Brembo BM-4 caliper

[timurrrr]

Originally Posted by CSG Mike

The base pads, along with light street driving, won't be terribly abrasive.

That's what the instructions supplied with the kit recommended.

Originally Posted by CSG Mike

Mixing any transfer from the street pad with the C1 will also have mixed results. Contaminated transfer will yield lower friction and... weird interactions

Forgot to mention that I did 1+ hour of light street driving with C1's after I put them in and before I went to bed them in.

Originally Posted by CSG Mike

Get the C1 really, REALLY hot, without ABS use, to burnish them.

Tried my best to do exactly that before the track day.

Originally Posted by CSG Mike

If you know you are touching ABS, but you're also 'giving it more pedal effort', wouldn't you say that's a bit self-defeating?

Where did I say I'm (intentionally) giving it more pedal effort (despite knowing that I hit the ABS)?

[CSG Mike]

Originally Posted by timurrrr

Where did I say I'm (intentionally) giving it more pedal effort (despite knowing that I hit the ABS)?

Originally Posted by timurrrr

I think they needed a bit more pedal effort (which I like)

Originally Posted by timurrrr

I can tell from the feel and the sound that I heard that I was indeed engaging ABS more often than I should have. "I have a lead foot".

The provided instructions with the kit are specific to the kit as provided, for standard street use. Your use case is not that.

Street driving the C1 will NOT create a transfer. Attempting to bed the C1 on the street will only result in unsafe driving. Please, do this at a safe venue only, or also consider getting the C1 pre-burnished.

I recommend you clean off your rotors, and re-attempt to burnish the C1 and get a nice transfer for better results.

[timurrrr]

You're misreading those quotes.
I meant that to achieve the same deceleration rate, the B-M4 kit seems to require a bit more pedal effort,
which is something I prefer over the lighter pedal effort of PP's.
That being said, math shows that the difference should only be ~10%, so it might totally be a placebo.

ABS engagement is about how much effort is enough, which is a separate parameter. That is something that I need to work on, I admit.
The higher effort overall means it's easier for me to modulate and not go too deep into ABS.

Originally Posted by CSG Mike

The provided instructions with the kit are specific to the kit as provided, for standard street use. Your use case is not that.

I bought a kit labelled "CSG Spec" and it came with instructions from Brembo basically saying "if you do anything differently, you're screwed".
I followed those instructions pretty closely, with the only major deviation being switching to the C1 pads and re-starting the instruction after completing the low-temperature part of the instructions with the supplied pads.

If you or CSG strongly think that customers should follow alternative instructions, those instructions should come with the kit, and should include "IGNORE THE INSTRUCTIONS PROVIDED BY BREMBO, WE KNOW BETTER".

Instead, I find out I need to add some zip ties on the forum.

Originally Posted by CSG Mike

Street driving the C1 will NOT create a transfer.

And I didn't expect them to. I street drove C1's to use their abrasiveness to scrub off what was left of the zinc coating, along with whatever transfer layer the supplied pads created.

Originally Posted by CSG Mike

Attempting to bed the C1 on the street will only result in unsafe driving.

Sorry, that's too late this time. Though I tried the safest way I could come up with: at midnight, on an extremely low-traffic section of an expressway with no traffic lights for miles. Are you saying it's physically near-impossible to heat up C1's enough while driving on the street?

Originally Posted by CSG Mike

Please, do this at a safe venue only, or also consider getting the C1 pre-burnished.

That wasn't an option when ordering the kit.

Originally Posted by CSG Mike

I recommend you clean off your rotors, and re-attempt to burnish the C1 and get a nice transfer for better results.

So, keep the C1's for some street driving (maybe even autox?), then at my next track day at the end of the first session do some accelerate-medium-brake-accelerate-medium-brake-... and then drive around the paddock / access roads for 15 minutes to cool down?
Or do you have any other practical recommendation how I should achieve that?

[churchx]

Originally Posted by timurrrr

...Sorry, that's too late this time. Though I tried the safest way I could come up with: at midnight, on an extremely low-traffic section of an expressway with no traffic lights for miles. Are you saying it's physically near-impossible to heat up C1's enough while driving on the street?...

There is option how to bed brakes even at lesser speeds (so probably more usable on public roads, with supposedly danger only for misleading other drivers by brake lights on). - keep pressing accelerator while dragging brakes.
But i guess there might be several drawbacks to this approach. Things that i can imagine, for example it may lead to much more rear brakes heat-up/wear then in normal accelerating/braking in cycle, as there is no mass transfer and unadjustable stock brake bias will be too front-biased for underbraked fronts in bedding this way (heard that this way is used to get heat in brakes/tires in some race series after tire heaters in those were banned. But they have brake bias valve for that). Also easy to miss overheating. Maybe something else that i don't know, as IIRC seen dragging brakes often shun off as bad thing to do.

