l have taken, from memory a half a coil from the rear springs on the 75 without any probs. l did however clamp the base of the springs down to the mounting plate on the De Dion tube, as it didn't feel like it was going to stay there when l had the car up on the hoist with the wheels off the ground.
The standard Koni yellows on the 75 work nicely, l have mine on full soft.
However on my Alfetta GTV which has the larger 28mm torsion bars with the matching rear springs, l sent the Koni yellows off to be tested and re-valved to Pace Engineering spec. l had raced it at Winton before and then after with about a month between the two meetings.
Words can't describe the difference, waaaaay waaaay better, three seconds better. Same tyres with a little less psi from the time before. One thing l did adjust, other than the dampers was lowering the rear end of the car by 6mm. The car rode the bumps better, l could brake latter, it felt spot on, front tyre wear was perfect from the inside edge to the outside edge. l could feel the difference even when driving to the track that morning, the ride quality over some very average back roads was nothing short of brilliant. When l get a chance l will do the same to the konis on the 75, l think it's worth the extra dollars.
lt's worth noting that l feel, ride quality and general road manner of the Alfetta is considerably better than the 75 even though the Alfetta has firmer spring rates and a 100mm shorter wheel base. At the end of the day the dampers play a very very big part in just about everything we do with our cars but are often over looked.
l will never forget when being shown through the new and almost finished home of Triple Eight Engineering building. l was allowed to go anywhere l needed to when installing the new signage on the entire building inside and out,(3 days work) but when it came to the shock/damper room l was to contact Trevor the general manager of Triple Eight engineering because the damper room is absolute top security, no one, but no one goes in there other than the two full time guys that do all the building and testing of the dampers. As Trevor said it's one of the most important rooms in the complex.
That rather privileged experience was pretty damn good. To see the build quality of the cars from inside the fabrication room, talking to the guys that actually do the fabrication from scratch, to the graphics bays where the cars get all the race livery. Is it any wonder the Americans are looking very very closely at our Supercar formula with the view to replacing the old Nascar formula, yes they want and admit they need to change. They want four opening doors, working lights, cars that look like the family car only with numbers and stickers. So you blokes that go around Knocking the Supercars, think again, it could be that the Aussie Supercars lead the way in the world of fast sedan racing, and l'm serious.
Sorry to get distracted at the end of this post, thought it worth telling. I’m proud of Aussie motorsport and damn proud of the quality of race cars we build and formulate in this country, not to mention the thousands it employs every day.