Viscous Coupling article.

[Steve Webb]

Big thanks go out to EvoDelta who has provided us with a comprehensive article about the viscous coupling. Its based around an Integrale, but the same VC is in our Q4's.
The article can be found here Vicous Coupling article (http://www.berlinasportivo.com/Technical/VC/coupling1.php)

Lots of info and loads of pics.

Enjoy.

Steve

[arjunior45]

thanks Steve {and Evodelta}. Compliments

Nick

[AlfaJack]

Not had a chance yet but look forward to reading it!

[Juan AR155Q4]

Sorry to bring this back, but can the article be uploaded again?

[AlfaJack]

.com seems to be dead again, here you go:
http://www.berlinasportivo.org/Technical/VC/coupling1.php

[Juan AR155Q4]

That's fast!!!!
Thanks.

[jimnielsen]

would it be possible to alter the front / rear torque split of the VC unit by modifying the rotating blades inside the unit? To, like, 40/60 Front to rear.

jim.

[Evodelta]

The VC doesn't control the ratio between front an rear, this is built into the centre diff.
It controls how far the front or rear wheels slip (relative to one another) before locking.

[jimnielsen]

yep, I see that now :) So looking at the components involved you would have to make / modify quite a bit of stuff to change the front / rear drive split, which according to the Q4 manual is 47% front & 53% rear. Was there ever a Lancia Delta Integrale that had a different torque split, with more torque going to the rear wheels - such that one could fit those parts direct into a Q4 system?

jim..

[Q4Jan]

The older deltas had it the other way around.
So 53% front and 47% rear. Not much use.

The 155GTA had more to the rear, and probably some race integrales. But i would be surprised those parts would fit easy, or would come cheap.

[Evodelta]

Jan's pretty much covered it - expensive. There are companies which could provide the parts, Bacci Romano in Italy being one.

But why?

[jimnielsen]

Well, I am sure that it would make little sense for most peoples Q4's however, I find that mine has too much front drive in slow 2nd gear corners which delays the ability to get back on the gas as quickly as possible. As long as you don't have to reduce speed to < 65 kph its pretty much ok, however in corners where more steering angle is required too much understeer is created when the amount of drive to the front wheels causes less grip to be available to keep the car turning. If front drive was reduced to 40%, then the system would produce faster lap times.

[Evodelta]

Maybe try changing your driving style and getting some lessons.
I understeered out of one too many hairpins, threw the keys to a rally driver who jumped in and promptly slid through them sideways.
That and a properly designed and set up suspension system which came afterwards. Just chucking on hard springs is never going to cure anything - quite the opposite, it will make things worse, the secret is in the damping.