EL SHELBY Posted June 30, 2009 Report Share Posted June 30, 2009 I could use some clarification on this. While watching the 24hr of Le Mans, some of the Rolex Series, and the Koni series I noticed that the brakes rotors used by these cars are neither slotted or drilled. I could be wrong but that's what it looked like to me. Now I'm sure the rotors these cars use are carbon ceramic and not steel and that may be the reason. I also recall reading an interview with Steve Saleen where he mentioned that the slotted and drilled rotors they place on the Saleen Mustangs do not provide any benefit but they are added for the bling. Baer sells their kits with slotted & drilled, Brembo will sell you either, AP Racing will sell either, SSBC I believe are only slotted, and the Griggs 4 on 4 kit does not come with slotted or drilled. Obviously the claimed benefit of the slotted or drill rotors is for cooling, but after watching the pros and reading what the manufactures claim, is there really any benefit with a slotted or drilled rotor? Are the vanes within the rotor more important then the surface treatment when it comes to cooling? Is it sufficient to have a good quality smooth faced rotor and cooling ducts? Can anyone help me understand this better? Link to comment Share on other sites More sharing options...
tekheavy Posted June 30, 2009 Report Share Posted June 30, 2009 Installed my Baer rotors a couple of weeks ago. Didn't notice any change in the feel of the brakes but they look so much better than the stock rotors. :shades: Link to comment Share on other sites More sharing options...
olblue1062 Posted June 30, 2009 Report Share Posted June 30, 2009 This is like the "best wax", "best oil" question. Search the internet and you will find thousands of conflicting opinions. I dont see them on NASCAR applications...I would guess this would be a clue as to their effectivness or maybe a rule disallows their use. Lots of theories out there. Brake vendors say they are the "greatest thing since sliced bread". I have drilled and slotted rotors, can't tell a difference in stopping but get lots of compliments. Good Luck Olblue Link to comment Share on other sites More sharing options...
FordFan1 Posted June 30, 2009 Report Share Posted June 30, 2009 I've seen many drilled rotors crack between the holes to ever think about running them. A slotted rotor will allow gases and brake dust to excape more easily from the surface of the rotor. Not to big a deal but kinda spendy for the minor improvement that most people will never notice. On my old Bullitt I found using a name brand (Brembo, Bendix) flat surface rotor along with cooling ducts worked best and also provided the longest life from both the brake pads and rotors. =-=-=-=-=-=-=-=-=- Link to comment Share on other sites More sharing options...
09KR0058 Posted June 30, 2009 Report Share Posted June 30, 2009 I seem to remember reading somewhere that the drilled rotors are just for show, and the slotted ones might (repeat: MIGHT) give a very slight improvement in dissipating heat in heavy braking environments. Link to comment Share on other sites More sharing options...
William Rodgers Posted June 30, 2009 Report Share Posted June 30, 2009 I seem to remember reading somewhere that the drilled rotors are just for show, and the slotted ones might (repeat: MIGHT) give a very slight improvement in dissipating heat in heavy braking environments. I have read the same. I have the Drilled/Slotted, they do look MUCH better. I would say the other benefits are minimal. I have also read the ones that crack are not well made and an import brand. Find a Sports car over $50k with-out them though, not many out there. Link to comment Share on other sites More sharing options...
kahmann Posted June 30, 2009 Report Share Posted June 30, 2009 Slotted rotors improve braking significantly on the track. The number one issue on any track day for me has always been keeping my brakes cool. The slotted rotors run a whole lot cooler than the traditional rotors. Keep in mind that, on the street, it's damn near impossible to get your brakes anywhere close to as hot as they'll get after a few laps on a road course. This may help to explain why guys with slotted/drilled rotors haven't noticed a significant improvement in braking since swapping out their OEM discs. I've heard guys complain about cracked drilled rotors, but I've never seen it myself. A solid set of pads, some ducting, and a set of slotted rotors will go a long way in helping you enjoy any open track events you attend. Good luck! Ken Link to comment Share on other sites More sharing options...
