Orpheus

Hi,

So, I started working on my car around 4pm, starting with fixing my clutch, which ended with me breaking my clutch slave cylinder. Thus, unfortunately, I haven't driven the car yet, as it is still disabled on jack stands. But I did finished with the Racing Brake Rear BBK installation! So, here are some pics, with weights where applicable: (I'll probably post my opinions after I get to drive it, which will probably be mid-next week... sigh...)

The package:


So, this is what was included: the rotors, some pads, brackets. No installation instructions or hardware. For installation, I followed the torque specs in the FSM. Note, I didn't use their pads--I used the Carbotech XP8's that I had already.

The RB components:



RB rotor = 8lbs (as advertised)


RB bracket = ~2.2lbs (this includes the pins, as you can see, since I was going to compare with the OEM bracket I took off, which still had the pins)

The OEM components:


"OEM" (actually PWJDM) rotor = 9.9lbs


OEM caliper bracket = 2lbs (as noted before, the pins and boots are still intact)

Comparing RB to OEM:





And finally finished @ 11pm!:





For the most part, quality is excellent. I would note though that there is about a 2mm clearance between the locking nuts of the hat and the brake pad plate, but should be fine. The pads are very slightly portruding towards the center of the rotor, maybe by 1/2 - 1mm, and a little low from the outer edge of the rotor. In fact, after bolting down the caliper, the springy plate that holds down the pads just barely hover above the rotor--there must be less than a 1/4mm of clearance there! (I carefully checked, since before bolting down completely, they actually did scrape against the rotor.) A little too close for comfort. Would be nice if the caliper bracket, holding the pads, was moved ~1mm or so higher.

Other than the very close clearances in fit, I was impressed by the quality of the rotors. To be honest, I was not expecting much since I've not even heard of Racing Brake 'till recently. But even upon close inspection, the machining and construction looks pretty good. Only flaw I saw was that the paint used for the hats are rough and bubbly towards an edge--I assume it was because the rotors are painted upright, and the paint pools on the bottom. But this really is a nit. Would also be nice if some instructions were included--took me a while to decide that the pad clips on the OEM bracket were not supposed to be transfered to the RB bracket.

So, as you can see above, the RB rotor = 8lbs (just as advertised), which is ~1.9lbs lighter than "OEM" (PWJDM rotors to represent.) The larger RB bracket only carried a 0.2lbs weight penalty over OEM. So, overall, there is a reduction of 1.7lbs in unsprung weight, per corner. As for rotating inertia, since most of the weight reduction is in the hat, towards the middle, and the rotor is larger, there might be more inertia in the RB setup. But who knows--it's neglible anyway compared to the rest of the rotating assembly. I would think the unsprung weight reduction is far more important.

Overall the kit is of very high quality, and compliments my Stoptech Trophy Front BBK. I'm very happy with this purchase. Can't wait to fix my clutch and test this thing out!

Orpheus

Hmm..... I looked closer at MPG's group buy thread:

https://www.s2ki.com/forums/index.php?showtopic=834413

I see in the pics that somehow they managed to get the pad brackets/shims between the caliper bracket and pads. As I noted, I decided that they were not supposed to be transferred, because I actually tried. In stock form, they would not fit over the thicker rotors, so I actually cut the center "tabs" off. That allowed them to fit over the rotors, but then I couldn't get the pads in. Also, the RB bracket has more space inside, so they don't fit quite right against the RB bracket either. Just pm'd MPG... wonder if I did something wrong.

FISH22

Very nice. How much was the kit?

Orpheus

$835--from the group buy link above. (compare to $3k for the J's Racing kit.)

deibit

did u file down your brake pads before installing them in the rear BBK? according to RB the rear pads should be 1mm thinner than OEM in order to work with this BBK.

I did order the rear +1 BBK as well (but the plain rotor version).. I hope to get it in the next days

Orpheus

the pads i had were partially worn, so i didn't need to file them. but yes, you can't use full size new ones since the rotors are 5mm thicker.

btw, i mentioned elsewhere, but Carbotech will allow you to custom order pads at different thicknesses for no surcharge.

deibit

I have ordered the ET800 pads for the rear.. lets see how they are, I don't have a front BBK, so I don't want to transfer too much torque to the rear..

In the fronts I will use the RB two piece rotors for OEM calipers paired with Carbone Lorraine RC5+ pads (those should give enough torque to balance the rear mini-BBK (we will see)..

Btw.. let us know what MPG answers about the installation procedure

Orpheus

this is what mpg said (hope they don't mind i post this):

"We will forward your question to RB and see if they can address your concern. As for pad hanging off the rotors, we don't see that as being a problem. We have seen many cars where pads are not fully aligned on the rotors and they don't cause any issues. If there are contacts between the pad backing plate and rotor, then that could cause problem.

There are some play on the mounting hole for the bracket. Maybe you can loosen the bracket bolts and pull the bracket out from the center as you tighten the bolts, that might move the pads out farther."

i guess i'm just gonna run the car like this. if the pads get damaged, i know who i'm gonna have a talk with.

i also asked hondaf1 about what to do with the pad clips. according to him, he had a prototype, which apparently differed from the production models in that the new pieces were designed to work without the clips. he confirmed that in order to use the clips, the inner tabs had to be grinded off, like what i did, and i guess rb decided that was beyond the scope of work customers should be expected to perform for installation.

deibit

mmrrr.. maybe we should direct the questions directly to RB (since they designed the BBK).. well, let's see what they answer then

Orpheus

Wrote to RB directly:

"I purchased your Honda S2000 rear BBK (+1 size) through MPG, from the S2KI group buy. I had 3 issues:

1. I was not sure if I was supposed to transfer the pad clips from the original caliper bracket to your bracket. To make it fit, I had to cut of the inner clips, so they would fit over the thicker rotors. After doing so, and placing them in your brackets, the pads would not fit. So, I assumed the clips were not supposed to be transferred. Can you confirm this?

2. After installation the lower portion of the pad is off the inner portion of the rotor by about 1mm in the middle. Would this be a problem? Would the rotor dig into the pad, and leave that section that is "hanging out" unworn?

3. The pad retaining springs/clips in the OEM caliper itself barely clears the rotors, as they hold in the pads. This is probably due to the pads being seated too low (see #2.) I estimate maybe 1/4mm of clearance. Maybe even less. A little close for comfort. If the pad clips had been transferred (see #1) this probably wouldn't have been a problem. Is this a worry?"

I'll post their response when they answer.