Stiff springs, standard strut inserts

[san_maru_zed]

Just wondering how this combo would go? I know ideally I would need to use strut inserts to compensate for the springs, but for the moment they are just out of my budget.

What I am mainly concerned about is the car bouncing with the stiffer springs.....is this likely?

Ray

[240ZX]

Does your car bounce up/down now? If not, that mean your inserts (shocks) are still functioning. Installing stiffer springs will not make your car bounce as long as your inserts remain functional...however, with the stiff springs you will be working the insert more due to the increase in spring force. All this means is the the insert life will be shortened. Consider saving your $$$ until you have enough to purchase new inserts and do the springs and inserts at the same time......this will save you from doing twice the work!

[Curtis240Z]

240ZX is right. Because the Z has MacPherson struts all around it is no small task changing springs and/or struts. IMO, it is not worth doing the job twice, wait until you get both before taking the suspension apart.

[moyest]

I had standard inserts (still in good condition) with stiffer springs for a couple of months, and the result was a bouncy ride.

Inserts are "rated" a bit like springs, and vary dependent upon the length etc. I think shorter inserts have a faster rebound rate, etc?? Not sure.

Anyway, the better the match (to your springs), the better the ride.

I agree you should wait to match up your inserts and springs properly.

I also agree with 240SX that the life of your existing inserts will be shortened, particularly because you will be compressing your existing shocks with what I assume are SHORTER springs (?), which tends to wear the inserts quite a bit.

You might also end up with the scenario that your shorter springs float around when you jack the car up. That is, if you have shorter springs on top of longer inserts, when the wheels hang down your springs won't be long enough when fully de-compressed. It'll be ok when your car is sitting on the ground, but when you jack it up (or jump off the end of a rural road bridge or some bumpy bits) the springs will float around. Not the best.

That's why I eventually got proper length inserts, so that I could pass my roadworthy checks!! :eek:

[Aussie Zed]

If you are really tight for cash an alternative to buying new gas inserts for your struts is to take the ones you already have out and change the oil in them. The oil run in standard shocks is (usally) very similar to ATF and replacing it with say 30W oil would up the damping rate by about 40%. Munroe shocks used to (a while back) offer a stiffer shock for lots of models just by running heavier oil and the same valving.

Wouldn't be too hard to do. Just need some new O-rings and maybe one or two other things.

If you have the time this would be a lot cheaper than forking out for new konis or something.

[260DET]

Shocks are like springs in that they may be obtained with various 'rates'. For the best performance the spring and shock rates should be matched to suit your use.

So basically there is not much point in uprating the springs and not the shocks. For the S30 there are very few people around who can match springs to shocks properly, it being such an old car none of the well known suspension modders like Pedders or Whiteline know.

[san_maru_zed]

AussieZed, that sounds like something dodgy I would do cheers for the idea.

[ZSaint]

When I first started autocrossing many, many years ago, I had a MGA. It had friction shocks on it. I took them out and drained the thin oil out of them and put in STP. It did not work as it would chatter over bumps and I would lift wheels all of the time. The shocks simply no longer worked. I once again changed the oil to 10wt and they worked very well. They were considerably stiffer than the original shock 'valving' and were satisifactory for my needs. I tell this story to remind people that changing from light/5wt oil to 30wt oil is a tremenduous change in viscousity. Be careful with these changes... a lot of bad things happen (to the shock valving) when they are too stiff.

[bpilati]

Actually MacPherson struts are at the front of the car, and Chapman struts are at the rear.

ZSaint is correct, don't over compensate with too heavy an oil. The suspension is a system; it's not just make everything firmer and it's now better. You have to look at the weight of the vehicle on each cormer. I think body roll and wheel camber are more important in handling than having rock stiff springs and shocks. Anyway, I think if you buy the Tokico sets with both shock and springs they are probably matched.

[SuperDave]

...I once again changed the oil to 10wt and they worked very well...

I'd like to experiment with this. Do the procedures for changing shock oil vary much from brand to brand?

I assume when you change the weight of the oil, you're changing the way it behaves on compression AND rebound?

Unlike double (or triple or whatever) adjustable shocks where you could adjust them separately?