Rotors upgrade - United Bimmer Community

**Rooz** · 07-17-2005, 06:51 PM

OK, am looking into doing some research before I actually replace my rotors. Now I was looking at Turner's website and they have a good selection at some very good prices.

But I don't know a all lot about rotor upgrades, and since you can't cut BMW rotors, why not upgrade them

So, what is better Cross drilled or Gas Slotted (Please don't tell me both bcs am not wanting to pay more, it's either one or the other)

And what are the pros and cons of them, I mean, are they noisy, create more dust.... Any feedback is very welcome

**Rooz** · 07-17-2005, 07:01 PM

Or should I just stick to OEM rotors?

**B_w.** · 07-17-2005, 08:16 PM

performance wise you should stick to oem rotors. unless you upgrade to bigger brakes you are not going to get improved stopping power. slotted and cross drilled rotors only look better than stock rotors. the downside to slotted/ cross drilled is that they will eat up the pads much quicker.

**Rooz** · 07-17-2005, 08:19 PM

cool, thx for info, I was getting the basic same idea from the stuff I been reading on them all day...

+ It appeards that they seem to warp easier...

**Spieluhr** · 07-17-2005, 09:22 PM

x-drilled/slotted will not warp any where near as easily as oem because htey remain much cooler due to the holes and slots. For me that is a huge buying point.

But what they also do is they allow the gas to be released as you know. With oem rotors there is a layer of gas between the pad and the rotor which does not allow it to stop as easily as a x-drilled/slotted rotor. However, as you know the down side to this is that the rotors and pads have much more contact and therefore eat pads a little quicker. However, I have not heard that the pad wear is bad enough to not get them.

**Rooz** · 07-17-2005, 09:45 PM

Quote:

The rotors are already showing excessive ammounts of corrosion and I am already on my second set of brake pads. All the pros I have spoken with state point blank that quality products should not break down this fast. I am on this site right now to order a THIRD set of brake pads. These brakes fade within 30 mins of stop light traffic and they hum like crazy. I do not mind the noise if I got what I expect out of "Performance" parts. I am about to get new factory parts put back on, they held up better and performed better. Review submitted: 2005-05-30

Quote:

The rotors shuddered and shook the whole car by the 5,000 mile marker or maybe less. The pads let off the worst brake dust that iv e ever seen. stopping pwer was still good but warping was the prob. on this upgrade. -- Review submitted: 2005-05-27

Quote:

Decent stopping power and less dust than stock. Took about 3000 miles just to bed in properly and noise was persistent through 6K miles, finally died down. PowerSlot rotors warped at 10K miles, had to be resurfaced. Would not recommend for this application. -- Review submitted: 2005-04-27

Those are all reviews from various sites but mainly tirerack

**cainchapman** · 07-18-2005, 01:26 AM

Stay away from Cross drilled. Read the attached file.

Your BMW calipers are very good. Upgrade the pad compound, fluid and get better tyres. Get braided brake lines fitted. Make sure your brake ducts are functional (if fitted).

I have got Brembo rear vented and slotted discs. I honestly didn't notice much difference. I just liked the way they looked really.

As I've stated before my system is fairly standard, Mintex 1166 Sprint pads, ELF fluid, and Brembo slotted rotors and tyres. 100-0kph stopping time. 30.80m! Ferrari F360 34.59m.

The 540iS weighs more than the Ferrari also. A light car will not generate as much heat in the discs as a heavy car, so heak soak should not be so significant for you.

**Rooz** · 07-18-2005, 01:37 AM

Yeah, I think am first going to get SS lines, and if am not pleased enougth with results, I'll see about diff rotors//calipers.

All I really want is just a small boost in brakes, nothing major....

**RealBmw 02** · 07-18-2005, 02:24 PM

the only advantage of the slotted rotors is going to be under heavy persistant use. As mentioned the gas buildup will be let out by the slots and therefore when your brakes are hot you will get better braking action. But this is not really necessary with stock calipers.

One of the main reasons BMW says that OEM rotors can't be turned is so that you buy new ones everytime you come to the shop. I used to turn my friends BMW rotors back when I was in shop in high school. We never had a problem with poor braking. I would just check them to make sure they have enough metal left so that I would not take them too small.

I think buying the SS brake lines first is the right move. You probably do not do enough hard braking to need new rotors or calipers. SS brake lines and new higher performance pads should be just fine for you.

**B_w.** · 07-18-2005, 08:33 PM

Quote:

x-drilled/slotted will not warp any where near as easily as oem because htey remain much cooler due to the holes and slots. For me that is a huge buying point.

But what they also do is they allow the gas to be released as you know. With oem rotors there is a layer of gas between the pad and the rotor which does not allow it to stop as easily as a x-drilled/slotted rotor. However, as you know the down side to this is that the rotors and pads have much more contact and therefore eat pads a little quicker. However, I have not heard that the pad wear is bad enough to not get them.

i have read that good brake pads should not produce gases under braking, therefore drilled or slotted rotors are not needed. because drilled or slotted rotors have holes and grooves cut into them they should actually have less contact with the pads and less mass. the more massive the rotors the better braking should be.

**Rooz** · 07-21-2005, 10:33 AM

well, I went ahead and ordered the lines, anyone knows how hard the upgrade is?

**Rooz** · 07-21-2005, 02:38 PM

humm.... I guess if they get here before Monday, I might just let my dad's mechanic do it.

Yeap, my car's going to his shop on Tuesday to have a nice little fuel system maintenance. He's going to take care of EVERYTHING related to my car's fueling system and clean//replace whatever's needed

**komodo** · 07-21-2005, 04:31 PM

Mind me asking how much you got them for, and from where?

**RealBmw 02** · 07-21-2005, 05:23 PM

Quote:

Originally Posted by B_w.

i have read that good brake pads should not produce gases under braking, therefore drilled or slotted rotors are not needed. because drilled or slotted rotors have holes and grooves cut into them they should actually have less contact with the pads and less mass. the more massive the rotors the better braking should be.

please refrain from making huge assumptions like this until you take basic physics classes. Here's how it actually works:

you want as little rotating mass as possible. The more mass you have, the more momentum and rotating inertia, and therefore the more force needed to stop the rotation. So, you want as little mass in the rotors as possible.

For example.... SUV's that have huge 20+ inch rims have a much greater stopping distance than the same car with stock rims. That is why huge rims are a lame. (I know the wheels are separate from the rotors, but since they both contribute to the car's unsprung weight, you can analyze them as one object)

However, you do loose a slight amount of contact patch when you drill or slot the rotors, so your braking will suffer slightly from this. However, it will not be greater than the fade you will encounter after long hard use from OEM rotors.

**Rooz** · 07-21-2005, 06:48 PM

The SS lines, I got them from UUC with shipping came to $126

The Brake fluid that they recommend, they sell it for $35 a bottle, and our cars need two. I bought the same exact fluid that they recommend from an ebay store for $12 a bottle.