C6 brakes...what a joke....

I'm not sure how many folks know this. Though I don't personally road race I try to stay on top of some of the F-body road racing crowd via frrax.com

Anyway, when the C6 Z51 came out we learned that the directional, cross drilled rotors were a bit of a joke. You see, there's only a left side rotor. The rotor on the Passeneger side actually ends up with the cooling vanes facing backwards....there's supposed to be separate right and left part numbers but GM apparently cheaped out.

This is a non issue for street bling types, but for real racers the backward rotor overheats quickly.

Well it turns out the Z06 has the exact same problem. It was so bad LG Motorsports put a set of Stoptech's on their C6 Z06. Read about their experience with their Z here: http://forums.corvetteforum.com/showthread.php?t=1229983&highlight=stoptech&forum_id=100

Anyway, I think this is a huge disaster and frankly its a sad joke GM was too cheap to put correct directional rotors on their flagship car. Next time you see a C6 Z51 check the rotor hole direction on the pass side...they're facing forward....

Yeah, old news.

Kinda odd GM did that.

Well I'm just now finding out the Z has the same problem, and I'm just really disappointed in GM over it. They can't even get their flagship car right. I thought we were turning a corner regarding the product. GRRRRRR.....

I have to agree that this is very disappointing.

I didn't realize they had done that.

I always have though it was "cheap" when GM would use a direction wheel design, and not make a "mirror image" wheel for the other side... of course, in the 80's and 90's with the C4, they actually DID make the mirror image wheels for it... but every other GM car did not get that treatment.

Obviously, this is much worse, since the wheels are mostly cosmetic, and this is functional.... on their ultimate performance vehicle, no less. :no:

Wow, that's both suprising and dissapointing. :confused:

It also looks like according to Corvetteforum that the holes in the rotors take chunks out of the pads....this is why you don't see drilled rotors on real race cars...notice LG's Z with the Stoptech brakes doesn't have the holes.

In one of the threads somebody quotes a Porche engineer saying that he wants to go to slots instead of holes but Marketing won't let him because everybody thinks the cross drilling is "performance"

Lou is a HARDCORE racer......he changed due to hearing about LPE's experience.

Personally, I wouldn't track hardcore with ANY stock brake setup.....but I wouldn't condemn GM for not putting on race pads for street cars....race pads and cool, wet weather is a guaranteed crash.

I'm not disapppointed that they didn't put race pads on the car Doug, I'm disappointed that they didn't shell out the cash to have correct right and left side directional rotors instead of all lefts.

I agree with you about the pads. A good set of racing pads will chew up the rotors and until they are hot they don't stop worth a flip...which is not a safe condition for a street car.

But the rotor thing is inexcusable and should be corrected.

Yeah, I've known about this before the car debuted.

It's a pain in the arse, but luckily the one sitting in front of my desk is facing to the left so I don't have to be irritated looking at it.

:D

That's horrible, especially on the Z06 - I mean what could that have possibly saved them?? A dollar or two per car??

I sure hope GM fixes this soon instead of letting the entire model ride out with everyone laughing at the 'cosmetic-only' Z51 brakes that people shelled out extra cash for.:o

In fact doesn't that almost do more harm than good, since you'd great more drag/pull on one side of the car, thus causing the car to pull to one side during hard tracking and braking?

didn't the C5 blanks have a left and a right? i've got the C5 conversion on my SS and i sware one rotor was driver and the other was passenger.

didn't the C5 blanks have a left and a right? i've got the C5 conversion on my SS and i sware one rotor was driver and the other was passenger.

Yes, I have C5 brakes on my car and they are directional R and L. In fact, I understand the Base C6 has the same rotors.. Its the Z51 and Z06 brakes they cheaped out on.

Been reading that Z51 guys are even switching to base brakes just to ditch the joke rotors.

okay let me get this straight...

real race cars dont like cross drilled because it eats up the pads...

soo really its better to go slotted...

and the Z06 and Z51 are both liable to lose control at high speeds?

as if one side of the car is going to brake more effectively then the other side... so theoretically if you heat up the brakes enough you'd start to spin... because you were braking on the left side of the car and not the right...

this is a big mistake... because when one gets confident with ones own car one tends to drive to the extreme... i know i've taken both of my cars up to very high speeds... and i know that the thing i was afraid most of after my last incident was my ability to slow down... and i almost hit a truck at 160mph...

soo... all in all if im going to upgrade my brakes i should go with slotted?

Honestly, I'd like to see real research on exactly how much of a difference it really makes on anything less than a full out race car.....I'm not saying that there is no effect, but I'd venture a guess that it's minimal at best.

Think about it, inside a wheel, as long as the rotor is spining, it's expelling hot gases due to the fan effect of the vanes inside the rotor halves.

The real problem with pad chunking seems to be that the holes aren't chamfered...and therefore have a cheese grater effect.

yea there's some argument on how much difference the rotor direction make..

What immediatly annoying are the pads short track life.. and then to make matters even worse, nobody can find replacements.. GM or aftermarket.. In the thread, one guy got Carbotech to make him a set of pads after senidng over a toasted pad as a template.

okay let me get this straight...

soo really its better to go slotted...

