Upgraded Brakes

[Defiant]

I could be wrong but drilling was originally meant for dissipating gas and save weight at the expensive of strength.

Eh, I doubt you could drill enough out of a disc to matter much, weight-wise.

As for the water- those of us who put mags on 510s and 240Zs found out very quickly how much wet discs mattered. It was a helluva lot for about fifty feet.

And the surface slots -not to be confused with cast-in internal vanes- still seems odd to me. I'd always thought they should sweep across the pad from the hub to the edge, enhancing any effect from centrifugal force. But Brembo says theirs go the other way, "sweeping" toward the hub.

Somewhere, I have a race prep flyer from Alston Engineering (later famous for chassis and tub kits for dragsters) for the Datsun 2000 which has instructions for how to drill the solid rotors (only about 5/16" thick to start with) to make ventilation VANES inside the solid rotor castings. They stress to not use them for more than one race. My god.

 

[Todd TCE]

Since we are having a good time beating the horse....

Another beef I have with the bs brake industry is comment that chamfering the holes in a drilled rotor will prevent them from cracking. First, this is simply not true. You may prolong the life of it, but thermal expansion is constant regardless of the edge on it. Granted the sharp edge does provide more of a stress riser.

Now the good part; next time someone tells you about their rotors being chamfered to prevent this ask them how they accomplish this on the INSIDE of the rotor. Sure, both the outer surfaces are chamfered, but that's only two of the four surfaces!

Anybody buy a set of those 40 gas slot rotors yet? Bet they weigh less....

 

[PaulPDX]

As for the water- those of us who put mags on 510s and 240Zs found out very quickly how much wet discs mattered. It was a helluva lot for about fifty feet.... Somewhere, I have a race prep flyer from Alston Engineering (later famous for chassis and tub kits for dragsters) for the Datsun 2000 which has instructions for how to drill the solid rotors (only about 5/16" thick to start with) to make ventilation VANES inside the solid rotor castings. They stress to not use them for more than one race. My god.

Since when was this thread about 1970s technology?

 

[ACM]

Where's my whip - I'll wait behind you Todd

Ducati used to run drilled discs on their factory race bikes a long time ago - drilled in between the faces, as Defiant decribed. As a zitty little sprog I used to drool over those bikes at Sports Motorcycles, back in the UK.

On motorbikes, cross drilling or grooving has a profound effect on their wet weather performance. It does also have a worthwhile effect on rotor mass too - that presupposes that you are not getting anywhere close to heat-soaking your undrilled rotors.

In the DSM world heat soak is a constant, unending battle with any setup vaguely approximating to stock. I can get my (stock) rotors Orange on an autocross - imagine how hot they'll get on the road (course). Any further mass removal from stock simply exacerbates the problem. And that gets you to Porterfield R4-1 pads at an ungodly price.

PaulPDX - the reason there are not as many multi-car pile-ups in the rain is because street cars come with splash guards covering the back side of the rotors. Try taking them off and see how your brakes are then in rain...I have - SP rules allow me - trust me it'll open your eyes. Wide. This is why bike rotors are all drilled or grooved.

Ok, I think I've drawn blood !

Charles

 

[HeDog]

Damn, I just thought that I'd post that I upgraded my brakes. I didn't think that I'd start a debate on the function/physics of the elements on rotors and what happens under extreme conditions. Sorry guys.

I just wanted to get rid of the rusty crap behind the wheel & figured that I'd put on zinc plated drilled/slotted rotors.

The rotors are iRotors & they were labeled as to what side they went on. I too was questioning the direction of the slot, but after looking at other cars rotors I found that the direction they had labeled on my rotors was the same direction that all drilled rotors I looked at were. So that's why they're on there like that.

As long as they stop me from running into crap, thats enough for me.

 

[spyderman]

Here is where I bought mine. They were labeled left and right and the drill/slot pattern mirrored from left to right. I talked in great length with the supplier about the specific reasons for the drill/slot patter and purpose as explained in earlier threads. Of course know-it-all Paul will jump in with some contradictory BS but I have done enough research to feel comfortable with my knowledge of the subject and choice of product.

http://www.powerstoprotors.com/index.htm