Rear rotors

[Kgolf31]

Originally Posted by Hops128i

trying to understand why it makes sense to use cheap rotors when tracking. I've read of exploding rotor failures at the track.

Originally Posted by TheSt|G

Shortsighted cheapness isn't limited to the street.

Internet talk goes a long way when people haven't touched a track.

If you crack a rotor, you swap it out. I've seen people with BBKs crack a rotor. Must be chinese junk, right?

Originally Posted by hoki06

I've never had any problems with Advance/Autozone/NAPA rotors on street or track cars. Since I've had no issues with them in the 3+ years of track abuse, I see no reason not to used them on my street cars.

Someone who actually understands.

[MarkkyyMan]

So then why do they make more expensive rotors?

Why don't we all just run American Racing wheels and save some doll hairs? They are all circular in shape and perform a function somewhat like others. I'm sure someone somewhere has autocrossed or done a track day with them.

Crack a wheel and swap it out.

[Taskmaster]

Because rotors and pads are consumables - they are meant to wear out with use. There is no performance benefit that I've seen from more expensive rotors. Why do more expensive options exist? Well, zinc coating to prevent rust and marketing mumbo jumbo like "slotted" or "Drilled" things you'll never need in your 5 minute trip to the grocery store.

[kobeballer96]

I know blank rotor is a blank rotor but I'm going to go with the centric 125 carbon steel rotors for the back since I already had bought the slotted from stop techs. I rather just have it all match for the black coating in the center and the veins on the inside, I agree with @kgolf31 there ARE a lot of people that just talk on the internet or by parts and garage queen their cars and just go buy what they read and not experience.

[MarkkyyMan]

When tracking or driving your car hard everything wears at an accelerated rate, wheels aren't going to last forever..

The point I'm trying to make is buy a quality product. Does it have to be top of the line and the most expensive thing? No.

If you ask the veteran drivers if they are running autozone rotors I am willing to bet that majority of them will say no..

[Taskmaster]

Originally Posted by MarkkyyMan

When tracking or driving your car hard everything wears at an accelerated rate, wheels aren't going to last forever..

The point I'm trying to make is buy a quality product. Does it have to be top of the line and the most expensive thing? No.

If you ask the veteran drivers if they are running autozone rotors I am willing to bet that majority of them will say no..

Uhh, you'd be wrong on that one. Go to Bimmerforums track section and ask for yourself.

[JimD]

A rotor must be made of steel of the right hardness and ductility (related to hardness). Too hard and your stopping distance will be long. Too soft and it wears too quickly. Not ductile enough and it might crack. Alloy helps as well as heat treatment.

It also must be dimensionally accurate or wheel balance will be affected.

$10 doesn't seem consistent with managing what needs to be managed. They're heavy, shipping from China seems like it would be more than that.

I don't think they need to come from BMW but I would be leery of a $10 rotor.

[Dackelone]

Originally Posted by MarkkyyMan

When tracking or driving your car hard everything wears at an accelerated rate, wheels aren't going to last forever..

The point I'm trying to make is buy a quality product. Does it have to be top of the line and the most expensive thing? No.

If you ask the veteran drivers if they are running autozone rotors I am willing to bet that majority of them will say no..

+1

I think it was 1Addict member @Drivehard that found his factory wheel bolts cracking(I think one or two broke clean off!)... so when you drive hard or do lots of HPDE... one needs to pay close attention to the critical parts of the car. AND replace critical parts BEFORE they fail.

As for cheap (Chinese ?) "blank rotors" performing just as good as OE rotors... well... we all should know you DO get what you pay for...

The BMW rotors cost more for a reason. ATE/Brembo/Zimmermann/Bosch/NAPA, etc...(insert your fav brand aftermarket brand name) rotors might seem to "perform" just like a BMW original brake rotor... but they surely DO NOT perform like one.

Its kind of like choosing tires... they are all "black and round". But.... it is a science in making them. For those that think a cheap tire or brake rotor is the way to go... just wait until you really NEED max braking performance out of them... It could be that the difference between OE(BMW parts) and OEM(aftermarket parts) could be shorter stopping distance of a few meters. But IF you had your family or even just yourself in the car and needed to stop NOW.... those precious few meters could mean the difference between a crash and a "close call". I know which ones I'd choose.

