Suggestions for best replacement front rotors?

[Iron Man]

If you really want to help minimize/prevent warping on cast iron rotors, you should freeze your rotors in liquid nitrogen. This will transform all of the retained austenite to martensite. The cryogenic treatment also involves tempering the rotor after freezing.

This will increase the life of your rotor and prevent warping.

[TheSt|G]

Originally Posted by Blacksport

Generally good advice....but listen to this; my Durango warped the rotors every 6k to 8k miles....Dodge rotors, aftermarket rotors, didn't matter. I finally put the Wilwood BBK with 16" rotors on the front...been on for over 20k, no warping, not even slightly....However, the rear rotors continue to warp every 6k miles...do I buy EXPENSIVE Dodge rotors for $190 each?? No, I buy cheap Summit drilled, slotted rotors for 50 bucks each, and throw the old ones on the WRP (warped rotor pile) in the back of the warehouse.

Dodge factory parts and BMW factory parts have little to do with each other.

[___whoosh___]

Originally Posted by uberschnell

http://www.ecstuning.com/News/BMW_E8...ors/ES2550968/

2-piece semi floating, will help cool the rotors faster + about 8 lbs. lighter then stock

I just snagged the front and rear full service kit from ECS with these front rotors
can't wait!

[uberschnell]

Wow, I wished I would have known this before swapping out my front brakes and rear rotors with non OEM parts. Even though it's been over 2 years with zero problems I feel better now knowing that they will never be as good as OEM parts

Seriously though, what do you tell all those 135i owners with cracked pistons in their OEM calipers? Let’s not kid ourselves into thinking BMW oem is not fallible or that you can't get equal or better performance from the right aftermarket parts.

People go cheap and then try and throw all aftermarket parts into the same bucket because of that experience. Being smart and doing your research can yield you good parts and saved money.

[Dackelone]

Originally Posted by TheSt|G

Dodge factory parts and BMW factory parts have little to do with each other.

+1. Not to mention the engineering(or lack there of) that goes into each marke.

Somehow I don't think I'd see a X5 with puny 114i rotors on it. But I see many American SUV's with tiny front rotors and rear drums. Not a recipe for "performance".

Originally Posted by Iron Man

If you really want to help minimize/prevent warping on cast iron rotors, you should freeze your rotors in liquid nitrogen. This will transform all of the retained austenite to martensite. The cryogenic treatment also involves tempering the rotor after freezing.

This will increase the life of your rotor and prevent warping.

Cryogenic treating brake rotors is a good idea and it works. You see lots of racers using it.

I have also heard of the NASCAR boys putting brand new rotors outside to rust. Then a year later they machine the rust off and use the rotors. Something about the rust hardening the metal. Not sure if thats a myth or not.

[Blacksport]

Originally Posted by uberschnell

http://www.ecstuning.com/News/BMW_E8...ors/ES2550968/

2-piece semi floating, will help cool the rotors faster + about 8 lbs. lighter then stock

Those rotors and hats are BAD A$$...I'm grabbing a set while they're on sale...I'll sell the BMW performance rotors on ebay...and notice there's a Left and Right rotor!!!!

[Blacksport]

Originally Posted by TheSt|G

Dodge factory parts and BMW factory parts have little to do with each other.

Yes, that's so true...I did NOT get a letter from Dodge extending my Hemi's warranty to 100,000 miles because of rod bearing failure. I DID get a letter from BMW extending my S54's warranty to 100,000 miles because of rod bearing failure.

[uberschnell]

Originally Posted by Blacksport

Yes, that's so true...I did NOT get a letter from Dodge extending my Hemi's warranty to 100,000 miles because of rod bearing failure. I DID get a letter from BMW extending my S54's warranty to 100,000 miles because of rod bearing failure.

And lets not even get started on the "high" quality of BMW OEM water pumps

[Iron Man]

Originally Posted by Dackelone

I have also heard of the NASCAR boys putting brand new rotors outside to rust. Then a year later they machine the rust off and use the rotors. Something about the rust hardening the metal. Not sure if thats a myth or not.

This is nothing but pure myth. Rust will not harden the rotors.

[Blacksport]

Originally Posted by Iron Man

This is nothing but pure myth. Rust will not harden the rotors.

Yes that's pure myth....but I know a few racers, Joe Huffaker is one, who will leave an engine block outside in the weather for a few months, believing it would relieve internal casting stress and stabilize the block's dimensions. We never did this, but we would nitrate the cranks of the Spitfires and MGs we raced in the 70s to harden the bearing surfaces. Being cast iron, they were very delicate.

