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Registered:
September 2002
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 Weight balance of the Supra
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Sun, 29 September 2002 10:04
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I'm aiming to build a track/drift-spec JZA80 Supra. 
As some of you may recall I am transplanting a 1JZ-GTE VVTi onto my JZA80. As you know this engine is commonly used in Japanese drift-spec Chasers and Soarers (for its awesome midrange torque) therefore there are some benefits to be had from this conversion...
Some have also said that the Supra is too heavy, but I'll be spending some efforts to lighten the car sometime down the track (titanium exhaust, carbon fibre panels etc). I've seen some Supras in the US weighing in at approx 1350kgs (with carbon fibre panels, stripped interior etc) so this weight should be light enough for track/drift duties...
However, can anybody tell me what's the weight balance of the JZA80 Supra front to rear (ie: is it 50:50, 60:40, 55:45??)
Any help is much appreciated! 
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Weight balance of the Supra
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Sun, 29 September 2002 13:41
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I'd imagine it'd be fairly close to 50:50, probably slightly biased towards the front.
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Location:
South Australia
Registered:
July 2002
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Re: Weight balance of the Supra
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Sun, 29 September 2002 17:40
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From personal driving experiences the older supras feel like they could use some waste uranium in the back to even it up, not so sure about newer ones. The are definitely front heavy, they've got a big engine up front.
Having said that though, it's not really that unbalanced, probably about 55 weight on the front, maybe less, but there's just so much weight there that it feels all skew .
I remember "oversteering" in one of the standard old supras (which admittedly have a bad reputation for weight distribution), it was like spinning the wheels in a front-wheel drive, it was just a straight line effort
Car-folio says that for a 1993 Supra Twin Turbo the weight distribution is 52%....?
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Weight balance of the Supra
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Mon, 30 September 2002 07:47
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The Mk2 Supra has a roughly 53.6/46.4 F/R weight distribution. They are supposed to oversteer when provoked as well...not sure. Hopefully I can get it back to 50/50 with the 1UZFE and the crbon bonnet.
That sounds about right for a JZA80, they are well balanced cars, just pretty heavy.
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Location:
South Australia
Registered:
July 2002
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Re: Weight balance of the Supra
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Mon, 30 September 2002 08:02
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The older supra (although not completely relevant to this msg) very much went in a straight line when the rear-end was provoked. They have bad body-roll and with a fully slipping diff, all the traction to the inside wheel (the one which follows a smaller radius) is lost and hence the car's rear end doesn't push the car into the corner so much as push it out. On top of this, the bump on the rear shocks is weak, and hence the front end can lift and lose grip and put the car in even more of a straight line, and even a bit of waggle. The car will lose the back end out, but it won't push the car neatly into and through the corner.
OF COURSE, all this can be changed with some decent suspension
Unlike the standard stuff.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Weight balance of the Supra
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Mon, 30 September 2002 08:16
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Why were you driving one with worn suspension and a slipping LSD then?
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Location:
Brisbane
Registered:
May 2002
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Re: Weight balance of the Supra
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Mon, 30 September 2002 12:01
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Sounds like a seriously rooted Supra to me. Neither of my Mk2's behaved like that - sure they oversteer at the limit, but they do so in an easily controlled fashion. Standard suspension isn't brilliant by modern standards, but it's still very good.
My black Supra kept up with a lot of far more modern machinery at Qld Raceway when I ran it out there - my best time was 1:08 on the sprint circuit if that means anything to anyone. By contrast, standard WRX's were usually around the 1:05 mark. Keep in mind I had standard suspension, B-grade tyres and a tired 6M under the bonnet! Pretty good effort for an 18 year old car if you ask me.
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Location:
South Australia
Registered:
July 2002
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Re: Weight balance of the Supra
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Mon, 30 September 2002 14:44
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I didn't drive with worn suspension, I meant "soft" on bump, but obviously it was interpreted incorrectly, sorry. An ordinary road car diff is usually fully-slipping, except for things like 4WD cars and some nissan pulsars etc etc. LSD = Limited Slip Diff....(like a multi-clutch diff centre to limit the difference in lost torque between the wheels) so a "slipping limited slip diff" is a bit of a misnomer.
I'm talking of an earlier model Supra than the one being enquired about, the Supras have never had a brilliant reputation for great handling - I'm just as much a fan of Toyotas as other people here, I'm not bashing them, I'm saying the suspension on the standard Australian setup isn't great, but the newer ones are likely better. If anything, do what norbie did - and relate your experiences in a Supra rather than constantly retorting to other messages, that would be a bit more constructive.
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Location:
Adelaide
Registered:
July 2002
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Re: Weight balance of the Supra
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Mon, 30 September 2002 16:48
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| FWDboy wrote on Tue, 01 October 2002 00:14 |
the Supras have never had a brilliant reputation for great handling - .
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Err you did read Norbies post right? 18 year old MkII keeping to within 3 or 4 secs of standard WRX's?? I'd say thats pretty good handling! Also i've driven a couple supras, namely the celica/supra, A MkIII (3litre) i think? It's the one before the JZ engine series i think it was a 89 or a 90. And these handled really well with the standard suspension setup yeah they are quite heavy and you do feel it thru lots tight turns but i've never driven one that has understeered like you mention i would definately say the suspension sounds like it is really worn out. The ones i've driven have been relatively easy to hang the arse out around corners and control it. Even the old celica/supra. I imagine it would have been a bit of beast in its day. You have to remember its all relative. Of course the old mkII supra's handling isn't great compared to todays standards but think back 18 or however many years ago when it was made!
Cheers
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I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
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Re: Weight balance of the Supra
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Mon, 30 September 2002 23:31
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Put it on some corner scales. You'll need to do that anyway to setup your suspension.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Weight balance of the Supra
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Tue, 01 October 2002 00:38
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Who are having a go at with "If anything, do what norbie did - and relate your experiences in a Supra rather than constantly retorting to other messages, that would be a bit more constructive".
I'm so sorry. Hows about this? I haven't had the privelege of driving a car on a racetrack yet. I have driven many Supras though, the wallowing feeling is much more apparent than in say, a Celica, but when you drive with it, it actually works, and well. Looks like there may be some truth to the whole deal with Lotus on the suspension... As for the LSD, well, the 5MGE one I drove didn't seem to have a problem lighting up both wheels when you hammered it around a corner, and launching it left two black lines, so I'm assuming they would indicate it was working well. Happy now?
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Banned by his request
Location:
moved to tamworth
Registered:
July 2002
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Re: Weight balance of the Supra
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Tue, 01 October 2002 01:00
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when your ready to set the car up give me a yell and we can scale and set it up for you. you will need coil-overs to set your ride heights for balance.
mick
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Location:
Melbourne
Registered:
July 2002
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Re: Weight balance of the Supra
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Tue, 01 October 2002 09:45
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I drive a MA70 supra and i can tell you that when driven correctly in semi stock form they have very good handling. BUT!!!
I have bilstiens in it but that is it (stock everything else includig height).
When I bought the car the shocks were worn and show handling traits similar to what FWDboy was describing but not as bad.
I had them rebuilt and it transformed the car with no change to the stock valving. The car handled like it was on rails and when the back end did slide it was perfectly controlled and still sat flat. (another) BUT!!!!!
The car then recived a 1JZ transplant and puts out close to 300hp at the flywheel. Although the car still turns in good on exit if the tail goes it's bad news. Lots of body roll and very savage it bucks like a bull.
So the moral is if you put in 50% more power the handling is probably going to be 25% worse.
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