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I have redrilled my gsl-se rear axles/rotors to 4x100 using a jig made by this guy: Menu
I am trying to find front gsl-se rotors that I can redrill to 4x100 with the same kit. Most front rotors are ribbed on the back and are not suitable for re-drilling as the new lugs wouldn't seat well on the ribs (see pic below)
Rockauto, summit etc will sell me StopTech rotors, and provide this generic picture (below). Has anyone bought stoptech fronts and can confirm they are flat on the back and can be re-drilled?
That picture is a slip over brake rotor and nothing like a first gen combined rotor and hub. It would be very sketchy to redrill a first gen hub for just the reason that you identified, the area where the studs are machined is ribbed and much thicker. Another thing to think about is that GSL-SE rotors are a poor design and marginal already, I have personally seen those rotors break at the bearing.
On my car I machine the brake rotor off of a stock hub and slide a second gen big brake over the resulting hub. I drill new holes in the second gen rotors to fit the 4X110 bolt pattern. Now I am using 4X100 Miata wheels with adapters that I machined. You may be able to find some 4X100 wheels with the correct offset to fit on an FB but if you intend to use actual Miata wheels where all of the good deals for light and wide wheels are you will need big spacers anyway.
This is with 15X9 Miata wheels and 245-40-15 tires.
This is with 15X9 Miata wheels and 245-40-15 tires.
Pictures aren't showing up but I get what you're describing. Trouble is the GSL-SE hubs have a wide track already, and there isn't the room to space them out further with adapters. Thanks for the input, maybe I can find some way to machine 4x100 hubs and then use slip on rotors overtop.
Hopefully the pictures show up now, the deal with Photobucket deleting all the linked pictures really hurt a lot of forums.
Your idea of a machined hub and slip on rotor is close to what I did. I used regular GSL front rotors, cut the brake disks off and slipped second gen big brake rotors over the resulting hubs. I think it is Coleman that makes an aluminum hub that takes a Wilwood rotor and caliper and isn’t too expensive I have some friends who use that and are happy with it. Aerospace Components out of Florida has made some aluminum hubs to fit a first gen and use second gen big brakes, they are normally drilled for the 5X114.3 pattern but I am sure that you could get them to drill whatever bolt pattern you wanted and they are very reasonably priced. Any of these 3 options would be much better than sticking with the terrible stock GSL-SE combined rotor and hubs which can and do fail.
As far as spacers I am not really sure what you are trying to accomplish. Almost all of the good 4X100 wheels have much more offset than the stock wheels from a first gen, when I converted to Miata wheels I had no choice but to use thick adapters. In the rear I had some room to tuck the wheels in so the spacers are only 20mm thick, but in the front the second gen rotor sitting on the hub is effectively a 10mm spacer and I still needed 40mm thick adapters which only left me with 5mm clearance between the tires and struts.
