Lexus GS300 gearbox

[The H]

Hi guys,

After some advice on gearboxes, as I'm getting fed up off only having 4 gears in my SZ, and the gearbox topping out at 135!

I know that the lexus GS300 has the same 2JZ-GE engine that my supe has, but it comes with a 6 speed auto box.

Is this likely to be a straight forward switch with the gearbox, as the bell housing should fit easily, if not be identical. The transmission tunnel may need a little work, but hopefully nothing major, as I will try and get the plastic gear selector cover and fabricate one to fit the supra fasacia.

Will I need the gearbox control thingy from the lexus, as the one in the supe will be set for a 4 speed auto box?

Also, does anyone know what the GS300 gearbox can handle in BHP?

So many questions! lol

[Martin F]

Interesting idea.

Are you sure it's not the cars speed limiter stopping you go greater than 135?

Originally Posted by The H

Will I need the gearbox control thingy from the lexus, as the one in the supe will be set for a 4 speed auto box?

You would almost definitely need the auto box ECU from the donor car.

It's not a swap that i've heard of before so would be interested to know how you get on. As you say, mechanically everything should line up (may need to shorten or extend the prop) it will just be all the ancillary items which would take a bit of work.

[Gambit]

Topping out at 135???

Is the n/a auto the same as the tt?

I think they are...

If I'm gunning it my car reaches for 4th at about the speed you say your box is out of puff.

Sorry if this sounds like a dumb question but you've not got the over drive switched off on the gear stick have you? (little button should be in)

[The H]

Originally Posted by Martin F

Interesting idea.

Are you sure it's not the cars speed limiter stopping you go greater than 135?




You would almost definitely need the auto box ECU from the donor car.

It's not a swap that i've heard of before so would be interested to know how you get on. As you say, mechanically everything should line up (may need to shorten or extend the prop) it will just be all the ancillary items which would take a bit of work.

The car was delimited when it was converted to mph, so I would assume that it isn't that.

When you say ancillary items, are you talking about thepanel that sits over around the gear selector on the transmission tunnel? Or have I completely overlooked something important?

[The H]

Originally Posted by Gambit

Topping out at 135???

Is the n/a auto the same as the tt?

I think they are...

If I'm gunning it my car reaches for 4th at about the speed you say your box is out of puff.

Sorry if this sounds like a dumb question but you've not got the over drive switched off on the gear stick have you? (little button should be in)

The overdrive is definately on and it goes through the 4 gears fine, red lineing at 6500. When in 4th, she'll get to 135 at about 6000 but just won't go any higher.

As far as I am aware, the N/A auto box is different to the TT auto box. There was a link on a different thread that showed the gear ratio's and max HP that both auto boxes could take as well as the manual ones. The TT auto box is a lot stronger and can handle quite a bit more power. When I was looking in to doing a NA to TT conversion, I could of used my existing box, but needed to add a couple of internal bits to strengthen it.

The car has had some engine work done, nothing major, but I'm figureing that 6 gears would increase top end as well as improving fuel consumption. Plus the GS300 is a semi auto with a knock forward/knock back to change gears (which makes the small boy in me very happy!! ).

I like the auto box, as it's a damn sight quicker off the lights than a manual, and it is a lovely lazy drive on long journeys.

[madwoody]

isn't the diff different as well think it has a low ratio so would make it slower at top end but faster gettin there instead of changing the auto box just change the diff to a tt one that would give you a high top end