Last Updated: 09/10/96

Cross Drilled Rotors

Cross-drilled rotors do actually run hotter by 2-3%. The benefit of the rotors is to allow the pads to vent the gasses made under extreme use. For street use there is little or no benefit. For auto-x tracks with hard braking corners they can help some. Auto-x is usually a little slow for the cross-drilled rotors to become effective. A track course with a 100mph to 20mph corner would yield a significant difference. I've had the cross-drilled rotors and metal master pads for about 20,000 miles with no side effects. I can't tell that the pads would be wearing faster.

Because of the lower mass of the drilled rotors they will heat up faster and to higher temperature than the non-drilled rotors. Consequently you'll want to put in some better fluid and/or cooling ducts. I use Motul DOT 3 synthetic brake fluid. It's a bright blue color. The only probably with performance brake fluid is they usually boil at really low "wet" temp. For example after 2 years when you're braking system has absorbed all the moisture from the air the fluid will boil pretty quickly. The Motul DOT 3 Synthetic boils at 300c (572 f) dry and 148c (298 F) "wet". As you can see the wet boiling point is less than half of the dry boiling point. No big deal just make sure you bleed your brakes at least once a year. You racers out there would want to do it after every event. And make sure there is NO air bubbles in the system.

Wilwood

From: Dan
I'm writing to tell everyone that Best Price Warehouse is in the process of introducing a new big brake kit for all newer Hondas and Acuras. Best of all, it will retail at around $1250! This will include new ~11.7 inch racing rotors, and new Wilwood four piston calipers. Also included are pads, new fluid, and stainless brake lines (I believe). Stock brake rotor diameter is either 10.2 or 10.3. This is a HUGE difference in swept area so these brakes should be phenomenal.

The kit is done, but still undergoing testing as we speak. The person in charge of this little operation is Terry and they should be released soon. The only limitation is that because of the huge rotor, it may not fit in some 15 inch wheels. You have to measure the drop center of the wheel (the inside circumference). Obviously it has to be a certain number of millimeters bigger than 11.7 inches. Most of them shouldn't be a problem. The calipers are very slim in design, so your offset shouldn't be a concern. No word, yet on whether it fits behind factory wheels, but I'm pretty sure it does. More info as it comes in.

Brembo Rotors

From: Duy Le
My '88 LS developed an annoying squeaking sound coming from the brakes when I drove around. I decided to replace them. Chief auto parts wanted $38 for semi-metallics up front and $42 for the rear organics. I decided to give Steve Millen Sport Parts in Costa Mesa, CA a call. I got a set of their Metal Matrix pads for $34 front and $32 rear! I couldn't believe it, the performance parts were cheaper! The installation was simple (up front that is.) The rear required me to take the calipers off so I could compress the cylinder.

The pads worked wonderfully! I almost threw my pregnant fiance through the windshield when I tested them on an empty road.

I saw that the front rotors were warped and scored (from the worn pads.) I went back to Stillen and bought a pair of cross drilled rotors. They were Brembo units with the cool gold cadmium plating.

The rotor installation took me about 30 min. No joke, I've gotten real good at taking the brakes off. Stillen recommends that you break in the rotors for 300 miles before doing serious stops. The first 10 stops have to be made at 35 mph down to 30. I guess this is to scrape the plating off the rotors. Warning kids!! Hold the steering wheel with both hands!!!!! There was a nasty shimmy every time I applied the brakes. The coating finally came off after 21 miles (freeway).

From: Shawn Church
Materials and Construction:
I purchased GRIP's front rotors and pads directly from the manufacturer in NY. Cost for 2 rotors and front pads came to ~$280 with shipping. A lower price may be available through a distributor. Over the phone GRIP's representatives were pleasant, although there was a delay in receiving the rotors as they were out of stock and I ordered over the Xmas holiday.

After receiving the components I inspected and weighed them. The rotors came out to ~10 lbs 2 oz each. They are Brembo units (serial number and name stamped on the rotor) and are coated with a yellow Cadmium plating. The rotors are cross drilled, counter sunk and radiused. The pattern is a curved spoke type with a hole drilled into each vaned partition (the ventilated section between the rotor surfaces is segmented by vanes. Each segment had a hole drilled into it from each side.). Each spoke consists of three holes radiating outward.

Installation:
Installation was exactly as stock. All pieces fit perfectly and no grinding or alteration was necessary.

Performance:
GRIP recommends breaking in the rotors for several hundred miles before making any hard stops. For their metallic "street" pads no special procedures are recommended. For their Carbon Metallic "race" pads, there is a burnishing procedure to follow. A break in period is highly recommended after any brake job.

After approximately 200-250 miles of break in, I began making periodic hard stops with the brakes. This of course resulted in the usual "hot brake" smell. Slight pad fade was present during the first few stops. Brake performance than steadily improved until about the 500 mile point where it leveled off. Low speed stops were noticeably better, although a slight warm up period was necessary (one or two modest stops) to get feel and performance up to spec each morning. High speed efforts (freeway speeds to triple digits) were outstanding with no pad fade whatsoever. I have not yet fully explored the braking limits of this setup from high speeds.

Other Items of Note:
The cadmium plating on these parts will undoubtedly protect the unswept surfaces from corrosion, but it is messy and noisy while it wears off the swept areas. It might be advisable to clean the pads after 100 miles or so.

The rotors make an interesting hum under hard braking, no doubt attributable to the cross ventilated setup. Pedal feel is still relatively smooth with perhaps a slight vibration (very difficult to discern).

Preventing Warped Rotors

You can minimize warping by torquing your lugnuts at 80 ft/lbs. Never let some mechanic use an impact wrench on the wheels. They will be WAY too tight. After your winning auto-x lap make sure you take a quick cruise just to circulate some air in the brakes. Also when they're really hot, don't park and put the parking brake up. It will warp your hot discs/drums in the rear. Having long contact with rotors after a hot session with the brakes can also cause some of the pad material to actually transfer to the brake rotor...and in only one spot. This causes an extra buildup of material in one location which will cause unsmooth feel from the pads as it travels over the location with extra material embedded on the rotor.

From: C. Capowski Actually, I ALWAYS drive my car for about another 5 to 10 minutes after an autocross run. This gives the brakes, engine and tranny to cool down a little. I do this at low speeds (about 10 mph). When you stop the car with hot pads and rotors, the rotor covered by the pad will stay warmer longer than the rest of the rotor. It is this uneven cooling that warps the rotors. The glazing is caused more by improper bedding in of the pads or rotors when first installed. The pads from performance friction get even hotter than the stock pads, this is good because the performance friction pads just get better the hotter they are. I still have not been able to make the pads fade at all. So I would suppose that the warping rotor condition would probably be even worse with these pads unless you take the necessary steps to let them cool off by driving the car. Doing this eliminates any warping.