Data System sensor - Ride Height

[silente]

Sometime ago i saw somewhere on the net an article to fit ride height sensor on a car in a cheaper way than with normal laser sensors, but i was not able to find informations about this topic anymore.

Does anybody have ideas on how to take this measurment without paying thousands euros to fit very very expensive sensors?

Thanks.

[Paceracing]

It depends how accurate you want to be. There are ultra sonic sensors out there which are cheaper than lasers but the accuracy and quality of data is questionable. If you are going to all the trouble of wanting to accurately measure ride height then lasers are the only way. A far cheaper method, (with results more comparable to an ultra sonic sensor) is to simply measure the suspension ride height using damper potentiometers. This is how the majority of teams in GT racing, etc do it.

[silente]

Hi PaceRacing,

Thanks for your reply.

I was doing with suspension potentiometers, but you completly ignore tyres deflection in this way, which is an important part.

Do you know the prices of laser sensors? I hear abut 2000 euros...

Maybe there is some non racing but fittable sensor wich allow to spend less for the same application..

[RichardScott]

The tarmac on the track is not completely flat so there will still be uncertainties in the data even when using laser ride height sensors.

[THR]

try talking to Sensopart, they are dead helpful, and cheaper than most suppliers of sensors.... depends what type of signal your logger needs, but he is very helpful guy! 0121-772-5104 say paul from incotech sent you.

[Casper]

Possibly this..........

http://www.jameshakewill.com/sus-pos-v1.pdf

[phoenix]

Originally Posted by RichardScott

The tarmac on the track is not completely flat so there will still be uncertainties in the data even when using laser ride height sensors.

Or even if the car passes over a pieces of rubber or other debris on the track?

[THR]

would be soo quick, it wouldnt matter

[silente]

Hi THR,

thanks for your reply!

Do you have aby link to the company you said? I found a lot of companies with the same name on the web.

Thanks!

[THR]

http://www.sensopart.com/
you can find the contact details on there.

[Paceracing]

Originally Posted by silente

Hi PaceRacing,

Thanks for your reply.

I was doing with suspension potentiometers, but you completly ignore tyres deflection in this way, which is an important part.

Do you know the prices of laser sensors? I hear abut 2000 euros...

Maybe there is some non racing but fittable sensor wich allow to spend less for the same application..

Yes you are right about the price and about tyre deflection being an issue which is not taken into consideration with suspension pots.

There are a number of types of laser out there, but the non-motorsport variants have a very limited life due to the harsh environment and often have poor thermal characteristics, (i.e thermal drift is very common on non-motorsport variants when mounted near a heat source such as the gearbox). The non-motorsport variants are often a false economy. The proper motorpsort sensors are more expensive because they have been designed specifically for the job rather than because they are a 'motorpsort' item.

[Paceracing]

Originally Posted by phoenix

Or even if the car passes over a pieces of rubber or other debris on the track?

Correct, however it is largely irrelevant, (even the painted white lines on the track show up in the data). What you are looking for is the trend of aero load / balance front to rear. You can see debris very easilly in the data and ignore it.

[phoenix]

Originally Posted by Paceracing

Correct, however it is largely irrelevant, (even the painted white lines on the track show up in the data). What you are looking for is the trend of aero load / balance front to rear. You can see debris very easilly in the data and ignore it.

If you are looking for a trend, does tyre sidewall deflection really matter?

[silente]

If you are looking for a trend, does tyre sidewall deflection really matter?

Yes, because you need to create a map with connection between real ride height and downforce. Formula cars are really sensitive to ride height and often don't follow a linear relationship..

[Greg Locock]

I'll gently put my toe in the water and wonder whose aero maps are so accurate that measuring the true rideheight is necessary, vs measuring the suspension ride height and inferring a tire deflection.

[phoenix]

Originally Posted by Greg Locock

I'll gently put my toe in the water and wonder whose aero maps are so accurate that measuring the true rideheight is necessary, vs measuring the suspension ride height and inferring a tire deflection.

That is more or less the meaning behind my question. Just as there will be transients from an irregular surface there will be transients from the sidewall flexing over bumps, and kerbs etc. If only a trend is required, then the tyre stiffness versus suspension stiffness could be used to compute what the total change in ride height is using only the suspension deflection data as an input.

[Andrei]

This is exactly what we have done in Formula BMW. I have lokked to suspension travel, computed wheel load and computed then wheel deflection. Of course, it was not very precise because I have only got some static vertical stiffnes of the tyre, but for Formula BMW it was good.
I just wanted to have a look at ride height to see if there is any influence, or it does not really have any effect.
I think, great accuracy in ride height is only good if you have an aero map. An this is not quite the detail you get everywhere.

[PeterT]

We have some lasers at a much more reasonable cost about 5th the cost of others around, www.kasensors.co.uk
Used them on everything from F1 to A1

[THR]

they look like the sensopart ones to me, ie just normal sensors from industry.. £100 odd for a laser one