[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] t3 dropped spindles? (kinda long and geeky)


On 18 Nov 2002, at 23:56, John Jaranson wrote:

> Just my engineering 3 cents worth.  Maybe a bit more.

Thanks John, for reworking this. It's good to get our facts straight on this. 
Yes, I think it's clear that VW intended the top of the tunnel to be the 
reference line for these measurements and for this line to be horizontal.

If the lower arm is already 10 deg upward at the stock setting, can you 
estimate the angle with different amounts of drop? I wonder how much more 
this stiffens up the suspension since the compliance is going to go as cos of 
that angle, for the static case.   

In the dynamic case I would expect it to be even worse, because the force 
vector from objects that the tire hits will not be vertical but angled up and to 
the rear. Once the available suspension motion is at right angles to this 
force, dynamically, the suspension will be out of travel. At that point the only 
compliance left is in the tires.  

Interestingly, if we continue this farther, with the arm angle even more 
steeply upward, hitting a bump looks like it would cause the suspension to 
jack the car and actually give negative compliance. Is this realistic, or am I 
missing something?  

It's easy to see that hitting larger objects lowers the angle of the force vector 
on the tire/suspension and gives us our worst case.  

I'm actually surprised that the stock lower arm angle is ~10 deg upward. I 
would have expected it to be horizontal or slightly downward, just to allow the 
system to work thru the horizontal. Maybe they thought that it would be best 
if the system only went thru horizontal below equilibrium (when the wheel 
dropped into a pothole,) but I don't see any advantage to that off hand.   

Do you have any estimates of what the arm angles are at the 2 stock 
extremes of travel?   

-
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054
USA

------------------------------------------------
To unsubscribe, E-mail to: <type3-off@vwtype3.org>
For more help, see http://vwtype3.org/list/

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]