mrvette
Phantom of the Opera
OK, so lets suppose I want to drill my rotors, how to do?? drill size? countersunk? where on the surface? one per fin? every other fin??
:crutches:
:crutches:
What benefits do slotted & drilled rotors offer?
- Thread starter JeffP1167
- Start date
big2bird
Charter Member, Founder Bird-Run, Cruise-In Bird-R
Buy them then. You'll never get a good balance on doing them with a drill press.
Hold the fort. You have hydroboost. You could use wooden pads and stop.
mrvette
Phantom of the Opera
rtj
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Turtle, good article, I seem to remember reading the slots act as a uniform cutter to condition the pads and prevent glazing. The directions for installation tell you to orient the slots a particular way, so there must be a reason.
Wilwood sells drilled rotors for circle track and drag racing and advertise faster acceleration due to lower inertia, but you can see they have a lot of holes.
All my cars have drilled rotors, two with the slots as well and I would not go back to solid disks. The difference was very noticeable on my old c5z.
big2bird
Charter Member, Founder Bird-Run, Cruise-In Bird-R
Good find Jim. Fact or fiction is what this place is all about. :1st:
rtj
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I thought I'd seen somewhere that the slots were for cleaning action. Here was the first mention I found today:
SRP Drilled Performance Rotor & Hat
For custom, show, and high performance sport driving, SRP rotors offer the high tech look and improved performance of a directional cross-drill and face slot pattern. In addition to the aesthetic appeal, the venting and cleaning action of the hole and slot pattern helps to reduce pad glaze and minimize irregular pad build-up on the rotor faces. The results are a smoother engagement feel at the pedal and consistent response from the pads. Each rotor is precision machined to less than .001" tolerance for overall flatness, parallelism, and radial run-out on long grain carbon iron castings. The rotors are finished with a black electro coat to provide corrosion resistance.
Here's the rotational inertia reference:
Ulltralite 32 Vane Rotor Drilled
When it comes to rotors, racers are constantly searching for the ultimate balance between the lowest weight and the ability to effectively manage heat. Decreased rotating weight in the drive line provides quicker deceleration under braking and quicker acceleration out of the corners. Lower weight also benefits handling with improved spring and shock control over the unsprung suspension mass. Wilwood's ULD-32 drilled iron rotors provides effective lightweight options for sprints, late models, modifieds, and other competition applications that race in low to medium temperature ranges.
SRP Drilled Performance Rotor & Hat
For custom, show, and high performance sport driving, SRP rotors offer the high tech look and improved performance of a directional cross-drill and face slot pattern. In addition to the aesthetic appeal, the venting and cleaning action of the hole and slot pattern helps to reduce pad glaze and minimize irregular pad build-up on the rotor faces. The results are a smoother engagement feel at the pedal and consistent response from the pads. Each rotor is precision machined to less than .001" tolerance for overall flatness, parallelism, and radial run-out on long grain carbon iron castings. The rotors are finished with a black electro coat to provide corrosion resistance.
Here's the rotational inertia reference:
Ulltralite 32 Vane Rotor Drilled
When it comes to rotors, racers are constantly searching for the ultimate balance between the lowest weight and the ability to effectively manage heat. Decreased rotating weight in the drive line provides quicker deceleration under braking and quicker acceleration out of the corners. Lower weight also benefits handling with improved spring and shock control over the unsprung suspension mass. Wilwood's ULD-32 drilled iron rotors provides effective lightweight options for sprints, late models, modifieds, and other competition applications that race in low to medium temperature ranges.
JeffP1167
Well-known member
I just got my rotors and brake pads. I'm actually disappointed in the pads though. If they are truly for J55 they are anemic looking at best. I would have thought they would have been larger then they are and are considerably smaller then the fronts on my 97 Camaro. The difference between my stock 12 inch front rotor and these 13" ones is very noticeable. But I am thinking about a C5 conversion after seening these pads that look like they belong on a motorcycle and not a car.
Kid Vette
Master-Baiter
Twin_Turbo
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I have a steel drilling fixture to do this
What kind of pads did you get? Modern friction materials require more unit area pressure (PSI) to work effectively than the materials they had in the 60's. So, I wouldn't be alarmed at the size of the pads.
mrvette
Phantom of the Opera
when swapping from my '87 to this '72 one of the first things I noted was the change in the brakes, entire '72 setup seemed thicker and heavier from calipers through rotors, much less pads....that is my recollection, anyway....
to I wonder if the modern replacement pads were needing/requiring more pressure than the stock vac booser could muster?? hence the pedal going to the floor when stopping good/on time??
but that still don't say anything to the huge disparity of brake booster opinions....
:goodevil::clobbered:
Kid Vette
Master-Baiter
I'm intrigued, Got a pic?
JeffP1167
Well-known member
I don't understand why a power brake booster would be the heart of the problem. My 82 vette stops very good, much better then my friends 90 vette and my 97 camaro leaves them both feeling pre-historic. Only reason hydro-boost was implemented was due to a diesel not being able to make vacuum. Even my windstar feels better in the braking department then my friends 90 vette.
However the only complaints I ever hear about are 84-96 base 12 inch brakes being a pain in the butt. Never heard of a ZR1 owner really complain. The front 12 inch brake rotors are only by looks marginally better then the rear rotors. Perhaps the company sent me the wrong brake pads who knows.
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JeffP1167
Well-known member
clutchdust
Millionaire Playboy
Based just on that picture I would agree there is an issue there. On the larger rotor, there isn't enough sweep of those pads to fully utilize the rotor's surface area. I would think that the height of that pad should be about 1/8" off the hat all the way up to about 1/8" from the outer edge of the disc.
Looks to me like the pads you have on the larger disc go to the smaller disc and the pads on the smaller disc go to something else entirely.
Looks to me like the pads you have on the larger disc go to the smaller disc and the pads on the smaller disc go to something else entirely.
Twin_Turbo
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That's normal that the pads don't sweep the entire rotor, not a problem at all. He has the pads correct, the larger ones arae for a front PBR caliper, JL9, J55 or 1LE. The rears are for the pbr rear parking brake combo calipers for the same brake options.
Front rotors are 13x1.1 rears are 12x.83
Front rotors are 13x1.1 rears are 12x.83
The wife's Volvo factory pads did not sweep all the way to the outer diameter. After maybe 30,000 miles a grinding noise began. Once looking at the car the pads were still good. The pads had worn enough into the rotor that it the rotor, had begun to rub on the caliper. The way the caliper is designed there is very little clearance. That is the only issue I ever saw with smaller pads. By the way since then I have replaced her pads. They now reach the OD of the rotors.
turtlevette
The Turdle
Race pads will eat the rotor. They're not meant to be cold stoppers.
Twin_Turbo
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