New OEM Cross Drilled Rotors for the Base Boxster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

blinkwatt · 08-22-2007, 10:41 PM

Quote:

Originally Posted by J-RAD

They don't.

Most pro race teams don't use cross-drilled rotors anymore. They use solid carbon, slotted, or other advanced technologies.

I stand corrected. It has been 2 years since I went to a ALMS event,lol I'm old and outdated at 19 years old.

porsche986spyder · 08-23-2007, 06:50 AM

Well, if you look at what I said earlier, the best of both worlds, Cross-drilled & Slotted would be the best as long as the surfaace area is larger than the stock application rottors. In which most cases, just about any aftermarket performance rottor that you buy to replace the stock ones are usually bigger. Never seen an aftermarket rottor that was the exact same size as the stock one, like someone said earier that would defete the purpose of having them cross-drilled or slotted. :ah:

insite · 08-23-2007, 07:08 AM

Quote:

Originally Posted by porsche986spyder

Well, if you look at what I said earlier, the best of both worlds, Cross-drilled & Slotted would be the best as long as the surfaace area is larger than the stock application rottors. In which most cases, just about any aftermarket performance rottor that you buy to replace the stock ones are usually bigger. Never seen an aftermarket rottor that was the exact same size as the stock one, like someone said earier that would defete the purpose of having them cross-drilled or slotted. :ah:

the best scenario is a solid or slotted rotor with cooling ducts. better airflow will do more than just slots or holes.

most racing teams avoid drilled rotors anyhow. drilled rotors tend to not handle heat quite as well as solid or slotted rotors. they are more prone to hot spots; this causes the ferrous material to change to austenite, which is harder than the surrounding material. this in turn causes high / low spots on the rotor, ultimately leading to poor surface mating between the pads / rotors. this problem is exacerbated by the ferrous pad material used in most race linings.

Franco · 08-23-2007, 07:28 AM

Hi, I have all 4 Drilled Zimmermann rotors sitting in the garage waiting for me to install them, I'll take a photo when i get back from work and post it.

Paid $332.00 US for all 4.

porsche986spyder · 08-23-2007, 08:20 AM

Quote:

Originally Posted by Franco

Hi, I have all 4 Drilled Zimmermann rotors sitting in the garage waiting for me to install them, I'll take a photo when i get back from work and post it.

Paid $332.00 US for all 4.

Do me a favor and measure the over all diameter of the Zimmermann Rotors and then measure them to the size of the stock ones and tell me what size they are. They should be slightly larger.

J-RAD · 08-23-2007, 07:26 AM

Quote:

Originally Posted by porsche986spyder

Well, if you look at what I said earlier, the best of both worlds, Cross-drilled & Slotted would be the best as long as the surfaace area is larger than the stock application rottors. In which most cases, just about any aftermarket performance rottor that you buy to replace the stock ones are usually bigger. Never seen an aftermarket rottor that was the exact same size as the stock one, like someone said earier that would defete the purpose of having them cross-drilled or slotted. :ah:

But then you're looking at a complete brake system upgrade. You'd also need to get larger calipers, a new master cylinder, new pads, and so on....you understand.

Actually, most of the aftermarket rotor applications I've seen are indeed the same size. Essentially, they've just simply taken a rotor blank and drilled it.

Nonetheless, I'll say this about cross-drilled rotors...they look cool!

porsche986spyder · 08-23-2007, 08:27 AM

Quote:

Originally Posted by J-RAD

But then you're looking at a complete brake system upgrade. You'd also need to get larger calipers, a new master cylinder, new pads, and so on....you understand.

Actually, most of the aftermarket rotor applications I've seen are indeed the same size. Essentially, they've just simply taken a rotor blank and drilled it.

Nonetheless, I'll say this about cross-drilled rotors...they look cool!

Nope. They are 1-2 inches larger and don't require any other upgrades. I have some on my car and the only other mod I did was to add better/newer pads. Everything fits.

Now there are some rotors out there that are massive and do require complete stystem upgrades like Bear and Brembro performance packages, but those rotors are somewhere in the neighborhood of 17-18 inches in diameter. My aftermarket ones are 1.25inches larger than the stock ones.

J-RAD · 08-23-2007, 11:23 AM

Quote:

Originally Posted by porsche986spyder

Do me a favor and measure the oreall diameter of the Zimmermann Rotors and then measure them to the size of the stock ones and tell me what size they are. They should be slightly larger.

