i just purchased a supra 3.76 Auto LSD Pumpkin and will be installing it in my sc300 auto. i need to know when can i do to correct for the difference in speed taht will show on the tach? i know it will read about 8 miles an hour more then what it really is. is there any collibration you can do or anything at all?

 

On the 97 it is even twice as difficult since it is controlled through the ODBII system. It has to be done digitally.

......or just lean your head to the right a little while driving.

 

is there any digital controller sold taht can do that.

 

Calculator..... Sorry. I know bad joke. It looks like the signal comes from “speed sensor #1” and runs right into the back of the combination meter. From what I’m seeing it dose not run through the ECU.

 

On the old cluster it runs pretty much directly into the gauge, but on the new cluster I was remembering it go through the processor on the main chip (not speaking about the computer ECU).

can you see that far into the unit david?

 

There is a yellow wire coming from the 10amp gauge fuse, through the "speed sensor #1" and into the connector on the back of the combo meter. I can post the EWD tomorrow when I get to work.

 

ok, i can see how teh wiring on the two cluster is totally diffrent. i have the
wiring diagram book for my car and all i need to know is there anything i can do to fix this. i tryed to search but nothing.

 

it is all a ratio, not an exact difference. in addition, it will read the reverse of what you are thinking.

Stock gearing: 4.27
New gearing: 3.76

After the swap, your actual speed will be 14% greater than what the speedometer will read.

The 3.76 gearing means that the driveshaft (and drive pinion) spins 3.76 times for each full rotation of the wheels (and differential ring). Your transmission is expecting one full ring revolution for every 4.27 driveshaft turns. But, after the swap, you will have spun the ring 1.14 times around for every 4.27 turns of the driveshaft (ie. the wheels are spinning at the higher rate than the transmission thinks they are and your speedo will be light, not heavy).

Thusly, your attainable top speed becomes higher, your speedo reads slower than you are actually going, and spinning the wheels requires more energy.

Perhaps the best benefit of the swap will be highway fuel economy. You will be able to go 85 and still get 20+mpg.

 

so there is nothing to corect the speedo to rear correctly? so if i am going 60mph then the speedo will read a little higher like 65-69, i hope there is someway to correct this. i heard of some kind of yellowbox? anyone know?

 

with the new gearing, you will be traveling at 68mph, but the dash will read 60.

your words above suggest that you have this backwards. re-read my previous post on the topic and you can see why it is that the speedo will rear improperly (and in what direction).

 

sorry for the confusion. thanks for clearing it up. do you know if there is a solution to this. maybe some kind of controller.

 

Right, it's when it gets to the back of the combo meter it hits the prom in the cluster, that's what needs flashed.

 

Try this on for size

 

If its obd II can lexus just recalibrate it for you. I know they do that to domestic trucks and cars all the time when going with bigger wheels or different rear ends.

 

... not to mention I would check if your new rear end is really LSD. What year of Supra TT did it come from?