Yes.....

and the Z06 and Z51 are both liable to lose control at high speeds?

as if one side of the car is going to brake more effectively then the other side... so theoretically if you heat up the brakes enough you'd start to spin... because you were braking on the left side of the car and not the right...

WRONG!

No-one has said this and they won't......

This whole thing stems from someone noticing the rotors being the same on both sides and the pad wear issues for hardcore trackers and racers....

No need to get this blown out of proportion...

I'll admit its a non issue on any car that doesn't see track time, but they took the time to put a rear diff cooler and a dry sump oiling system on the 06 and they can't get the rotors right?

The car is supposed to be track ready right off the lot, instead the brakes are just driveway jewelry. I'd rather them have made the vanes straight/non-directional than have one rotor on there backwards.

as if one side of the car is going to brake more effectively then the other side... so theoretically if you heat up the brakes enough you'd start to spin... because you were braking on the left side of the car and not the right...


Nobody said that....the car will brake on both sides, it just that cooling will be piss poor on the pass side, leading to premature rotor fatigue and cracking, premature pad wear, increased brake fade, etc.

I don't think its going to cause you to lose control per se, but its certainly not a desireable outcome for a $70,000 supercar.

I'll admit its a non issue on any car that doesn't see track time, but they took the time to put a rear diff cooler and a dry sump oiling system on the 06 and they can't get the rotors right?

The car is supposed to be track ready right off the lot, instead the brakes are just driveway jewelry. I'd rather them have made the vanes straight/non-directional than have one rotor on there backwards.

Look at the rotor vane direction on the pictures in this thread....post #132 the yellow Brembos swirl counterclockwise (toward the front on the driver's side) while the Motive, post $137 do just the opposite....so who's right? Does it truly make a nickel's worth of difference?

http://forums.corvetteforum.com/showthread.php?t=1183363&page=7&pp=20&highlight=c6+z06+brake+part+numbers

No, real race cars don't use them because they stop slower than blanks. Cross drilled is a marketing gimmick. Porsche engineers have stated that the only reason they have them is because their consumers demand them. Same with the Corvettes I am sure.

http://www.ls1tech.com/forums/showthread.php?t=353903

well doug... allow me to learn a bit...

if the reason for cross drilled rottors is to reduce heat... and by using them backwards, they accually build up heat, thus getting hotter...

so while one side is accually cooling down, the other side is heating up...

the brakes would be less effective wouldnt they? because they are hotter...

soo... because brakes on one side are being less effective, thus giving a loss of control...

probably the only problem with this philosophy is that brake rotors get up to 2thousand degrees anyway...
but the only reason disc brakes work is because they convert the kinetic energy into heat... yet, when the brakes hit the max temperature, they become uneffective at converting kinetic energy to heat... but thats whats nice about ceramic pads is that they change temperatures so quickly...

Look at the rotor vane direction on the pictures in this thread....post #132 the yellow Brembos swirl counterclockwise (toward the front on the driver's side) while the Motive, post $137 do just the opposite....so who's right? Does it truly make a nickel's worth of difference?
Good question. Fbod vented rotors were "straight" vents and so it didn't matter. I'm going to hazard a guess that if it does matter and you put a directional on backward, the shape of the rotor wants to move air from outside to the hub which is backwards from how the air is supposed to move through the rotor. The again you could be onto something and it makes no difference, I never really thought about it.

The drill holes don't do squat. It is the vanes/vents that cool the disk.

I'm pretty sure whatever direction the vanes are designed the point, they need ot be consistant on both sides.. as in the rotors, on whatever direction the vanes point, should not be simply flipped and run in reverse.


Honestly, for a car as important and high visibility as this, GM has to step up and do two things. Replace every Z06 rotor with the correct directional rotor. Then make sure there is at least plentify supply of pads, so the people tracking their cars aren't left out cold without replacement pads.


GM doesn't want to get stung with another "half a'sd execution" perception. Come on, its a $70k car that they hvae been touting as the high performance track star.

The drill holes don't do squat. It is the vanes/vents that cool the disk.

They actually make it worse because 1-it takes away mass, meaning there's less rotor there to store heat, and 2-they cause stress fracture and heat risers.

Cross drilling is 100% bling, nothing more.

Good question. Fbod vented rotors were "straight" vents and so it didn't matter. I'm going to hazard a guess that if it does matter and you put a directional on backward, the shape of the rotor wants to move air from outside to the hub which is backwards from how the air is supposed to move through the rotor. The again you could be onto something and it makes no difference, I never really thought about it.

If it makes no difference then why do directional vane rotors exist at all?

GM Cheaped out, end of story. Will 90% of the owners know the difference? No, but 90% don't need the magnesium roof & engine cradle or dry sump oiling system or 505 hp LS7 either. Whether we will notice is not the point.

If it makes no difference then why do directional vane rotors exist at all?

GM Cheaped out, end of story. Will 90% of the owners know the difference? No, but 90% don't need the magnesium roof & engine cradle or dry sump oiling system or 505 hp LS7 either. Whether we will notice is not the point.


My guess is that some engineer found a few degrees of difference up at around 1k deg+++ and thought, hey why not? The "fan effect" is just a bonus....but possibly more effective than direction. I'd guess the extra mass of longer vanes in the directional rotors helps a tiny bit too.

Until someone can find the actual engineering data that shows that it truly makes an appreciable difference, I ain't losing any sleep over it.

