Grumpy666

If slotted and cross-drilled are the only options, slotted is the lesser of the two evils - as long as the slots are fairly shallow. The original intent of holes/slots was to provide a path for the gasses that were generated from the pads at high temperatures. The outgassing of the pads was an artifact of the binding agents used in the formulation of the pad material. At high temperature it would boil and generate the gasses, which would be trapped between the rotor and pad. This would reduce the coefficient of friction between the pad & rotor, which reduced braking ability.

This outgassing is not a problem with current generation pads, which negates the need for holes/slots. There is some speculation that slots help prevent pad glazing, but I think the jury is still out.

Holes are bad, especially if they are drilled and not cast into the rotor. Drilling holes in rotors causes the formation of stress risers, which are the precursor to cracks, which eat pads and reduce rotor longevity. Holes also reduce the rotors ability to absorb and dissipate heat (less mass). And yes, they do reduce unsprung weight a very small amount, but IMO, it's not worth the tradeoffs. The only valid reason for holes is to reduce the weight of big-*** rotors - other than that, it's just aesthetics.

Take a look at what the NASCAR boys are doing - you won't find any holes in their rotors.

Grumpy666

Fantastic deal? Have you priced a set of rotors for non-MB cars? Typically, they're 3-4 times cheaper, with no difference in construction or quality. With this group buy you're just getting screwed a little less. It's like: When do you play in a crooked poker game? When it's the only game in town.

SlowE55

WOW!! Let me know where I can find a set of four 2-piece rotors of similar size for $375 and let me know what car. I want that as a track car.

vrus

For those of you that were on the fence about these rotors, BUY THEM NOW AT THIS PRICE!!!! You are getting a great deal!!

e55 baller

COUNT ME IN
iturk182@aol.com

Rock

Hey Grump, can't ya see we're trying to conduct a little business in here. Thanks for raining on our parade. Now stop before you to scare away the sheep.

On a serious note, thanks for your input. I agree that we "overpay" but that started back when we purchased these cars.

Are you suggesting that these rotors offer no significant benefit over the stock units?

e55 baller

all i care about is 34 LESS Lbs, better looks. Don't care if it stops the same or even 2 feet less or more.

eride

i'm in.

Grumpy666

OK - here's a site where you can get slotted Brembo rotors for various cars. I selected a C5 Vette and E39 M3, both of which would make a good track car. The front rotors for either car are $157 for a pair. The rear pairs are $122. Shipping is $70. Total cost: $349.

http://www.autoaccessorystore.com/ho...izard=&s=&mid=

If you install the Evo rotors and track the car, you will probably discover a new shade of gold for your calipers. The reduced mass of those rotors will translate into reduced cooling capability. It could get ugly.

Rock

UPDATE:
This is the list of members who have made and oral commitment to participate in the EVOsport rotor buy:

Those In:
1. Rock
2. Kev04C320
3. Kens-E55
4. Rotex
5. Loren
6. GTA23109a
7. eride
8. Sam E55
9. laj e55
10.e55 baller
11. MGO427

If I left your name out please let me know.

PLEASE- After you place your order next week, post that you have done so (in this thread). We need to keep track of the total number of orders.

I assume all that have posted are very serious and will place an order. So, since we have over twice the people needed to hit the 1,500.00 pricing, I am going to e-mail Simon to see if we can get an even greater savings.

Grumpy666

I'm not trying to be a rainmaker - I'm offering an experienced opinion that is not confused by marketing hype. I just want you guys to be aware of potential problems before you make a buying decision. Consider it a small dose of reality.

Those Evo rotors will probably work OK for a normally-driven street car, but don't expect improved braking. The braking performance of a car like the E55 is limited by the tires, not the brakes. Have you ever done an emergency stop and felt the brake pedal pulsating? That's the ABS intervening because the tires are trying to lock up. Bigger brakes will not stop you in a shorter distance, but a bigger tire contact patch and/or more tire-to-pavement friction will.

And I doubt if there will be an acceleration improvement, either. The benefit of reduced unsprung weight occurs as the vehicle begins accelerating - getting the rotating mass into motion. With the E55, hard acceleration results in tire spin and ESP intervention (it applies the brakes). Having less unsprung weight will result in more tire spin and ESP activity. Best case, you may get a slightly higher trap speed due to the 34 fewer pounds.

However, there may be some braking improvement with the lower unsprung weight if you track the car, but after the first couple of laps, it will start to circle the bowl. The lighter rotors are smaller heat sinks and the advantage of lower unsprung weight will fade as fast as the brakes. The OEM rotors are larger for a reason, but even they aren't adequate for tracking - unless you like gold calipers.

raycanales

Grumpy you got me sold ... I guess Im just going to keep my Stock AMG brakes ...

I think you make sense .... for looks I would rather have the Brembos with their Calipers too ...

where do I get the calipers ....?

does that site sell them too?

Grumpy666

Don't know. I did a quick search for performance rotors in response to another poster and clicked on one of the sponsored links on the right of the Google page. I'm sure there are many other sites with equivalent or better prices. Do a search for Brembo calipers and go from there.


For the forum:
I'm not trying to dissuade anyone from buying the Evo rotors. If you like the way they look and you're happy with the price - go for it. Just be aware of the issues I stated earlier. My opinion is you're buying aethetics, not improved performance. There are other upgrades on which I would rather spend the money. Do what you think is right for you.

