What 8 inch front springs do others use?

[chunstone]

I'm not enjoying the very stiff front springs that came with the car. Asking around at Canby, one fellow said 200 lb springs would give me a better ride. The existing springs are 8 inches long, 2-1/2 inch ID and 3-1/2 inch OD. I believe that the struts are 280zx?? Not sure how to identify. Looking for some resources for spring suppliers or good used springs.
Next thing is to find new wheels to make the front track narrower and widen out the rear. Thanks, Neil.

[datzenmike]

Give me the thickness of the wire and the number of uncompressed coils... in other words coils that are not touching each other. Be as accurate as possible including the inner and outer diameters. The more accurate the better the answer. I'll work out your present spring rate. If it's 200 then this will save you buying the same as what you have and know to go lower. From what I see 175-225 seems the range for a young 510 owner. I have a 710 and 150 springs but I am much older and like my comfort. Spring rate is what YOU like.... everyone is different.

Length is immaterial. An 8" low spring rate will have a lower ride height than a stiffer spring rate that is 8." The chances of a ride height and spring rate that you like that is exactly 8" is very unlikely.

If the ride height is lower than you want you can stack rubber shims under the spring to raise the body. This will not affect the spring rate.

If you have adjustable coil overs you can run any spring length and rate you like

[Tedman]

First make sure you're not riding on the bumpstops! No matter what spring rate you have, your effective spring rate will shoot up nonlinearly once you're into the bumpstops on compression. You can check this by wrapping a zip tie around the strut piston shaft, sliding it down against the top of the gland nut, then go for a spirited test drive. If you still have stock rubber bumpstops, you might have to wrap another zip tie tightly around the shaft under the bumpstop to hold it up against the underside of the top hat. Aftermarket urethane or Foamex ones usually have enough stiction that they stay up by themselves. If, after your test drive your other zip tie ends up at the level of the bumpstop, that is a problem. At that point, you'll need to raise your spring seats, or shorten your struts to get more travel in compression. If the problem is mild, you might be able to trim the stock rubbers to gain enough travel, or replace them with progressive rate bumpstops.

I don't know what kind of springs you have, but many of the 2.5" ID coil over springs are marked with the spring rate or part # from which you might be able to find the rate. For Eibachs , the last 3 digits of the part # are the rate in lbs/in. Eibachs are pretty popular, and available in 8" x 2.5" ID in 25 lb increments, as are most other brands. A!so, you need good strut inserts if you want a good ride with 200+ lb/in springs. Cheap Monroe's or KYBs won't cut it, IMHO.

[chunstone]

Thanks for the tip about the markings on the springs, they were facing in, so I did not see them.
The springs are Eibach, Ground Control, 90010,gc200.64.67. Looks like they are 2.5 inches in Dia, 380 lbs. 5 coils?
The springs are sitting on the adjustable nut which sets on the collar at the very bottom of their adjustment.
I'm not looking to lower the front of the car.

[Tedman]

380 lbs/in front spring rate seems quite high for a street car but there's a couple of trains of thought, here. Seems the Canadians prefer high spring rates and no rear anti-roll bar, while in the States we tend to run softer springs, a larger front bar and an adjustable rear bar. The key to making the stiffly sprung Canadian setup work are shocks (dampers) tuned for high spring rates. Basically racing shocks ($$). If your shocks aren't up to snuff, your ride quality and handling will suffer. I'm sure the Canadian guys will chime in. I'd be interested to hear what they have to say.

[Tedman]

Is this for a Wagon? DIfferent ball game. I doubt your wagon has super stiff rear springs to match those 380 lb/in fronts since no one ever manufactured them that I know of. I'd just swap the front springs for some 200 lb/in Eibachs, add some Foamex or conical urethane bumps stops, and maybe raise the front ride height depending on how the zip tie test goes. If the car in your avatar is the car in question, your car will most certainly be riding the bumpstops on stock length 280ZX struts.

[datzenmike]

My 710 is lowered and on springs that are 150, up 50% from stock. I consider it quite firm and am happy with it there. If you had 300 pound springs how would you experience it being twice as stiff??? It hurts twice as much???? Or is stiffness logarithmic??? No matter what spring you use no two people will agree on weather it's too soft or too firm.... or just right. I call this the Goldilocks effect. The numbers can only tell you which way to go if you find them too stiff or too soft.

[duke]

IMO, desired spring rate really depends on your usage, dampers, tires, sway bar stiffness, engine weight, etc...

