GT350 SHW Composite Brake Discs

[Tob]

While I can rationalize the above I don't believe it to be the case here. Look at some of the names that Ford has stuck with the past few years on their halo Mustangs. Many look to have been chosen for the GT350 effort but a few didn't make it. Some examples:

- Bilstein had their DampTronic dampers on the TP GT500. BWI's "Magneride" dampers has toppled anything Bilstein had available. Multimatic too.

- Honsel (of Germany) was casting the GT500 PTWA blocks. This engine will use a similar bore treatment but the source of the blocks hasn't been revealed yet.

- Recaro made it. Then again, who are the Big Three using in their place? Lear? Faurecia? Recaro continues to dominate the performance segment.

- Goodyear has finally given way to Michelins. Do you think they used cheaper grade materials to gain a competitive advantage and thus a contract here?

- Brembo rotors no longer reside between Brembo calipers. The fact that SHW has bumped Brembo is indeed significant.

I highly doubt SHW used a "lower grade" material formulation for a rotor submission in order to receive favorable consideration. These rotors look to be (based only on a visual comparison at this point to other SHW rotors) GT350 specific. While SHW has been clear about expansion they don't appear to be willing to do it at a loss based on a review of their financial statements. I know many might find it a bit dry but I found a lot of relevant insight within one of SHW's latest reports (look closely at pages 14 and 15). The "Eurozone" has been a bit rocky as of late but SHW has immersed themselves in areas where they look to do well (and Germany itself isn't in a bad position either). There's a lot to disseminate from that report but here's a snippet of 2013 regarding their brake business. Keep in mind that their brake division is relatively small, especially in comparison to Brembo.

But I digress, my point lies in my belief that SHW doesn't look to be winning contract bids (such as this specific one) by knowingly accepting financial losses therein. They may have been willing to provide them at a reduced profit margin but that doesn't mean that their number was simply lower than Brembo's (for example). My guess is that Ford engineers simply tested with specific goals in mind and these units achieved what they were looking for in terms of braking performance, durability, and cost.


For comparison, note how much larger Brembo is (it really is a good read if you're up to it!)

 

[GT Premi]

But that points back to your question of "how" they were able to underbid Brembo and still put out a quality product. On a size scale, SHW is more like a boutique house compared to Brembo; the defacto juggernaut in the brake business. If they're not willingly taking a loss for the sake of future gains, they must be putting them out there at razor thin margins or at cost. When I said "lower grade" formulation, I didn't mean to imply "substandard." I only meant that perhaps the construction materials may not be as high as Brembo. Brembo can simply use economies of scale to be able to use better quality materials with the cost spread across a much larger base.

But anyways, like you, I, too, wonder how they were able to undercut Brembo. For all we know, they didn't undercut Brembo but, rather, Ford decided to take a no-compromise approach to braking, considering all the raspberries they have received about the brakes throughout the S197's chassis run. Maybe they just want to shut the rags up about it.

 

[Tob]

Well put.

As to material, again, SHW provided a rotor that met the specifications that Ford engineers were comfortable with. They've had plenty of time to evaluate them and change what they needed to. The proof lies in how well they perform. I'm confident that Ford got this one right. What will be interesting to see is if Ford uses a Brembo CC rotor on the R model...

 

[GT Premi]

As well as whether they use the newer "spiral" technology or the pressed powder method. I've read that the continuous fiber spiral is less prone to cracking than the pressed powder. I wish I could remember the link so I could share it.

 

[Tob]

I've been through a number of SHW's financials now and searched for information that I figured they might have let slip in or around Germany. They've been tight lipped but I do have a sense that the agreement to supply rotors for this car is a big deal (at the very least for a successful marketing opportunity) to SHW as much as they already supply rotors for some pretty well respected vehicles.

Note the second to last sentence in the following snip. I believe they meant "Big Three" (I've noticed a few German to English translations throughout the company literature that are off a bit) instead of "Detroit Three." I think they are talking about the brake rotor prototypes they supplied Ford.

SHW revised this part of their "financial position" presentation for their November release. Note the car they now show that they didn't before. Someone should let them know that the secret is now out and they can show the GT350 instead of a just GT.

And I found some interesting sidebar gems while scouring through some of the various pdf's about the brakes as well.

