Differences Between Brembo 380mm/380mm BBK and 365mm/345mm BBK

[SenorFunkyPants]

Originally Posted by AP Racing - Chris_B

If you assume tire grip is the same, the brake system still needs to overcome the rotational inertia of each wheel/tire. This gets substantially more difficult at the higher speed since the rotational kinetic energy is also 4x higher. You can maintain a relatively constant deceleration rate, but to lock up a tire at 150mph will usually take more effort than at 75mph.

Its the "more effort" that I'm trying to get an idea of....is it 10% 50% 200% more? I realise that an exact figure is not something anyone is going to be able to pull out of the air but approx would do. I'm trying to get a better understanding of the forces involved in braking relative to speed. I know I can easily trigger the ABS on my M3 at 100mph but would there be a speed at which I couldn't?

[AP Racing - Chris_B]

Originally Posted by SenorFunkyPants

Its the "more effort" that I'm trying to get an idea of....is it 10% 50% 200% more? I realise that an exact figure is not something anyone is going to be able to pull out of the air but approx would do. I'm trying to get a better understanding of the forces involved in braking relative to speed. I know I can easily trigger the ABS on my M3 at 100mph but would there be a speed at which I couldn't?

You are right about coming up with an exact figure! There are a ton of interdependent variables that cannot be easily accounted for, which is why testing is always necessary. In my experience, it will take more effort at higher speeds. This is a good thing, because we don't like flat spotted tires. Of course the actual amount of increase depends on the initial bite the pads and rotors have at that particular temperature, track and tire temps, road surface, shock settings, how much ale was consumed the night before.........

[lucid]

Originally Posted by sparkyg

I measured the weights of the kit

365 mm slotted rotor 24.5 lbs

6 pot monobloc front caliper 12 lbs

front caliper bracket 2.0 lbs



345 mm slotted rotor 15 lbs

4 pot rear monobloc caliper 8 lbs

Rear caliper bracket 1.5 lbs

All weights measured on digital scale used for shipping so prob +- 0.5 lbs

Thanks for the update on the brackets.

[lucid]

Originally Posted by sparkyg

I measured the weights of the kit

365 mm slotted rotor 24.5 lbs

6 pot monobloc front caliper 12 lbs

front caliper bracket 2.0 lbs



345 mm slotted rotor 15 lbs

4 pot rear monobloc caliper 8 lbs

Rear caliper bracket 1.5 lbs

All weights measured on digital scale used for shipping so prob +- 0.5 lbs

It just occured to me ask about the pads. Do your caliper numbers include pads? Thanks.

[Gary@RENN-Spec]

In response to whether the 365/345 Brembo kits clears OEM 18" wheels:

We just finished fitting these behind the OEM 18". The spokes of the wheels clear the calipers with no problem. There's plenty of room left; however, the brake lines on the calipers are very close to the balancing weights on the stock wheels (see below pictures).

We recommend going with a minimum of 5mm spacers if you wish to keep the original balancing weights; otherwise the front wheels will need to be re-balanced with low profile balancing weights.

The rears will have zero issues.


Here are some photos of the fitting:

[sparkyg]

Originally Posted by lucid

It just occured to me ask about the pads. Do your caliper numbers include pads? Thanks.

Yes include pads.

[sparkyg]

Originally Posted by Gary@RENN-Spec

In response to whether the 365/345 Brembo kits clears OEM 18" wheels:

We just finished fitting these behind the OEM 18". The spokes of the wheels clear the calipers with no problem. There's plenty of room left; however, the brake lines on the calipers are very close to the balancing weights on the stock wheels (see below pictures).

We recommend going with a minimum of 5mm spacers if you wish to keep the original balancing weights; otherwise the front wheels will need to be re-balanced with low profile balancing weights.

The rears will have zero issues.

Thx Gary, that's awesome news. Will do on the low profile wheel weights

[lucid]

Originally Posted by sparkyg

Yes include pads.

Thanks. Added the specs you provided to the weight savings thread.

[sparkyg]

Putting winter tires on today and as Gary said you MUST change wheel weights to low profile if you have any weights on the farthest outward (away from car) side of the rim.

Any standard wheel weight will have 1-2 mm clearance on the bleed port but <1mm clearance on the brake lines.

Otherwise the fitment is great.

I am not sure how the AP 368mm kit is gonna fit the stock wheels. It is that tight with the 365 mm front.

[Jaypod]

Originally Posted by sparkyg

Putting winter tires on today and as Gary said you MUST change wheel weights to low profile if you have any weights on the farthest outward (away from car) side of the rim.

Any standard wheel weight will have 1-2 mm clearance on the bleed port but <1mm clearance on the brake lines.

Otherwise the fitment is great.

I am not sure how the AP 368mm kit is gonna fit the stock wheels. It is that tight with the 365 mm front.

I think I read that that 10mm spacers are required for the AP kit on the front to fit the stock 18's

[TOOMANYCARS]

That's mighty close. I suggest a 10mm spacer is required with the 365mm front kit if user plans to keep the stock 18s.

[sparkyg]

Yeah a 10 mm spacer would certainly fix things but it is still close on the brake line.

Low profile wheel weights is a better investment and cheaper too.

Both are good solutions. I am not a fan of spacers

[STALKER]

Sparkyg,
Any more feedback on the Brembos.