Correcting drive ratio for accurate speed
 

Hi all,

I'm coming from the motorcycle world (Honda CBR 600/1000). This is my first "toy" car.

When I changed my final drive on my motorcycle, there was a speed sensor on the output of the transmission that I could jack into with a device to correct the speedometer. (SpeedoDRD or SpeedoHealer)

Does such a thing exist for calibrating new tires diameters or differential gear ratio changes so that the speed on the dash is correct? Does the speedometer read the speed from the output of the transmission or does it take it from the ABS which must have individual speed sensors?

And yes I know speedometers are not accurate because of the pull/slip characteristic of tires (Longitudinal Force versus slip ratio) and because of tire growth with increased speed, but I still want to be able to adjust it.

I'm pretty sure that this can be done with the Toyota Techstream software and the correct cable plugged into the DLC. Perhaps someone here familiar with the software can verify this.

Yeah, but I want to control it myself. I basically want to break into the pulse wave from the hall effect sensor and adjust the frequency with an IC.

Apparently you can get cracked or less feature packed versions of tech stream (with cable) for like $50 on ebay. Not sure how reliable they are, but if they are it's a very good option to have.

I got it for $27, cable included. I have no idea if it is one of the features.

Well if you can check I would greatly appreciate it Mr. Sportsguy83!

Just to help me, if by tomorrow afternoon I haven't posted anything, please quote me again or send me a PM to remind me.

:thumbup:

Which cable do we need? The mini connector with less pins? If you've got a link to the one you bought that's even better!

TechStream can reset the TPMS' right?

I got THIS one because the software version was the latest one.

If I were to do it again, I would get a cable in USA and to get the latest software just go and get it from pirate bay or similar.

The techstream that is running around has been proven not capable of resetting TPMS. We still don't know if it is because its some type of "Techstream lite" or because there is a specific cable the dealer uses we that don't have access or what.

And I'm assuming it's the same hardware for both the BRZ & FR-S?

Hahaha, awesome. The one thing I for sure wanted it for!

Yeah, same hardware and software.

Just downloaded TechStream from the second best website in the world (ft86club.com #1 of course).

http://i995.photobucket.com/albums/a...Techstream.jpg

But I guess without connecting to the car I can't really check that I can calibrate the speedometer.

I found a cable online. It looks like a 30$ go F yourself for two plastics bits and a wire, but still not bad.

[ame="http://www.amazon.com/16-Pin-V7-11-010-TOYOTA-Software-Techstream/dp/B00AC2FN7Q/ref=sr_1_1?ie=UTF8&qid=1354290894&sr=8-1&keywords=techstream+cable"]Amazon.com: 16-Pin V7.11.010 MINI VCI V7 for TOYOTA Cable & Software TIS Techstream: Electronics[/ame]

I played around yesterday with the software, and it is very basic and limited in what can/can't be done.

Basically the only thing that can be done is change the car settings (DRL turn off, light sensonr sensitivity for the BRZ, turn alarm on/off, simple things like that).

There are a lot of options around, but the software just does not work. When you try and access it (like say the TPMS, changing VCT/TRAC features) the software tells you the system is not responding or not available.

This won't do the trick for speed compensation. I didn't even see the option anywhere.