G'day everyone,

Thanks for the kind words.

I'll take some time to answer this properly so we can use it on the suspension tech forum, give me a few days. It's a very popular question and points to one of the most popular retail misconceptions in suspension tuning. We have a lot of material used in training to explain why but need to format into one of our tech discussion papers.

In the meantime, please consider following;

- HRT's V8 Supercars use front rates of around 12 kg on a car that weighs considerably more, runs on slicks and would lap Wakefield in under a minute.

- Our P-Rex XRD (97 Sti) used 8.5 kg to do the 1:05's.

- The fastest road based car we run at the moment is Project EVO VIII which is primarily setup for tarmac rally but was configured for slicks for an endurane race at Wakefield last December. It qualified 2nd on the grid at 1:04's and used 9 kg.

- There is a direct relationship between tyre grip potential and spring rate. The more grip you can generate the more spring rate you need. Conversely, the lower the grip potential the less spring rate you CAN USE.

- There is a direct relationship between road surface and optimum spring rate. The better the road surface the less suspension travel you can get away with and consequently the higher the spring rate you can GET AWAY with (though not neccessarily need).

Be back soon

Cheers

Jim
Whiteline