Block spacers for springs

[TominMO]

I will be installing some KYB Gas-adjust shocks on the rear of my T4WD which should firm up the dampening nicely.

If we don't necessarily want to install longer springs but would like stiffer stock springs, can we accomplish this by using rubber block spacers? Also, what are the lengths, IDs and spring rates of our stock front and rear springs? (I don't take possession of my Tercel until Saturday, so I can't just go out and measure things myself.)

Edit: I notice on Rock Auto that they have front variable-rate springs for heavier loads (part # CC212, $48 for the pair). Is this a good way to go as well?

[Petros]

block spacers will not change the rate of the spring, only make it longer (give you some lift).

Somewhere on this forum there is a discussion about spring rates, stock vs. various other car springs. I do not remember where it is but there is also information about what are the consequences of changing the spring rates will be.

[TominMO]

block spacers will not change the rate of the spring, only make it longer (give you some lift).

Somewhere on this forum there is a discussion about spring rates, stock vs. various other car springs. I do not remember where it is but there is also information about what are the consequences of changing the spring rates will be.

Ah, OK, I thought maybe putting in block spacers would have the same effect as cutting a spring, to get a higher rate. I will look for that spring rate discussion of which you speak.

[Petros]

I found my earlier post:


FRont stock Tercel4wd: 250 lb/in
Rear stock: 270 lb/in

'88 Corolla GTS/Celica front: 270 lb/in
Pathfinder rear: 328 lb/in

'85 MR2 front: 285 lb/in '
85 MR3 rear: 344 to 1300 lb/in (variable, gets stiffer as it compresses, it should ride at about 450 lb/in)

IF anyone can give me the dimensions of the Camry spring I can calculate the spring rate for that too. I need, accurately measured, the wire dia.(you must use a caliper or mircometer), the outside coil dia. the number of active coils (not total, but ones that actually compress).

One thing that might be interesting to try is to install the MR2 rear struts into the front, with the MR2 front top strut mount, and perhaps one of these heavier springs like the MR2 fronts in the rear.

Also realize there is another issue beside spring rate, we need to know the free length because with a higher spring rate the ride height will not come down as much with the weight of the a lighter car on the stiffer springs. As Snyth found out if you do not have enough extension left on the strut (same is true with the rear shocks), you will damage top seal when the strut extends, topping out, going over bumps.

Also, if you cut a spring down to reduce the ride height these numbers are no longer valid, the spring rate gets stiffer as you cut off each coil. Though it is not a strong effect, if you have say 7 active coils (as on the pathfinder rear springs) and you cut one off, it only gets stiffer by a ratio of 7/6=1.167 or about 17 percent (from 328 to 383 lb/in). This will hardly be noticeable, you need large changes to notice a difference.

We should get some more spring rate information from other cars too, what we want to do is try and keep the ratio of front to rear spring rates about the same as stock to keep the balance similar. OR we will also have to add different anti-sway bars to correct the in-balance. With the stock anti-sway bars, if we get the rear springs too stiff relative to the front, you will increase oversteer and risk lifting a rear tire in a tight turn. IF we get the front springs too stiff relative to the rear we risk heavy understeer, and lift a front wheel in a hard turn.

I want stiffer rear springs since the car already has understeer, it should tighten up the rear and reduce body roll, and reduce the understeer. I will need this before I get the 4age engine swap done anyway to handle the extra power without going squirely. I will want to install some better rear bushings as well.


the full thread is here: https://tercel4wd.com/forums/viewtopic.php? ... te+#p43986

[TominMO]

Thanks Peter!

[splatterdog]

So far I've kept stock spring rate but added these-http://www.oreillyauto.com/site/c/detai ... &ppt=C0361

I don't put them in the coil as it says to do. I cut off enough of one end to reduce the od and match the spring top perfectly(cut it square too!), and put it on top of the spring. The shape of our upper spring pockets holds them in perfect and the nice round/flat spring tops don't hurt either. You definitely need to unbolt the sway bar from the axle and the e-brake cable clamps on the floor pan so the axle can drop far enough. Even then it's tight. A simple 2 bolt style spring compressor helps a lot.

It's gives better than an inch because of the upper spring pocket ridges on the spacer. They do compress/conform to the car's spring pocket some, but it adds more than if placed between coils. I would imagine they slightly reduce road noise being much thicker than a normal spring isolator too.

[dlb]

coming back to an older post here. splatterdog, you mentioned you installed the donuts but kept the stock spring rate. i'm wondering if you replaced the springs with something new or are using the same old 25 yr old springs. i'm looking at using the same spacer in my 4wd corolla wagon vs messing around with trimming some pathfinder springs.

[splatterdog]

I put them on top of the original springs. Same rate, just taller now. The top side is flat/square and the upper spring pocket both work to hold the spacer in place. On the corolla I'm assuming it has rear struts? You would have to put the spacers in between the coils then. Between the spring and strut or spring and top plate would likely shoot out. You would need to weld a collar to the strut or mount to hold the spacer in place.

Pathfinder springs work in corolla's too? I thought they had independent rear susp..

[dlb]

thanks, SD. the 4wd corolla wagon has a virtually identical rear axle setup to the t4, even similar size springs, so the donut should work well for it. just trying to track some down here now.