[kobeballer96]

Originally Posted by Dackelone

+1

I think it was 1Addict member @Drivehard that found his factory wheel bolts cracking(I think one or two broke clean off!)... so when you drive hard or do lots of HPDE... one needs to pay close attention to the critical parts of the car. AND replace critical parts BEFORE they fail.

As for cheap (Chinese ?) "blank rotors" performing just as good as OE rotors... well... we all should know you DO get what you pay for...

The BMW rotors cost more for a reason. ATE/Brembo/Zimmermann/Bosch/NAPA, etc...(insert your fav brand aftermarket brand name) rotors might seem to "perform" just like a BMW original brake rotor... but they surely DO NOT perform like one.

Its kind of like choosing tires... they are all "black and round". But.... it is a science in making them. For those that think a cheap tire or brake rotor is the way to go... just wait until you really NEED max braking performance out of them... It could be that the difference between OE(BMW parts) and OEM(aftermarket parts) could be shorter stopping distance of a few meters. But IF you had your family or even just yourself in the car and needed to stop NOW.... those precious few meters could mean the difference between a crash and a "close call". I know which ones I'd choose.

David you couldn't have said it better! Now one more question what's the best trans fluid before I place my order for my rear rotors? Car is at 20k miles. I want it to shift smooth! I already have SSK waiting to be put on and UUC black street mounts and CDV delete.

[MarkkyyMan]

Originally Posted by Dackelone

+1

I think it was 1Addict member @Drivehard that found his factory wheel bolts cracking(I think one or two broke clean off!)... so when you drive hard or do lots of HPDE... one needs to pay close attention to the critical parts of the car. AND replace critical parts BEFORE they fail.

As for cheap (Chinese ?) "blank rotors" performing just as good as OE rotors... well... we all should know you DO get what you pay for...

The BMW rotors cost more for a reason. ATE/Brembo/Zimmermann/Bosch/NAPA, etc...(insert your fav brand aftermarket brand name) rotors might seem to "perform" just like a BMW original brake rotor... but they surely DO NOT perform like one.

Its kind of like choosing tires... they are all "black and round". But.... it is a science in making them. For those that think a cheap tire or brake rotor is the way to go... just wait until you really NEED max braking performance out of them... It could be that the difference between OE(BMW parts) and OEM(aftermarket parts) could be shorter stopping distance of a few meters. But IF you had your family or even just yourself in the car and needed to stop NOW.... those precious few meters could mean the difference between a crash and a "close call". I know which ones I'd choose.

Yeah, your example was a much better choice than mine.

[kobeballer96]

Soooo what trans fluid Is good? Motul synthetic trans fluid 75-90 I think was the weight? Im trying to add anything else I might need in my final order lol

[Dackelone]

Originally Posted by kobeballer96

David you couldn't have said it better! Now one more question what's the best trans fluid before I place my order for my rear rotors? Car is at 20k miles. I want it to shift smooth! I already have SSK waiting to be put on and UUC black street mounts and CDV delete.

O - I would use Redline ATF-D4. You will need a little over 2.1 liters. So buy three quarts and a hand (fluid) pump and you will be fine. Some guys run the D6... but that's just a little bit thinner fluid compared to the D4. Yes, its safe to run a ATF fluid in your manual trans.


Also... you should also change your diff fluid. Spec'd is Castrol SAF-XJ or SA. Its a GL5 75w140 gear fluid. Some guys use Redline MTF or their 75w90 gear fluids. Ask the shop which fluid they recommend. I am using 75w90 Redline in my e39 with no issues. In my 135i I am using Castrol SAF-XJ.

You will need a 17mm allen(trans) and a 14mm allen for the diff plug. You will also need to suck out the old diff fluid with some sort of suction pump. Hornbach over here sells a nice fluid suction pump for 25 euros.


Dack

[kobeballer96]

Originally Posted by Dackelone

O - I would use Redline ATF-D4. You will need a little over 2.1 liters. So buy three quarts and a hand (fluid) pump and you will be fine. Some guys run the D6... but that's just a little bit thinner fluid compared to the D4. Yes, its safe to run a ATF fluid in your manual trans.


