My custom brake rotors

[ToRy 70]

Well, this all started when I knew my daily driver's rotors were due to be changed soon. I thought about getting a new pair, or stealing them from my turbo car that isn't running yet. Well, if that's the case, let's swap them and get some of those cool billet rotors for the turbo! Every car wins.

Except Pete at airkewld isn't making 4-bolt rotors anymore. I even tried to get some rotors with a blank pattern so I could machine them myself, but no soap. So I decided to make my own, including the design. Pete's 3-piece design with swappable wheel bolt patterns is cool, but I don't care much for changing wheels so I decided to make mine 2-piece. While I did the design myself, my friend Nacho is the machinist at our shop and he did all of the work on the hubs for an undisclosed amount of cash and a case of MGD. I was finishing my last quarter at school, so it was nice to have the car worked on without actually being home.

Starting with two 6.5" billets of 7075 aluminum and 1/2" plates of hot-rolled steel.



I drew up the rotor pieces in CAD and had them waterjet cut. I made six rotors total.



Blanchard ground to the proper .375" thickness. I countersunk the holes for flat-head bolts.



Rather than pay the waterjet operator to cut the holes, I made an identical rotor (1/8" thick) on the plasmaCAM we have at our shop with the crossdrilling in place. I reamed them out and then used it as a pattern to drill through the real rotors. Now I also have something cool to make a background for a garage or shop clock.



Here's Nacho scraping off the outside to the final diameter.



I don't have any progress pictures of the hubs, because Nacho lathed them while I was still up at school. So jump ahead with me:



Then I had the hubs hard-black anodized, while all the rotors got a nice clear zinc coating. After that, I pressed in the bearing races and wheel studs, and we're all set.







I haven't put them on yet. I got some stock disc backing plates that I want to add 2" vents onto for ducting before I bolt these on for good. I have to re-weigh these again for the official figure, but they came in around 11 pounds, which is about 3.5 # lighter than the stock cast iron. Not as much weight reduction as I had hoped for, I suspect I could have used less steel in the spoke design. But I had a lot of fun making them.

The only regret I have is that no one will ever see them! These are my wheels:

[Steve Arndt]

Nice work!

[Bruce2]

I have to re-weigh these again for the official figure,

Please do.
If you make the spokes of the rotor thinner, you'll reduce weight. I can see lots of potential to remove weight from the Al hub, but now that it's anodized, you probably don't want to touch them.
You could cut the tips of the wheel studs off.

[Stray Catalyst]

That's beautiful work! You and Nacho do a great job together, but it's funny that your wheels won't let anybody see the find work you've done.

Stray

[ToRy 70]

Thanks guys! Bruce, I know there's a lot of places to lose weight, but I think I'm done with 'em. I could tune them to the last ounce but truth be told it's stuff like this that keeps me from actually driving my damn car in the first place.

I think if I started over I'd use more aluminum for the rotor to bolt to. Instead of carving the whole hub from one block, I'd probably turn plates on the lathe that weld to a smaller bearing housing. That means using 6061 instead of 7075, which I think was overkill anyway.

I'll get the official weight, but just be happy with them anyway.

[Chris V]

Very cool...Do the rotor to hub bolts go into aluminum threads or steel inserts?

Just look at what open wheel cars use:


http://www.speedwaymotors.com/Wilwood-I ... 30767.html

[ToRy 70]

The bolts are threaded directly into the aluminum... I thought about doing steel inserts but the truth is that 7075 is just as strong as most mild steels. Even though I made extra, I don't plan on swapping them often. The waterjet shop that cut my rotors often make custom ones for motos that look just like the ones you posted, so they definitely knew what I was up to.

[vwo60]

I did a similar exercise except i used a 300MM vented rotors from a nissan along with a set of four spot calipers, works great,

[ToRy 70]

Neat! Any pics?

[PhillipM]

My rotors bolt straight into the aluminium, never had any trouble with 'em. Mine are a bit lighter though!

[Bruce2]

My rotors bolt straight into the aluminium, never had any trouble with 'em. Mine are a bit lighter though!

Pictures!

[Bruce2]

Here are some rotors I'm working on.
The first one is a rear rotor that is designed to replace a stock 914 rotor.

[Bruce2]

I just got these rotors a few weeks ago. They have the same dimensions as a stock Karmann Ghia rotor. Very similar to ToRy 70's rotors, except that the hubs on mine are cast

[Piledriver]

Here are some rotors I'm working on.
The first one is a rear rotor that is designed to replace a stock 914 rotor.

Can you have the IDs turned on those for 911 parking brakes?

[ToRy 70]

Very cool. How are the rear rotors assembled together? What are you using for the drive hub?