Rotors.... for 4.8is with hawk Pads??

[X5rolls]

Originally Posted by FSETH

Rotors and bearing are two seperate items and changing rotors doesn't require any actions to the bearings. They are behind the rotors and stay attached to the car. They will not come off when you remove the rotors.

This is my last ditch effort to try to talk you out of drilled rotors...don't do it.

As far as I know, any pads will work with drilled rotors, but they will wear faster than if you used them with plain rotors.

I also suggest getting an indy to do the brake job if you are not comfortable. At minimum, I would find someone who has knowledge and experience doing brake jobs to help you if this is your first time.

Good luck.

Thanks for the feedback - I'm leaning towards stock parts now, they are well designed and manufactured. Can these rotors be turned or are they like a few others that are not recommended for turning? They are original as are the brake pads currently on the X5.

As far as doing the brake job, I've done so many on other vehicles I've lost track just not on the X5. I looked at the brake installation notes in the articles section (thanks for those who contributed) and it's about as easy as it can get. Just hate doing work on vehicles in the cold. I should have installed the heater years ago, grrrr.

[FSETH]

Originally Posted by X5rolls

Thanks for the feedback - I'm leaning towards stock parts now, they are well designed and manufactured. Can these rotors be turned or are they like a few others that are not recommended for turning? They are original as are the brake pads currently on the X5.

As far as doing the brake job, I've done so many on other vehicles I've lost track just not on the X5. I looked at the brake installation notes in the articles section (thanks for those who contributed) and it's about as easy as it can get. Just hate doing work on vehicles in the cold. I should have installed the heater years ago, grrrr.

I wouldn't recommend turning the rotors. BMW rotors are notoriously thin to save weight in the first place. You would have to measure them to be sure it was even possible though. Even if they are OK to turn or reuse as is, they would most likely be below the minimum thickness before your new pads wear down. I would just change out the rotors with the pads, personally. You will want to change out the brake fluid as well.

[X5rolls]

Originally Posted by FSETH

I wouldn't recommend turning the rotors. BMW rotors are notoriously thin to save weight in the first place. You would have to measure them to be sure it was even possible though. Even if they are OK to turn or reuse as is, they would most likely be below the minimum thickness before your new pads wear down. I would just change out the rotors with the pads, personally. You will want to change out the brake fluid as well.

That's what I was concerned about - I don't really mind spending the $ to do the right thing (replacing rotors too) but if they were they type that could be turned it would save hundreds of dollars on a brake job I'd rather do myself anyway. Fluid change now makes sense too, had that done under normal maintenance when it was at the dealer around 35k miles.

[TowX]

Here's why you don't put drilled rotors on your car, when the rotors weren't designed to be drilled:

These rotors were OE Porsche Zimmerman rotors, drilled by a "reputable" Porsche specialist. They came with my 911 when I bought it 4 years ago so I thought I'd give them a try. I'd been on track at MidOhio, pulling 135 on the back straight every lap when I started to get a bad vibration under braking. So I slowed down and pitted in. Didn't even make it to my garage when it went BANG, loug enough that a couple of folks thought there'd been a wreck. And the right front tire locked up immediately. Had I not pulled in, it could have broken at speed on the track and would have caused a major spin at best, or even worse.

Now I run Porsche 996 Twin Turbo calipers and rotors on my 911, rotors that were drilled from the factory. I've put 2 years on those rotors, probably 30 or more track days, and no issues at all.

Oh, and drilled rotors will reduce your brake performance. Think about it- you remove about 20% of the friction surface. So not only do you need to increase your pedal pressure to stop, but you also can put extra heat into the brakes. Sounds crazy? If you need greater pressure, and need to be on the brakes longer, there's less cooling time between braking applications. When I went from the stock solid rotors to the drilled rotors that broke, my brake temps went up almost 100 degrees. Yes, I have a pyrometer that I use to check caliper and rotor temps. After the rotor broke, I put the old stock rotors back on and the temps went down. Oh, and my lap times went up close to half a second with the brake friction I got back.

[admranger]

Originally Posted by TowX

Oh, and my lap times went up close to half a second with the brake friction I got back.

I'm sure you meant that the lap times decreased with the non-drilled rotors, right?

BTW: that rotor in the pic looked just fine and any competent driver would have been able to drive around any problem caused by that crack!

[TowX]

Originally Posted by admranger

I'm sure you meant that the lap times decreased with the non-drilled rotors, right?

BTW: that rotor in the pic looked just fine and any competent driver would have been able to drive around any problem caused by that crack!

Yea, yea. You're correct. Lap times decreased.

Would have been hard to get around the track with the right front tire locked up, even though I do spend time in right hand turns with the RF tire off the ground.. Hard to tell in the pic, but when it broke, the surface at the crack had a step in it. As it cooled it flattened out. Actually took a huge chunk out of my Hawk HT10 brake pad.

[admranger]

Originally Posted by TowX

Yea, yea. You're correct. Lap times decreased.

Would have been hard to get around the track with the right front tire locked up, even though I do spend time in right hand turns with the RF tire off the ground.. Hard to tell in the pic, but when it broke, the surface at the crack had a step in it. As it cooled it flattened out. Actually took a huge chunk out of my Hawk HT10 brake pad.

Just drive faster around corners so your right front is in the air!

Seriously though, that had to be scary. There are stories on bimmerforums of rotors shattering from cracks (on track). Those cars did not fare as well as yours. When I raced, the cheap blanks would crack (not drilled rotors mind you, regular ones) way before they would be close to their thickness limits, and I had brake ducting right to the hub!

To the OP: Drilled rotors are worthless. Rotors with the holes cast in them are ok, but since 99.999999999999999999% of drivers and 100% of X5 drivers don't need the slight reduction in rotating mass that this provides, why bother? You have objective evidence provided by TowX, you don't need to recreate the experiement with your X5.