Also... you should also change your diff fluid. Spec'd is Castrol SAF-XJ or SA. Its a GL5 75w140 gear fluid. Some guys use Redline MTF or their 75w90 gear fluids. Ask the shop which fluid they recommend. I am using 75w90 Redline in my e39 with no issues. In my 135i I am using Castrol SAF-XJ.

You will need a 17mm allen(trans) and a 14mm allen for the diff plug. You will also need to suck out the old diff fluid with some sort of suction pump. Hornbach over here sells a nice fluid suction pump for 25 euros.


Dack

Thanks David!


Nicolas and I are having a EPIC shop craft time I think Sinister is coming too! Feel free to join us!

[Dackelone]

Originally Posted by kobeballer96

Thanks David!


Nicolas and I are having a EPIC shop craft time I think Sinister is coming too! Feel free to join us!

WHEN ? This weekend?

[kobeballer96]

Originally Posted by Dackelone

WHEN ? This weekend?

Next month!

[Dackelone]

Originally Posted by kobeballer96

Next month!

Ok... keep my in the Loop. I have my FMIC I'd like to install soon.

[Kgolf31]

Originally Posted by MarkkyyMan

So then why do they make more expensive rotors?

Why don't we all just run American Racing wheels and save some doll hairs? They are all circular in shape and perform a function somewhat like others. I'm sure someone somewhere has autocrossed or done a track day with them.

Crack a wheel and swap it out.

A Wheel and a Rotor are two completely different things.

Also, why do you go to a grocery store and you have a Name Brand and a Generic Brand...both contain the exact same ingredients and do the same thing, yet there are people who buy Brand X that is 2x the cost of Brand Y. Because marketing.

Originally Posted by Dackelone

+1

I think it was 1Addict member @Drivehard that found his factory wheel bolts cracking(I think one or two broke clean off!)... so when you drive hard or do lots of HPDE... one needs to pay close attention to the critical parts of the car. AND replace critical parts BEFORE they fail.

As for cheap (Chinese ?) "blank rotors" performing just as good as OE rotors... well... we all should know you DO get what you pay for...

The BMW rotors cost more for a reason. ATE/Brembo/Zimmermann/Bosch/NAPA, etc...(insert your fav brand aftermarket brand name) rotors might seem to "perform" just like a BMW original brake rotor... but they surely DO NOT perform like one.

Its kind of like choosing tires... they are all "black and round". But.... it is a science in making them. For those that think a cheap tire or brake rotor is the way to go... just wait until you really NEED max braking performance out of them... It could be that the difference between OE(BMW parts) and OEM(aftermarket parts) could be shorter stopping distance of a few meters. But IF you had your family or even just yourself in the car and needed to stop NOW.... those precious few meters could mean the difference between a crash and a "close call". I know which ones I'd choose.

Thanks for making a really good point.

Why do people continually think PSS tires are good tires for the track? Look through the forums and continuously people recommend them without blinking and they are the tire to go with. However, dig through the BS and you'll see they are absolutely terrible, they degrade...and fall apart on the track! However, they are a name brand, well known...and people go with them.

Now, look at Hankook, or Dunlop. Both are typically cheaper than a PSS tire, yet no one without experience on the tire ever recommends them. They aren't an OEM Brand tire, so they are simply ignored.

I feel this is the same with rotors, unless it isn't an X brand, it is crap.


Look at NASA GT3 cars, look at BMW CCA Cars, Spec E30...etc, etc. I can almost guarantee you none of them are running OEM rotors. There is no reason to.


BTW - Your stopping distance is determined by tires, not rotors. Stand on the brakes and let me know what happens. Wheels will lock up and ABS will freak out.

If you want to actually stop, wider, gripper tires is the solution, not a rotor.

[Taskmaster]

Originally Posted by Kgolf31

A Wheel and a Rotor are two completely different things.

Also, why do you go to a grocery store and you have a Name Brand and a Generic Brand...both contain the exact same ingredients and do the same thing, yet there are people who buy Brand X that is 2x the cost of Brand Y. Because marketing.





