Real reason for 87-89T hubs?

1. A bolt-on hub has a plain 66mm bore, the slip-on hub has a stepped bore 66mm and 68mm.... the rotor I.D. is 68.1mm, the wheel I.D. is 66.1mm

2. The bolt on rotor has a shorter hat as it mounts to the backside, but is also thinner, so the inner surface of the rotor is almost the same as the slip-on turbo rotor

3. If using a bolt-on hub lathed to allow slip-on rotors, there will be a 1mm gap around the bore between the hub and rotor, you can lathe the hub bore a bit and machine a spacer ring, much like many wheels are sold with a large 73.1mm bore and a spacer ring to reduce it for the application, which in most mid-80's and up nissans is 66.1mm

4. Lathing a bolt-on hub should not cost more than obtaining a slip-on hub, but your results may vary… a "fair" price for lathing the hubs is $40 each, use your judgement

5. There are currently 2 big brake kits designed for use with bolt-on hubs lathed down to ~150mm to accept the rotor as a slip on, using longer studs as well -- htey are designed to use the 66mm bore

6. Using a bolt-on hub with a slip-on rotor ultimately removes the 66mm bore from use by any corresponding wheel, bolting on a hub-centric spacer with a 66mm lip may sound like it fixes the problem for the wheel, but consider that there's nothing centering the spacer except the lugs anyway, so you can skip the hub-centricity and use the lugs to center your wheel directly

7. R32 GT-R rotors and calipers work perfectly on slip-on hubs, all you need is 4mm of washers between the caliper and mounting ears, and of course z32 conversion lines

Same process as Z32 brakes…likely because R32 and Z32 suspension and brake setups are nearly identical.

Alright, well it seems I may be well served to find some late model turbo hubs, and as luck would have it there actually is an 88 z31 in a nearby pick n pull, though it is probably not a turbo…anyways, I'll be heading up there probably Monday and while I'm at it I think I will grab some J30 hubs, as I believe they are the same, no? At least, I think I read that in the brakes thread, and even if they aren't I can sell them to an s13 owner for use.

J30 are not the same

Ah, that's a shame. Guess I'll snag them to sell to the 240 crowd but I'll have to either do some machining or hope the 88Z is a turbo at the yard to save some money on my hubs. I actually like the idea of fabricating my own stuff but I am also a lazy slob sometimes.

For some stupid reason, nissan like other manufacturers switched to sealed bearing hubs in the 90's… so we share a spindle design with s12, r31, and the elusive m30, anything newer is nothing like