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The mkiv Supra Owners Club

6 Speed Value / 5 Speed Conversion


adarmo

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Hi guys

 

Long term lurker here keep meaning to buy a Supra but haven't got around to it yet.

 

I'm looking to buy an Manual NA Supra with the intention of later dropping the Soarer V8 in

(hope that goes down better here than V8 conversions do on the RX7 forums)

 

I have searched but it's taking ages to find all the answers so I hope someone might just know it all (and tell me)

 

Is the NA 6 speed exactly the same as the TT 6 speed (It appears so, V160 right ?)

 

Other than the brakes and diff (and the box) is there any other benefit to buying an SZR facelift ?

 

Am I correct that the diff is a small case but the brakes are the same as the TT ?

Will a small case diff be OK with a 300bhp V8 ?

 

If I decided to get some money out of the SZR by selling the 6 speed and replacing it with a 5 speed is it a simple swap of box, prop, flywheel ?

Am I right in thinking I'd net around £1500 by doing this ?

 

Is there a 5/6 gearbox / auto / TT / NA diff ratio info posted anywhere ?

So I can work out what's best for a V8 ?

 

Thanks

 

Mark

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Some answers,

 

The box is the same as the TT's

 

Diff ratios can be found here...

 

http://mkiv.supras.org.nz/specs.htm

 

The small diff will be fine with that power, all the later TT's had small diff cases.

 

The brakes on a facelift SZ-R are not guaranteed to be the larger ones.

 

not sure if benefits but other SZ-R diffs would be, no traction control and manually adjustable drivers seat.

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Thanks Scooter - very handy link.

 

I've managed to figure out how the gear ratio calculator (old post on here) works too, looks like ideally I'd want to keep the 6 speed and get a TT ratio diff to get the cruising rpm down without raising the gearing too much in the lower gears.

 

How agricultural is the 6 speed compared to the W58 ?

 

Josh - If I buy it I'll bear you in mind - still trying to work out what base car makes the most sense - I'd rather get a pre 95 to avoid needing CATS

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If I decided to get some money out of the SZR by selling the 6 speed and replacing it with a 5 speed is it a simple swap of box, prop, flywheel ?

Am I right in thinking I'd net around £1500 by doing this ?

 

 

You would have to be insane to even consider this! Why?! Surely it would be better to wait and save the £1500? The six speed gives you the peace of mind that a W58 running at near the limit of it's power would not provide.

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I'm sick of looking and don't want silver or white and there's an SZR nearby. It also has the better: clutch, diff and brakes

 

I can afford £1500 but at the same time if it's not as nice to use as the W58 then why have it ?

Also a V8 shouldn't really need 6 gears and shouldn't break the W58.

 

AFAIK imports pre 95 can get away without CATS as VOSA don't have them specifically listed - certainly this is true of import MX5s. Although they are sold as Eunos Roadsters which may be why they get exemption as their model name is different - so it may not apply to Supras

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I'm sick of looking and don't want silver or white and there's an SZR nearby. It also has the better: clutch, diff and brakes

 

I can afford £1500 but at the same time if it's not as nice to use as the W58 then why have it ?

Also a V8 shouldn't really need 6 gears and shouldn't break the W58.

 

AFAIK imports pre 95 can get away without CATS as VOSA don't have them specifically listed - certainly this is true of import MX5s. Although they are sold as Eunos Roadsters which may be why they get exemption as their model name is different - so it may not apply to Supras

 

The only people who get away with as said above is NA's as they don't exist in the database. Everyone else need a feline in the drainpipe :) But there are friendly test centres all around the country sympethetic to our cause :innocent:

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I had some 'issues' when I MOT'd the V8 Supra but was told (by VOSA) that a non cat emissions test must be done on an engine aged 05/1992 and before. If you do an engine swap to a later engine, the emissions test will be based on that so cats would be needed.

 

My car was a 1994. I ran a 1996 LS400 lump (to benefit the lower mileage engine) with 1992 Soarer intake and ECU. As the emissions are ECU controlled, this decided the test.

 

I did have trouble getting one place to MOT my V8 but after a phone call to VOSA to clear things up I took it elsewhere and passed no problem.

 

Obviously, if you have an engine not in the database (ie. a 2JZGE) then the test should default to a non cat test - but a 1UZFE, 2UZFE and 3UZFE are all in the database and will be tested for cats.

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And pre 95 cars still have to have cats unfortunately!
Not if you use the stronger early (1991/2) Soarer 1UZ. The emissions test is based on whichever is earlier, engine or chassis.

 

There are plenty of V8s in Australia and the USA running the W58. Check Club Lexus and the Australian Soarer forums (ALSC and Soarer Central). Since you have to do a conversion anyway, you could also consider the 6-speed out of a 350Z (preferably the later box - code "CD009").

Edited by garethr (see edit history)
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