Thanks for making a really good point.

Why do people continually think PSS tires are good tires for the track? Look through the forums and continuously people recommend them without blinking and they are the tire to go with. However, dig through the BS and you'll see they are absolutely terrible, they degrade...and fall apart on the track! However, they are a name brand, well known...and people go with them.

Now, look at Hankook, or Dunlop. Both are typically cheaper than a PSS tire, yet no one without experience on the tire ever recommends them. They aren't an OEM Brand tire, so they are simply ignored.

I feel this is the same with rotors, unless it isn't an X brand, it is crap.


Look at NASA GT3 cars, look at BMW CCA Cars, Spec E30...etc, etc. I can almost guarantee you none of them are running OEM rotors. There is no reason to.


BTW - Your stopping distance is determined by tires, not rotors. Stand on the brakes and let me know what happens. Wheels will lock up and ABS will freak out.

If you want to actually stop, wider, gripper tires is the solution, not a rotor.

Thanks for saving me the trouble.

[kobeballer96]

Originally Posted by Kgolf31

A Wheel and a Rotor are two completely different things.

Also, why do you go to a grocery store and you have a Name Brand and a Generic Brand...both contain the exact same ingredients and do the same thing, yet there are people who buy Brand X that is 2x the cost of Brand Y. Because marketing.





Thanks for making a really good point.

Why do people continually think PSS tires are good tires for the track? Look through the forums and continuously people recommend them without blinking and they are the tire to go with. However, dig through the BS and you'll see they are absolutely terrible, they degrade...and fall apart on the track! However, they are a name brand, well known...and people go with them.

Now, look at Hankook, or Dunlop. Both are typically cheaper than a PSS tire, yet no one without experience on the tire ever recommends them. They aren't an OEM Brand tire, so they are simply ignored.

I feel this is the same with rotors, unless it isn't an X brand, it is crap.


Look at NASA GT3 cars, look at BMW CCA Cars, Spec E30...etc, etc. I can almost guarantee you none of them are running OEM rotors. There is no reason to.


BTW - Your stopping distance is determined by tires, not rotors. Stand on the brakes and let me know what happens. Wheels will lock up and ABS will freak out.

If you want to actually stop, wider, gripper tires is the solution, not a rotor.

Stopping distance I know this thank you running BFG Rivals

[hoki06]

Originally Posted by TheAxiom

Thanks for saving me the trouble.

+1 I didn't feel getting into this argument once again

[Kgolf31]

Originally Posted by TheAxiom

Thanks for saving me the trouble.

Originally Posted by hoki06

+1 I didn't feel getting into this argument once again

It needed to be said. I'll just leave it at that.

[MarkkyyMan]

Originally Posted by Kgolf31

A Wheel and a Rotor are two completely different things.

Also, why do you go to a grocery store and you have a Name Brand and a Generic Brand...both contain the exact same ingredients and do the same thing, yet there are people who buy Brand X that is 2x the cost of Brand Y. Because marketing.





Thanks for making a really good point.

Why do people continually think PSS tires are good tires for the track? Look through the forums and continuously people recommend them without blinking and they are the tire to go with. However, dig through the BS and you'll see they are absolutely terrible, they degrade...and fall apart on the track! However, they are a name brand, well known...and people go with them.

Now, look at Hankook, or Dunlop. Both are typically cheaper than a PSS tire, yet no one without experience on the tire ever recommends them. They aren't an OEM Brand tire, so they are simply ignored.

I feel this is the same with rotors, unless it isn't an X brand, it is crap.


Look at NASA GT3 cars, look at BMW CCA Cars, Spec E30...etc, etc. I can almost guarantee you none of them are running OEM rotors. There is no reason to.


BTW - Your stopping distance is determined by tires, not rotors. Stand on the brakes and let me know what happens. Wheels will lock up and ABS will freak out.

If you want to actually stop, wider, gripper tires is the solution, not a rotor.

I understand a wheel and a rotor are different, the point was it is an important component don't buy junk.

Go buy meijer root beer and come back and tell me it's made with the same ingredients