98 to 00 SC400 VVTI (drive by wire?) YES OR NO!

[lowboost]

I was told that all the 98 + and VVTI V8 engines are drive by wire. I own a 01 Tundra and its got a cable throttle body on it. I just found this out when I was jumping off a friends car. Does this mean that the SC400's and LS400's etc are all cable drive? I wanted to know if the SC400 98 vvti was drive by wire or cable like the older models? I cant seem to find out anywhere, does anyone here have a 98 model car and would care to answer my simple question?

 

[Lextreme II]

I think only the 2001 and up SC430 has DBW. We just removed one and it was cable.

 

[lowboost]

I think only the 2001 and up SC430 has DBW. We just removed one and it was cable.

thanks for the fast response, that helps a lot. Now what about converting it to a manual, has anyone had any problems with that or do they just use AEM to take care of the transistion.

 

[JBrady]

DBW arrived in 1998 on all Lexus V8 cars. These engines HAVE a cable but the cable does not directly engage the throttle plate. Now, if you go full throttle the mechanism will open the throttle maybe 20%. I believe it is a limp mode failsafe. Otherwise the only thing the cable does is move the TBS imput and the computer actually controls the plate via an electic motor and gear assembly on the opposite side of the cable.

 

[lowboost]

looks about like my tundra style throttlebody, but its just like any older toyota for the matter that you can just pull it back to rev it up. I'm still sourcing a wrecked sc400 so i can do a complete swap into my supra.

 

[JBrady]

looks about like my tundra style throttlebody, but its just like any older toyota for the matter that you can just pull it back to rev it up. I'm still sourcing a wrecked sc400 so i can do a complete swap into my supra.

I am unsure what you mean.

Let me clarify, on the 98-00 1uzfe in the GS, LS and SC400s there is a throttle cable per say but it does NOT move the throttle plate in the throttle body. There is nothing connecting the two EXCEPT a tab that will eventually contact the throttle shaft IF you move the throttle cable about 80%.

The entire operation of the throttle plate is done by electric motor and is NEVER directly moved by the throttle cable under normal operation not even full throttle.

 

[turboandrew]

In order to have the throttle cable fully open the throttle plate, you will have to take apart the mechanism and change the tab location so that it does fully open the throttle plate. I have plans to do this myself, but it's on a long list of things to do.

 

[Lextreme II]

My VVTi arrive next week perhaps I can take some pictures.....

 

[JBrady]

In order to have the throttle cable fully open the throttle plate, you will have to take apart the mechanism and change the tab location so that it does fully open the throttle plate. I have plans to do this myself, but it's on a long list of things to do.

I had a Tundra throttle body that I openned with the same intention. I tried to bend the tab back to relocate it but it broke off. I am careful but the material would not accept the change. I had envisioned creating a "puck" out of hard nylon that would connect the two shafts. This is still a possibility. I am unsure how the system will react to positive cable imput to the throttle shaft. I would guess 99% of the time there would not be any issue. I do wonder about the times the electric motor would make one selection and the cable input would conflict.

One of my biggest complaints is how the throttle reacts at low speeds and actually creates a BIG lag and then LURCH trying to smoothly flow with stop and go rush hour traffic VERY DISSAPOINTED in this programing my Lexus.

I am also not certain about the torque management between shifts. Does the ECU pull timing, pull throttle, either or both? If throttle it could help in full throttle driving conditions. Otherwise it is more the response issue that is not pleasant.