| New DTM calipers from AP racing (caution automotive porn) |
Subject: New DTM calipers from AP racing (caution automotive porn) by ghoffman on 2009/5/29 17:09:51 These are the first set of AP's Radi-Cal calipers that are presently being used in the DTM (German Touring Car) Series. They weigh 6.2 pounds each, have 25mm thick pads and have an air bridge that goes over the top of the caliper and cools the outside face of the rotor and caliper. I will post more later when they are mounted on my car. The red caliper shown is the big (8 pounds) Brembo. A version of this was used by Tony Stewart to win at the Glen. Benefits: AP Radi-Cal vs. Brembo and other 6 pot calipers: 1. Radi-Cal Design a. Arrangement of caliper mounting points much closer to rotor centerline = massive stiffness increase b. Smaller, more square box where pads reside = less deformation under load than a long pad box c. Integrated diagonal support bridge d. Offset caliper body design decreases deflection e. Material removed around piston bores to increase cooling and lower weight f. Article on design concept: [url]http://www.autofieldguide.com/columns/1207euro.html[/url] 2. Provision for integrated carbon fiber air bridge a. Increases airflow to outboard rotor face, caliper body, fluid, and pads, dramatically reducing total system temperatures 3. Forged monobloc vs. cast monobloc (Brembo) & two-piece squeeze-forged (StopTech) a. AP is Stiffer/stronger b. AP is Lighter- 6.4lbs. vs. roughly 8lbs. 4. Internal crossover ports a. Less places for caliper to leak b. Less chance of corrosion c. Less weight d. Less chance of damage during wheel install 5. No dust boots, only internal seals a. They just burn up anyway on the track 6. Raw anodized with machined logo vs. painted caliper with silkscreen logo a. Very little color shift- calipers look good even after heat and abuse b. All parts look same, no uneven paint, chipping, flaking, shrinkage, or problems with brake fluid c. Logo wont smear, fall off, or yellow 7. Pad is roughly 25mm thick, vs. 14-17mm thick a. Far superior pad wear, less pad changes, more heat capacity in pads because of greater pad volume 8. Stainless Steel Pistons a. Much less heat transfer to caliper and brake fluid than aluminum pistons 9. Anti-knockback springs standard a. Knockback big problem with uprights. More confidence when pedal is there= faster lap times pedal is there when you need it, every time. 10. Stainless steel abutment plates a. Brembo has none- pad will eventually wear away caliper body, knock around in caliper 11. Racing/Testing a. These are exact same parts used in DTM, and very similar to those in NASCAR, F3, etc. [IMG]http://i67.photobucket.com/albums/h287/gshoffman/Brakes/P5250402.jpg[/IMG] [IMG]http://i67.photobucket.com/albums/h287/gshoffman/Brakes/P5250403.jpg[/IMG] [IMG]http://i67.photobucket.com/albums/h287/gshoffman/Brakes/P5250404.jpg[/IMG] [IMG]http://i67.photobucket.com/albums/h287/gshoffman/Brakes/P5250405.jpg[/IMG] [IMG]http://i67.photobucket.com/albums/h287/gshoffman/Brakes/P5260414.jpg[/IMG] [IMG]http://i67.photobucket.com/albums/h287/gshoffman/Brakes/P5260412.jpg[/IMG] |