EL SHELBY Posted June 30, 2009 Author Report Share Posted June 30, 2009 Slotted rotors improve braking significantly on the track. The number one issue on any track day for me has always been keeping my brakes cool. The slotted rotors run a whole lot cooler than the traditional rotors. Keep in mind that, on the street, it's damn near impossible to get your brakes anywhere close to as hot as they'll get after a few laps on a road course. This may help to explain why guys with slotted/drilled rotors haven't noticed a significant improvement in braking since swapping out their OEM discs. I've heard guys complain about cracked drilled rotors, but I've never seen it myself. A solid set of pads, some ducting, and a set of slotted rotors will go a long way in helping you enjoy any open track events you attend. Good luck! Ken As you have it stated here has always been my understanding but what I think I'm beginning to understand that cooling ducts are all that is needed to keep the rotors from over heating and the slotted and/or drilled rotors are there to allow for the out gas of the pads to ensure consistent pad contact with the rotor. That leads me to believe that depending on the pads used, slotted and drilled rotors may not be necessary. I'm really over thinking this, but I like knowing the mechanics of how things like this work. Link to comment Share on other sites More sharing options...
STILLEN Posted June 30, 2009 Report Share Posted June 30, 2009 I could use some clarification on this. While watching the 24hr of Le Mans, some of the Rolex Series, and the Koni series I noticed that the brakes rotors used by these cars are neither slotted or drilled. I could be wrong but that's what it looked like to me. Now I'm sure the rotors these cars use are carbon ceramic and not steel and that may be the reason. I also recall reading an interview with Steve Saleen where he mentioned that the slotted and drilled rotors they place on the Saleen Mustangs do not provide any benefit but they are added for the bling. Baer sells their kits with slotted & drilled, Brembo will sell you either, AP Racing will sell either, SSBC I believe are only slotted, and the Griggs 4 on 4 kit does not come with slotted or drilled. Obviously the claimed benefit of the slotted or drill rotors is for cooling, but after watching the pros and reading what the manufactures claim, is there really any benefit with a slotted or drilled rotor? Are the vanes within the rotor more important then the surface treatment when it comes to cooling? Is it sufficient to have a good quality smooth faced rotor and cooling ducts? Can anyone help me understand this better? Slotted rotors help with the outgassing of the pads at the track, and also "wipe" the pads, keeping the pad surface fresh. These are what we recommend for track use. Slotted/drilled rotors are for the street only. Under heavy track use, drilled rotors can crack. During street use this is rarely a concern with a quality drilled rotor.. Added note: there are many companies out there buying cheap offshore blanks and having them machined without any cnc design or engineering r&d done. These are the rotors that crack under street use. FYI...all Stillen and AP Racing rotors are guaranteed for the life of the rotor against cracking/warping under normal conditions. However, using drilled rotors on the track will void the warranty (we can tell if you have used them at the track). Link to comment Share on other sites More sharing options...
ilmor Posted June 30, 2009 Report Share Posted June 30, 2009 I have no idea, but I'm putting on a set and I'll find out later this year. A couple of guys here use slotted / drilled on the tracks and I've seen no issues reported so far. Link to comment Share on other sites More sharing options...
07SGT0547 Posted July 1, 2009 Report Share Posted July 1, 2009 I have no idea, but I'm putting on a set and I'll find out later this year. A couple of guys here use slotted / drilled on the tracks and I've seen no issues reported so far. I have about 5 Open Track sessions on my slotted/cross-drilled rotors over the past 2 years... When I pull the wheels/tires off to rotate them, I'll check to see how they held up... Just got back from Mid-America @ Hallett, and probably drove my car the hardest and fastest I have ever driven it on the track And while I had absolutely NO braking issues during the 100+ degree day, I probably need to check to see how the rotors and pads have held up... As always, will report back with pics... Gregg 07SGT0547 Link to comment Share on other sites More sharing options...
zdle Posted July 1, 2009 Report Share Posted July 1, 2009 Slotted rotors improve braking significantly on the track. The number one issue on any track day for me has always been keeping my brakes cool. The slotted rotors run a whole lot cooler than the traditional rotors. Keep in mind that, on the street, it's damn near impossible to get your brakes anywhere close to as hot as they'll get after a few laps on a road course. This may help to explain why guys with slotted/drilled rotors haven't noticed a significant improvement in braking since swapping out their OEM discs. I've heard guys complain about cracked drilled rotors, but I've never seen it myself. A solid set of pads, some ducting, and a set of slotted rotors will go a long way in helping you enjoy any open track events you attend. Good luck! Ken +1 ...........so true , the road course is where a drilled /slotted rotor is efficient, When I ran my stock brakes at willow springs in the summer they did not like the longer sessions,,,,,,,,,,,,,,the Baer 14" drilled /slotted never complain they run silent and 75 deg cooler.....or I'm getting better at driving .............. Link to comment Share on other sites More sharing options...
