Mistical

Does anyone know how to or have any information/resources on changing the gear shift of a 1997 SC300 into a gear selectable transmission? I would love to change mine to a gated shifter and have it selectable, so that when I put in 2nd it is in 2nd and not in 1st...and so on. I want to be able to up shift to 3rd and not have to worry about it downshifting cause I applied a little to much pressure to the gas peddle. I want it so that 1st is 1st, 2nd is 2nd, 3rd is 3rd, 4th is 4th with a switch between full auto and semi-auto: or 4th is simply full auto as it is right now. The gated shifter would be nice for selection purposes and since there is no direct 4th gear.

Does anyone have any thoughts, ideas, resources, or anything to help me make this happen?

Your help is appreciated.

lex400sc

This feat is very unpractical, but doable if you have the cash. In order to convert to the 98+ gated shifter, you'd have to swap to a 5-five auto tranny from another 98+ SC or GS400, reprogram the tranny ECU professionally to match shiftpoints with an engine it was not designed for (non-VVTi 1UZ-FE), swap the gauge clusters with a 98+ SC, and of course swap the shifter and the woodtrim shift cover (which does not match the center console controls). You can also buy the center console units for a 98+ SC from Lexus parts for a couple thousand, but the burlwood finish on this doesn't match the woodtrim finish of the pre-98s. The 98+ SCs came with a snow ect mode on the tranny, but I'm not sure if you'd gain that ability in the change over or not.

SC300T

I'd love to have full un-edited control over the tranny, too.
I've wanted a feature like this for years.

The e-shift from the ECU in a GS400 won't hold a gear like you want. There would have to be some major re-programming to eliminate the kick down that the ECU sometimes sends.

The standalone ECU from AEM (for the Supra) may work. It has editable tiptronic modes on the automatic tranny functions.

The tiptronic that comes closest IMO is the VW/Audi. It will hold the gear you select. The only exclusion is if you select a gear that the engine can't smoothly run, it won't accept. The VW tip won't allow you to start in 2nd or 3rd gear, though, which would be good for soft launches or in snow.

I'd also like to have full control over the torque convertor lockup functions. Having a full lock in 2nd and 3rd under WOT would help acceleration (but would be tough on the bands)

lex400sc

So Scott, are you saying that the ECU is a major power drain on the drivetrain? wouldn't PWR ECT eliminate this? Also my friend with a 98 GS400 *claims* that the e-shift will hold gears (??) I don't think he ever tried anything drastic like dropping it into 2nd on the freeway, but he has downshifted on the freeway, which jerked the car. Can you confirm?

Mistical

Thanks lex400sc and SC300T for getting back to me.
The whole tranny swap thing is a great idea, but also an easy way to get raped by Lexus. You can do the Supra 6 speed swap and add a turbo probably for the same price.
Didn't the 98 or 99 SC300 have a 4 speed auto transmission with a gated shifter? I may be incorrect, but I understand that the transmission is a drive-by-wire setup, meaning that it pulls a cable to electronically tell the transmissin which gear to select. So when you put it into the 2nd gear position it electronically signals the transmission to enter that gear. So...if the above is true....then could you change the upper shift lever and mechanism to the 99 version? As far as the snow mode, isn't that a traction control thing that would simply need to be programmed to work correctly. Regardless, that is just a switch and if we were lucky, we could just use our current switch and forget about the snow traction thing.

SC300T

The e-shift simply gives you buttons to select the maximum gear that the transmission will use. (It will hold the gear you select but is free to downshift further on its own).


e-shift in 2----ECU will choose 1st or 2nd gear
e-shift in 3----ECU will choose 1st, 2nd or 3rd gear
e-shift in 4----ECU will choose 1st, 2nd 3rd or 4th gear
e-shift in 5----ECU will choose 1st, 2nd 3rd 4th or 5th gear

It all depends on conditions. If you have 4th selected and you press the gas too far, it may downshift on you---very bad design, IMO. Say its rainy out and you're in a turn with 3rd selected, you squeeze the pedal to get some more acceleration, but instead of holding the gear you get a kick down and the car slides sideways. What you wanted was for it to keep 3rd.

Also, you can't select 1st gear manually.

It's basically no better than a gated automatic, except the control is on the steering wheel.

Its definitely not as good as the audi design IMO.

lex400sc

IC, do you know how the Prelude VTEC's sport-shifter works?

Mistical

Does anyone have a scamatic of a 1997 SC300 tranny and shift lever? How about one for a 98/99/00? I think if we look at the specs of the mechanism, we can see if this is even possible. Any one have a service manual?

....and the BMW 3 series has one of the best "semi-auto" transmissions I have ever seen. Besides it being smooth and sporty, it stays in the gear you tell it. In a rolling stop, this 330 stayed in 4th gear. It doesen't shift out of 1st like many others, it stays in the gear you tell it. It is pretty much the ideal design that we all would like in our automatic Lexus'.

Mistical

Is there anyone with some helpfull info and/or resources?