So... How resist is titanium to detonation really???

http://www.facebook.com/media/set/?set=a.378225772197029.94061.219671674719107&type=1

damn....

If you have to ask, you can't afford it...

In reply to Ranger50:

I'll bet you the price will make your head explode.

I'd just wanna leave it on my desk and

stare at it...

Why would you show me this as I'm already lusting over magical spinning triangles?

The0retical wrote: In reply to Ranger50: I'll bet you the price will make your head explode.

The ~$1500 per rotor price point they are shooting for isn't completely insane when you look at aluminum side housings or any other pseudo-exotic rotary part.

From what I understand, Ti really isn't that hard to cast compared to some other metals out there. I've seen a few FSAE teams making things out of cast Ti that don't seem to be Ti for any other reason than bragging rights. I'm glad to see some manufacturers making some badass parts out of Titanium.

The0retical wrote: In reply to Ranger50: I'll bet you the price will make your head explode.

Can't be as bad as buying 10 pistons at $125/each..... then buying aluminum rods at $800 a set. Compounded with a $2500 crank.... $3500-7500 cylinder heads.

Rotaries are cheap.

MG Bryan wrote:

The0retical wrote: In reply to Ranger50: I'll bet you the price will make your head explode.

The ~$1500 per rotor price point they are shooting for isn't completely insane when you look at aluminum side housings or any other pseudo-exotic rotary part.

In perspective, that's roughly twice the cost of a new rotor.

And it may potentially save you the expense of a ~$5,000 three-bearing eccentric shaft, which you kinda need if you plan on venturing into the quintuple digit range.

So what middle eastern sultan is going to build a 4 rotor out of those?

Ranger50 wrote: Can't be as bad as buying 10 pistons at $125/each..... then buying aluminum rods at $800 a set. Compounded with a $2500 crank.... $3500-7500 cylinder heads. Rotaries are cheap.

And don't forget the $1000 for cam and lifters, and valvesprings that can be almost as much, and the lifters, rockers, and valvesprings will need replacement on a regular basis if you have a cam with decently awesome lobes on it.

Rotaries are expensive until you realize just how cheap they really are.

Price out cams for a DOHC anything lately? A friend of mine is stoked that he can get cam blanks for his engine project for only $850. That is a pair of unground blanks that he needs to send to his cam grinder, who will charge untold extra money for them. Yeesh.

Granted, this is for special blanks for the rare version of the engine that used geared cams instead of chained, which he needs to use for arcane reasons that I've already forgotten (my brain was resetting while he explained), so one of the cams needs to have the lobes cast in reverse order since it rotates backwards... but the price for "normal" cams wasn't significantly cheaper.

JtspellS wrote: So what middle eastern sultan is going to build a 4 rotor out of those?

I can't see a four-rotor built with these parts running much more than your typical professionally built big-block Chevy.

Go to your local drag strip - lots of those amateur racers are using engines that run in the $20-25k range.

Knurled wrote:

JtspellS wrote: So what middle eastern sultan is going to build a 4 rotor out of those?

I can't see a four-rotor built with these parts running much more than your typical professionally built big-block Chevy. Go to your local drag strip - lots of those amateur racers are using engines that run in the $20-25k range.

Agree, would still like to see it and a tuner that has enough guts to push it.

JtspellS wrote: Agree, would still like to see it and a tuner that has enough guts to push it.

So who wants to bankroll me 75-90k to test it out???? BTW, that is a certified SFI 25.2/3 chassis with most of the bells and whistles to run low 7's on stock suspension.....

20B version anybody?

PFFFT... I get the KIWI-RE 4 rotor deal.... still only 2.6L.... and they can make 1700hp...

Something else I realized - the hyperlight rotors already on the market that are Mazda castings that have had the everloving wee milled out of them tend to run in the $1000-2000 range each. So a $1500 price target isn't expensive, it's in the ballpark of the current market value for a lightweight rotor.

Something about a multipiece rotor that sees the weird orbiting squeezing effects gives me the willies. They get forced around like a kooshball in there, and I wonder how they keep the inner/outer interface from fretting itself to death.

Knurled wrote: Something about a multipiece rotor that sees the weird orbiting squeezing effects gives me the willies. They get forced around like a kooshball in there, and I wonder how they keep the inner/outer interface from fretting itself to death.

That is why you see all the hazards about milling the irons flat.

I assume they are planning on using fancy coatings to deal with titanium's propensity for galling?

Ranger50 wrote: That is why you see all the hazards about milling the irons flat.

That's not what I mean. I mean the issues with combustion pressure pushing (irregularly, at varying angles) on what is for an IC engine a fairly long and wide surface (Very High pressures can/will dent OEM rotors!) and, to top it off, it pushes on one of three faces, in sequence. So the rotor is getting squished around like somebody rolling a stress ball in their hand.

Combine that with Titanium's natural lack of stiffness, and, well, let's hope they aren't using their customers for primary testing. For drag use, it doesn't matter, since drag engines have lifespans measured in minutes even if all goes right. I worry about the guys who buy these for hot street cars or trackday warrior duty.

If any of you have a Facebook account, why not ask Mazdatrix themselves these questions? Not trying to be mean, but my engineering-fu is weak and I'm genuinely curious about those downsides now that you have brought them up. Provided they don't fail during testing, I'd sure like a set for one of my JDM S5 13BTs...

Detonation issues aren't so much with the rotor itself as with the seals. That's the weak link.

Knurled, James, you don't mind if I ask those questions on the Mazdatrix FB post, do you?

carguy123 wrote: Detonation issues aren't so much with the rotor itself as with the seals. That's the weak link.

I always thought it was the seals too...

Titanium is a nice "springy" metal.. so it would probably resist deformation well as it would spring back into it's original shape