My guess again, GM couldn't support the extra cost with real data and chose to spend their efforts elsewhere......the cooling of brakes is helped 1000X more by GM's efforts at brake ducting.

The performance gain was minimal when compared to the cost.

Well, again Doug, then why not just cast 1 rotor PN# with straight vanes, at least that way both sides are equal rather than the potential for a temp differential. The ducting on the pass. side isn't going to do much good if the rotor is pumping air opposite of the duct.

It would seem uber obvious to me, granted I'm not a bean counter or an engineer, just a lowly consumer, that if separate L and R rotors were cost prohibitive, then maybe we should stick to a uni-directional rotor. DUH!!

This whole thing stems from someone noticing the rotors being the same on both sides and the pad wear issues for hardcore trackers and racers....

No need to get this blown out of proportion...
so rotate your pads! :p

well, the next problem is, people can't find any replacement pads.. GM or aftermarket.. there are none available.. (one get got a custom set from Carbotech)

well, the next problem is, people can't find any replacement pads.. GM or aftermarket.. there are none available.. (one get got a custom set from Carbotech)

Now THAT is a problem...but why the subcontractor hasn't ramped up production is beyond me...:confused: Maybe Z06's are selling faster than anticipated? ;)

I suspect that'll be remedied in the next few weeks at most.

I have a set of C6 Z06 brakes on order for my C5.....so I guess I'm putting my $$ where my mouth is....we'll see. :D

well doug... allow me to learn a bit...

That's why we're here :D

if the reason for cross drilled rottors is to reduce heat... and by using them backwards, they accually build up heat, thus getting hotter...

so while one side is accually cooling down, the other side is heating up...

the brakes would be less effective wouldnt they? because they are hotter...

soo... because brakes on one side are being less effective, thus giving a loss of control...

Whoa there little buddy....the cross drilling is for gas release and NOT cooling of the rotor....it's in fact detrimental to cooling due to the loss of mass in the rotor....and the loss of surface area.

Vane direction is all we're really debating here....and I've found two of the world's best mfr's doing the opposite of each other, so what's right???:confused:

I'd guess that ANY fan effect due to vane direction is severely hampered by the close tolerances of the inside radius of the rotor face to spindle hub...not a lot of area here to either pull air or push it....

Add to that a brake cooling duct is moving a ton of air directly at the rotor and it's easy to surmize that it would overtake any small fan effect of directional rotors.

This truly sounds like a much bigger issue that real world engineering could support the additional cost.

Give me functional brake ducting any day. :bow:

Now THAT is a problem...but why the subcontractor hasn't ramped up production is beyond me...:confused: Maybe Z06's are selling faster than anticipated? ;)

I suspect that'll be remedied in the next few weeks at most.

I have a set of C6 Z06 brakes on order for my C5.....so I guess I'm putting my $$ where my mouth is....we'll see. :D

If I understand, they bolt right up too? Since the mounting ears on the z06 calipers offset it the right amount.. No bracket needed right?

Well, again Doug, then why not just cast 1 rotor PN# with straight vanes, at least that way both sides are equal rather than the potential for a temp differential. The ducting on the pass. side isn't going to do much good if the rotor is pumping air opposite of the duct.

It would seem uber obvious to me, granted I'm not a bean counter or an engineer, just a lowly consumer, that if separate L and R rotors were cost prohibitive, then maybe we should stick to a uni-directional rotor. DUH!!
And there is the correct answer, ha. Or they should have simply stuck with rotors from the base car.

If I understand, they bolt right up too? Since the mounting ears on the z06 calipers offset it the right amount.. No bracket needed right?


Yes. :cool:

And there is the correct answer, ha. Or they should have simply stuck with rotors from the base car.

But with the bling of cross drilled....the minutely larger mass of the longer vanes, etc...it makes sense to do a directional rotor.

That's why we're here :D



Whoa there little buddy....the cross drilling is for gas release and NOT cooling of the rotor....it's in fact detrimental to cooling due to the loss of mass in the rotor....and the loss of surface area.


That's called pad outgassing, and it hasn't been an issue with good performance pads in over a decade. The holes were originally for outgassing but now they are obsolete.

I honestly thought the slotted BAER rotors in my Pro+ set I used to run on my '94 Z/28....were better in the rain because they let the water out from under the pads....and of course were like boat anchors on the track.

Here's some better info from StopTech's site on curved vane rotors...

http://www.stoptech.com/tech_info/wp_brakesystems_upgradeselections.shtml

AIR COOLING
Most of the enormous amounts of heat generated during deceleration must be dissipated into the free air stream.

Most high performance (and/or heavy) cars today use some variation of the "ventilated" brake disc in which air entering the center or "eye" of the rotor is forced through the interior of the rotor by the pumping action of the rotating assembly. The most efficient practical way yet devised to accomplish this is through the use of the "curved vane" ventilated brake rotor originally designed for the LeMans winning Ford GT 40s in 1966. In this design the interior vanes are curved to form an efficient pump impeller. They also stabilize the rotor from distortion and serve as very effective barriers to stop the propagation of cracks due to thermal stress. In laboratory testing STOPTECH's innovative design developments in the 48 vane rotors have increased air flow through the rotor by an astounding 61% over some OEM rotors and from 10-15% over racing rotors of the same size. This results in a cost effective but very stable direct replacement rotor that runs typically 15% cooler than stock and 7% cooler than racing designs.

http://www.stoptech.com/tech_info/faqs.shtml#15

This link explained their AeroRotors® rotors and claims them to be a good air "pump"...

