np89 Posted January 9, 2015 Share Posted January 9, 2015 Hey guys, just noticed on TOYODIY, while lookign something up for someone else, The UK Spec Autobox, is different from the J-Spec Autobox UK - 35000-1B330 J Spec - 35000-1B310 I know that the general consensus is that the Auto Transmission is only good for about 550BHP, i.e about 500Lbs/ft torque (gearbox heat killer), my question then is, could it be possible that the UK Spec box is superior? Does anyone know how they differ? Can they handle more perhaps? Transmission gurus Go!! Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted January 9, 2015 Share Posted January 9, 2015 The European at transmission can handle more power yes. Quote Link to comment Share on other sites More sharing options...
np89 Posted January 9, 2015 Author Share Posted January 9, 2015 Any ideas of numbers/ratings? Quote Link to comment Share on other sites More sharing options...
mellonman Posted January 9, 2015 Share Posted January 9, 2015 I belive the only differance is the gearing for the speed sensor on the gear box its self , being km vs miles something to do with the number of teeth i read on here somewhere Quote Link to comment Share on other sites More sharing options...
Abz Posted January 9, 2015 Share Posted January 9, 2015 Isn't it to do with coolers? Quote Link to comment Share on other sites More sharing options...
Kaan W Posted January 9, 2015 Share Posted January 9, 2015 I believe the electrical connectors are different too as when I bought a built box before none of the connectors matched up, they said it's because the box was for a jspec car as I never stated my car was uk spec when ordering. Could be wrong though. Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted January 9, 2015 Share Posted January 9, 2015 Any ideas of numbers/ratings? Can't remember specific numbers but the European A343E Transmission is stronger than the A340E of the JSpec Cars. Quote Link to comment Share on other sites More sharing options...
mellonman Posted January 10, 2015 Share Posted January 10, 2015 Can't remember specific numbers but the European A343E Transmission is stronger than the A340E of the JSpec Cars. I thought that the A343E was for the TT and the A340E was for the n/a is it not ? Quote Link to comment Share on other sites More sharing options...
David P Posted January 10, 2015 Share Posted January 10, 2015 The gearbox code numbers are a mystery that I've yet to unravel? I'm reasonably sure that the boxes are the same spec, but are wired differently because the ECU's are slightly different. The Aristo version has additional oil plumbing but I have not yet had my hands on one to play with. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 10, 2015 Share Posted January 10, 2015 You would need to get the Aisin Warner parts book and spend hours looking at valve body springs, clutch packs and brake bands, blah blah, to be sure, but I would highly doubt the torque handling of a UK spec auto box is any greater than a Jap spec. In my limited experience of people putting more torque through MKIV auto boxes, it's the lack of torque unloading during shifts that kill them more than sheer torque. the stock ecu goes to some lengths to reduce torque during and just after gear changes occur. Most aftermarket ones do not do this and the sudden shock loadings seem to kill the `boxes. Got two dead TT auto boxes here nowe, both off cars with aftermarkey ecus, single turbos and otherwise excellent maps, but WITHOUT torque limiting on gear changes. If I had the time and inclination I should strip them and see what's failed. but i suspect sprag clutches. NOT that I am an auto box guru... Quote Link to comment Share on other sites More sharing options...
mellonman Posted January 10, 2015 Share Posted January 10, 2015 You would need to get the Aisin Warner parts book and spend hours looking at valve body springs, clutch packs and brake bands, blah blah, to be sure, but I would highly doubt the torque handling of a UK spec auto box is any greater than a Jap spec. In my limited experience of people putting more torque through MKIV auto boxes, it's the lack of torque unloading during shifts that kill them more than sheer torque. the stock ecu goes to some lengths to reduce torque during and just after gear changes occur. Most aftermarket ones do not do this and the sudden shock loadings seem to kill the `boxes. Got two dead TT auto boxes here nowe, both off cars with aftermarkey ecus, single turbos and otherwise excellent maps, but WITHOUT torque limiting on gear changes. If I had the time and inclination I should strip them and see what's failed. but i suspect sprag clutches. NOT that I am an auto box guru... Piggy back ecu is not such a bad way to go then after all. Quote Link to comment Share on other sites More sharing options...
David P Posted January 10, 2015 Share Posted January 10, 2015 (edited) Without timing retard at gearchange events, the clutches don't last very long. That's why I have programed the AEM to cut the ignition timing to 6 degrees before TDC at change-up events with my flappy-paddles. Edited January 10, 2015 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Kaan W Posted January 10, 2015 Share Posted January 10, 2015 My overdrive gear went after doing a long pull and that's with torque reduced on shifts too. Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted January 10, 2015 Share Posted January 10, 2015 The gearbox code numbers are a mystery that I've yet to unravel? I'm reasonably sure that the boxes are the same spec, but are wired differently because the ECU's are slightly different. The Aristo version has additional oil plumbing but I have not yet had my hands on one to play with. I'll just leave the link here regarding what Transmission was used in what model http://www.supra-forum.com/articles/general/transmissions/ There have been some conversions from the JSpec transmission to the EU one because of strength differences but i honestly don't know how much they differ. I aggree that the killer for both boxes will be the gear changes without Torque reduction. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 11, 2015 Share Posted January 11, 2015 Well the writer doesn't know the difference between longer and shorter ratios The Euro spec figure for top gear is actually shorter than the Jap spec transmission. Has he got them back to front I wonder? Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted January 11, 2015 Share Posted January 11, 2015 You're right. May be mixed up. The EU Transmission has a longer 4th gear Quote Link to comment Share on other sites More sharing options...
garethr Posted January 11, 2015 Share Posted January 11, 2015 Well the writer doesn't know the difference between longer and shorter ratios ...In my experience, half the automotive forum world doesn't understand higher/longer vs lower/shorter. It's always a good topic for an argument, though. I was taught "higher number = lower/shorter gear". Obvious when you consider that 1st gear (2.804:1) is lower than 4th gear (0.753:1). Quote Link to comment Share on other sites More sharing options...
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