tberry

can someone give me diameter&thickness of stock coupe F/R rotors?thanks. I want to get cross-drilled/slotted rotors for my coupe preferably Zimmerman or Brembo (yes primarily just for look b/c I got rims that expose them). Also a good deal online place to get some Porterfield/Minetx/EBC pads F/R as well. If you have URL for both or either one I really appreciate it. Search on "cross-drilled rotors" didn't turn up much info. Thanks again.

tberry

okay i'm reposting in hope that this will move up and get more attention. Stock rotors info anyone? thanks.

tommy

If no one posts before then, I'm putting on my snows and mudflaps sometime over the Turkey holiday, so I'll measure then.

Hopefully, though, someone will have the info up before then.

Remember that an increase in the size of the rotors will increase unsprung weight, which is a bad thing for acceleration. Of course, if you get lightweight calipers, that could be offset.

Mach430

I don't have the specs on the stock rotors, however we do carry drilled or slotted rotors from Brembo for almost all Mercedes models. They are the same size as your current rotors, as you can not put a larger rotor on a brake without changing the bracket. Also, a larger rotor on a caliper designed for a specific size would result in some of the rotor not being used.

tberry

Yes I was on Evosport website to look for some but couldnt find any. Can you email me or post quote on how much will a set of Front/Rear cross-drilled/slotted rotors will cost? Also, what kind of price you can give on rotors set in combo with Porterfield/Mintex/EBC pads (all F/R). Thanks again. My e-mail is kkyaw@houston.rr.com

Xeon

Mach...would you please PM me the price list for the rotors too!

Matt230K

Or post the prices here for all to see!!

tberry

mach, since there is a high demand have you though about doing a groupbuy for F/R cross-drilled/slotted rotors for the Coupe? Look forward to your response. Thanks again.

Lynn

Adverse effects on acceleration of larger rotors is due to the increase horsepower needed to get the increased mass moving. Lighter calipers will only offset the heavier calipers by a very small amount since to calibers are stationary with regards to the rest of the car.

By the way, this is why Porsche invented drilled rotors. They needed to lighten their relatively low powered race cars. They wanted to reduce overall mass, but most importantly mass attached to the engine. Improved braking because of the venting of gasses between the pads and rotors was an additional, possibly unexpected, benefit

Mach430

Prices:

Front: $119 each
Rear: $100 each

Brembo currently does not have any in stock, so it will take about 2 weeks to complete orders.

Thanks

Ben

mleskovar

What are the facts about drilled and/or slotted rotors? I haven't had any luck finding good explanations on the pros and cons.

BlackC230Coupe

thats the price for the brembo rotors? is there any pics we can see of them?

i would only be intrested in brembo rotors.

MacPhisto

Where'd you hear that?!?

Porsche first used drilled rotors on the 917 in the 1970 season. The primary purpose was to help keep the brakes cooler, to solve a problem they were having on certain tracks with the brakes overheating and the brake pedal getting spongy. The primary purpose was in fact to vent the gasses between the pads and rotors and improve braking.

Obviously, they would not compromise the structure of a rotor by drilling it for the mere purpose of reducing weight a miniscule amount.

On a street car, drilled rotors are largely for marketing and cosmetics.

(BTW, rotors are not "mass attached to the engine.")

tberry

Mach430...thank you for the reply. Any chance of a group buy price? say if we get like 5 buyers, 10 buyers? Thanks and hope to do business soon.

Lynn

I heard that on a two hour long prgram about Porsche race cars on Speed Channel last weekend. Drilled rotors were first used on the 910 and 909 hill climb cars. It was stated in the program that the purpose of drilling the rotors was to reduce the mass of the car. The 910 and 909 were built to push the limits of lightness, so that these concepts could be applied to the 908/3.

The rotors are mass attached to the engine as are the flywheel, the clutch, the rotating bits of the transmission, the universal joints, the ring and pinion gears in the differential, the axel shafts, the constant velocity joints, the hubs, the wheels and the tires. At the other end of the engine we have the crank pulley/damper, belts, tensioner pulleys, alternator, water pump, air conditioner, power steering pump, and supercharger (for some of us), and their pulleys as attached mass.

Mach430

These are genuine drilled or slotted Brembo rotors. They are not Brembo rotors that are drilled/slotted by someone else. At this time, we are not planning on a group buy for the rotors.

The benefits of a drilled/slotted rotor are for weight and heat dissapation. On factory brakes, they do not make much of a difference, and are usually only used as an aesthetic upgrade.

Matt

so would those rotors from Brembo work with the stock Calipers? Is it just a swap of the old rotors to the new ones, or is there more that needs to be done?

tberry

Hmmm $440 seem a tad high. Any chance for free shipping or something? Also, any pkg deal deal with brake pads?

MacPhisto

Yeah, I saw most of the program, too. Not all of it, though. Was pretty good!

I didn't see the parts with the 910 and 909, although I would have loved to have seen it. Esp. the 909 - there isn't a lot out about that car, and it is a fascinating car (tiny and under 1000 lbs).

I don't think the 910 used drilled rotors. The 910 was known for its rotors - very thin, lightweight rotors made out of beryllium. They cost $1000 each in 1968! Lots of pics of those beauties around - they are not drilled.

I've also never seen any written references to the 909 having drilled rotors.

The 908/3 did have drilled rotors, like the 917, for the 1970 season. 1970 seems to be accepted among race historians as Porsche's first use of drilled rotors. The reasons were multiple - to improve cooling, increase responsiveness in the rain, help the pads wear more evenly, and decrease weight. Porsche was obsessed with weight, to be sure, but was well aware of the cooling effects of the holes.

As far as mass attached to the engine - I agree. I misunderstood your original statement.

Mach430

These are direct replacements for your stock rotors. Nothing else is required.

Mach430

I don't recommend any aftermarket pads to be used with the stock MB brakes.