Which is better, slotted or drilled rotors?
StopTech provides rotors slotted, drilled or plain. For most performance applications slotted is the preferred choice. Slotting helps wipe away debris from between the pad and rotor as well as increasing the "bite" characteristics of the pad. A drilled rotor provides the same type of benefit, but is more susceptible to cracking under severe usage. Many customers prefer the look of a drilled rotor and for street and occasional light duty track use they will work fine. For more severe applications, we recommend slotted rotors.
How do I tell what direction the rotors go on the car?

http://www.stoptech.com/tech_info/img/rotor_drilled_cutaway.jpg

(Driver's perspective looking forward)

The StopTech AeroRotors® are directional. If they are not installed on the proper side of the vehicle, airflow will be restricted and cooling will be severely diminished. The vanes on a rotor act like a centrifugal air fan, drawing air from the inside of the rotor and flowing it to the outside. The vanes of a directional rotor should arch back like arms on a pinwheel. On the top side of the rotor, the vanes should curve toward the back of the car.

http://www.stoptech.com/tech_info/img/slotted_rotor.jpg
(Driver's perspective looking forward)

The slots on StopTech AeroRotors are cut in the OPPOSITE direction of the vanes. The pattern on a drilled AeroRotor also has the same appearance. The direction of the slots or hole pattern should not be used to determine what side of the vehicle to place a rotor. Different manufacturers may have different strategies for slot and hole patterns.

The only correct way to determine what side a directional rotor goes on is the internal vane direction.

Here's the thread on Z06vette.com.....they seem to agree that it doesn't matter to 90% of the Corvette drivers, but is not the best thing....

Most complained about the penny pinching....but no-one knew if it was planned or a supply problem (the rotors are marked LEFT).....but honestly, it couldn't have cost that much, if an more at all to do both sides right.

There aren't even any replacement pads available yet, so it might just be a supply problem and GM thought the release date meant more than a 5% or less brake problem...

Still waiting on an official response from Chevy though....

I did read, however, that Mercedes does the same thing.....

http://www.z06vette.com/forums/showthread.php?t=90293

I really hope GM fixes this crap. It irritates me, and I don't even own the car.

The z06 calipers are still a nice piece though. Wouldn't mind getting my hands on a set of them. Makes you wonder though, that if GM did in fact cheap out, and it wasn't a supply issue, why did they decide to cheap out on rotors on a car that already has 20 damn brake pads.

I think that there's much more to this saga than what we know right now....

Well, I can say this,

The vanes will work in either direction, to a certain extent. Directional will work better than non directional, and also better than lefties on the right.

As for calling it a pump....... well, a pump compresses air. While there may be minimal compression, it is mostly centrifigal force pulling air through the vanes...Wider at the outside, narrower on the inside.

In maximum baking applications, I would suggest going with a set of aftermarket rotors AND pads, I would suggest that anyway if you are racing.

touting this as a race ready car, that could be driven daily on the street, I really don't get why they skimped. Because there will be some yahoo that will buy it, drive it daily then take it to the track on weekends, and like an earlier post said, go into the turns hotter as he learns his car, and will get into trouble.

And the slot's/holes are for venting gas, as an earlier post stated, and in no way cools the rotors, other than releasing hot gases.

Anothe quote from the Z06vette.com thread....

I just went and checked out a new Ford GT and guess what i found?
It looks like Ford felt like saving a little $ on their brake rotors also because the holes are drilled the same direction on both sides!
I dont know if the vanes are straight or curved ,just that the holes are drilled the same as on the C6Z06(in an arc going the right way on one side and the wrong way on the other).

are the ford GT's rotors the same part# on each side? they might have only had one drill press but the internal vanes are different.

I just checked out pictures of the GT and sure enough, it's the same rotor on both sides.....at least in their official pictures it is.

Wow. This is sad for both Ford and Chevy.

Wow. This is sad for both Ford and Chevy.

Don't forget Mercedes Benz too...

Seems like all of their engineers are satisfied with the one rotor....and all of us "internet engineers" might just not understand their view of the cost vs benefit ratio.

I find it odd that the C6 Z06 rotors are even stamped LEFT though......:confused:

but are the vanes on the inside of the ford and mercedes the correct way or are they the exact same part number for each side?

but are the vanes on the inside of the ford and mercedes the correct way or are they the exact same part number for each side?


Can't say for sure, but knowing how and where the holes need to be drilled (or cast) they indicate the vane direction.

But it still makes no sense to make a directional rotor and only make the left one. Why not straight vanes if you want the same part for both sides?

It seems like they all cheaped out. Someone outside engineering had to kill the right rotor in all of the cases.

Somehow I doubt theres any scientific data that actually shows one rotor working so much worse because it faces the wrong way then the other one on these cars.
I am sure at least one of the 3 cars already named in the thread got extensive testing. In reality all 3. I can almost guarentee that there is no noticiable difference in the way one side stops over the other.
I agree with the porsche engineers here thats it's all marketing perception and people think its great because aftermarket manufactors tell us it is and we buy their expensive stuff and no one wants to believe they are wasting their money.

