ZHeadV8 Posted January 11, 2005 Share Posted January 11, 2005 Hi Guys, I have searched and searched but not come up with what I am looking for so here goes : Thank you for your engine advice and help, I am now on course with an LS6 - gearbox advice from you guys (and Mike in particular, thanks) was either a T56 or preferably a G-Force custom ....BUT...... The engine supplier is telling me that the high BHP engines (over 450) will destroy a T56 and I should be looking at an auto box. The models given were GM400 and Hydromatic. Please forgive me, I do not know either of these boxes as they are not common here in the UK. The question is simple, is the guy talking crap ? He can supply 400 - 700BHP engines, the latter being twin turbo but will not warranty a T56 with them because he says the engine will literally "break" the box under full load on a drag strip. So how the hell do the Lingenfelter engines cope ? Does anyone have seriously high BHP and torque running through a manual T56 or G-Force box without trouble ? Quote Link to comment Share on other sites More sharing options...
mark Posted January 11, 2005 Share Posted January 11, 2005 I've had my t-56 rebuilt twice. Mine is a road course car. Both times synchro's went. Also ended up trashing third gear after a weekend of driving with out synchro's. I think a drag car would be harder on the tranny than a toad course car. Mark Quote Link to comment Share on other sites More sharing options...
ZHeadV8 Posted January 11, 2005 Author Share Posted January 11, 2005 So maybe the guy is not so full of crap after all, maybe he really does know his stuff. He is suggesting a very powerful engine, whether a twin turbo or just a 500BHP LS6 is yet to be decided and is concerned about exactly what you say. Thanks for the feedback. Anyone else have a view ? I will be gutted if I spend 18months and $60K on a car that eats it's gearbox. Quote Link to comment Share on other sites More sharing options...
WickedWild Posted January 11, 2005 Share Posted January 11, 2005 I'm sare that there is a manual tranny that can put up with the power levels that your going to throw at it. Will a stock T-56 hold it probobly not for long. The new vet and the Viper both are available with a manual transmission that deals with those power levels and higher. Do some reasearch on the LS1 board, and or see if you can find out what Lingenfelter uses. Quote Link to comment Share on other sites More sharing options...
qwik240z Posted January 11, 2005 Share Posted January 11, 2005 The Dodge Viper uses a T56 and it is over 500HP. Also the Mustang Cobra has a T-56 and it is over 400HP so maybe some of the T56's are stronger than others. If you beat on them too hard I am sure that even those that are rated for the higher HP and torque will break. I will be using the T56 in my 240Z with a stock (for now) LS1 so I don't see any real problems unless I really bang alot of gears too hard. But I really don't drive that way and I plan to keep my R180 LSD rear so I will be extra careful. Quote Link to comment Share on other sites More sharing options...
ZHeadV8 Posted January 11, 2005 Author Share Posted January 11, 2005 That's what I thought, I thought the Aston Martins used T56's as well to handle the power which is why I was surprised when the engine supplier said they were not up to it (he sells them new and used so could easily have made a sale if he wanted) Quote Link to comment Share on other sites More sharing options...
mark Posted January 11, 2005 Share Posted January 11, 2005 The shop that did my t-56 had 2 Z-06's in for tranny rebuilds while he was doing mine. They will break when pushed hard enough. Mark Quote Link to comment Share on other sites More sharing options...
johnc Posted January 11, 2005 Share Posted January 11, 2005 The Dodge Viper uses a T56 and it is over 500HP. The T56 in the Viper shares little with the T56s you guys are talking about purchasing. The gears are shot peened and receive special heat treatments, the synchros are stronger and of slightly different design, shift forks are strengthened, the input shaft is a stronger material with special heat treatments, etc. Even then, the T56 is a weak point in the Viper's driveline when road racing. Lots of folks who race basically stock Vipers, ACRs, and Comp Coupes in VRL have to go through their transmissions at least annually. Adding a pump and a cooler helps. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted January 11, 2005 Share Posted January 11, 2005 Yup, you know it's sad but true... Sorry, Metallica ringing through my head... Anyway, The T56 will not handle the extended use/ abuse of 400+ HP. What John says and Mark experienced is true... I've been talking with Paul at http://www.fivespeeds.com about rebuilding my T56 in my Vette with road race strength shafts, and better syncros/ shotpeened gears... There are a few companies out there building options for the LS1/LS6 platform... I'd check with Paul, or Keisler, or contact Richmond Gear about the ROD 6 speed or 5speed trannies.. there are PLENTY of choices out there if you want to row your own... And again, I'd search into a Fivespeed... The T56 unit is HEAVY! Cheers! Mike Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted January 11, 2005 Share Posted January 11, 2005 Even the auto's have to be built for that kind of HP. The 400 is probably the strongest of the 3 speeds, the 4l80e is kind of a 400 with overdrive and electronics. The powerglide can be built for that kind of hp as well, what about the brin and the jerico transmissions that they use in circle track? You can select gear ratio's in them, just a thought. Quote Link to comment Share on other sites More sharing options...
