B210 front end lowering

[RedBanner]

... Use 240z springs, and cutting a 210 spring does raise the rate, just not the same scale as a progressive.

[ggzilla]

How does it raise the spring rate? They are 100lb/inch springs. Cut them 2 inches, and they are still 100lb/inch rated.

[Kramer1981]

How does it raise the spring rate? They are 100lb/inch springs. Cut them 2 inches, and they are still 100lb/inch rated.

 

To truly understand spring rate, consider the spring being staight instead of coiled. Cutting makes it shorter in a linear sense, there fore stiffer. The shorter the length of the wire, whether coiled or straight, the stiffer it is.

 

When you cut a spring, you are reducing the number of active coils, or making the overall uncoiled wire length shorter, thereby INCREASING its stiffness. Same thing happens when you use those twist in coil spring boosters, you are taking a coil out by preventing it from flexing, again making the active coils stiffer.

 

That is why if you go junkyarding, you can compare a chevy caprice front coil to a cadillac fleetwood front coil, provided both cars are similar year of manufacture, you will find the cadillac spring is taller, somtimes larger in outer diameter. That is why chassis wise both cars are pretty similar but the caddy rides alot softer. The caddy has more active coils.

 

Anytime you remove or render one coil useless, the spring rate increases and the ride stiffens. True lowering springs will have the same outer diameter, wire diameter, and number of active coils as oe springs, they will just be shorter in height meaning each coil will be closer together.

 

Basically if you wrap your brain around the fact a coil spring is a prybar, the longer the prybar is the more it deflects under load. The smaller diameter the wire that the spring is made of, the more it will deflect.

[ggzilla]

210 front spring rate w/o AC is 92.4 lb/in

210 w/ AC is 90.7 lb/in

 

They are 14.8" long stock

 

So the longer the spring (more inches), the more pounds it can carry (until the point where the coils bind).

 

With about 1200 lbs on the two front springs is 600 lbs per front spring static loading. Weight will shift during cornerning and braking and so can be considerably more on the spring.

[0r0B210]

 

 

 

 

Grind down the weld so it's reasonably smooth so the bottom spring perch is free to slide down the strut tube and secure with an adjustable split collar.

 

 

Cutting a coil also increases the spring rate making it stiffer. It quickly becomes too stiff and once cut, you can't go back. Try 3/4 or one coil and see if you like it. Cut 1/2 coil at a time even. Once assembled you can jack the body. carefully release the split collar and slice spring off on the car. Slide the perch up and support with the split collar. You will likely have to compress the spring before tightening the collar, I used a block of wood and a hydraulic jack to push everything up, then tightened.

 

There are lower limits to doing this. Remember the strut length isn't changed and if too low it will bottom out. Ideally a shorter strut tube and internal parts possibly a 280zx strut can be used. I put a similar Maxima strut on my 710 and it was about an inch and a half shorter right off the bat.

 

You can also use a shorten strut cartridge and shorten the strut tube by cutting and welding it.... not for the faint of heart or ill equipped.

 

Lowering will affect your front wheel camber and swapping to a zx may throw it way off and necessitate using camber plates to compensate for this.

 

Lowering will also introduce varying amounts of bump steer to the steering. The cure is bump steer spacers.

 

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Über-late question:

Would a 280z strut insert fit in my B210 strut housing, that way I can just cut the coils, or lower the spring perch?

[datzenmike]

Don't know. The strut has to be the same length or shorter. If shorter you can stach washers under to shim the insert up.

 

Does the B 210 have the original internal damper and valves? If so, just replace the oil with heavier viscosity..

[ggzilla]

You don't need to cut the strut nor fit shorter inserts. If lowering more then 2" then it is recommended.