I think this thread is suffering from ricer syndrome. The most expensive, most shineyest, most hyped part has to be the best because umm it does and we all know the 5 inch tip is better then the 4 inch chrome tip which is better then the 4 inch matte finish tip, which is better then the 3 inch HKS tip which is better then the 3 inch generic tip, when in reality it's all a marketing perception and the car can't perform past the limits of any of the tips, so it doesn't really matter.

Actually my definition of rice is when parts are on a car for the appearance of performance but they don't actually function.

The bastardized brake rotors would fit into that category. Somehow I don't think a properly designed and functioning set of 14" 6 piston brakes is "rice".

Lou is a HARDCORE racer......he changed due to hearing about LPE's experience.

Personally, I wouldn't track hardcore with ANY stock brake setup.....but I wouldn't condemn GM for not putting on race pads for street cars....race pads and cool, wet weather is a guaranteed crash.

Man, I'm glad you told me that. I've been driving my Camaro on snow tires with race compound pads on it for the last few winters and am currently doing it right now.:D If I'd known that, I'd have surely killed myself by now.....

Actually, other than the noise and dust, they work good to great on the street, even in the cold.:)

Honestly, I'd like to see real research on exactly how much of a difference it really makes on anything less than a full out race car.....I'm not saying that there is no effect, but I'd venture a guess that it's minimal at best.

Some friends at the 12 hours of Summit Point in 2005 were running a BMW M3 and accidentally got two matching rotors on the front (two lefts or two rights, I forget which). When they pitted, one set of pads was "junk" (cracked, extremely worn, etc) and the rotor on that side was cracked and discolored by heat (it appeared to have been much hotter than the opposite side, one rotor was a little blue, one was purple/black). So, that seems to indicate that the rotor direction does, or can, matter. These were Performance Friction rotor rings on an AP "strap rotor" floating hat assembly.

But, this was a "full out race car" (as you stated).

Somehow I doubt theres any scientific data that actually shows one rotor working so much worse because it faces the wrong way then the other one on these cars.
I am sure at least one of the 3 cars already named in the thread got extensive testing. In reality all 3. I can almost guarentee that there is no noticiable difference in the way one side stops over the other.
I agree with the porsche engineers here thats it's all marketing perception and people think its great because aftermarket manufactors tell us it is and we buy their expensive stuff and no one wants to believe they are wasting their money.

I think this thread is suffering from ricer syndrome. The most expensive, most shineyest, most hyped part has to be the best because umm it does and we all know the 5 inch tip is better then the 4 inch chrome tip which is better then the 4 inch matte finish tip, which is better then the 3 inch HKS tip which is better then the 3 inch generic tip, when in reality it's all a marketing perception and the car can't perform past the limits of any of the tips, so it doesn't really matter.

You are an idiot. Thanks for playing.

Man, I'm glad you told me that. I've been driving my Camaro on snow tires with race compound pads on it for the last few winters and am currently doing it right now.:D If I'd known that, I'd have surely killed myself by now.....

Actually, other than the noise and dust, they work good to great on the street, even in the cold.:)


BUT, you're an experienced driver who knows how to drive on race pads...I've done it too.....but I wouldn't sell a car to who knows who and not expect to get sued for them smacking into something....

There are always compromises made for production cars that will see 90% of their life on the street.

What is acceptable dust, noise and cold pads to you are certianly not acceptable to a majority of the Corvette owners (PITA's that they are).

Some friends at the 12 hours of Summit Point in 2005 were running a BMW M3 and accidentally got two matching rotors on the front (two lefts or two rights, I forget which). When they pitted, one set of pads was "junk" (cracked, extremely worn, etc) and the rotor on that side was cracked and discolored by heat (it appeared to have been much hotter than the opposite side, one rotor was a little blue, one was purple/black). So, that seems to indicate that the rotor direction does, or can, matter. These were Performance Friction rotor rings on an AP "strap rotor" floating hat assembly.

But, this was a "full out race car" (as you stated).

But there again, this was in hardcore race conditions...not everyday spirited street driving.

You are an idiot. Thanks for playing.

Lose the attitude...no need for that here........:think:

Lose the attitude...no need for that here........:think:


No attitude, I'm not really planning on coming back to this thread and it saved me a lot of typing trying to explain it nicely.

Brakes cool from the inside out. The rotor naturally "throws" air out from the center (and is backed up by the information you posted). Trying to use the veins backwards to pull air in, against the natual energy that is pushing it out is not a good idea, and doesn't work very well. Brake ducts are effective, but it's because they concentrate cool air into the center of the rotor and it is naturally distributed by the rotation and the veins of that rotor. None of this is really up for debate. So, when Aaron91RS started referring to people as "ricers" because they wanted brakes that were designed and built properly, it became obvious that he missed the point. The point is that they took the time to build 6 piston calipers (usually considered an upgrade) and put them on a $70,000 sports car and didn't bother to optimize the package at the additional cost of $100 or less to the manufacturer. Many people look to GM parts for inexpensive upgrades to existing cars (like you, putting C6 stuff on your C5), but when it's not really an upgrade, or not as much of an upgrade as it could/should be, due to the manufacturer taking an unacceptable shortcut, it's frustrating. Chris posted this because it seems dumb for GM to save $100 (or very likely $100-ish) on a $70,000 car and seriously flaw the performance of the brakes in the process. It's probably not an issue for 99% of the guys who buy these cars, but for that last 1 or even 10%, it's a very big frustration to spend good money to "fix" a brand new car to make it perform as it should have from the factory.

