Titanium Brakes

[Dave K]

Just curious on your opinions/thoughts on the ZMI Brake system, with Titanium rotors.

http://www.zmibrakes.com

The rotor is really thin, compared to a Brembo, etc., with no center vanes, so the weight is very low, but so is the mass to absorb heat.

Any thoughts?

-Dave
"Everything should be designed as simple as possible, but not simpler"

 

[swall]

According to my chart from Tempil (the people that make Tempil heat sensitive sticks), dull red starts somewhere between 1000F and 1100F. The hotter you go, the more red the object becomes, then orange, yellow, white, then meltdown (around 3000F for steel).

 

[ntsqd]

I was recently sent this chart, but we were specifically talking about steel so I had no idea if it was relevent to TI:

TEMPERATURE MEASUREMENT COLOUR SCALE CHART

Lowest visible red
475° C
525° F

Lowest visible red to dark red
475-650° C
525-1202° F

Dark red to cherry red
650-750° C
1202-1382° F

Cherry red to bright cherry red
750-800° C
1382-1472° F

Bright cherry red to orange
800-900° C
1472-1652° F

Orange to yellow
900-1100° C
1652-2012° F

Yellow to light yellow
1100-1300° C
2012-2372° F

Light yellow to white
1300-1550° C
2372-2822° F

White to dazzling white
1550° C and higher
2822° F and higher

I am somewhat familiar with working on Sprints. I've been around some dyno Engine development for a 360 for a car an engine shop employer partly sponsored. That necessitated working on the car too.

DO NOT blow air across the face of the rotor. If it doesn't warp it, the differential temp induced stress' will try REALLY hard to crack it.
Blow air into the center of the rotor. Design the scoop with the intent that the air can only escape thru the vents in the center of the rotor towards the rotor's OD.

I can't believe that there would be much weight savings btwn an aluminum hat and a TI hat, but I looked up the Thermal Conductivity of each on matweb. TI's 7 W/m-K beats Aluminum's 190 W/m-K by a substantial amount.

 

[swall]

The very first range is wrong. 475C is actually 887F. I'm not sure you would see any red at 887F unless you were in total darkness.

 

[BarneyD]

The TI rotors don't have just TI hats. The entire rotor is titanium. Thus the weight savings. I think it knocked off around 30lbs of rotational mass on the NSX and about 45 lbs of unsprung weight. (rotational mass being the rotors, unsprung weight being the rotors and the aluminum calipers in the brake kit combined). The owner of the car noticed a nice boost in acceleration as soon as he drove the car.
Barney

Barney Demonbreun
Technician for Gary Force Acura, and owner of;
Ashland Motorsports
1304 Big Marrowbone Rd.
Ashland City, Tn. 37015