spring rates on 240sx

[unborn]

I'm in the process of building a suspension for my 91 240sx. At this point the only mods i have are my white line bars and a set of 40d strut bars. I am however unsure if it is possible to run a 350lb 5inch spring on a coil over conversion kit. I know the car has a lack of wheel travel in the front. Will a 350 rate in addition to the white line bar on full stiff up front be enough to avoid slamming the bump stops? Ill be using the car for both street and road course use. Thanks for the info

Unborn

[Peter]

G'day Unborn,

I think the secret of answering your question is not so much about the spring rate but the ability of the shock contained within the strut to control the springs you are referring to.

You can twist up a bit of spring steel wire and make it is stiff as you like but if the shocks cannot control it you are in big trouble.

If you are interested in spring rates around the numbers you are mentioning - I would suggest you have a look at the Group4 Coilovers.

Regards

Peter
peter@whiteline.com.au

[allwaysideways]

hi, what would the results be of running a stiffer spring with a worn shock or shock that isn't uprated?

[Peter]

Hi,

The short answer is "Dangerous" ie: the shock will not have the capacity to control the spring which will continue to oscillate without control. This causes tyre contact with the pavement to be lost which is a loss of grip. A basic rule here is that springs control bumps and shocks control springs. A couple of articles worth a read can be found here:

http://www.whiteline.com.au/faqshocks01.htm

http://www.whiteline.com.au/faqsprings.htm

Regards

Peter
peter@whiteline.com.au