Z-Dreamer Posted January 11, 2005 Share Posted January 11, 2005 Hey Mike, isn't G-Force making a upgraded T56 now? http://www.gforcetransmissions.com/tran_gt-56.asp I don't know if it would be up to the rigors of roadracing, but add them to the list of companies making a aftermarket T56. Mark Quote Link to comment Share on other sites More sharing options...
Mikelly Posted January 11, 2005 Share Posted January 11, 2005 Mark, http://www.fivespeeds.com is a Gforce Vender that builds Gforce equipped trannies CHEAPER than Bubba offers them... And from my research, BETTER too! Mike Quote Link to comment Share on other sites More sharing options...
ZHeadV8 Posted January 11, 2005 Author Share Posted January 11, 2005 The link goes to a different site Mike, apparently http://www.fivespeeds.com is up for sale now as a domain name ?????? Was there when I looked a few days ago. Looks like I need a custom box to handle the power - back to your original advice of getting one put together to suit the engine and car. Would a T56 cope with a standard 405BHP LS6 engine without trashing the synchros ? Quote Link to comment Share on other sites More sharing options...
johnc Posted January 11, 2005 Share Posted January 11, 2005 Would a T56 cope with a standard 405BHP LS6 engine without trashing the synchros ? Synchros are not trashed by horsepower, synchros are trashed by the driver. Improper shifting will trash the synchros because they have to take a load that someone who is proficient at shifting doesn't place on the transmission. Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted January 11, 2005 Share Posted January 11, 2005 '94 and newer t56s ( Camaros ) are rated at 450 ft lbs of torque, Vettes, and Vipers are higher. There are Cameros with moded engines and stock t56s running in the 9s in the 1/4, so they can handle more than advertized. Quote Link to comment Share on other sites More sharing options...
mark Posted January 11, 2005 Share Posted January 11, 2005 Synchros are not trashed by horsepower, synchros are trashed by the driver. Improper shifting will trash the synchros because they have to take a load that someone who is proficient at shifting doesn't place on the transmission. How true, Sometimes it is much easier to just jam it in there and make it go rather than doing the heal toe dance. Incompentence cost money. I speak from experience. Mark Quote Link to comment Share on other sites More sharing options...
SBC_400 Posted January 11, 2005 Share Posted January 11, 2005 I know a lot of the guys in the trans-am series use jerico's and weisman transmissions Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted January 11, 2005 Share Posted January 11, 2005 this might help http://www.5speedtransmissions.com/ Quote Link to comment Share on other sites More sharing options...
DavyZ Posted January 11, 2005 Share Posted January 11, 2005 Hey Mike' date=' isn't G-Force making a upgraded T56 now? http://www.gforcetransmissions.com/tran_gt-56.asp I don't know if it would be up to the rigors of roadracing, but add them to the list of companies making a aftermarket T56. Mark[/quote'] I remember seeing a price of $1000 if they rebuilt your existing T5 to their specs. Not bad considering 600 hp/500 lbft is what they can handle. I'm sure a T56 is more, but with the right gear ratio, why bother??? Davy Quote Link to comment Share on other sites More sharing options...
Z-Dreamer Posted January 11, 2005 Share Posted January 11, 2005 Thanks for the info Mike! I think the site Mike is refering to is http://www.5speeds.com Mark Quote Link to comment Share on other sites More sharing options...
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