http://www.race-cars.com/partbd/messages/19906.htm

 

I don't believe this for a second...

 

Sorry to dig in the thread, but;

It is true, If you are friend of Mazda in facebook they have photos of titanium rotors, amazing.

 

Hm. Titanium alloys have low thermal conductivity (1/2 to 1/3 of cast iron) but also about half the weight. With lots of ventilation maybe it works?

Mentioned here: (middle of page)
http://www.thebrakeman.com/rotortech

http://fsae.com/eve/forums/a/tpc/f/1.../m/30210856721

 

I saw titanium rotors yesterday at Sevenstock 14 so yest it is true. I believe there are pictures of them on Mazda's facebook page.

 

Titanium, Billet, Oem

 

Going on a limb here.. but I imagine they are insanely expensive.

On a different note.. close friends build/designed a F500 car that has been a notable contender for many many years.. and they run 13" brake rotors up front, and a 6" on a jackshaft.
They made a set of Ti brake rotors for it.
COMPLETE FAILURE as brake rotors. Ad it turns out when under pressure and temperature there is a meqasure of lubricity inherent to Ti. And I gather they had less and less friction the harder you pressed on the brakes.

That being said.. I would think as Rotors for a 13B/20B/26B they would not only be light.. but there would be a measure of lubricity under pressure and temperature.. which would be great in cases where the rotor got too close to the housings....

I would be curious as to the expansion rate on them.. vs Iron/Steel.

 

Me too

 

Ti has lower thermal expansion coefficient than iron/steel.

 

The problem with armchair engineering whther Ti rotors will work or not is that you do not know the alloy. The characteristics of Ti alloys vary greatly from one to another and in fact are constantly evolving as high-tech industry has its way with Ti and other alloys, which was in the past difficult because the aerospace industry sucked up a huge portion of available supply. With the more modern aluminum, magnesium, as well ascomposites finding braoder use in aerospace engineering and production along with advances in machine and casting techniques, etc. the demand for Ti has "slackened" to the point that mere mortals can afford to purchase it, and manufacturers are also able to play around more with development of new alloys, coatings, etc.

 

Jeff said he was aiming at $1500 per rotor. Compare that to E&J's billet rotors for $2500 a pop.

 

either way, tough sell.

at least without a few years of testing.

 

Well thats in the ballpark for a top end road race engine build. If you go over to Racing Beat, and buy the lightened race rotors, that have locked, and hardened hardware... thats not far off the price for those. And I would imagine they are going to be a good deal lighter as well.

Toss in some Ti Stationary, and Rotor gears.. and NOW you are talking!

 

Bah! And here I was thinking titanium *brake* rotors, which also exist...

I agree with the others that the right alloy is critical, and keeping therm from galling. Fortunately it seems that Ti alloys have lower thermal expansion than cast iron, so the clearances would get larger at temperature, not lower. At $1500/ea, it might be more appealing than $2500 each, but if the cheaper rotor lunches early, the savings vanish quickly. Testing, testing, testing.

David

 

Isn't TI awesomely stronger than either steel or iron? AND Lighter...these rotors weigh in @ 5.5lbs = REV HAPPINESS!!

 

Titanium is no stronger than steel.

Steel and Titanium are generally much stronger than cast iron.

Titanium is lighter than steel and cast iron.

Titanium is better than steel when both strength and weight are critical.

David

 

Titanium is hard but also very brittle....I ran a titanium exhaust on my s2000 at the track for 2 years...brittle and the metallurgy also indicates this as well, not just my experience. I am very curious to what would happen when detonation occurs.

 

"Titanium" can range from hard and brittle to twice as soft as plain steel depending on the grade of alloy. The key is understanding the grade of titanium, and in the case of a welded exhaust, how to weld it. Titanium welds are easily contaminated by oxygen or nitrogen and the result is weak, brittle metal at the weld.

David

 

Yes this is true, titanium when welded should be completed shielded by argon to make sure the welds are not contaminated as argon is a neutral gas in welding. My exhaust was a "one off" piece made by Tracy Sports in Japan, of course it was made at the Nippon Steel factory. Very high quality control. The walls were only 1mm thick, but regardless my exhaust seemed to be brittle...it was a one piece header back with no flex pipe so there was extra stress on the welds.

I would like to know what grade of titanium was used for the rotors and curious to see how it fares against detonation.

 

Just to throw this out there... titanium may be brittle sure, but like cast iron isn't?

 

True....but in brittleness....its comparing apples and oranges. I did a lot of research (this peaked my interest in the different type of metals)...a pliable titanium alloy, does not have much titanium in it to begin with, they mix the alloy to offset the natural characteristic of the titanium, but with that it gains weight. I can't remember his SN, but on the S2ki forums there was an engineer that had a lot of experience in metallurgy. He got down to molecules on titanium, aluminum, steel and so forth. It was fun to watch people argue when he had science and formulas on his side LOL.

I doubt the people designing those rotors are going to divulge us with the type of titanium alloy they use. We'll just have to wait and see someone rich enough to use them and see how they hold up!

 

Looks like Mazdatrix will test these titanium rotors soon.
http://www.rx8club.com/showthread.php?t=230169

 

cant wait for the results

 

Just to clear some things up. I want everyone to take note that everything about this rotor is truly revolutionary, a game changer and very innovative. The actual surface body where the compression takes place is Ti. Where the bearing is, it is freeze'd in with a cog (like how they do with thermal plugs). Furthermore, the apex seals are completely different and shaped as a spade.

If you think this is awesome, wait until Jeff comes out with his e-shaft he is working on. If you think this is awesome, you are in store for a huge surprise. Imagine a shaft that is completely set apart from all the stock ones you have seen.

 

It has been a couple months now, any update on this? test results maybe?