There's something behind the cross hatch finish that you see. Another thing - note the somewhat random hole pattern cross drilling on the rotor in the following photo. Cracking (again) is a concern here and if you look at a different SHW rotors you see a different pattern. If you scroll back up to the GT350 rotor (or friction ring) shown earlier in this thread you can see a similar, minimalist, pattern. See the Quality Testing sidebar "A ventilated brake disc must withstand..."? I initially was thinking they were referencing the vanes but I'm now believing they are saying that the cross drilling is "ventilating" and that "tearing" is actually cracking. Its a bit of a generic statement but if their ventilated rotors can indeed withstand 500 (minimum) top speed-to-12.4mph cycles without cracking, color me impressed.

Cross hatch comes from turn milling.

This last photo caught my eye. Look at the floor. The building. The atmosphere. I worked in a massive stainless steel foundry in Lockport NY, about twenty years ago (now called "ATI Specialty Materials"). You never forget the warmth. The unique smell from the processes going on. Floor looked the same. I loved it. And I like the fact that a brake company with just over 300 employees can have the resources, both natural and human, and the engineering know how to compete with a company like Brembo and supply what may arguably be the best system we've ever seen from Ford Motor Company. Bravo.

 

[ford20]

What's the difference between this and the 2 piece rotor setup where you can disconnect the hat from the rotor itself?

 

[Ry_Trapp0]

What's the difference between this and the 2 piece rotor setup where you can disconnect the hat from the rotor itself?

positives are that the radial pin mounting setup allows the ring to expand in diameter separately from the aluminum hat, which of course expands at a much different rate. this prevents the ring warping that can occur with conventional 2-piece rotors(caused by the different temperatures and rates of expansion that the aluminum hat and iron ring experience) when they are up to temperature. the current mounting methods of conventional 2-piece floating rotors allow for
lateral movement, but not radial, thus the binding between the hat and ring leading to the warping.

of course, the downside is that these rotors aren't servicable, can't just replace the ring.
[and that they're drilled UGH!]

 

[sunburned]

What's the difference between this and the 2 piece rotor setup where you can disconnect the hat from the rotor itself?

Dude, read some of the posts above you...

 

[ford20]

Dude, read some of the posts above you...

Thank you for the brilliant commentary. Some of the things I was wondering I didn't see mentioned. Maybe they were and maybe I skipped over it without realizing it. Anyway, Ry touched on one of them though. The uniform expansion which would help in preventing the rotor from warping. Does it still provide movement like in a full floating rotor to hep prevent some pad knock? I know that a full floating rotor isn't exactly ideal due to the movement allowed in the hat which causes a clunking sound which in a street car is an unwanted sound. That being said I think it was Alcon that basically has a two piece rotor that is fully floating that allows movement whithout the clunk associated with a fully floating rotor and allows for uniform expansion that isn't going to lead to warping . Does anyone know if this may be the case as well? Is there some movement in the ring to allow it to move as well?

Not to mention what kind of benefits it would provide compared to the race setup that Ford Racing is using on on the Boss 302S. I too would have thought that with all of the miles and laps driven with this braking system Ford would have just moved it over to the GT350. I am curious about the drilled rotors as well because it looks like they are somewhat dimple drilled instead of cross drilled but they do go all the way through the rotor surface. The only cars on that first list that I would expect to see at a track day would be the GT3 Cup which has slotted rotors, maybe the R8 Lemans which has drilled and the Gallardo which has drilled as well. I wonder how well they stand up to the abuse despite that they are more than likely much lighter cars than the GT350 would be.

 

[DHG1078]

- cross-drilling promotes cooling and a bit of de-gassing, but often causes stress risers leading to cracking

i hate to say it, but i don't have high hopes under heavy use, because i've read some comments from lambo gallardo(which is equipped with similar discs when not optioned with CCs) owners, as well as a few audi RS owners, who've had to replace the factory SHW rotors after track use due to cracking around the - you guessed it - cross-drilling. granted, i believe all of the audi RS cars are 4000+lbs, but the gallardo is still lighter than the GT350 should come in at.
from my research, it looks as though porsche has put the most time and cash into ferrous disc research(decades worth), going as far as casting the 'cross-drilled' holes in to eliminate the stress risers caused by actual drilling, but even they weren't able to eliminate eventual cracking around the holes. it leads me to wonder if the cracking isn't caused by stress risors, but rather the temperature differential(and thus expansion rate) at the holes compared to the material around them. with the holes and the material around them constantly expanding and contracting at different rates as a vehicle is being used, something has gotta give, right?

...i might have fried my brain for the night...

