How good is a stock 240 suspension?

[John Coffey]

A stock 240Z with a perfect stock suspension is generally horsepower limited on a racetrack.

Get the basic platform solid before doing any modifications. Putting better springs/shocks on a car with worn suspension bushings, structural rust, worn mounts (engine, trans, diff), worn bearings, or a bad steering rack is asking for trouble.

If the basic platform is marginal and then you increase the loads via bigger tire and rims, high rate springs, etc. you are increasing the chances of failure.

My "order of mods" suggestion:

1. Structural rust

2. Bushings

3. Bearings

4. Mounts

5. Steering

6. Shocks

7. Springs

8. Anti-roll bars

[jcdozier]

In reading through the posts, I note 2MANYZS comments about brakes. I did the upgrade to Toyota 4WD front calipers last year. It's a simple upgrade, even for the mechanically-challenged like me and doesn't have to cost much either. MSA now has an upgrade "kit" for about $300, but I just got used calipers from a Toyota 2WD truck and rebuilt them. Used calipers, new seals, etc. and I was still under $150.

The caliper upgrade was part of a general suspension "project" in which we replaced the springs, the strut inserts and all of the old rubber bushings with polyurethane bushings. The 1971 240-Z handles much better now.

JIM DOZIER

[XYZ]

JC - When you switched calipers you went from stock Z calipers to the toyota calipers, straight swap? Is there any retro-fitting? Did you upgrade the lines from rubber to braided hose? Did you change the rotor (I believe that's the correct term) as well? This may seem like a stupid question, but what is advantage of the toyota caliper over the Z caliper? I want to upgrade my brakes as well when I rebuild my suspension and need to figure out the best upgrade. I've seen people actually change the rotor size to a larger diameter and I wondered if doing that means you can also change the stud pattern from 4 to 5 to get into a larger selction of wheels. Any feed back would be great.

[jcdozier]

XYZ:

The Z caliper has two pistons - one for each pad - the Toyota 4WD caliper has four pistons. The calipers you want for the "upgrade" are from 1979-84 Toyota 4WD trucks.

The swap requires cutting the backing plate (also called the splash plate?), which I did with a Dremel tool. The "S"-shaped brake lines on the caliper will also have to be bent slightly to line up with the brake hose bracket - not a problem so long as you do it slowly and carefully.

I did not change out the rotor - I don't race or autocross, so I don't need the additional heat dissipation provided by slotted or drilled rotors. I did change out the rubber brake hoses to steel braided hose, but only because I wanted the stiffer feel.

There is a good brake article, including the 4WD conversion, on the Z-Car Club of Washington's web site. Go to www.zccw.org/tech/ then open the "Brake System" section and click on "Z-Car Brake Systems & Modifications".

[XYZ]

Thanks for the feadback JC.