Front Brake "Upgrade" Part 1 - E46 Brakes - Paint, Specs

  I got these awesome, super stock calipers off a wrecked up 01 325i. Already painted red for me. Extra performance right out of the bag folks!

Specs

Rotors

  Why would you try putting these on an E36? I'll tell you. The E46(99-05) 325 & 328 have 11.8 inch rotors up front. The stock e36 rotors on my car are 11.2. I'm gaining about a .6 inches. Not much but, it is an improvement in rotor circumference.

  The calipers are identical, the pads the same, it's the carrier bracket that differs. These will increase my radial braking surface resulting in a whopping 6% braking increase over the front axel! Can you even believe it? A laugh and giggle there for sure, obviously. However, all be it a small increase upgrading to E46 rotors and calipers all around, with stock pads, will accumulate around a 13% increase total which, is something.

11.8 inches on the E46 325, 328 rotors

Calipers

  I was curious about the sizing of the piston diameter on my stock E36 calipers versus the stock E46 calipers. Some pictures for confirming sizes of the piston diameter below.

• The serial numbers on the calipers differed slightly. 
• The weight was about the same. 
• The piston diameter was also the same.

2.085 outer roughly.

1.565 inner roughly.

.250 (1.4) thickness.

Bracket  
The bracket was certainly different. It moves the caliper out further from the spindle to accomdate the larger rotor. The slide pins are in the exact same location allowing for use of an E36(325, 328) or E46(325, 328) caliper.

Caliper brackets side by side. Its hard to see the spacing of the threaded holes at this angle. Sorry. They are just a bit more than a 1/2 inch different.

 Prep and Paint

  Of course before I put these on my ride Id like to make them, not red. A good spray down with brake cleaner. Some medium grit(220) sandpaper to get started. I used the rotary tool to get in the tight spaces. This creates a good bit of dust, please be cautious and wear a face mask here. If I had a media blast cabinet, that would have made this a dream. Its on my list.

Tools of the trade for prep

• Heavy wire brush
• Large pliers
• Rotary Tool with a metal brush on it
• 120 Grit Sandpaper
• 220 Grit Sandpaper
• Brake Cleaner
• Not sure what I was doing with the wheel cleaner there

  After sanding and a rinse. They are ready for paint. I'd advise removing the carrier pins. This can be done with a 7mm Allen wrench or socket.

  They look so good after a good spray. Unfortunately as with most spray paint techniques, these may not hold their color forever. We will see. A lot of people really have great success with powder coating however, the cost is substantially more. I do not have that kind of cash flow for this project.

Strut prep and paint - Let's make em' hot again

  Since I bought the front struts and springs used, from up north, I knew they would need a little clean up and some rust removal. Not a big issue for me as these things tend to hold up better than folks expect.

  I started off by cleaning the struts thoroughly. Some degreaser, sweat, and brake cleaner later they were better.

  Once I got most of the grim off it was time to take care of the tough spots. I pulled out my bottle of rust arrester from the hatchback days (technically its still around though). I lathered them nicely in this and let them fizzle. Please be careful with that stuff folks. Its really nasty. After letting them sit over night, it was time for the good stuff.

  I used a wire brush to break up some of the cracked and peeling powder coat. Then used some 220 grit sandpaper to rough em up just a bit.

  Laid down 2 coats of primer.

  I started to sand them again with 400 grit but, they were smooth enough for me so I went ahead and put down some "almost-bilstein-yellow" paint back on them.

Time to let them dry. I shot over the yellow with a little lime green as well. Just for fun. I had some ideas for some more color however, I'm running short on time. I still need to lay some clear coat on these.

  Since rear springs also had a little rust on them I went ahead and rust arrested them as well. After which I primed them and then, shot them with a light coat of under coating.

Materials

Before

After

  I dare say they turned out great. Of course you can't see the pretty writing that says they are H&Rs anymore. Sad for all those folks who want to climb under my car and inspect them. This undercoating holds up pretty well but, it isn't as good as the molded poly shielding around the H&Rs. We will see how these do long term.