You either understand this, or you don't. He obviously didn't. He has his opinions (that we who are concerned are ricers) and I have my opinion (that he's an idiot). We can agree to disagree, or we're going to have to this time.

I'll report myself to the admin now.

Have a wonderful day!

:bow:

No attitude, I'm not really planning on coming back to this thread and it saved me a lot of typing trying to explain it nicely.

Brakes cool from the inside out. The rotor naturally "throws" air out from the center (and is backed up by the information you posted). Trying to use the veins backwards to pull air in, against the natual energy that is pushing it out is not a good idea, and doesn't work very well. Brake ducts are effective, but it's because they concentrate cool air into the center of the rotor and it is naturally distributed by the rotation and the veins of that rotor. None of this is really up for debate. So, when Aaron91RS started referring to people as "ricers" because they wanted brakes that were designed and built properly, it became obvious that he missed the point. The point is that they took the time to build 6 piston calipers (usually considered an upgrade) and put them on a $70,000 sports car and didn't bother to optimize the package at the additional cost of $100 or less to the manufacturer. Many people look to GM parts for inexpensive upgrades to existing cars (like you, putting C6 stuff on your C5), but when it's not really an upgrade, or not as much of an upgrade as it could/should be, due to the manufacturer taking an unacceptable shortcut, it's frustrating. Chris posted this because it seems dumb for GM to save $100 (or very likely $100-ish) on a $70,000 car and seriously flaw the performance of the brakes in the process. It's probably not an issue for 99% of the guys who buy these cars, but for that last 1 or even 10%, it's a very big frustration to spend good money to "fix" a brand new car to make it perform as it should have from the factory.

You either understand this, or you don't. He obviously didn't. He has his opinions (that we who are concerned are ricers) and I have my opinion (that he's an idiot). We can agree to disagree, or we're going to have to this time.

I'll report myself to the admin now.

Have a wonderful day!

:bow:


:bow: Best Post EVARRR!!!1111!!!1!

I'll report myself to the admin now.

Have a wonderful day!




:lol:

Lose the attitude...no need for that here........:think:

Yeah TB you're a big stupid, meanie head!!! You suck!!! :(

It's odd how the armchair experts in this thread are calling people internet engineers when all they are doing is speculating themselves (i.e.; Aaron91RS).

The brakes are seriously flawed bottom line. And whomever designed them is a dumb@ss. Ok, ok the beancounter that placed the constraints that caused this. Opps did I post that in the GM leghumping section of CZ28.com? That reminds me why I don't post here anymore.

I'm done here. bye

But there again, this was in hardcore race conditions...not everyday spirited street driving.

i know its been said before, but there is no need for dry sump oil systems on street cars either :)


its just very odd that a $70,000 "supercar" that is supose to be pretty damn close to a race car off the lot would have been cheaped out on the rotors. GM really shouldn't have done it simply because its what it is, a high profile, expensive sports car.

Guys, I don't disagree...but even $1 per car is huge as for as the beancounters go.....but I do agree that it should not have been saved here...on this car.

I also don't know why Ford & MB did the exact same thing, so don't just crucify Chevy over it.

Why is it that AX & RR guys are so self-righteous though? I've met more people like this in this part of the hobby than any other.... :think:

Funny I am an idiot and yet no one has posted independant scientific tests showing it doesn't work.
I'm sure Ford, Chevy and MB all 3 overlooked the same thing :rolleyes:

Funny I am an idiot and yet no one has posted independant scientific tests showing it doesn't work.
I'm sure Ford, Chevy and MB all 3 overlooked the same thing :rolleyes:

If everyone else jumped off of a bridge.....

GM put the correct veins in the rotors on the C5 and even the lowly C4's (with the HD package at least). GM has always done it right....until now.

I swore I wasn't coming back here, but I was referred back by someone.

From Brembo's FAQ's (because Brembo wouldn't know anything about brakes).

http://www.buybrakes.com/brembo/faq.html#q28

Which direction should the discs rotate?
It is a popular misconception that the slots or drillings in a disc determine the direction of rotation. In truth, for an internally vented disc, the geometry of the vanes dictates the direction of rotation. There are three vane types in use:

Straight
Pillar vane (comprised of many small posts)
Curved vane
The first two vane types are non-directional, and can be used on either side of the vehicle. The curved vane disc, however, is directional. A curved vane disc must be installed with the vanes running back from the inside to outside diameters in the direction of rotation. Please see figure. Orienting the disc in the manner creates a centrifugal pump. The rotation of the disc causes air to be pumped from the center of the disc, through the vanes, and out through the outside diameter of the disc. This greatly enhances the disc's ability to dissipate heat.
Additionally, all of Brembo's slotted discs are directional as well, regardless of the vane geometry. The discs should be installed such that the end of the slot nearest the outer edge of the disc contacts the pad first. Please see figure.

BACK TO TOP



http://tetra.mech.ubc.ca/CFD03/papers/paper30PD1.pdf

The airfoil shaped veins cooled the best, but they do not specifically note the direction of rotation.


