Toy Motor

Supragal Class One Homer And a special thank you to our last minute draft in: Alex

Those that were indeed in on it: IanC tDR Branners Mawby whitesupraboy

APRIL FOOLS!!!! Yes, that's right folks - it was all an elaborate hoax dreamed up by us mods to top previous April Fools gags. Bob.

It's fine by me if people wanna bury their heads in the sand. Forget I ever mentioned it! I knew this would just worry people... Bob.

Sorry if folks think I'm taking the piss. I was asked to share info on this so I did. I really am not too bothered whether you believe me or not but I do draw the line at being called an outright liar I'm not saying these failures are guaranteed, just what I expect to happen, with evidence garnered from my work and personal experience of these cars. Mods could you please lock this thread as it's only causing bad feeling and dragging my name through the mud Bob.

Dunno, never tried it I just drove the damned things. Hard. lol Supra-Man - you ain't wrong there! Bob.

To answer Ian and others, We had a target number of operational hours for each test mule. Of these operational hours, we worked out an average in real world conditions that each component or part of the vehicle would see X, Y or Z stress levels. We concentrated on the Z stress loading, Z being full operational load. Testing was done on the real road and non manned simulated testing was also completed on test 'rolling road' rigs which were fully motorised and servo'd to mimic driving over different surfaces, corners etc. Retro fitting a non LSD would alleviate the situation, yes. Extra welding was implemented to extend the floorpan and chassis life in this area beyond any warranty period and potential legal liability period - that being 12+ years. Further durability testing after the modifications put the lifespan to 15+ years which was more than expected, so quite a result, really. Any further welding in that area just moved the point of fatigue failure to a non-reinforced section. By increasing the size of the rails and mounting areas the issue could have been removed entirely, but if you recall, the design brief for the JZA-80 was to be as light as possible. So around 16kg was saved by simply increasing the weld thickness rather than the subframe mounting point size. Management figured that a 15 or so year lifespan was an acceptable tradeoff for keeping the weight down. Bob. p.s. I'm really really sorry to have brought this into the open Please forgive me! I think I'll just not talk about my time with Toyota anymore.

I honestly don't know if there were any improvements made throughout the life of the model Sorry! I left in early '95 during which Supra sales were extremely strong. It was my favourite project from my time there. Bob.

I agree, such an item would only accelerate the fatigue by transferring a greater amount of the operational load to the floorpan. Bob.

Hi Digsy, Nice to meet someone else so involved in such work! Who are you working for? I didn't get involved with the engine stuff myself, I think most of the long term testing and the 'abuse' stuff was done on a dyno cell, although we did get to test the oil sump baffling thing which stops oil starvation on hard turning. I do recall spending a couple of days with another guy, Stuart, going round and round as fast as possible, thinking about it still makes me woozy today lol but at least I was the one driving, he had a laptop to control as well and back then they were as big as a chest freezer hahaha! We did actually break one doing that - the pickup didn't pick up the oil, and suddenly the engine went tight, lost power, and wouldn't restart after we stopped it, nasty. I had to click on the TVD link before I knew what you meant! That's a cool feature of the site by the way! Yes the pulley fell apart, they normally did at about that mileage, probably a few thousand either side, although it depended on if it was an auto or a manual and the way people drove the manual (one day spent deliberately changing down so it hit the rev limiter, honestly, if you had much mechanical sympathy before this job you wouldn't afterwards!). They are just a bit that wears out, 100k miles between component swaps was OK to the bean counters - well out of warranty and they figure a sodding great squeal would get people to the garage before it fell off! As for the strength of the engine, I don't know. I think we fixed all the dodgy bits with parts that were such a leap up from the ones that were the weakest link (goodbye!) that it accidently ended up really strong. I know I threw a conrod once on the downshifting / overrevving stuff, the rod bolt snapped. But I really can't help with that. It's a great engine! Bob.

The ST205 model GT-Four has 5x100 PCD hubs if I recall correctly. Bob.

Have you seen the recent tech thread concerning the rear subframe / floorpan? http://www.mkivsupra.net/vbb/showthread.php?t=104457 Although I would think yours isn't quite old enough to show failure signs as yet. Is it LSD equipped? I distinctly remember those sounds under load which tended to lead to diff failure, they were as a result of awkward diff loadings caused by the fatigue. Other symptoms were twisted / warped driveshafts and occassionally props Bob.

Both the SMIC and the rad look in acceptable condition Ben. We did actually trial front mounted intercoolers in the early development of the Supra, albeit with a side mounted rad to go with it! There wasn't a lot in it between the two in 400PS trim but that was comparing to the 400ps trim beefier SMIC which was later cut when the car was detuned to approx 320ps spec shortly before production. So we went with the conventional setup of front mounted rad and SMIC as the production costs were significantly lower - plenty of cores to choose from for both these items but we'd have needed to go bespoke for the other way round. From my experience, a FMIC should give a good gain if you are running a higher boost level than standard. The same goes for a better SMIC because really you just need more cooling area to accomodate more air being present in the IC at any given time under load. With either, cooling will have to be properly addressed and monitored because you are putting more thermal stress on the motor. Bob.

No, they physically won't fit as the bolt holes won't line up. Bob.

Again, thanks for the warm welcome guys! Ian - I've replied to your thread about it in tech. Bob.