You must be one of the few guys who figure a gt-r brembo kit is “not good enough” lol. I’d understand if you were on stock brakes and were balling west west style on mods…but isn’t this move a little much? Just put it in a 997 gt3 fund…
It’s a contingency plan in case I use ceramic brakes on track and they change my life. The unsprung weight diet package would also include BBS FI-R in 19x9 @ 17.2 pounds. That’d drop 54 pounds by my count. Probably not worth it for $25k. Just comforting to know it is possible.
Going from your heavy"ish" flow formed bbs wheels to a lightweight forged option would have tremendous benefits IMO Plus, saving weight on a wheel will be more beneficial than the rotors. Hell, if you are really gonna dump money like that, might as well figure out how to pick up a set of CF wheels the GT350R is coming with from the factory. They are torture testing them in the conti challenge series, where I believe they won last weekend at mosport.
The moment of inertia I for a cylinder or circle has a second order dependency on radius. Since most of the wheel mass is on the barrel, you are getting a lot of rotational mass penalty for the I = m r^2 barrel of the wheel. The brake rotor will be closer to the rotation center and thus less penalty on I.
This is for the rotational physics, obviously unsprung mass reduction be the same no matter where you remove it for suspension dynamics (aside from maybe the suspension itself).
My impression is that most of the weight is trimmed out of the spokes. How much lighter is a forged barrel?
I am really only speculating about wheel mass distribution, but here is an article with some discussion, nothing to earth shattering http://www.superstreetonline.com/how-to/wheels-tires/modp-0906-performance-wheel-test/
[quote]But rotational inertia is affected not only by a wheel’s weight and shape, but more importantly how the weight is distributed throughout the wheel and its overall size. Two same-weight wheels could have vastly different amounts of rotational inertia if the weight or metal in the wheel was distributed differently. A wheel with a heavy hoop will have more rotational inertia than an identically heavy wheel whose weight is mostly in the hub.
Read more: http://www.superstreetonline.com/how-to/wheels-tires/modp-0906-performance-wheel-test/#ixzz3g6HMY06S
[/quote]
The carbon fiber wheels on the 350R are made by Carbon Revolution. They are listed on TiKORE’s website. TiKORE is the sponsor on AZ that sells ti lug bolts. The wheels are listed for $15.8K.
http://www.tikore.com/single-piece-carbon-fiber-wheel-cr9-set/
I find it interesting that they don’t give an actual weight for the wheels. At $15.8K the wheels better weigh less than ten pounds each for 19 inch diameter.
They weigh 15lbs Jimmy. I inquired about these wheels last year and they told me they couldn’t even sell them to me with their standard warranty lol.
That is stupidly expensive for a wheel that still weighs a lot. Then to not even offer a warranty, wow.
From a Nissan GT-R forum:
[quote]There are several different methods of construction for “carbon” brakes. Each one has its own merits.
The three main types are:
CFRC (carbon fiber reinforced ceramic) - which is what AP Racing/Stillen, Alcon and Mov’It brakes use [Stillen calls it CCM-X); the process is pioneered by the British company Surface Transforms [ST] who is the manufacturer for the discs that AP, Alcon and Mov’It use. The carbon is laid in continuous pieces and then the ceramic material is added to strengthen the structure. CFRC is superior because it is extremely durable and doesn’t oxidize as quickly as other forms. CFRC is lifetime of the car if kept properly cool, but it’s the most expensive production process.
CCM (ceramic composite material) - is what the SpecV, ZR1, LFA and Ferrari rotors utilize. It’s the more ubiquitous carbon construction type, utilizing a ceramic core with chopped carbon fibers in a matrix of ceramic and resin that’s heat cured. It’s generally the cheapest construction method, but it’s not as durable or effective as CFRC.
CCB (carbon ceramic brakes) - this is what Audi, Porsche, Bentley and Lambo use. It’s a core of ceramic material reinforced with carbon fiber and covered by another layer of ceramic material (better for street use).
Then there’s the carbon-carbon construction that you mentioned, which is straight up carbon. Carbon-Carbon is real race car stuff [F1], utilizing super lightweight carbon discs and full carbon pads. Carbon-Carbon needs heat to operate properly (warming up), but also needs proper cooling to keep from overheating.
There are carbon-carbon options for the R35, but no one is really utilizing them (Jotech does have a customer car with them right now though).
What Brembo is doing now with these CCM-R products seems like it’s their own kind of variation of the CFRC construction, so thus the higher price tag versus the “dime a dozen” ZR1 CCM rotors.
[/quote]
Looks like they clear non-bent 19x8.5 peelers. :
They didn’t clear my bent peelers (bend confirmed by tire shop) with 8mm spacers putting them at ET35.
Brembo GT 380s with OEM Peelers
https://lh5.googleusercontent.com/-9mFRE_7WH7s/Tp4XSE_K1LI/AAAAAAAAAF0/9DVOLpRdkMY/s800/D7K_1843.JPG
Another quote on why these are worth $14k:
https://farm4.staticflickr.com/3876/14654786885_47481cfb3e_o.jpg
I don’t know West, I think this kind of money would be better spent on more of your creative weight reduction. Carbon fiber roof, hood, front fenders, and trunk perhaps? Maybe carbon fiber door cards? Reduced weight would help with brake performance also. Just a thought.
I’m pretty sold on the idea of a ceramic disc. Turns out the ones on new cars aren’t even as good as this. The benefit on the nose heavy Audi is I only have to do the fronts. This is like a $40k job on a 991.
It’s sort of a question of what technology is in supercars and track ready street cars in 2015. You can pony up and buy a $100k car, or try out some of this technology on a chassis like the S4.
Interesting way to look at it. What pads do you use with these and how long do they last?
Pagid RSC1, RSC2 or RSC3 (3 is endurance). I imagine they’d last over 1 year. These pads are not available for Audi ceramics and have spotty availability on Porsche, Ferrari.
The 750 degree post cool down temps I see on the paddock with steel rotors would likely drop below 450 degrees.
I’m going to ask the impossible question here: anyone tried a street pad on the track that they actually like?
I’m using PFC 1038 (AKA TRD pads) and they are ok. They will survive a handful of hot laps but then they fade and the bite drops so much that your braking zones are extended big time. Of course, that’s to be expected on a street pad. But mind you, this is on a 355mm bbk already with no backing plates. Some brake ducting will help.
Curious to know anyone’s experience with the new fangled stuff. HPS 5.0 or something similar?
I tried the stoptech street perf pads (albiet only on the street). Really didn’t like those. No bite.
On the Boxster I used Portersfield R4-S pads to get some more initial bite on the street. Haven’t tracked them but they also sell a model with a name like R4 that is track-only. I like them.
I’ll look into R4s/R4. Thanks for the tip!
I used pagid RS29 before and LOVE those. But uh yeah. Noisy is an understatement.
http://daniwao.files.wordpress.com/2010/02/unicorn.jpg?w=406&h=304
If you were in the green/blue run group, then maybe, but you’re driving the car hard as hell. Imagine if you were running r-comps :o Just bite the bullet and run some track pads ;D My .02
I’ve been down that road and it ended poorly, I would highly suggest just getting the track pads and doing swaps.