Porsche Brembo 996 BBK conversion

[Actuary]

They shouldn't be any different but BMW CSL rotors are also 2-piece rotors. I was looking at them after they arrived and even though they're bigger than old rotors, the weight is much less according to my internal weight meter. They're also $150 cheaper than the ECS ones. It's really cool how BMW made their 2 piece look like a 1 piece for the surface. It's very discrete. The wheel covers the hub so I guess it doesn't matter that much.

Thanks for the info!! I have the front ECS rotors and would like to have a matching rear on my 996 setup. In addition, the ECS front rotors are holding up much better for me on the track. I"m likely to stick with the OEM CSL rotors in the back, especially given the cost. But it would be good to know if the rear ECS rotors can clear the 996 brakes.

[Arith2]

Has anyone tried ECS 2-piece rear rotors with Rally Road adapters on the 996 conversion? I'm wondering if the fit is similar to stock rotors, or if the ECS rotors are too thick for this setup.

They shouldn't be any different but BMW CSL rotors are also 2-piece rotors. I was looking at them after they arrived and even though they're bigger than old rotors, the weight is much less according to my internal weight meter. They're also $150 cheaper than the ECS ones. It's really cool how BMW made their 2 piece look like a 1 piece for the surface. It's very discrete. The wheel covers the hub so I guess it doesn't matter that much.

[D-O]

Has anyone tried ECS 2-piece rear rotors with Rally Road adapters on the 996 conversion? I'm wondering if the fit is similar to stock rotors, or if the ECS rotors are too thick for this setup.

I did not use them, but I did seriously consider them. When I called ECS to price the replacement friction rings they informed me that they no longer sell them separately, but will give you a discount on replacement rotor assemblies when the time comes. I do not recall what the discount was, but from a purely price perspective they did not make sense vs. the OEM crosssdrilled rotors. HTH anyone considering them with the idea that replacements will be comparatively cheap.

D-O

oops - just noticed you were inquiring about the rear rotors - I was only referring to the fronts!

[Actuary]

Has anyone tried ECS 2-piece rear rotors with Rally Road adapters on the 996 conversion? I'm wondering if the fit is similar to stock rotors, or if the ECS rotors are too thick for this setup.

[Arith2]

I found out the stock 18s do not clear. The caliper hits the spokes. I calculated close to 10mm was needed so I ordered 12.5mm spacers. I'm sure they'll fit after but I want to know if I can use less. Wheel spacers are just bad in general but in my case, a necessary evil.

It's amazing to me how much weight you save with this also. Stop calipers are heavy hunks of junk.

[Titaniu//M]

Finished up my front 996 conversion this morning. Will do the rears next weekend. Thanks to Tbonem3 and all those who contributed to this thread, the conversion went (almost) flawlessly.

Just to add to the wealth of information in this thread:

• Two of my rotor set screws were rounded out. The previous tech who did my front brakes reused them, despite the hex head being rounded off. I could not get them off, with a hex or Torx bit. I think this is a pretty common problem on BMWs. I tried using a Dremel to cut a slit in the top of the screws, then using a screwdriver to get them out, but this did not work. If you encounter this situation, grab a drill, use a bit about 75% the size of the head of the set screw- and drill into the hex head until you hit the rotor. The head of the set screw should pop off easily, and I was able to get the rotor off. The threaded portion that remains of the set screw should come out of the hub easily with vice grips, since there is no more tension holding them on.
• BUY NEW SET SCREWS when you are shopping for parts, they strip easily and cost $1 each at the dealer
• If I had to repeat this I would buy 6 Centric caliper seal kits total, 3 for each front and rear. Then, I would select the best fitting seals from the kits and use those. They are cheap enough this is a good idea IMO.
• If you do not buy the seal kits from Ohio Performance, you can buy the lube separately. It is called Centric disc brake assembly lube.
• I had some great results wetsanding the color coat with 2000 grit before applying clear. I then wetsanded the clear and buffed with Meguiars M105 and M205 to get a very smooth finish.
• BBS LMs in 19x8.5 ET +32 size clear the fronts with ease. I bought spacers just in case, but they were not needed.

[Arith2]

I accidentally ordered 99635294902 instead of 99635294903

Off to the stealership I go... and at least I'm getting some genuine pads. They may cost more but they'll perform better. OE and OEM do seem to differ a little when it comes to these Porsche pads, unlike BMW.

[Arith2]

Something I would suggest is some antiseize on the places these DISSIMILAR metals are touching. The alignment pins, the screws, and the center hube. Be VERY conservative with the amount used so nothing gets flung. Dirt will also collect wherever exposed.



DO NOT use on exposed surface, only contact points, where dissimilar metals touch. Since caliper brackets are aluminum, I'm putting it on the surface of the steering knuckle it bolts to. It looks anodized so it probably won't react there. I'm just doing it for safe measure.



DO NOT use this on bracket bolts or caliper bolts or threads. This could cause those to loosen. It's highly unlikely but don't become that one person it happens to. Small rotor bolts are ok.

The reason to do this:
Aluminum and steel react with each other slowly over time quite severely. A good example is a transmission bolt. Our engines are iron so the corrosion is much less but non-M guy have a heck of a time with this. There's a metal reaction chart. I believe aluminum and steel are far apart meaning the have more reaction.

Good luck with the swaps everyone!

[maupineda]

Thanks for noting this! Any chance you could provide some more details/pictures on where exactly the washers go? Also, what size/type washers you used?

The washers are 20OD 11ID and 0.8mm thick. I posted a photo on the DIY install thread.

[Tbonem3]

I would not use regular lube on seals, but specific caliper rebuild fluid (not even brake fluid).

[maupineda]

Thanks for noting this! Any chance you could provide some more details/pictures on where exactly the washers go? Also, what size/type washers you used?

Hi! Yes. I will post some more photos tomorrow

[duracellttu]

Hi, I did not source my seals from them but went with the centric kit from FCP Euro. I wonder if they will bring some lube with them. if not, is this something I can source from the typical auto parts stores (Autozone, etc)?

Any silicon grease will work for the seals. Super Lube is a good option. See the link below.

https://www.amazon.com/dp/B0081JE0OO

[duracellttu]

it is, in fact, there was contact (not enough to actually bind the rotor), I posted more images in the installation thread. I need 1.6mm spacer to center the calliper. This will be addressed for the final assembly.

Thanks for noting this! Any chance you could provide some more details/pictures on where exactly the washers go? Also, what size/type washers you used?

[scotty737]

This project is finally coming together for me, and I am finishing up the paint on 2 remaining calipers. However, my parts ordering debacle is apparently not over. First I received 2 crossover lines that were different part numbers, but the same part. Then, I tore one of the rear dust boots so I ordered a new seal kit for the rear calipers from Amazon. I received it today and only got 1 seal. So for those of you looking to buy parts for this, do not order the seal kits from Amazon. Not really a "caliper kit" as the description suggests.

I had the exact same thing occur from rockauto. The bag had the right part number, but one one seal instead of the whole rebuild kit.

[maupineda]

Wow that guide pin sure is close to the rotor!

it is, in fact, there was contact (not enough to actually bind the rotor), I posted more images in the installation thread. I need 1.6mm spacer to center the calliper. This will be addressed for the final assembly.