You are so close here it's painful. You are correct in that drilling does add stress to the rotors and isn't great for longevity under heavy use. You are missing one key point. The holes ARE the stress risers. Holes, along with imperfections within the material itself, prevent dislocation movement (dislocations are small angular distortions within the materials crystal latice and can move through a material when a force/stress is applied) within the material. Because dislocations can't move through the cross-drilled holes, and thus must move around them, you have a much higher dislocation density (and thus stress density) immediately around the holes than anywhere else. This is why cross-drilled rotors are notorious for cracking around the holes. Casting the holes in eliminates stress (and dislocations) caused by the drilling operation which helps, but you can't eliminate the stress risers without eliminating the holes. At least not with todays tech.

+10 internetz for using the term "stress risers" though.

 

[Ry_Trapp0]

Is there some movement in the ring to allow it to move as well?

Not to mention what kind of benefits it would provide compared to the race setup that Ford Racing is using on on the Boss 302S. I too would have thought that with all of the miles and laps driven with this braking system Ford would have just moved it over to the GT350. I am curious about the drilled rotors as well because it looks like they are somewhat dimple drilled instead of cross drilled but they do go all the way through the rotor surface. The only cars on that first list that I would expect to see at a track day would be the GT3 Cup which has slotted rotors, maybe the R8 Lemans which has drilled and the Gallardo which has drilled as well. I wonder how well they stand up to the abuse despite that they are more than likely much lighter cars than the GT350 would be.

some lateral movement may be designed into these rotors by the way of the mounting pins flexing to some degree, but they don't allow lateral movement in the sense of conventional 2 piece rotors. i've heard some say that this lateral movement could actually induce pad knockback, but don't quote me on that, i definitely don't know for sure.

as far as the boss 302R/S brakes are concerned, they aren't anything special, they're VERY similar to the production GT track pack/boss 302/base GT500 brakes. but they're also only hauling down ~3300lbs of car(CTSCC GS minimum weight for the boss 302R floats around that number) vs the ~3600lbs or so of the GT350, and they also see brake service after every single race.

You are so close here it's painful. You are correct in that drilling does add stress to the rotors and isn't great for longevity under heavy use. You are missing one key point. The holes ARE the stress risers. Holes, along with imperfections within the material itself, prevent dislocation movement (dislocations are small angular distortions within the materials crystal latice and can move through a material when a force/stress is applied) within the material. Because dislocations can't move through the cross-drilled holes, and thus must move around them, you have a much higher dislocation density (and thus stress density) immediately around the holes than anywhere else. This is why cross-drilled rotors are notorious for cracking around the holes. Casting the holes in eliminates stress (and dislocations) caused by the drilling operation which helps, but you can't eliminate the stress risers without eliminating the holes. At least not with todays tech.

+10 internetz for using the term "stress risers" though.

awesome!!! posts like this are why i still come here, love me some tech!

as far as using "stress risers", i spend a LOT of time on corner-carvers and pirate4x4 where the terms "triangulation" and "stress risers" show up in text more than the word "the"

 

[Tob]

Single shear.

 

[DHG1078]

Single shear.

Which comment is this directed at?

 

[Tob]

Sorry DHG. It was aimed at Ry. As a fellow CCer, I was just letting him know he had forgotten an important one, beyond stress risers or triangulation. That's all.

 

[DHG1078]

Sorry DHG. It was aimed at Ry. As a fellow CCer, I was just letting him know he had forgotten an important one, beyond stress risers or triangulation. That's all.

Oh, I was skimming through the thread and couldn't figure out what that went to lol.

 

[Ry_Trapp0]

after looking up info on the multimatic DSSV 'spool valve' shocks used in the Z28(because it's getting old hearing "it has formula 1 shocks, bro!!!" without any actual tech) i stumbled upon piles of interesting info on carbon-ceramic brakes. i'll try to throw it all in here later tonight, but, long story short, i literally don't know why any single person would want them after reading this info. they make sense for the GTE/GTLM racing class, where every fraction of a second and every ounce makes a difference in the OEM dick measuring contest, but that's about it, lol.

Single shear.

touche, sir! i don't know how i could leave that one out!

 

[Darren5.0L]

Tob, excellent collection of research, and a great resource to pour over until Ford makes some additional details public.

 

[Tob]

Thanks Darren. I'm always ready to dig when the opportunity presents itself. Hopefully there is more data released in Detroit.