East Tennessee Region SCCA

Besides going to the dealer who do you recommend getting tire sensors programmed in my FRS?

Uh....take em out and save the weight!

A lot of the better tire shops will have a generic tool that can probably do it. I'd call Fisher, Matlock, Murrel Bros, etc, and see if they can help you.

thrdeye wrote:Uh....take em out and save the weight!

Weight. ... you're joking right? I'll keep them in and take off 10lbs of body weight and screw the weight for removing TMPS sensors and looking at a idiot light every day

Hey, it's unsprung and rotational mass.

The miata uses some wizardry with the speed sensors in the ABS - nothing in the wheel.

Besides, this is how you deal with idiot lights.

http://www.target.com/p/scotch-vinyl-el ... lsrc=aw.ds

Ryan .....I thought the link would have taken me to duct tape

thrdeye wrote:Hey, it's unsprung and rotational mass.

The miata uses some wizardry with the speed sensors in the ABS - nothing in the wheel.

Passive systems just use wheel speed. If one wheel is turning faster than the others consistently, it assumes that tire is low and turns the light on. No wizardry, just programming.

lcoleman wrote:

thrdeye wrote:Hey, it's unsprung and rotational mass.

The miata uses some wizardry with the speed sensors in the ABS - nothing in the wheel.

Passive systems just use wheel speed. If one wheel is turning faster than the others consistently, it assumes that tire is low and turns the light on. No wizardry, just programming.

So does the system depend on the other three being correct to know that the fourth is low? Or is there some kind of base calibration?

The system on my Mazda3 has a calibration button that you hit if you change the wheel/tire configuration and it remembers the readings. So, no, at least in this case it doesn't depend on a comparison to the others.

It works fairly well. I've played with it and it can detect when one tire gets about 5 psi low. I think it has to be reading a change in wheel rpm for some period of time though, as pushing the car through the twisties doesn't upset it and you know there is quite a bit of change in rolling diameter there.

Yes, every passive system I've come across has a reset button or menu option. +1 for brief changes in speed not triggering the light. I'm assuming it is smart enough to disregard the outer tires going faster than the inner tires in a turn.