[Iron Man]

Originally Posted by Blacksport

Yes that's pure myth....but I know a few racers, Joe Huffaker is one, who will leave an engine block outside in the weather for a few months, believing it would relieve internal casting stress and stabilize the block's dimensions. We never did this, but we would nitrate the cranks of the Spitfires and MGs we raced in the 70s to harden the bearing surfaces. Being cast iron, they were very delicate.

The colder temperatures outside is what would stabilize the microstructure of the block. Cryogenic treatment is just a more robust process, since it goes to such low temps. Nitriding and carburizing are all common forms used to surface harden steel/iron alloys, especially gears and bearings. Cryo treatment transforms the entire thickness of a piece, not just the surface.

[Kgolf31]

Originally Posted by Blacksport

Yes, that's so true...I did NOT get a letter from Dodge extending my Hemi's warranty to 100,000 miles because of rod bearing failure. I DID get a letter from BMW extending my S54's warranty to 100,000 miles because of rod bearing failure.

Interesting...never heard of that.

Got a scanned letter or something I could look at?


BTW, I keep on hearing the term warped in this thread. I would like to know how that happens on a car that is daily driven.

[TheSt|G]

Originally Posted by uberschnell

And lets not even get started on the "high" quality of BMW OEM water pumps

Are we really going to debate Dodge being the bottom end of western car makers?

[uberschnell]

Originally Posted by TheSt|G

Are we really going to debate Dodge being the bottom end of western car makers?

No, no. Just saying that sometimes OEM is not the end-all best option for parts.

[TheSt|G]

Originally Posted by uberschnell

No, no. Just saying that sometimes OEM is not the end-all best option for parts.

I don't think OEM is ever a good choice, which is what I've been saying this entire thread.

Also, I accept that everyone makes mistakes. Fortunately as BMW owners we are in a fairly unique position in the car community where there is a fairly high level of both technical ability and disposable income surrounding our brand. As a result, we have well made products like Stewart water pumps and Zionville radiators that provide permanent lock down solutions for our few design errors.

[Blacksport]

Originally Posted by Kgolf31

Interesting...never heard of that.

Got a scanned letter or something I could look at?


BTW, I keep on hearing the term warped in this thread. I would like to know how that happens on a car that is daily driven.

Oh I have the letter, trust me...When the S54 first came out in 01, both in the M3 and the M roadster, many of the engines quickly developed rod bearing failure...BMW had spec'ed special Castrol 10w60 oil. This oil must be carefully warmed up, and also the pressure relief valve must allow for adequate bypass to keep the pressure from sky-rocketing with a cold engine and a high-revving idiot behind the wheel. These guys would unload the M3's from the boat, hitting 8500rpm before parking them. The rod bearings were shot before they hit the dealers. BMW fixed the problem with a more "appropriate" pressure relief valve and a "cold-engine" RPM limiter, to keep brain-dead, no-nothing idiots from blowing up their S54's because they were too stupid to warm them up. Very important tip: It takes 8 miles of driving to bring the oil up to temperature. Forget water temp, the water can be at running temp, and the oil still cold....

Kgolf, if you're still with me, here's a tip on rotor warping: everybody knows that a "floating" rotor is much less prone to warping than a 1-piece rotor. So if you have 1-piece rotors, how do you keep them from warping? You probably can't in the long run, as I've found out with my Durango's rear discs. Stopping a 2.5 ton vehicle is hell on brakes. My Viper warped the rear discs, too. But here's what you can do to reduce warping: if you just had a fairly hard stop, maybe a traffic light quickly changed when you were racing an old Camaro, while you're sitting at the light, DO NOT have your foot on the brake...the rotor will cool down evenly except where the pads are clamping it...that un-even cooling will warp the rotor over time.

[Kgolf31]

Originally Posted by Blacksport

Oh I have the letter, trust me...When the S54 first came out in 01, both in the M3 and the M roadster, many of the engines quickly developed rod bearing failure...BMW had spec'ed special Castrol 10w60 oil. This oil must be carefully warmed up, and also the pressure relief valve must allow for adequate bypass to keep the pressure from sky-rocketing with a cold engine and a high-revving idiot behind the wheel. These guys would unload the M3's from the boat, hitting 8500rpm before parking them. The rod bearings were shot before they hit the dealers. BMW fixed the problem with a more "appropriate" pressure relief valve and a "cold-engine" RPM limiter, to keep brain-dead, no-nothing idiots from blowing up their S54's because they were too stupid to warm them up. Very important tip: It takes 8 miles of driving to bring the oil up to temperature. Forget water temp, the water can be at running temp, and the oil still cold....

