spring rates for rough tracks, opinions and advice sought Options

[Seabird]

For those who run on Sebring and equivalently rough tracks what is a good starting point for torsion bars and spring rates on a -4 with DOT R type tires and Koni Sports.

I have done a search and see a lot of advice from West Coast drivers. Also spoke to the experts at Elephant (F 23mm R 250#) but again they have limited rough track experience.

Thanks in advance!

[brant]

the 4's are actually better track cars up to a displacement point of around 2.4

if you want more displacement than the path is usually a 6
but head to head a small 4 can be faster than a small 6

now the classes are a completely different story... and those 2 cars don't go head to head in their respective classes.

but back to the point
the 4's aren't really disadvantaged
the vintage rules get specific usually about the technology of the day
so for example most clubs won't allow crankfire or Mega squirt because neither were invented in 1972

the 6 cylinders are locked into a 1972 rules base so they are usually 2.0 motors with locked in technology. they are about 50% conversion cars.

I'm not sure if SVRA has a cut off year
historically most vintage clubs used a 1972 cut off
(some are going forward with 1981 these days)

factory built 914's only had a 2.0/6 or a 1.7/4 available in 1972
so for a club with that cut off you have those 2 options to choose from. a lot of guys used to get pissed when their 2.0/4 wasn't allowed into a club...

the E production ranks for the 1.7 are actually probably a better set of competition than a 2.0/4 would face in 1973.... although some vintage clubs have small enough attendance that they might run those classes in the same run group.

(the 2.0 will probably run D production, or D production-1981)
depending upon how many new cars are in your club, 1981 ranks can be tough competition... I'm sure chris foley could weigh in on that discussion.

basically newer cars with newer technology are always getting faster and faster. so for example the technology in a 1983 944 will be a superior design to a 1973 914...

the same adage applies to other cars... so a 1978 or 1981 sports car with the same weight and balance and tune could be faster in the 1981 ranks. luckily there are not many 1981 cars in most vintage racing clubs so the 914 is still pretty competitive in D production

ultimately... the most competitive car is going to be built for just one sanctioning body... thus my recommendation that if you are going into svra really build to their rules and you'll have a more competitive car when you get there.... you may give up something in nasa, but you won't have the frustration of having to re-do or undo any of your hard work and money

reading the rule book first is the most important step to building a competitive car.