Also, when I look at the pic of the rotors above, all I see are what look to be off-the-shelf rotors with with a machined MB adapter plate rivited to them. Maybe $150 in parts and another $50 in machining - for all four. Of course, this is just my opinion and I could be wrong.

dsc

A question I have is - if you are losing the mass at the hud (now aluminum) and not at the rotor disk itself don't you retain the same heat sink advantage as stock but with overall less weight as long as the disk weigh the same. Also, the hubs are bolted on the disk not riveted. The passenger disk will cool MUCH more efficiently than stock due to the correct directional ventilation unlike our stock rotors, on which the driver’s side vents properly but MB used the same rotor on the passenger side causing the vents to face the wrong way. In addition if the rotor retains the same heat sink capacity with less weight shouldn't corning improve due to less rotational inertia at the hub?

2K6E55

I want in... Does Simon have enough for all of us?

e55 baller

<<And I doubt if there will be an acceleration improvement, either. The benefit of reduced unsprung weight occurs as the vehicle begins accelerating - getting the rotating mass into motion. With the E55, hard acceleration results in tire spin and ESP intervention (it applies the brakes). Having less unsprung weight will result in more tire spin and ESP activity. Best case, you may get a slightly higher trap speed due to the 34 fewer pounds.

Basically 34 unsprung pounds translates to a 57.8 sprung loss which translates on average to an effective gain of about 5.78 Additional HP -- you may see an ET improvement of 0.05 and 0.5 mph.

I have my car on a diet so adding the brakes will get me down to 3960 lbs with a 1/4 tank of gas. I have already taken out about 60-75 lbs. In total my 100lb effective diet should net me 1mph and 0.1 less ET.

I'll take that.

SlowE55

Those are not 2-piece rotors though. I was probably dreaming to think that such a beast existed. At cost, maybe.

Even with additional cooling (crazy brake ducts, etc), I am pretty sure the calipers will still change color. The E55 is simply very heavy and powerful to go around a road course. A road car definitely has many compromises.

These EVO rotors look awesome. I doubt there is significant performance benefits. Yes, every bit helps and it all adds up. IMHO, the E55 is the wrong platform to try and squeeze the last bit of performance out of it though. I catch myself wanting to do it all the time. In the end, it's an emotional choice rather than a logical one. :p

Kens-E55

Hm-m-m-m Interesting reading here Grumpy
As to the benefit of these rotors - I've got first hand experience on 2 other vehicles where I went with heavier rims and tires and kept the brake system stock. Vehicle #1-The result was I LOST 10 MPH in the 1/4 mile. Yes, I went from a 93mph trap speed down to 83mph. Extreme-Yes -- I added 90 lbs of rims and tires to my Dually - but true none-the-less ---I did lose 10mph!!

Vehicle #2 more realistic---Lexus GS400 where I went from stock 17" wheels/rubber to Plus1 going up to 18" wheels and tires ONLY!
The result was a 4mph loss in 1/4mi trap speed! (98 down to 94)
Too boot, that set-up only totalled an extra 36 lbs in weight!
- I'm willing to bet - lose 35 lbs in rotors, and most of us will see a gain in trap speed of at least 2mph!

Other benefits - The truck you can forget about panic stops
These lighter rotors will make the car feel much "lighter" to brake from normal speeds

I could go on with other advantages but I've rambled on enough.

The rotors will be a benefit that is noticed!!

dragonAMG

Mine arrived today. The construction of these rotors look even better in person. The rear rotors seem VERY LITE.

That being said, they were a bit knicked up... huge gouges in the 2 front rotors (not too happy about this). Not just scratches..... gouges in the metal. Extremely poor packing job likely caused this. Simon/Evosport, I'll be calling you on Monday to discuss this.... not a happy camper. Not only did I pay more than all you guys (I wasn't even going to try to get the same price), but my rotors were effectively "damaged"... not cool.

Here are some pics...

laj_e55

that is not acceptable

OzE55

While goods should always arrive in "new" condition - these are brake parts and that surface wont ever be seen once installed.

dragonAMG

With stock wheels maybe not, but I will have HRE 840r in black... my fear is that the gouges will definitely be visible. If the gouges were on the face, it would be a different story. The gouges are on the bevel which will NOT be covered by the wheel. One of the main reasons I bought these was for aesthetics.

Just like the picture below.... the bevel where mine is all hacked up is definitely visible.

OzE55

In your case you're absolutley correct - send them back!

FlyByNight

Wow, I really don't like how close to the edge those last set of drilled holes are... don't they look like they are inviting a nice crack?

Loren

Rock

Despite the points that Grumpy makes, I still believe that reduction in unsprung weight is a big advantage, especially during spirited driving. Ask anyone that has replaced their stock wheel/tire set-up with a lighter package. The track argument may be valid but I would venture to say that 99% of us will not track our cars (1/4 drags do not count).

Also, after a search of other floating rotors for European and Japanese cars I found that the cost is often times $300-$400/rotor, so this is right in line with what we will be paying.

Finally, I did hear from Simon and the price will stay at $1500.00 even with 10+ orders. Simon stated he could handle the orders but 2-4 weeks maybe needed for shipping.