I'm about to begin a very large brake overhaul (New rotors, front calipers, rebuild rear calipers, ABS delete, and full fluid bleed).
Well, knowing that I'm eventually going to want to buy a set of competition rims and tires for the car, and which will probably end up in a 5-lug swap, I decided to purchase 5-lug rotor's and drill them for my current 4-lug set-up.
I originally ordered Brembo blanks, however the vendor was out and brembo was on backorder. They offered me a set of RotorPros zinc coated and slotted rotor's as an even swap (full set is about the same price as the brembo's). After reading through a few posts on EvoM about these rotor's I decided to accept the swap and try them out.
The rotor's came in yesterday, and they sure do look pretty. Unfortunately the fronts look to be useless to me. They have about 9 different lug holes drilled into them, which I assume is to fit multiple lug patterns, but this leave me no room to drill for my 4-lug set-up. This kind of threw me, because the image on the vendor's website doesn't show this.
So I'm thinking about it, and here's what I've come up with: Without doing any sort of stress analysis I believe that most of the stress experienced by the rotor hat is supported by the pressure of the rotor being pressed between the wheel and the hub, NOT the wheel studs. IF two or more of the studs fit correctly with no modification, I might be able to get away with drilling for the remaining studs. The drilled hole's would most likely have one "open" side. I'd probably go this route if the car was street only, but I plan to use the vehicle as an Auto/Rallycross vehicle next season, and not sure if they'd stand up to that abuse. Opinions?
Here are the other options I've thought of:
1) Return the rotor's and wait for the brembo's. The car is JSB for now anyway, for other projects. No big hurry. Do the brembo blanks have the same deal going on, or should they only have the 5 holes?
2) Keep these rotor's and buy a set of 4 lug rotor's. Less desirable option, as I have to spend more money, and the rotor's will probably only be used for a year or so.
3) Just do the 5-lug swap now. I already have everything for the rear's, I'd just need front hubs, and wheels. Most expensive option, but if I'm going to do it anyway, might as well be now, right? Been looking at the How-to. This mentions 93-94 hubs only. Is there a reason for that, or is that just to retain ABS? Is there any difference model to model (aka, GS, GST, GSX)
4) Return and buy 4-lug rotor's from Rock Auto. The wheel's I think I want can be ordered in a 4-lug set-up (Team Dynamic's RallyPro's). As long as I don't change my mind I'm good.
Looking for opinions, and maybe someone has a different idea I haven't thought of.