Quote:

Originally Posted by porsche986spyder

Nope. They are 1-2 inches larger and don't require any other upgrades. I have some on my car and the only other mod I did was to add better/newer pads. Everything fits.

Now there are some rotors out there that are massive and do require complete stystem upgrades like Bear and Brembro performance packages, but those rotors are somewhere in the neighborhood of 17-18 inches in diameter. My aftermarket ones are 1.25inches larger than the stock ones.

I'm going to let you think about that some more for a bit.

pecivil · 08-23-2007, 11:35 AM

so what I am hearing is that Porsche, Lambo, Ferrarri, etc put stock drilled rotors on just for looks, and a solid rotor is better.

I understand the logic as to why drilling has its problems, but I really hate to believe porsche puts drilled rotors on a GT-3 strictly for marketing, when solid is better.

Hummmmmm.....

porsche986spyder · 08-23-2007, 11:40 AM

Quote:

Originally Posted by pecivil

so what I am hearing is that Porsche, Lambo, Ferrarri, etc put stock drilled rotors on just for looks, and a solid rotor is better.

I understand the logic as to why drilling has its problems, but I really hate to believe porsche puts drilled rotors on a GT-3 strictly for marketing, when solid is better.

Hummmmmm.....

Ditto, I couldn't have said it any better. It's obvious that all of the "S" types including the Boxster come with better brakes, and I hate to think that the crossed drilled ones they come with are useless. Makes no sence.

insite · 08-23-2007, 11:42 AM

Quote:

Originally Posted by pecivil

so what I am hearing is that Porsche, Lambo, Ferrarri, etc put stock drilled rotors on just for looks, and a solid rotor is better.

I understand the logic as to why drilling has its problems, but I really hate to believe porsche puts drilled rotors on a GT-3 strictly for marketing, when solid is better.

Hummmmmm.....

check out the ones they actually race. earlier in this thread is a photo of a GT3 RSR. solid rotors. cross drilled were all the rage for awhile, but time and experience have shown that in racing applications, there are better ways to go. for the street / light track, drilled rotors are fine & they look cool. in terms of performance, they're simply not the best option.

porsche986spyder:

check your measurements. a rotor that's 1.25" in diameter larger than stock will hit the caliper. even if it COULD fit, your pads wouldn't sweep the outermost portion of the rotor. also, the largest sports car rotors i'm aware of are 15.7" / 400mm diameter. a 17" / 18" disk w/ caliper won't fit inside the wheels. not to mention the inertia starts to really work against you when you go too big on rotors.

porsche986spyder · 08-23-2007, 11:38 AM

Quote:

Originally Posted by J-RAD

I'm going to let you think about that some more for a bit.

I don't get your point? I asked him to measure the stock vs. the Zim. ones because I know they should be bigger. When I say "they" I'm reffering to the aftermarket Zim. ones. Mine are not this brand but are aftermarket. Since I thew away my stock rotors and can not find the exact size of the O.E.M. ones. I only remeber they were at LEAST 1inch larger in diameter because I held them up next to each other. Does this help clarify?

blinkwatt · 08-23-2007, 11:41 AM

Quote:

Originally Posted by porsche986spyder

I don't get your point? I asked him to measure the stock vs. the Zim. ones because I know they should be bigger. When I say "they" I'm reffering to the aftermarket Zim. ones. Mine are not this brand but are aftermarket. Since I thew away my stock rotors and can not find the exact size of the O.E.M. ones. I only remeber they were at LEAST 1inch larger in diameter because I held them up next to each other. Does this help clarify?

If they were a inch bigger then they wouldn't fit the brake caliper.

chaudanova · 08-23-2007, 12:15 PM

Quote:

Originally Posted by porsche986spyder

Nope. They are 1-2 inches larger and don't require any other upgrades. I have some on my car and the only other mod I did was to add better/newer pads. Everything fits.

Now there are some rotors out there that are massive and do require complete stystem upgrades like Bear and Brembro performance packages, but those rotors are somewhere in the neighborhood of 17-18 inches in diameter. My aftermarket ones are 1.25inches larger than the stock ones.

I think this is where there is some question in this thread... haha... 17-18" diameter... when the OP mentioned for you to think about this... i think he was referring to this part of what you said. Picture this... 18" diameter Rotors would be equivalent to my 18" diameter WHEELS.