I put together a Dyno day today at Swift Motorsports with a bunch of guys that I motor with here in the northeast. More on that in another thread, very interesting results, to say the least.
The purpose of this thread is to figure out why the speedos didn't work in both my cars while on the rollers. I can't imagine the MINI would take a speedo signal from the rear wheels, although the rear wheels were the only ones not spinning.
Any thoughts...?

 

the mini does use the rear wheels for speed sensing.

 

So the speedo picks up the signal from the ECU from the rear wheels?

 

i believe it uses the ABS sensors just like the way they use then for the tire pressure.

 

When my car was on the Dyno its speedo didn't work either. The guy there told me the guy senses the rear wheels not moving and goes into a diagnostic mode. I don't know if its the truth or not..but the car does throw lights and crap so it senses something.

 

My ABS, Traction Control, and tire lights were on the whole time. I called onasled and stumped him with this question, if you can believe it!

 

get out the bentley manual and look for a speed sensor in the schematics

 

When the car first goes on, the rollers offer no resistance. Matt, the owner of Swift, said it's like the car being on ice. That has to be why all the lights come on, but to get the car straight on the machine to tie it down you have to "drive" it to move it from side to side.

 

There's sensors in front and rear. If it senses the fronts moving, but not the rear or vice versa it'll throw the DSC light on and speedo will not work.

 

I don't have a Bentley manual(i know, i'll go sit in the corner when i'm done typing) maybe someone will chime in that does.

 

haha i have one, i just dont feel like flipping thru the pages right now and tracing wiring schematics

 

I can see why the lights would come on, it's just very odd that it would disable the speedo. We are obviously confusing the hell out of the electronics.

 

well im sure thats why its not moving, its just confusing the computer.

we need to experiemnt.

someone get up to around 90 on a patch of ice and yank the ebrake.

 

Is it safe to say to get a "good" run with the DSC/ASC off, we would have to be on a machine that will spin the rears as fast as the fronts?

 

That would be a pretty big patch of ice. Probably wouldn't qualify as a "patch" more like a lake.

 

ok, lets change it.

small lake or large pond

 

orrr disconnect the wheel speed sensors in the rear And you don't need to wait for winter!

 

So, here's a question. If I have 16 inch wheels with a 45 series tire. Is it possible my MINI is actually reading the correct speed?