Why is it that AX & RR guys are so self-righteous though? I've met more people like this in this part of the hobby than any other.... :think:

Most of them are frustrated with being asked the same questions over and over that a basic search would usually turn up the answers to and then getting argued with about stuff that's widely available knowledge.

Oddly, the same road race/autocross guys are the best guys ever to meet at the track. Every single one of them will help the competition (unlike most of the drag racers I know, who seem to form a clique and talk to nobody but their friends. Maybe it's because there is money involved....).


It appears that GM, Mercedes, etc have decided that (assuming that the other cars have the veins running backwards and not just the drilled holes) they could save a few bucks and risk someone noticing that they cut corners. Again, as we already stated, for street use, it's probably not an issue for most people. But, for a performance car (and a 500 hp one at that) that they took the time to build roughly 14" diameter brakes, hang 6 piston calipers on and then not finish the job properly is just not acceptable. If they felt that it needed 6 piston brakes with 14" rotors, why didn't they feel the need to cool them properly?

Of course, they also know that cross drilled rotors are just there to be pretty, so maybe they designed the whole system with "curb appeal" in mind and didn't intend for it to work well at all.

Funny I am an idiot....

I'll stand by my original statement.

Funny I am an idiot and yet no one has posted independant scientific tests showing it doesn't work.
I'm sure Ford, Chevy and MB all 3 overlooked the same thing :rolleyes:

I find it strange you are arguing that there's no negative effect of the rotor trying to pump air in opposite of all the centrifugal force caused by the rotation at, oh, 100+mph.

I think Trackbird's example is sufficient info. Its RICE not to put the correct parts on the car.

Bling cross drilled rotors are hardly better than fake plastic intercoolers.

There's some better info here...starting around post #6....

http://www.z06vette.com/forums/showthread.php?t=92672

Pay particular attention to post #19.....Jeff Ritter from StopTech...

Okay, I read the first 20 posts or so and got tired of checking to see if someone clarified this. Sorry if I'm reposting something that's already been said:

If the slots are going backwards, that does NOT mean it's going to add extra heat to the rotor. It's just not going to cool as efficiently.

Regardless of your brake setup, braking is going to cause the rotors to increase in temperature. Good cooling characteristics will slow the increase, and reduce the time the rotor takes to cool again afterwards.

Backwards slotted rotors have better cooling characteristics than rotors with no slots at all (all other things being equal).

There's some better info here...starting around post #6....

http://www.z06vette.com/forums/showthread.php?t=92672

Pay particular attention to post #19.....Jeff Ritter from StopTech...
quoted for the lazy:

Under the heat stress placed on rotors at the track, drilled rotors WILL crack more easily than slotted ones, period, end of story. Drilled rotors are a marketer’s dream. Porsche sent the world down this path by introducing drilled rotors on the 911, and it remains that way today. People want their brakes to look like a 911’s. We always ask if our customers plan to track their car. If they do, we universally recommend slotted over drilled. Directional rotors make a huge difference depending on their proper orientation, and vane design is absolutely one of the most critical determinants of rotor performance. Metallurgy is extremely important as well.

Also quoted from Post #19....

So, it’s tough to fault GM on their pad choice to ship the car. I think it was actually a good choice, and the brakes will work great on the street, autoX, canyon driving, etc. Most people who drive the car under these conditions won’t run into any problems. Here’s what probably should have happened though…They should have had Ferodo make the DS3000 in this pad shape as well (or any other pad manufacturer make their top of the line, full-out race pad in that shape…i.e. PFC ’03, Pagid RS-14, Hawk DTC-70, etc). GM could have sold them at launch as an official GM performance upgrade part. The only problem is, now they are condoning, if not encouraging taking the car on the racetrack…which raises warranty issues, etc. The fact that the car was marketed as track-capable is a fine line. How do you define ‘track capable,’ what type of track are we talking about, how long are the sessions…the list of ambiguity goes on and on, and there are valid arguments on both sides of the coin. As an aftermarket manufacturer, I can tell you that this is a VERY sticky area. You want your product perceived as race-ready, but you can’t account for all of the stupid things people will do with your product, and how they will hurt or kill themselves in the process. For example, here’s one of our solutions…when we ship our big brake kits out the door, we put a neon pink sticker on the pad box that ships with the kit that reads, “for street use only…do not use these pads on a racetrack.” Well guess what, we still get 1 call a week with customers complaining about pedal vibrations. Our first question is, “did you use the pads we sent with the kit on the racetrack?” Yes is the answer more times than not. Well then, of course you have a vibration, as you’ve taken the pad outside its temperature range and gotten an uneven deposit on your rotor!
The whole scenario is extremely complicated, and the issues that arise are endless. So, just keep these things in mind before you completely crucify the guys that built / designed this beautiful machine. As a much smaller company, we have a hard enough time dealing with these issues. Fighting these battles within a giant organization in which there are many differing goals and agendas must be terribly stressful for the technical team. I can assure you that their feedback and what the marketers heard them say is not the same thing. All I’m saying is think about pointing your displeasure in the appropriate direction before you call out David Hill and pants him at the next national vette meet. I can assure that the engineers on the team wanted more power, more carbon fiber, better handling, and couldn’t give a rat’s ass if the brake pads squeaked a bit on the street, or if the idle was a tiny bit lumpy as a tradeoff.