kahmann Posted July 1, 2009 Report Share Posted July 1, 2009 +1 ...........so true , the road course is where a drilled /slotted rotor is efficient, When I ran my stock brakes at willow springs in the summer they did not like the longer sessions,,,,,,,,,,,,,,the Baer 14" drilled /slotted never complain they run silent and 75 deg cooler.....or I'm getting better at driving .............. They definitely run cooler, but your driving has just as much to do with it as well! If you're on the brakes all day, they're obviously going to smoke a whole lot quicker. I recently bought a nice little infrared heat gun for track days. I'll try to get some readings on different brake surface temps on comparable cars' rotors and post them up. Ken Link to comment Share on other sites More sharing options...
kahmann Posted July 1, 2009 Report Share Posted July 1, 2009 Baer sells their kits with slotted & drilled, Brembo will sell you either, AP Racing will sell either, SSBC I believe are only slotted, and the Griggs 4 on 4 kit does not come with slotted or drilled. SSBC does offer drilled rotors nowadays FYI. They didn't for the longest time, until only recently. They're called the 'big bite' rotors. Not real important, just a quick correction. Ken Link to comment Share on other sites More sharing options...
07-2937 Posted July 2, 2009 Report Share Posted July 2, 2009 Ive seen cross drilled rotors destroyed on the track a bunch of times, and the person driving the car was a semi professional test driver. but for the most part ive only seen these on three "track cars"" Link to comment Share on other sites More sharing options...
bigcarl1 Posted July 2, 2009 Report Share Posted July 2, 2009 My drilled and slotted rotors with cooling ducks cracked after 20hr of track time.now I'm trying the slotted only and have 6hr of track time with no cracks. Link to comment Share on other sites More sharing options...
gth0007 Posted July 3, 2009 Report Share Posted July 3, 2009 Brakes are like everything else on your car. What is required is based on what you are going to do with the car. Ford spent a lot of R&D time/money deciding on the brake set-up on the Mustang GT. When Shelby added the modifications, the added horsepower and handling didn't require bigger brakes assuming you're only going to use the car for pleasure and maybe an occasional "track day" at a car event. So adding the bigger brakes definitely looks great and will make the car brake better when pushed really hard. So no matter what brakes you choose, slotted, drilled, or plain, the decision comes down to what you want rather then what you need. If you're going to race the car in the SCCA F-Stock Autocross racing then you should consult with other racers and see what they've done to their cars to make them work and hold-up. The Shelby GT has been very successful thus far SCCA F-Stock Autocross series. It's the driving of the Shelby GT and the racing of the Shelby GT that will create the legacy, not the storing of the car in the garage and creating "show queens". NOTE the August 2008 issue of Grassroots Motorsports magazine has an excellent article on "modified Mustangs" (Pg 63,) that race in the various SCCA series'. The Shelby GT is listed as a "the pick of the litter". The article discusses the Shelby GT, Steeda Q350, Ford FR500C, Roush Stage 3, Saleen Gurney, Griggs GR40ST/TT/RT, GT-500, and others. :happy feet: Link to comment Share on other sites More sharing options...
ilmor Posted July 3, 2009 Report Share Posted July 3, 2009 Brakes are like everything else on your car. What is required is based on what you are going to do with the car. Ford spent a lot of R&D time/money deciding on the brake set-up on the Mustang GT. When Shelby added the modifications, the added horsepower and handling didn't require bigger brakes assuming you're only going to use the car for pleasure and maybe an occasional "track day" at a car event. So adding the bigger brakes definitely looks great and will make the car brake better when pushed really hard. So no matter what brakes you choose, slotted, drilled, or plain, the decision comes down to what you want rather then what you need. If you're going to race the car in the SCCA F-Stock Autocross racing then you should consult with other racers and see what they've done to their cars to make them work and hold-up. The Shelby GT has been very successful thus far SCCA F-Stock Autocross series. It's the driving of the Shelby GT and the racing of the Shelby GT that will create the legacy, not the storing of the car in the garage and creating "show queens". NOTE the August 2008 issue of Grassroots Motorsports magazine has an excellent article on "modified Mustangs" (Pg 63,) that race in the various SCCA series'. The Shelby GT is listed as a "the pick of the litter". The article discusses the Shelby GT, Steeda Q350, Ford FR500C, Roush Stage 3, Saleen Gurney, Griggs GR40ST/TT/RT, GT-500, and others. :happy feet: If racing in F Stock autocross, the decision is easy - only pads may be changed, but not rotors! After reading all this I'm thinking of selling my Baer rotors before even taking them out of the box. I mostly liked the looks of them, but for performance if the pads and s/s brake lines alon are just as good, why bother? Link to comment Share on other sites More sharing options...
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