Rotor insall question
12-11-2002
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Rotor insall question
Hey all... I just bought some drilled/slotted rotors and am confused as to which rotor goes on which side. The boxes are marked left and right but I've seen many pictures in magazines that look opposite of that. Its hard to describe but should the slots go toward the caliper on the outer edge of the rotor of the inner edge if the wheel is moving forward.... I searched for members rides but couldnt find any good pictures. I know some people have them here, if you could put a picture of the proper way they get installed that would be great.. I looked at grey's DIY but its hard to tell what side of the car that is from the picture.... thanks for any help...
12-11-2002
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Oh yeah, I think the Left is the driver's side and the Right is the passenger's side.
This picture is of the passenger's side. Just look at the calipers. If it was the driver's side then the caliper would be on the right.
This picture is of the passenger's side. Just look at the calipers. If it was the driver's side then the caliper would be on the right.
12-11-2002
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Rep Power: 0 OK then the way mine are marked would look like what you have there, but look at the inside cover of Superstreet.. they always have this BF goodrich ad that looks the opposite! What gives? Did they install there's backwards or does it really matter?
12-11-2002
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Rep Power: 0 here look at this picture of someones driver side, the pattern of holes mattches your passenger sides, now who is backwards! The only difference I guess is the side the caliper is on.. but does it matter if the holes/slots hit the brake pad first on the inner or outter side of the rotor... in your setup it looks like it would ht the pad on the inner side, but on this picture it looks like it hits the pad on the outer side... Am I making sense here?
12-11-2002
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Rep Power: 395 Wait, damn it. Now I can't remember which way our calipers go. No, I've got it right.
Um... Imagine that the holes are dimples aren't holes and dimples, but they're solid. Imagine the rest of the rotor isn't there. Which way would you put it on now? We go forward more than backwards and you want less resistance. You put them on like I did. If you put them on the other way it seems to me that the pads will get used up more. I can't explain why though. Maybe it doesn't matter. To me. the way I have it in the picture looks like the right way to do it. Doesn't matter where the caliper is.
Um... Imagine that the holes are dimples aren't holes and dimples, but they're solid. Imagine the rest of the rotor isn't there. Which way would you put it on now? We go forward more than backwards and you want less resistance. You put them on like I did. If you put them on the other way it seems to me that the pads will get used up more. I can't explain why though. Maybe it doesn't matter. To me. the way I have it in the picture looks like the right way to do it. Doesn't matter where the caliper is.
12-11-2002
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Rep Power: 0 OK thanks for your help, since the box came marked that way I'll trust the manufacturer, also since you already have them installed on your ride that way and I take it they are still working good then I'll do it that way. I think I'll just follow your DIY it seems straight forward.
12-12-2002
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Rep Power: 0 Thats wrong.. they go against the calipers...as in the slots are supposed to look as there backwards (like more pad will be used up). The Wilwoods even have an arrow on the rotor showing which way there supposed to go. Just look at my pic, kinda hard to tell but still.
Attachments:
[IMG]/forums/themes/orbitz/paperclip.gif[/IMG] Wilwood Brake Kitxx.jpg (36 Kb)
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[IMG]/forums/themes/orbitz/paperclip.gif[/IMG] Wilwood Brake Kitxx.jpg (36 Kb)
12-13-2002
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Quote
[hr]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.[hr]
[hr]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.[hr]
12-13-2002
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Rep Power: 0 Hey thanks for that diagram... According to that it looks like yours are backwards then... and you have the curved slots, but my rotors have straight slots but I think I'll install mine like it shows in the diagram.. this is getting too confusing!!!
12-13-2002
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Rep Power: 395 Yeah, according to this: "The discs should be installed such that the end of the slot nearest
the outer edge of the disc contacts the pad first."
I think I understand what the difference is. The way I have them makes the sweep of the slot across the surface of the pad from the inside (side closest to the center of the hub) of the pad out. The other way (supposedly correct way) makes it so that the sweep of the slot across the surface of the pad goes from the outside edge of the pad to the inside.
Wait, let me think... What's the difference? I guess each sweep of the slot across the pad is supposed to remove glazing (or other debris on the pads surface. If this glazing is thrown outwards into the caliper by the sweeping motion then I guess it could build up in there and eventually cause binding of the caliper against the rotor. Hmm... Maybe.
Although, isn't the centrifugal force of the rotor turning on the hub enough to prevent the slot from removing any debris from the pad the other way (the correct way)? Hell, that must not be it then? Hmm...
Oh yeah, one other thing is the initial moment of contact betwean the slot and the pad. The correct way makes sure that only the smallest part of the slot contacts the pad at first, Then more and more is swallowed up by the pad and there's a sort of transitional effect. Yeah, that's it. My way of mounting the rotors means that my pads will be used up quicker than normal. The slots are not transitioning and they are forced against the pad (during hard braking) and they take off more of the pad material than they would otherwise.
Okay, mystery solved. I'll change my rotor direction and update the DIY soon enough. I'll also install some SpeedBleeders and update the DIY with bleeding your brakes and some other nifty things.
the outer edge of the disc contacts the pad first."
