Just askin' 
I'm making a basta...a hybrid braking system, and I need rotors with a 71mm bore and a 4x100 bolt pattern. I could always get the rotors machined, but I'd prefer off-the-shelf for future ease if possible.
-
Dec. 10, 2008 11:20 p.m. Keith SuperDork
-
Dec. 11, 2008 12:09 a.m. oldopelguy HalfDork
That's huge Keith. I would start with the '95 Neon 4-lug or the Saturn SL1, they had the biggest center holes I could find when looking for rotors to use on the back of my Opel.
-
Dec. 11, 2008 6:05 a.m. John Brown SuperDork
Try Saturn Ion or Chevrolet Cobalt maybe? GM usually has the largest hub bores around.
-
Dec. 11, 2008 6:43 a.m. mw New Reader
I'm pretty sure nothing has that combo. Just buy which ever 4x100 rotors are cheapest or have the most good replacment options available.
-
Dec. 11, 2008 6:47 a.m. John Brown SuperDork
Or turn the hub lip down a little, seeing how under normal circumstance you will use 5 rotors to 1 hub.
-
Dec. 11, 2008 7:03 a.m. jrw1621 Reader
Here is reference tool http://www.adaptitusa.com/referencebook.htm
BMW 320i
4x100 and a CB of 72.56
-John
-
Dec. 11, 2008 7:35 a.m. walterj HalfDork
Wilwood will sell you rotors with no holes if you have the means to machine them
-
Dec. 11, 2008 7:40 a.m. jstein77 HalfDork
First gen RX-7?
-
Dec. 11, 2008 9:13 a.m. minimac Dork
I use www.alloywheelguide.com or www.alloywheelsinternational.com
linky sucky try this instead
www.alloywheelsinternational.com/WHEELFITMENTGUIDE1.html or http://www.alloyguide.com/
-
Dec. 11, 2008 9:45 a.m. belteshazzar Dork
jstein77 wrote:
First gen RX-7?
4x110
-
Dec. 11, 2008 10:06 a.m. Keith SuperDork
Great reference John, thanks.The 320i has drums on the back as far as I can tell, so unless it has non-vented front rotors that's not going to work.
I'll take a closer look and see if the hubs can be turned down. Honestly, at the rate that this car will use rear brakes, having to machine the rotors isn't really that big a deal when I think about it.
-
Dec. 11, 2008 10:11 a.m. Tim Baxter Online Editor
Keith, I don't know if it'll help, but according to this the E21 323i used the same rear rotors as the E30. All other E21s were (as you suspected) drums in the rear.
-
Dec. 11, 2008 10:33 a.m. Keith SuperDork
According to the A-Dapt-It website, the E30 has a 57mm bore. Hmm, more research to do...
-
Dec. 11, 2008 11:53 a.m. John Brown SuperDork
Line Code UP
Part Number 85898
Description Brake Rotor Only -
Rear - Ultra Premium
Attribute Features & Benefits:NAPA Ultra Premium Rotors Are Precision Machined For Smooth Brake Operation.,Product Features:Out Of The Box "No Turn Guarantee",Brake Rotor Type:Disc Brake Rotor Only-dih Parking Brake,Mounting
Type:Type K - Rotor Only. Wheel Studs Are Pressed Into The Hub Only. The Rotor Is A Loose Fit On The Hub & Is Retained By Either Machine Screws Or The Wheel Nuts. See Diagram For More
Information.,# of Bolt Holes:4,Bolt
Circle Diameter:100 mm,
Diameter:10.15",
Height:2.36",
Thickness When New:.395",
Maximum Lateral Runout:.002",
Discard Thickness:.331",
Vented / Solid:Solid,
Center Hole Diameter:2.444"
-
Dec. 11, 2008 12:14 p.m. Keith SuperDork
John Brown is the man. 2.444" (aka 62mm) is not a big enough hole, but now I know.
-
Dec. 11, 2008 12:57 p.m. fiat22turbo SuperDork
Why can't you use vented rotors on the rear?
-
Dec. 11, 2008 12:59 p.m. Keith SuperDork
Because my calipers aren't wide enough to cover them, and I don't want to lose parking brake functionality by using front calipers. I'm trying to retain Miata calipers so I have commonality with the other three cars in the garage that run them.
-
Dec. 11, 2008 1:08 p.m. Jensenman SuperDork
John Brown wrote:
Or turn the hub lip down a little, seeing how under normal circumstance you will use 5 rotors to 1 hub.
+1. This way if something goes bad at a track day etc you have a reasonable chance of finding something at PepZone etc.
Why not turn the axle snout and the flange OD to the same as a Miata and have anyone but Dutchman Motorsports redrill them for 4x100? Then you can use readily available proven stuff.
-
Dec. 11, 2008 1:36 p.m. Keith SuperDork
I'm going to disassemble this axle to figure out what can and can't be resized. Looks like finding off-the-shelf rotors that are readily available isn't going to happen, so it's time for plan B.
-
Dec. 11, 2008 6:18 p.m. Type Q HalfDork
John's link didn't specify whether the "CB" dimentions were front or rear. The rear hubs for a 90's vintage Civics and Integra's are larger in diameter than the fronts. It still may not be big enough for what you need.
