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Hi from an ex-Toyota newbie! :) (APRIL FOOLS!!!)


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Hi Bob.

 

Nice to see you on the board :). I'm a powertrain Engineer by profession myself, and during my many musings about durability and how much modification the Supra base engine can take I've often mentioned that although the stock 2JZ does seem to be able to take an almost bottomless pit of extra power, you can't really be sure of what will break first unless you have access to one of the original development team members. Now it looks like we have exactly that :)

 

In my experience, engine development usually ends with one last annoying niggle getting sorted out, which then becomes the engine's Achilles' heel. Its not too clear where this is on the Supra with regards to modifying for power - there actually doesn't seem to be one. I've also said that (in line with the persistent rumours) you dont go out to design a 400 or 500 hp bottom end unless you are planning to manufacture one, or in the 2JZ's case, unless you were originally planning to release one. If the 2JZ was orginally planned to be 400hp+ then that would make a lot of sense, but even so the stock base engine does seem to be good for at least 200hp above even that. I don't hold with the view point that Toyota built extra headroom into the base engine to pander to the Japanese tuning scene. I'd be happy to be proved wrong if you know otherwise!

 

I now you said you were a durability test driver and not an engine development guy, but do you happen to know what kind of durability tests the engine itself was subjected to? I'd also be interested in specific system tests like high and low speed valvetrain, or abuse tests (low oil, etc).

 

How many road miles were the tests designed to mimic? The many occurances of TVD failure at 100,000 miles ish should have been within the scope of your testing. Its probably the most common age-related engine component failure on the stock engine. Any ideas why it wasn't caught during development?

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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.

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Hi Bob,

 

welcome to the club, I expect there will be plenty of other stories around the camp fire.

 

Hope that you and Gary are going to stick around for a long while.

 

Ed, is there a way to stalk members so you don't miss any of their posts.

 

Mike

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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.

 

I've worked for Lotus Engineering for 14 years. Powertrain design mainly, plus a little bit of Project Engineering and Development.

 

I've done sump surge testing, too. I actually threw up after a few months of it, pulling up to 0.9g all summer while looking down at my laptop. I don't even get motion sickness :)

You actually failed an engine doing that? Wow - either that was one extreme test or someone got the design badly wrong (or forgot to fill it up with oil :) ) I was pecking around the edges of oil aeration for weeks and weeks on the same poor old test car. We had to stop every few laps to let the system re-prime and stop clattering, but the engine never died on us. And the 2JZ doesn't even have hydraulic tappets!

 

So how did you end up working on Toyota's flagship product? We really get any work from them, although we do use the 2ZZ in our products. I would have thought they kept the sexy stuff in-house.

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