Odd 411 litterature

[Lars S]

Have anyone read this report from 1969? - if not you can previev a few pages and also buy it here:
http://papers.sae.org/690489/

/Lars S

_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[raygreenwood]

I just previewed that. Thank you!.....I may actually buy it just to see some of their conclusions....howoever what the author remarked on early on in the document ....is exactly the problem VW ran into with the 411/412.

To paraphrase a lot.....Larger/Heavier cars are easy to control for ride comfort with larger springs.....because they have the weight and inertia to operate them. If you dont have the weight....you cannot have as stiff of a spring unless you have longer "lever".....(meaning connected suspension components)...to operate them.

I think VW did very well for what the issues were. This is a light car by today's standards....about 2250 lbs.

The factory springs are actually quite capable and have a lot of energy for such a light car...which is why there is actually quite a bit of tuning improvement that can be done without actually having to change the factory springs (as long as they are not worn out).

Just looking at the layout of the front suspension...you can see what VW did.

Look at the length of the control arms. Some of the longest I have ever seen....mounted from the center pivot point instead of outboard. This generates leverage to operate what are actually pretty big in diameter, long and stiff ....coil springs.

When I compare the 411/412 springs to the ones on the front end of either my 90 model cabrio or my 2006 Jetta or my current 2012 Golf.....the 411/412 springs are roughly twice the size as anything on the water cooled vehicles...AND those three vehicles have the entire engine and drive train weight on those struts and springs.

They offset this....by having really short control arms so the leverage ratio to operate on the smaller springs is less. They maintain a smooth ride and decent compression and rebound handling.

You can also sense that the 411/412 was just on the edge of being correct for its spring size...using leverage....but not quite right......because if you follow the lead of the author of this article...and add about 150-200 lbs to the trunk....it tames and stabilizes teh front end...and take up for teh weakness in rebound valving.

Of course....if you drive it too long with a load like that on the stock strut cartridges and suspension bushings....you will destroy them. Ray