Kgolf, if you're still with me, here's a tip on rotor warping: everybody knows that a "floating" rotor is much less prone to warping than a 1-piece rotor. So if you have 1-piece rotors, how do you keep them from warping? You probably can't in the long run, as I've found out with my Durango's rear discs. Stopping a 2.5 ton vehicle is hell on brakes. My Viper warped the rear discs, too. But here's what you can do to reduce warping: if you just had a fairly hard stop, maybe a traffic light quickly changed when you were racing an old Camaro, while you're sitting at the light, DO NOT have your foot on the brake...the rotor will cool down evenly except where the pads are clamping it...that un-even cooling will warp the rotor over time.

@Blacksport, I own a Z4M...and have 30 liters for 10w60 sitting in my garage to do oil changes every 3k miles or after track events for the reason of avoid rod bearing wear.

I wanted to see the letter because I want to have documentation in case I ever have to replace my rod bearings, I can get BMW to compensate me.


About the warped rotors, I've never had warped rotors during autocrossing or track events....only pad deposits that can be mistaken as a warped rotor. That is what I was trying to say. Yes, you can warp a rotor...but it is very hard to do so.

[Blacksport]

The letter doesn't pertain to your S54, only 01's and maybe 02's...they had the problem fixed by then...but I'll dig out the letter and email it to you, if you want....PM me your email...BTW, I turned down that Z4M I was looking at...I'm still looking, but have too many projects going already...

Changing the oil after an event is good...but the most important thing you can do to protect your rod bearings is warm the oil completely before your event....

[Kgolf31]

Originally Posted by Blacksport

The letter doesn't pertain to your S54, only 01's and maybe 02's...they had the problem fixed by then...but I'll dig out the letter and email it to you, if you want....PM me your email...BTW, I turned down that Z4M I was looking at...I'm still looking, but have too many projects going already...

Changing the oil after an event is good...but the most important thing you can do to protect your rod bearings is warm the oil completely before your event....

Yea, it is nice to have an oil temp gauge to know where you're at.

No need to send the letter, I thought it was across the board for all S54s.

Keep on looking at the Z4Ms, you'll find a steal sometime sooner or later.

[TheSt|G]

Rod bearing recall was due to the bearings themselves not being made to spec for early S54 engines, not a spree of lead foot cold start dock workers. After attempting to blame it on the owners, and then oil pump software, BMW initiated a recall in 2004 for E46 M3s with the model year of '01 to '03. The '03.5+ E46 M3 already had had the issue fixed at the factory(and in reality, all '03s were fine), as well as all Z4M coupes as they were produced long after the issue. The S54 Z3M coupes were never included in the recall despite all being built with the faulty bearings.

[Iron Man]

Originally Posted by Kgolf31

About the warped rotors, I've never had warped rotors during autocrossing or track events....only pad deposits that can be mistaken as a warped rotor. That is what I was trying to say. Yes, you can warp a rotor...but it is very hard to do so.

Cast iron rotors can warp from a microstructure change within the rotor. Some rotors will have retained austenite in the structure, which is relatively soft, and it will transform to martensite under stress or severe temperature change. This transformation also involves a change in volume, which causes the rotor to warp, since the volume change is not uniform. That is why a proper controlled freezing/cryo treatment, followed by tempering, of the rotor will help prevent warping.

[Blacksport]

Originally Posted by TheSt|G

Rod bearing recall was due to the bearings themselves not being made to spec for early S54 engines, not a spree of lead foot cold start dock workers. After attempting to blame it on the owners, and then oil pump software, BMW initiated a recall in 2004 for E46 M3s with the model year of '01 to '03. The '03.5+ E46 M3 already had had the issue fixed at the factory(and in reality, all '03s were fine), as well as all Z4M coupes as they were produced long after the issue. The S54 Z3M coupes were never included in the recall despite all being built with the faulty bearings.

Yes and no. The bearings were "upgraded", but so was the pressure relief and the cold RPM limiter. My 01 had the "faulty" bearings as you say, but I never had a problem with them...Blackstone labs analyzed every one of my oil changes and all reports came back as close to perfect as you could get...it was entirely possible to have an early S54 and have the rod bearings enjoy a long and healthy life...if you took the time to properly warm the engine before putting any stress on it....However, the general consensus among experts is: the bearing width is too small, and when BMW "upgraded" the bearings, all they did was add a little clearance.