Corner weights for WR, MB or even RR?

[marcz]

Has anyone here corner weighted their quattro? I need to find out this information so we can start planning the coil/damper specification. AS the car has never been in a state of complete assembly, I have no way of knowing this until after it is built and unfortunately the car will probably have the suspension in it before the motor is built.

A set of figures for a standard Ur would be fine and a good starting point but if any of you who have competition cars have actually corner weighted your car, I'd love to know your results.

I don't even know the front to rear ratio, let alone the full corner weight information so if anyone can help with some figures, I'd be VERY VERY grateful.

Cheers

Marc

[puglife]

Ian simmonds and I have done abit of research into this marc....

Not yet complete as i lost some data and have been busy doing my uni dissertation but:

Audi UR Quattro Weight List

should give you a good starting point.

[marcz]

Nice one Jay! That is indeed a great start... and quite a surprise too! 810kg Front 490kg Rear is pretty shocking really and I would never have thought it was that bad. That is then compounded by the entire motor sitting way our in front of the wheels. I would have guessed it to be more like 750/550 at the absolute worst. I have heard the expression "lead-tipped arrow" before... now I know which car they were talking about

I should also weigh some of the components you don't have figures for while the car is in bits and those bits remain standard/original.

Thank you very much for that.

[puglife]

No worries marc Yes if you can help fill in the blanks... I stupidly sold all my WR engine that i'd stripped down after weighing everything only to lose the file with the weights in!

I'm going to transfer everything across to my own site once i get it all finished.. Will be doing some more maths on stuff as well as trying to remake some smaller bits for people

[A1quattro]

it wouldnt matter if engine was pushed back a foot the weight would still be the same over the front axel, but would help a little bit with under steer . the engine and box are very heavy [as we all know] we have set my rally car up several times , i will dig the settings out. its not as bad when two people sat in front seats, makes it around 45/rear55/front

[Julian]

Originally Posted by A1quattro

it wouldnt matter if engine was pushed back a foot the weight would still be the same over the front axel,

If you push the engine (and transmission) back a foot then you must unload the front axle and increase weight to the rear. To suggest that the axle weights would remain the same is a physical impossibility!

Use an easy mathematical analytical tool, what you look for is the vehicle's center of gravity along the longitudinal axis:

So, first take a datum point, anything will do, say the back of the rear bumper; any component in the car will effect the C of G by its mass (weight) multiplied by its distance from the datum. So take the engine and transmission, moving it back a foot reduces its distance from our chosen datum and hence brings the car's C of G rearwards - by inspection this obviously changes the car's axle weights.

(any point would do as a datum, but if you use one that isn't at an extreme end then you end up with positives and negatives in the calculations!)

[marcz]

Originally Posted by A1quattro

we have set my rally car up several times , i will dig the settings out.

Still looking forward to seeing some figures if they're available

[John Stone]

Got it, after thinking will I ever find that data in my huge pile of receipts, open the folder at about the 50mm down point and got the page in one....
This was all measured when the car had the G60's fitted with new pads and rotors all round in 2005.
Front; left 399kg, right 438kg
Rear ; left 265kg, right 288kg

There is other data, more relative to the suspension efficiency, rolling resistance, adhesion and more with the Bilsteins fitted, could fax it to you Marc if you like?

John