What spring rate?
 

I'm fixing to get some new springs to go with performance struts, and was wondering what spring rates people would recommend. Its a street car, but I'm willing to sacrifice a 'bit of comfort for the sake of performance for weekend backroading, autox, etc.

It was suggested to me to do 225/250, but I've heard other places that this might be a bit soft...

What shocks have you got? Higher spring rates generally speaking require better shocks.

With good shocks like Konis you should be able to use mid 300lb springs without a problem, something around a 25mm front anti sway bar. Can't suggest a F/R spring rate.

Usually only coilovers have different spring rates to choose from.
is that what you have?

As for standard performance drop springs, you pretty much choose the brand and have to go on hearsay for how they perform.

I'll probably be going with tociko illuminas on all 4 corners. No adjustable perches, just struts and springs.

Do those rates sound "soft" to you guys?

well it is known that illuminas explode above 250lb/in springs.
I have illuminas and 250 rear and 225 front QA1 springs.

huh......?

It looks like I can get rate specified springs from qa1, but they're not listed for individual applications. So I have to choose a spring based on the diminsions. Anyone know where to find the diminsions of the stock springs for a 280zx?

If you're anywhere near 250 pounds, I recommend only the Bilstein Hd shock though I doubt a vendor has them with that rate.

I think suspension techniques springs are around 220 pounds.

Short of the QA1 springs, it looks like the stiffest ride I can get from springs would be to get Tein fronts at 140lbs and Suspension Techniques rears at 182lbs. For refrence, I posted a list of spring rates for various brands at https://www.zdriver.com/forums/showp...2&postcount=59

There anything wrong with mixing fronts and rears from different brands like that?

Looks like the biggest problem with mixing different brands is that they all come in sets of 4 :(

Guess I'll just settle with the suspension techniques for now.

Here is the info from the link above:
Here's some more spring information that I just received from a parts distributor.

Tokico (progressive): 140lbs front / 165lbs rear

Suspension Techniques: 125lbs / 182 lbs

Eibach (progressive): 68-148lbs / 85-306lbs

Ground Control Coilovers: 200lbs / 225lbs

:::::::::::::::::::::::::::::::::::::::

What would the effect be if your front springs had a higher rate than the rear? As in, what if one day I put coilovers on the front with a 250lb spring rate and I still use the ST 182lbs coils in back? ...oversteer/understeer?

That completely depends on the application.

Sanford Silverberg ran a 280zx in Improved Touring (yes, successfully) and ran rear springs at such a rate that he couldn't run enduros because the shocks would get too hot with his rear spring rate around 600.may have been more.

I think he's back in earlier z cars in E production.

It's an old 510 racer trick.

Any suspension works if you don't let it.

This way he doesn't have to worry about rear toe or camber issues.