Tech Article: 5-lug Conversion and Stage I Brake Upgrade for the 280ZX.

by Philip Childs

This upgrade is not for the faint of heart, I started out hoping for a bolt on upgrade to my 83 280ZX Turbo brakes and ended up with custom machined rotors, hubs and pads.

My first mistake was my brilliant discovery that a 5-lug 84-86 300ZX hub fits on a 280ZX. This started me in the quest to fit a set of 90+ Z wheels on my 83 and get a brake upgrade at the same time.

So, I buy the hubs, rotors and calipers, I take the 280ZX hub and rotor off and discover that the 5-lug 300ZX rotor is a 11" rotor, the 4-lug uses a 10.5" rotor. After, determining that there was no room to fit a bracket to mount the caliper in the correct position I sent the rotors out to get them turned down to 10.5", I also ordered adapters to compensate for the 90+ Z wheels front drive offset.

Next, I install the turned down rotors and calipers and found out that the hub (where the lugs are) hits the caliper ( I should have had them turned down by the same amount as the rotors), 10 minutes with a body grinder and that problem was solved. Then I install the adapter, only to find out that it hit the caliper also, another 5 minutes with the body grinder and I had this one licked. Now it's time to install the brake pads and guess what they hit the rotor, another 30 minutes with the body grinder and now everything fits fine. Finally I bleed the brakes, install the wheels and the front is done.

Next month: 5-lug conversion of the rear and installing a proportioning valve.

Parts list.
1. 4-lug Hubs and Rotors from a 84-85 300ZX NA 4-lug or for the masochist, 5-lug Hubs and Rotors from a 84-85 300ZX Turbo 5-lug or from any 86.
2. Grab the bolts that mount the calipers from the 300ZX, you will need them for mounting your new calipers. You will also need 4 12mm X 1.25 nuts, the Toyota calipers are not threaded. Calipers from a 88 V6 4X4 Pickup.
3. If the calipers didn't come loaded then you will need pins springs and pads.
4. Brake fluid, I used Motul DOT-4 racing fluid.
5. If you are installing front drive offset wheels you will need adapters, for the 90+ Z wheels I used 1" thick for the front and 1.5" thick for the rear.