The Acura Legend GS brake caliper upgrade is a low cost OEM upgrade for our cars, this swap is second only to the Brembo made 4 piston calipers found on the 06-08 TL-S and the 05-12 RL and JDM exclusive models. The system uses a sliding caliper design with 42 and 38 mm pistons. These pistons are arranged side by side and provide a larger surface area with which to contact the inner brake pad, which in turn pulls the outer pad into contact with the brake rotor. In addition to the larger caliper biting area the Legend brake calipers use a larger rotor than a stock CG accord. The Legend is equipped with 282 X 28 mm rotors. This equates to 11.1 inches in diameter versus the 260 X 23 (10.2 inches) mm rotors used by the CG accord. There are a few different ways to mount the Legend GS calipers on our car, the method you choose is dependent on the rotor you want to have. The best choice for a rotor that involves the least amount of work is a brake rotor from the 4th generation Prelude with a VTEC H22. The prelude rotor is 11.1 inches and is drilled with a lug pattern of 4 x 114.3. This rotor is 282 X 23 mm, the Acura legend GS caliper bracket is designed to handle a 28 mm thick rotor. This means if you have the 28T bracket that comes with it you'll either have to deal with an additional 5 mm of piston extension, possibly causing damage to the dust boots, or you'll have to find a 23T(V6 6GA) or a 25T. While the 23T(V6 6GA) is the ideal bracket for the prelude rotor the 25T will work, but it will be slightly too large for the prelude rotor. The 25T will be less of a gap for the pistons to fill compared to the 28T. Most of the preceding information pertains specifically to the 4cyl 4 lug CG cars. If you have the 6cyl 5lug knuckles then you have the option of several different setups and you can use either the 23T(V6 6GA), 25T, or the 28T you'll only need to get the proper rotor for it. The last number in the rotor size is the thickness front to back in millimeters, just as the number of the bracket relates to width in millimeters for the rotor. The reason why the factory setup for the 4cyl brake calipers will not work is because of the slide pin design. The 4cyl caliper bracket slide pins thread into the ears on the side of the caliper rather than bolting into the slide pin like they do on the 23T(V6 6GA), 25T, and 28T brackets. Pictures further down in the thread will show the difference in the slide pin bolts. Also you can see what you should look for if you are hunting in a junkyard, if you happen to be browsing and see these particular slide pins the caliper is definitely worth further inspection. There are a few vehicles from Honda and Acura that have the brackets that will make this work. The list is short but it has been confirmed to work on the 4cyl mount for the bracket. 6GA V6 caliper brackets (23T) 95-98 Honda odyssey (25T) 94-95 Acura Legend GS (28T) When it comes to selecting a set of pads it would be best to pick a set that is for the brackets you will be using. This is so that they will fit into the shims that are on the bracket with no problems. You can use your stock brake lines, you should replace the washers on the banjo bolt though. The following are suspected to work but are not confirmed. The number in parenthesis is the suspected bracket type. I will edit this list and move things around as more information regarding these vehicles bracket compatibility comes to me. 5th generation accord wagon (25T) All NSX (28T) Other Odyssey (25T) Honda S2000 (25T) Ridgeline (28T) Pictures Used Legend GS rotor with a 28T bracket Used Legend GS rotor with a 25T bracket Used Legend GS rotor with a 4cyl 23mm bracket 28T 25T Ears of a Legend GS rotor Slide pin bolts, the difference is very obvious. The 25T and 28T have the same slide pin bolts, they are up top. The 4cyl 23mm are on the bottom. Bracket mounting bolts. Legend GS on top, 4cyl 23mm on bottom. GS bolts are too long! The lineup 4cyl 23mm, 25T, 28T, left to right The 10.2 CG rotor on top of the GS 11.1 rotor Side by side 23mm on the left, 28mm on the right Behind 18 x 7.5 Racing Harts Compared to stock brakes behind the same wheel Behind 15inch steelies, I can't speak for sawblades or SE's. I haven't had the opportunity to measure the gap yet but everything moves freely. This is what you should look for if you are browsing for these in the junkyard. A small bolt head on the outside and a circle with flat edges on the inside of the caliper ear. I hope this helps everyone, and if you have any questions PM me and I will answer them to the best of my knowledge.