Stan.....
Been racing a 510 for about 6 years now....
Looking at changing my springs right now (or at least for next season) Would love to open up a conversation adn explain my theories etc etc. Basically the car has been running on 850's (rear) for about 4 seasons. I feel these are weak and need replaced adn would like to go stiffer. My brother, who also co-drives (another class) feels that the springs need to go softer. Swapped in an old set of 800's for the last race of the season and we both gained about 4/10's hmmm.... colder or just a better setup. Talked to other dimers and have heard from 850 -1000 in the rear.
Email me at [email protected] to chat.

Hank Bene