I think I understand what the difference is. The way I have them makes the sweep of the slot across the surface of the pad from the inside (side closest to the center of the hub) of the pad out. The other way (supposedly correct way) makes it so that the sweep of the slot across the surface of the pad goes from the outside edge of the pad to the inside.
Wait, let me think... What's the difference? I guess each sweep of the slot across the pad is supposed to remove glazing (or other debris on the pads surface. If this glazing is thrown outwards into the caliper by the sweeping motion then I guess it could build up in there and eventually cause binding of the caliper against the rotor. Hmm... Maybe.
Although, isn't the centrifugal force of the rotor turning on the hub enough to prevent the slot from removing any debris from the pad the other way (the correct way)? Hell, that must not be it then? Hmm...
Oh yeah, one other thing is the initial moment of contact betwean the slot and the pad. The correct way makes sure that only the smallest part of the slot contacts the pad at first, Then more and more is swallowed up by the pad and there's a sort of transitional effect. Yeah, that's it. My way of mounting the rotors means that my pads will be used up quicker than normal. The slots are not transitioning and they are forced against the pad (during hard braking) and they take off more of the pad material than they would otherwise.
Okay, mystery solved. I'll change my rotor direction and update the DIY soon enough. I'll also install some SpeedBleeders and update the DIY with bleeding your brakes and some other nifty things.
12-15-2002
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Rep Power: 395 I reversed my rotors BTW. Now they're pointing the way they should be. I'll take some pictures for the DIY and I'll update it too. Now I'll have to break my brakes in again. Well, not as much as before, but the pads will seat differently now. I also re-chamfered the holes (the cross-drilled ones). I read somewhere that it lessens the chance that your cross-drilled rotors will crack. As you use up the rotor's surface you'll need to re-chamfer the holes from time to time. Did mine, so I'm all happy now. [IMG]i/expressions/face-icon-small-smile.gif[/IMG]
12-20-2002
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Rep Power: 0 What is re-chamfer grey? and so with brembo slotted and cross drilled rotors, we will need to install it in the direction like the black car?
12-20-2002
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Rep Power: 395 This is the correct way to install the rotor... This is the driver's side.
Chamfers are little counter-sinks around each hole. See how they're all shiny in the picture? I countersunk them slightly. Very slightly. I was talking to my father (a mechanical engineer) about this and he said a very light chamfer is the best. You don't want to remove too much material because then you're basically widening the hole and weakening it. However, if you don't have any chamfer at all then around the edge of the hole is a 90 degree transition and that spot is a high stress point. Apply a force to it in a certain way and it's more likely to break. Although my dad thought that the force needed to break it in that spot would need to come from a different direction that the brake system is capable of generating. He would need a mathematical model to get the complete picture though. That's why I re-chamfered them (they were already chamfered when I got them. I already ate through some of the rotor in the year that I've had them on.
Chamfers are little counter-sinks around each hole. See how they're all shiny in the picture? I countersunk them slightly. Very slightly. I was talking to my father (a mechanical engineer) about this and he said a very light chamfer is the best. You don't want to remove too much material because then you're basically widening the hole and weakening it. However, if you don't have any chamfer at all then around the edge of the hole is a 90 degree transition and that spot is a high stress point. Apply a force to it in a certain way and it's more likely to break. Although my dad thought that the force needed to break it in that spot would need to come from a different direction that the brake system is capable of generating. He would need a mathematical model to get the complete picture though. That's why I re-chamfered them (they were already chamfered when I got them. I already ate through some of the rotor in the year that I've had them on.
12-21-2002
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Rep Power: 0 Dang grey,
you're rotors are more rusty than my stock rotors. Where is Shrewsbury? you live in a snowy area with salted roads probably. My caliper is still shiny silver. I was going to get brembos, but if they rust that much in a year, I dunno anymore. Does the rotors from aem or wilwood rust like that. Or maybe should I just go with the tenzo ones, which are black...haha. no fear of rust on black i hope. thanks for the help grey.
you're rotors are more rusty than my stock rotors. Where is Shrewsbury? you live in a snowy area with salted roads probably. My caliper is still shiny silver. I was going to get brembos, but if they rust that much in a year, I dunno anymore. Does the rotors from aem or wilwood rust like that. Or maybe should I just go with the tenzo ones, which are black...haha. no fear of rust on black i hope. thanks for the help grey.
12-21-2002
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Rep Power: 395 That's just the surface 'cause it was wet. Once you go out and apply the brakes once or twice the surface becomes shiny once again. The top is rusty though. That does kinda suck. It was zinc coated like the middle, but I guess it wore off? Anyway, all rotors will rust. Unless they're ceramic or something. The Wilwood ones probably rust as well, unless they're made with a lot of nickel. Then they wouldn't be as effective in stopping though. If the Tenzo's are black, then it's just a coating. It'll wear off and the worn off part will rust just as mine does. Every coating wears off where the brake pad touches it and that spot will rust. It's normal.
08-22-2003
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Ok guyd, just thought I throw this in to even confuse you more. Each rotor company has their own direction from which their veins, slots or drilled hole patterns spin. Powerslot is against the rotation of the wheel. Brembo is different.
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