wheel hop continued

[slngsht]

I would suppose that the location that the shocks are mounted would have alot to do with the spring rate. If the leverage arm is shorter a lighter spring would act stiffer than the stiff spring with a little more leverage applied. The mounting point on the control arm and the angle of the shock would effect spring rate too. JBH you are also running a sway bar. The Ultralites do not. That is why I had asked if he used a sway bar. If you are running a sway bar a lighter spring could be used depending on the size of the sway bar. I was simply suggesting that if slgsht hadnt tried it, to give a look. If you run out of shock adjusment then you can start to adjust spring rates instead of replacing or revalving shocks which is more expensive way to do it. Springs are realatively cheap . It sounded like slgsht had used up the shock adjustment just trying to give him somewhere else to look. What do I know Im probably all wrong.

 

I still have more shock adjustment available... out of 24 clicks, I had both R & C at 10, then both at 20, now R = 20, C=10. I can loosen up compression more to perhaps resolve the wheel hop problem, but don't know the effect on transient handling. One problem is I don't get enough seat time in places where I can really test this stuff.

[Obi wan]

I run 600s in the front and my car is a little lighter than yours. I think you could stand a bit more up front. Are you using sway bars?

 

Hello,

 

You mean 600 lbs spring in the front on a 600 kg (1300lbs) car ?

[WestTexasS2K]

yep

[JBH]

You mean 600 lbs spring in the front on a 600 kg (1300lbs) car ?

 

That's why I asked...seems like a lot of spring for a light car.

 

The geometry may be different, but I bet that car doesn't roll more than a couple mm when you turn. I am also guessing you are not driving it but on the smoothest of roads. I also am not sure damper is a relevant term for your car.

[Obi wan]

 

That's why I asked...seems like a lot of spring for a light car.

 

The geometry may be different, but I bet that car doesn't roll more than a couple mm when you turn. I am also guessing you are not driving it but on the smoothest of roads. I also am not sure damper is a relevant term for your car.

 

Surely it is a pb (without talking about a possible or not, problem of geometry)

 

Look : my car is 545 KG (1000lbs) & I have 250 lbs in front vs 170 lbs rear ! ...... and it is VERY STIFF for road use (excellent for track)

 

maybe you could try something smoother

 

 

cheers

[WestTexasS2K]

I drive my car 6-10k miles a year with those springs 600F/275R on every road type in the country with no problem. It is firm but not harsh. It does exhibit a limited amount of body roll but not alot as you would expect. I know of 5 other Ultrlites that run the 550-600 range as well. They are all used for track/street/autoX driving. Our front control arms are much shorter than the ones that I have seen on the Caterham, Stalkers, Birkins so we dont have the same shock ratio that alot of other cars have.

[SR27.Seth]

Maybe a little stiffer front springs will also help reduce the weight transfer from back to front. Helping keep the rear planted if you run out of shock adjustment.

 

I know this is going to get a few disagreements, but raising front spring rates will not reduce weight transfer under braking.

Secondly- the spring rate thing- I could take two cars of the exact same weight and general suspension configuration and depending on where I mount the springs I could have the same wheel rate with a 100 in/lb spring or a 600 in/lb spring, so comparing spring rates from LSIS to LSIS is meaningless, seriously, meaningless.

[WestTexasS2K]

see told ya I didnt know anything . Thanks for straightening us up on the issue.