Brembo GT BBK problems ?

[nightrain]

Okay guys... so i installed brembo GTs on my car couple of months ago, and since then I've been getting vibration ONLY when braking... i have bed in the pads, check tie rods, ball joints, all seems to be ok... just yesterday when i checked with couple of other m3s with brembo GT, my front brembo looks different... let the pictures talk

These are mine..
Front

Rear


And these are the brembos on the other m3s





You can notice that my front brembo has lesser number of holes (they go like 4-3-4-3, while it is supposed to be 4-4-4-4), and the rotor hat seem to be different (also they have different clamps that holding the rotor)

I believe the front and the rear should look like this
(rear rotor on the top, front rotor on the bottom)



I have checked the part number on the boxes, they all seem to be correct for e92 m3



For additional information, here are some part numbers on the brembo rotor hat on my car
-FRONT : P0 0891B12A10
-REAR : 90168512A03

So what is likely to be the issue ? did i receive the wrong brembo rotor ?

[tbone28]

My rotor is also 4-4-4

[spdy330]

Not 100% certain what size you purchased with out digging. The front rotors are different than mine but maybe your fronts are not 380's?

The front rotors also look like they may be on the wrong side but I am not sure if this would cause vibrations as I am not an expert.

When looking from the side the front drilled rotors should look like the are swooping to the back while the rears appear to be swooping to the front. This is based on a 380X380 setup.

[spdy330]

My fronts are also drilled 4-4-4 while my rears are 4-3-4.

Originally Posted by tbone28

My rotor is also 4-4-4

[spdy330]

Searching your part number it does look to me like those are the wrong rotors. They look like rear rotors to me. See this link that I found, all the pictures with this part number are the same.

http://www.streetperformance.com/par...2p19013a5.html


Edit:

According to Race Technologies you can get the fronts in either type "D" or Type "H".

Looks like you got Type "D".

http://www.racetechnologies.com/page3-42/GTSystems

[guess2098]

your front rotor mount looks like rear one, but rear rotor is rear for sure

[nightrain]

Originally Posted by spdy330

Not 100% certain what size you purchased with out digging. The front rotors are different than mine but maybe your fronts are not 380's?

The front rotors also look like they may be on the wrong side but I am not sure if this would cause vibrations as I am not an expert.

When looking from the side the front drilled rotors should look like the are swooping to the back while the rears appear to be swooping to the front. This is based on a 380X380 setup.

Thanks for your response... These are 380/380 6 pot/4pot setup. i was told by the shop just now that these are italian spec brembo GTs, they are 380 x 32mm instead of 34 mm (us version)

Yes it looks like they are mounted on the wrong side but the direction of the air vents are correct, swooping to the back... However i am wondering if the wrong direction of the rotor holes is the cause of the vibrations ? Can anyone confirm this ? if this is the cause i will go back and swap them..

Originally Posted by spdy330

Searching your part number it does look to me like those are the wrong rotors. They look like rear rotors to me. See this link that I found, all the pictures with this part number are the same.

http://www.streetperformance.com/par...2p19013a5.html


Edit:

According to Race Technologies you can get the fronts in either type "D" or Type "H".

Looks like you got Type "D".

http://www.racetechnologies.com/page3-42/GTSystems

What are the difference between type D or H aside from the design ?

Originally Posted by guess2098

your front rotor mount looks like rear one, but rear rotor is rear for sure

That what i thought too, but by looking at them there is no way to mount the rear rotors to the front because it looks like they have different rotor hat ?

[spdy330]

Since the direction of the air vents are correct I would leave them alone. When they installed mine I questioned many times on why my front and rears were in the opposite directions of each other. It looked very strange to me but I found out later that is how they are designed, at least for the US versions.

[THE TECH]

Mine are also 4-4-4 & 4-3-4.

Did you add any spacers?

Your wheels could also be the culprit.

[CarbonFoot]

Mine are also 4-4-4 F and 4-3-4 R. The cooling veins and drilled pattern swooping in the opposite direction on your front rotors sure make them look like rear 380 rings.

[PINHEAD]

your front rotors are wrong
i can tell from your hats and the hardware. fronts have a fatter flat bracket that holds the floating screws. It looks like you have both rear rotors for all 4 corners.

[e92involved]

Originally Posted by PINHEAD

your front rotors are wrong
i can tell from your hats and the hardware. fronts have a fatter flat bracket that holds the floating screws. It looks like you have both rear rotors for all 4 corners.

I bet that is your problem...

[HP Autowerks]

Indeed the front rotor hat looks someone out of place, but you should check with your supplier to see if this is really the case with Italian spec kits. That said, the judder or vibration may or may not be cause by the incorrect hats, but rather uneven deposit of pad material on the surface of the disc during the bed-in process.