That being said, I personally use Summit Racing house brand springs. They are inexpensive, so trying different rates isn't a huge financial investment. I haven't tested them to see if the stated rates are accurate, but assuming they are there isn't a difference between inexpensive (within reason) and expensive coilover springs, especially on a street car.

[bertvorgon]

You do NOT want 380# springs!

Even for full on road racing we found 350 was what was needed MAX, in a 510, and a proper shock to control it, which you will NOT get off the shelf.

As Tedman said, go for the 200# springs and as large a front anti-roll bar as possible. The "decrease" in body roll, with the reduction of weight transfer alone, helps tremendously in a wagon. I did basically this set up with my wagon way back. This setup did REDUCE under steer in my wagon.

Yes, our "Canadian" setup has the 300# springs but those of us running that used to slalom and still drive our cars hard enough to require that rate. And that is really the salient point, there is a difference in how we all drive and what we demand from our car(s).

IF...there is/was a spring shop or race shop around you, they might have a "spring checker", the device used to tell what a springs rate is. That would actually be really cool, as you would KNOW what you have and then make an educated choice for a different spring rate.

Also as TEDMAN said, you absolutely must not hit the bump stops and it is worth a spirited drive, as YOU would, to make sure and check that your not hitting them. Instantaneous loss of control can happen in the right conditions when the suspension bottoms out.

Good to see you on here, been awhile since our Winthrop meet!

[chunstone]

This is a great education for me.
Yes it's a wagon and the rear axle is a 4 link setup, which I will be questioning in a subsequent suspension topic.
I do have a front sway bar.

The amount of the "shock" (are they also referred to as a damper, or strut insert?) piston shaft that is exposed is 4-1/2 inches. In order for the suspension to bottom out, the springs would have to compress 4-1/2 inches or more? So if that were true, when I get some, say, 200 lb 8 inch springs, should I then use the zip tie test, correct?

Could I reason that with the existing 380 lb springs currently on the vehicle, that no way, could the springs compress enough to hit the bumpstops?
Also wondering if I need to replace the stock setup at the top of the "tower" with adjustable camber plates? I have read that Ground Control adjustable camber plates are easy to install and "lowest" price?
I have some complete adjustable Ground Control camber plates that came with the car, but I would have do some cutting to make them work, which I do not wish to do.

Stock bump stops OK?

As long as I have to completely remove the strut, (remove or just drop enough?) to put on new springs, should I remove the shocks (damper or strut inserts?) and inspect for leakage, manufacturer, length or travel, etc?
I really appreciate the help, thanks, Neil.

[bertvorgon]

Morning, PM sent today.

[chunstone]

Thanks bertvorgon!

I installed 200 lb springs that I received today. Had to raise the adjustment nut 1-1/2 inches (it was right on the bottom with the 380 lb springs) to get back to what height the front end was before. Took it out for a test drive and felt good, did not hit the factory bumpstops. The zip ties were only pushed up a little over an inch.

Found my old files of invoices from the previous owner showing, "2 Tokico HZ3038 ZX front inserts, labor to cut strut cups and install inserts", Billed by Troy Ermish, dated 7-18-2000.
The same invoice also showed labor for the 4 link installation, $600, and the rear coilovers, $475.

After installing the 1/2 inch Experimental Engineering spacers, wheels and tires, I noticed that the welded on collars stick out a good 1/4 inch beyond the strut tube. I'm thinking that I can grind down those welded collars (maintaining support for the treaded collars) and gain at least a 1/4 inch of clearance.

Question I have, is there a way to bring in the whole strut further in so the tires do not stick out so far, making the front track width closer to the rear track width?

Thanks, Neil

[JordanTr]

Adjustable front lower control arms will help improve the fender clearance since you can shorten them to pull the wheels inward. If you have wheel-strut clearance still, higher offset wheels will pull the tires inward.
I have adjustable lower control arms to narrow the track a bit to fit 16x8 rims with 215/40 tires.

Flattening out one part of the coilover sleeve perch is no big deal.

[chunstone]

If I get adjustable front control arms,

do I also need adjustable tension bars (control tie rod/bar)? CX racing kit for $437.75
Or Techno Tuning GTX2 Front control arms and TC rods for $595.

Do I also need adjustable camber plates? DP racing for $305.

Are there other options for less $$?
Thanks.

[datzenmike]

You guys are rich!!!!!!!!!