Funny I am an idiot and yet no one has posted independant scientific tests showing it doesn't work.
I'm sure Ford, Chevy and MB all 3 overlooked the same thing :rolleyes:

Sounds like apparently someone overlooked it, for whatever reason. Your arguement is going to sh*t, by the way. What could you have expected by calling people ricers for caring about the way the hardware on an expensive sportcar is supposed to work?

If the slots are going backwards, that does NOT mean it's going to add extra heat to the rotor. It's just not going to cool as efficiently.

What's the difference? Net effect in the end is increased rotor temp on one side of the car vs. the other.

Regardless of your brake setup, braking is going to cause the rotors to increase in temperature.

Duh!

Good cooling characteristics will slow the increase, and reduce the time the rotor takes to cool again afterwards.

Yes, and a properly cooled but smaller rotor will actually stop better than a bigger, poorly cooled rotor. So GM chose big, poorly cooled brakes when they could have saved just as money by doing the proper rotors and less diameter and less caliper.

Backwards slotted rotors have better cooling characteristics than rotors with no slots at all (all other things being equal).

There's a difference between SLOTS and cooling vanes inside the rotor. We aren't talking about the dumb slots, as the Z06 rotors aren't slotted anyway, we're talking about the internal cooling veins between the two rotor surfaces. There's not been a domestic car built I can remember that had solid front disks, so yes obviously vented discs cool better than non vented, but its the same principle as above....a properly cooled rotor will have as good or better stopping power as a bigger rotor that is not properly cooled.

Even if this was $50 per car, they're going to sell maybe 5000 of these cars a year, so they have saved $250,000.....pennies compared to what these guys drop on countless other non-product related luxuries.

i really don't get how anyone could argue how a centrifugal air pump being turned the wrong way is a good thing.

Yeah TB you're a big stupid, meanie head!!! You suck!!! :(

It's odd how the armchair experts in this thread are calling people internet engineers when all they are doing is speculating themselves (i.e.; Aaron91RS).

The brakes are seriously flawed bottom line. And whomever designed them is a dumb@ss. Ok, ok the beancounter that placed the constraints that caused this. Opps did I post that in the GM leghumping section of CZ28.com? That reminds me why I don't post here anymore.

I'm done here. byeI love it when people who can't spell "oops" correctly (and use "whomever" in place of "whoever") call other people dumbasses.

:p :)

I'm done here. Bye.

;)

Apologies -- I didn't realize that it was the vents which were directional. I thought we were talking about slots.

Regardless of the vane angle, at any reasonable speed (say, greater than 10mph), centrifugal force will pull air out of the vents. The only possible way to prevent that would be to have the vanes between the vents curved so far that they came back towards the center of the rotor.

I'm not saying there isn't a problem -- I just see this getting blown way out of proportion and I'd like to settle some nerves. Yes, there is going to be inconsistent heat buildup from one side of the car to the other. But, if you're working the brakes hard enough to get the right side to the point of failure, you're operating too close to the limits of the hardware anyway and you should upgrade your brakes.

But, if you're working the brakes hard enough to get the right side to the point of failure, you're operating too close to the limits of the hardware anyway and you should upgrade your brakes.

See that sounds awfully close to a cop-out. If the braking limit on that side of the car is reduced 20%, then it takes 20% less of a driver to reach the limit...

Yeah, you went and bought a $70,000 car advertised to be track ready, oh and so you better drop another $3000 on brakes first. Enough with the excuses guys...no it is not the end of the world but it is a bid disappointment for a company supposedly figuring out how to build great cars.

GM always misses on the details.

......

GM, MB & Ford always miss on the details.

There, fixed it for you... ;) :D

BTW, I agree that it must have been those evil beancounters again, because there's no excuse otherwise.....:mad:

I guess I should be happy that the Viper's rotors aren't drilled?

I wonder if the vanes go the right way on both sides.

If the slots are going backwards, that does NOT mean it's going to add extra heat to the rotor. It's just not going to cool as efficiently.


What's the difference? Net effect in the end is increased rotor temp on one side of the car vs. the other.


You know, it's the same as if you're going 40mph, and you have wired up the radiator fans to run backward, it's not going to add any extra heat to the the radiator... :)

(therefore the engine isn't going to run any hotter, right?)

Just because the air can't flow correctly through the cooling surfaces, shouldn't make any difference at all.... :eek:

In fact, I should just take the fans off for weight reduction. And the air dam on the bottom of the car. Taking that off won't add any extra heat to the radiator either...... :cool:

You know, it's the same as if you're going 40mph, and you have wired up the radiator fans to run backward, it's not going to add any extra heat to the the radiator... :)

Ah but John it doesn't matter which way the fan blades are curved...

You know, GM wired the intercooler pumps backwards on all the Ion Redlines and Cobalt SS's too. They need to fire whoever this dyslexic engineer is in their pumping department.

Hhmmmmm....notice that this is definately the right side, **edit** the vanes are wrong direction......:confused:

http://img499.imageshack.us/img499/9659/p10301036gw.jpg

Aftermarket rotors? :lol:

Nope....the guy bought a set of rotors and calipers from a dealer....

But my bad, the vanes are wrong....:think: