DIY: 262mm>282mm front brakes conversion
Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!
Aim: To convert existing 262mm brakes ( DC2/4,EG6,EK4,EG2,lateEG5 ) to 282mm setup found on DC2r,HRV,Preludes. Shown here is my EG5 that has previously upgraded to DC2/4 calipers, 262mm rotors, hubs along with 1" BMC & booster.
Required: 282mm rotors for prelude ( DBA 200 eqv ), OE 17CL15VN Nissin calipers from Prelude/dc2r/hrv, caliper brackets machining, rotors redrilled for 4x100 stud holes, DB1206 eqv pads of your choice. 1" brake master cyl and brake booster setup from dc2r/Prelude high recommended if you dont want a mushy pedal.
Steps: This guide is intended for those who already have the 262mm setup on their cars, if you have the 240mm brakes then you need to upgrade to the 262mm setup 1st, minus the calipers and rotors. I wont be going thru every nut and bolt and the tools you need, just the bare essentials you need to complete the tasks.
Calipers:
I bought these calipers from this forum, they were off a Prelude originally, with the 25T bracket. The caliper bracket needs to be milled ie machined 2.7mm off where it bolts onto the knuckle. I had this done at an engineering shop in Perth.
Before Milling:
http://img296.imageshack.us/img296/7...5024fc4.th.jpghttp://img296.imageshack.us/images/thpix.gif
After Milling
http://img125.imageshack.us/img125/8...5057ri4.th.jpghttp://img125.imageshack.us/images/thpix.gif
Rotors:
http://img407.imageshack.us/img407/5...5054gx7.th.jpghttp://img515.imageshack.us/img515/6...5056jb0.th.jpghttp://img515.imageshack.us/images/thpix.gif
The rotors used are for a Prelude ( DBA 200 ) that came out with 282mm rotors with 4x114.3 stud pattern. They have the same 47mm height, 23mm thickness as the DC2r's ( DBA 478 ) but crucially a smaller 64mm bore hole instead of the bigger 70mm and different stud holes.
The orig 262mm rotor also has a 64mm bore that fits onto its 64mm hub, so using this instead of the DBA 478 saves you needing to machine to 3mm hub ring to ensure the rotors stay centre on the hub.
To redrill the rotors, the 4x114.3 pattern is much easier to redrill, as the 5x114.3 pattern overlaps the 4a100 pattern on 2 of the holes and therefore you wont get a clean drill.
With the 4x114.3 pattern, 2 of the pre-existing pilot holes are already lined up at 100mm apart ( they are the contersunk holes for the rotors retaining screws )
I had the rotors redrilled by a fren who has a mech workshop. He made up a 64mm boss to centre the 262mm rotors onto the 282mm rotors before clamping them together prior to drilling. He also managed to drill and contersunk a hole for 1 retaining screws. The orig setup had 2 retaining screws, while some cars such as late model Toyotas have none so this is optional and you can leave one of them or both out if it's too much mucking around to drill the contersunk hole for the retaining screw(s).
Bolt up:
The machined caliper bracket bolts straight up onto the exisiting knuckles, and the brake line bolts up to much the same spot as before there is no need to mod the brake hose ( thank you Mr Honda! ).
Clearance with rotors and wheels:
The calipers actually cleared my fat fives by a lot more than I was expecting, as seen in the pics below:
http://img523.imageshack.us/img523/8...5065rf3.th.jpghttp://img523.imageshack.us/images/thpix.gifhttp://img515.imageshack.us/img515/3...5068jm6.th.jpghttp://img515.imageshack.us/images/thpix.gifhttp://img523.imageshack.us/img523/9...5072he4.th.jpghttp://img523.imageshack.us/images/thpix.gifhttp://img515.imageshack.us/img515/5...5053ha8.th.jpghttp://img515.imageshack.us/images/thpix.gif
Summary:
http://img515.imageshack.us/img515/7...5064jm9.th.jpghttp://img515.imageshack.us/images/thpix.gif
As seen in the pic above, the difference in the size of the pads and calipers is substantial. The downside of this conversion is the increased rotational weight (+1kg per rotor ) and unpsrung weight ( +1kg per rotor +1.2kg per caliper + 300g per pair of pads ). The bigger caliper w/pads and rotor weighs in at 12kg.
On the upside those DB1206 pattern pads are simply HUGE for any car, let alone in a 1050-1150kg EG/DC2. They are prob some 15% smaller in surface area than a VZ HSV single piston caliper pad. Thus they heat up less and last longer under track conditions and cost less to maintain in the long run.
I wont go into details of the choice of pads and rotors and how they fare on the track, that's for another review post down the track.
