plain rotors vs cross drilled

[mytrplseven]

I know that all performance cars seem to use cross drilled rotors with "performance" pads but I'm asking, "for a street car with occasional autocross stints, are plain rotors more effective with stock pads"? (also posted on Rennlist).

[RedCarGuy]

I don't have data on hand to back it up but yes, I think plain rotors are more effective than drilled. You'll never see them on a race car as they don't handle repeated heat cycles well without warping or cracking between the holes.

Bottom line, you won't see any noticeable performance difference on a street car or the occasional autoX. If you really need to boost braking performance, you have to go bigger.

[Cajundaddy]

Cross drilled crack often and that bothers me a lot. I prefer plain or slotted.

[racer]

More than likely, your brakes will never get hot enough at an autocross to benefit from cross drilled rotors. In fact "cold brake" characteristics can come into play and be more important, especially if you are the only driver and wait time between runs is long.

[Charlie44]

Drilled rotors are a pain, and completely unnecessary in your application.

[jjeffries]

... but they look cool!

Just kidding.

John

[Ernie944]

What about these ?Anyone here has experience with them?....Mytrlseven....I know one things from my experience with my 944 brakes ,,,A good set of brakes pads such as ...see pics & S/S brakes lines all around will make spirit driving your 944 a lot more fun yet will be nice on the street.The S/S brakes lines doesn't expend like the rubber one & give a nice firm brakes pedal feeling,I just love them,the AXXIS are a very nice brake pads good in dry or wet situations plus have the advantage of being almost dust free which help keep your wheels clean.BTW I have no affiliation with AXXIS or the S/S brakes line ,,,Was just very satisfy with both.

[SilverLined]

Every time I see a street-driven drilled rotor, the wear profile is terrible. Grooved, wavy, etc, and must feel awful. Can't imagine the pads fare much better.

That said, I think they're not drilled for heat reasons (better to have more thermal mass than less), but rather pad degassing. Drilled rotors will provide immediate bite in a wet/cool situation where your solids may need a moment to "wake up"...

[Fast Freddy 944]

Drilled rotors dont work on everyday vehicles, the one that is driven in traffic and crappy weather. They work best in racing conditions and nothing else. One might get some miles on the cross drilled, and the performance will probably be slightly noticable, but they can and will crack rendering vehicles unsafe. For day to day driving, stick with non-drilled smooth rotors.

[mytrplseven]

This question was a follow-on search trying find out why my braking action is not as good as it should be. I figured that if the boffins at Porsche chose plain rotors with decent pads, it was the proper combination. You guys have reinforced my supposition that my cross drilled zimmerman rotors with Hawk hi-perf pads may be my undoing. they do look cool though.

[Ernie944]

Originally Posted by mytrplseven

This question was a follow-on search trying find out why my braking action is not as good as it should be. I figured that if the boffins at Porsche chose plain rotors with decent pads, it was the proper combination. You guys have reinforced my supposition that my cross drilled zimmerman rotors with Hawk hi-perf pads may be my undoing. they do look cool though.

Exactly what I was saying ...Good vented rotors ...Not the cheap the aftermarket cheap stuff,the rigth brake pads combine with S/S brakes lines all around + cailpers which work A1 will do wonder for your brakes system ,LOL never mind the cool look that belong in the garbages can.

[RedCarGuy]

Take Ernie's advice:

1. make sure your calipers are working properly and not leaking. When installing the pads, check that they move freely by hand with no binding
2. do the stainless brake lines at all four corners. I can also attest that this brought me a nice gain in pedal feel and brake response.

[Mike Goebel]

These are for a Turbo Ssssss

928.351.044.60SL Brake Rotor - Front Right - Slotted - Brand: Sebro
$164.71

928.351.043.60SL Brake Rotor - Front Left Slotted - Brand: Sebro
$164.71

Mike G.

[wildcat077]

I had bought some custom slotted rotors from LC Motorsports a few years back for my race car.Not sure if they're still in business , but they were operating out of Phoenix NY at the time.
Basically he takes whatever rotor your car uses and has them slotted , the workmanship was top quality and the turnaround time was quick.With the currency exchange and cost of shipping to Canada these days , i just use regular rotors for the race car , along with adequate cooling ducts and i have no issues.My 89 911 has 996TT brakes ( upgrade ) and i find the Sebro slotted rotors outlasted the drilled Zimmermans that came with the brake kit.

A properly functioning stock 944 brake system is more than adequate for a 944 !