under power this is needed. it's either that or bigger parts which come in the form of a bigger trans. could a 4L65E hold up to a stock 8.1L, yes in properly built form. it would shift too hard to make it hold up and not slip. could gm have used the 4L85E behind the duramax, yes, but again it would have had to shift too hard. there comes a point where you're only trying to find the happy medium between shifting hard enough to prevent slippage and breaking parts. if you want the quick shift without the harsh feel there is only one way to get it and that's to run a higher stall converter. if you have a trans that has the quick shift feel but doesn't shift hard, you don't have a real quick shifting trans. run it hard and put it on the scan tool/log. from there you'll see that the shifts aren't as quick as you'd have guessed... <{POST_SNAPBACK}> Hmm, interesting. So how much bigger than stock does the aftermarket converter need to be to reap the benefits of this 'best of all worlds' setup? Link to comment Share on other sites More sharing options...
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