vintagelex

So for those who looked at my previous thread, it seems like I will have to actually build up the front struts from new parts since Monroe doesn't make front quick struts. I could do quick struts in back and assemble the fronts, but I'd rather just have all 4 be the same, which leads me to my question.

All the springs I look at (Moog, Raybestos, etc) are constant rate fronts and variable rate rears. Is this normal, or just to strengthen the suspension for towing and heavy loads? I really wouldn't want the car to be higher in the rear than the front, it's not the right car for that 70s muscle car stance lol. So, anyone here have experiences with the rear springs? I was gonna go with Moog all around, if there's no problem with the rears being variable rate.

LeX2K

Unless your springs are very rusted or broken just reuse them. Aftermarket springs like Moog are generally junk.

Power6

You won't find a variable rate front spring for this chassis. As said above, the aftermarket stock replacement springs are junk, not made specifically for this car, and the rates are all wrong so don't bother. Some aftermarket performance springs will be good quality, but also made to ride low and hence too stiff.

Either keep the stock springs you have now, or if you have some sagging pony up for new stock springs. Stock springs are linear rate front and rear for most of the years I have seen, you don't mention which generation you have...

LeX2K

The coils for the rear are tapered so the individual coil size varies, I guess this could be said to be a variable rate spring. But if you need new coils either buy new from Toyota or source from a wreckers. There have been a few lowering coils that are decent but long term from what I've read they don't hold up that well either. And like Power6 says they ride much more harshly, if you want this type or ride buy a Civic it will deliver the teeth rattling goodness.

Power6

Lexus2000 bud it is a common misconception, taper or variable wire width does not make a spring variable rate. A spring is a torsion bar like the sway bar. There are two parameters that determine spring rate and that is the diameter and length. Only one of those can we effectively change after the spring has been manufactured and that is length. Shorten the length, and stiffen the spring.

The only way to make a variable rate spring then, is to change the length as the spring compresses. This is done through tight coils that "stack" on top of each other, making the spring shorter and therefore stiffer as the coils meet up. That is how you vary the rate of a spring. You can see the difference typically when you look at the spring. Below is a varible rate spring on top, note the section of closely coupled coils. Liner spring on bottom. Tapered springs are usually the mark of a linear rate spring, the reason to taper the coils is so they don't stack up and vary the rate, its just a packaging consideration.



* notes for geeks: as always nothing is as simple as we like to make it. Almost every "linear" spring has some variance in rate, look at the front springs in a strut, as you compress the ends of the coil lay down on the spring seats a little bit, effectively the spring gets slightly shorter, and therefore the rate goes up. In practice this change is very small so we still consider it a linear rate spring. The change is nowhere near the amount of rate change in a variable rate spring where multiple coils are binding together.

vintagelex

Thanks for all the input - just to clear up any confusion I am NOT trying to "improve" handling or make it stiffer or anything like that by replacing the springs, my goal would be to have new springs while keeping the ride hight and the feel same as original. That's why I was asking about the spring types, that's all. And yes the originals are pretty rusty, the mechanic I took it to also says he would replace them. Our other car, which is an E46 BMW (year 2000) recently had a spring snap, and it was not even rusty - so I thought it would just make sense to replace these while doing struts, that's all.

LeX2K

If you want to retain the original ride then get the spring from Lexus. I stand corrected on the variable rate spring, good info thanks for that.