[Will_]

Bumping to revisit the pad swap issue. Can it be done easily without removing the caliper? Seems to be conflicting reports in this thread. I imagine you need to tilt the pad in such a manner that it can clear the bridge. If anyone has a video that would be great, tried searching YouTube but to no avail.

[timurrrr]

Originally Posted by CSG Mike

Standard Goodridge line used on all Brembo kits. Zip tie on each side of the rubber bracket; gives you a very easy quick visual reference to see if it moved.

[...]

Yes, you can use factory brake lines if you wish.

Thanks, now I finally understand what zip tie you were talking about in your earlier review.
Here's how I put them, 2x at the bottom to increase the chances of at least one staying put:



Showing the bracket and zip ties to a few of my "more mechanically experienced" friends, I learned about multiple other total/near-total brake failures among people who used the brake lines that come in Brembo GT kits.

I've decided that a minor difference in pedal feel does not justify a non-zero additional risk of a brake failure and a major accident.
I understand that regularly checking those zip ties can minimize that risk, but I also don't want to be checking the zip ties between each track session like a paranoid.

You said I can use factory brake lines, can you please confirm which factory lines I should use? "Base" or PP Brembo? Or either will work?
Don't want to learn the hard way when the car is on the lift with the Goodridge lines off that I got the wrong lines.

[timurrrr]

Originally Posted by callisto

Can the BM4 calipers be swapped in on Performance Brakes by a mechanic/tuner, or is it necessary (or at least a very good idea) to just buy the full brake kit?

To elaborate on what Mike already said, B-M4 seem to be designed to work with the base rear caliper.

A combination of B-M4 front with PP rear will likely cause too much rear brake bias. But might be within what EBD can correct for.

As a data point, my data logs shows that gen1 car with PP Brembos all around was locking up the fronts before the rears, so a bit of extra rear bias might not be such a bad thing. GT Radial SX2 tires with ~1" lowering. Note that changing the level of grip or the height of the center of masses affects the "optimal" brake balance.

[CSG Mike]

Originally Posted by timurrrr

Thanks, now I finally understand what zip tie you were talking about in your earlier review.
Here's how I put them, 2x at the bottom to increase the chances of at least one staying put:



Showing the bracket and zip ties to a few of my "more mechanically experienced" friends, I learned about multiple other total/near-total brake failures among people who used the brake lines that come in Brembo GT kits.

I've decided that a minor difference in pedal feel does not justify a non-zero additional risk of a brake failure and a major accident.
I understand that regularly checking those zip ties can minimize that risk, but I also don't want to be checking the zip ties between each track session like a paranoid.

You said I can use factory brake lines, can you please confirm which factory lines I should use? "Base" or PP Brembo? Or either will work?
Don't want to learn the hard way when the car is on the lift with the Goodridge lines off that I got the wrong lines.

Use Spiegler lines. They have a fixed bracket.

[CSG Mike]

Originally Posted by timurrrr

To elaborate on what Mike already said, B-M4 seem to be designed to work with the base rear caliper.

A combination of B-M4 front with PP rear will likely cause too much rear brake bias. But might be within what EBD can correct for.

As a data point, my data logs shows that gen1 car with PP Brembos all around was locking up the fronts before the rears, so a bit of extra rear bias might not be such a bad thing. GT Radial SX2 tires with ~1" lowering. Note that changing the level of grip or the height of the center of masses affects the "optimal" brake balance.

EBD is reactive. It's better to have the system working properly to begin with, rather than relying on EBD to reduce force after spin is already detected.

[timurrrr]

Originally Posted by CSG Mike

Use Spiegler lines. They have a fixed bracket.

What's the part number for the Spiegler lines?

Also, would still appreciate knowing which OEM line is compatible.
You did say "[Spiegler lines] also are like 2.5x the price", I don't know if the minor brake pedal feel difference is worth it.
After all, I was ok with the pedal feel/feedback of the PP Brembos with OEM lines.

[CSG Mike]

Originally Posted by timurrrr

What's the part number for the Spiegler lines?

Also, would still appreciate knowing which OEM line is compatible.
You did say "[Spiegler lines] also are like 2.5x the price", I don't know if the minor brake pedal feel difference is worth it.
After all, I was ok with the pedal feel/feedback of the PP Brembos with OEM lines.

You can use either OEM line.

or

https://www.counterspacegarage.com/s...-brz-frs-front

[Dylans47]

Originally Posted by Lynxis

There is some competing information regarding pad swaps with the BM4 in this thread:









So does the whole caliper need to come off to swap pads or not? Maybe @CSG_Mike can clarify? If pad swaps are no more difficult using the BM4 than the standard caliper, the extra $100 for the BM4 is really compelling but as someone who swaps pads at every track day, having to fiddle so much would get old fast.

Any update as to if the caliper must be removed? I can't imagine that is the case, but that would be a deal breaker.

[Code Monkey]

Originally Posted by CSG Mike

Use Spiegler lines. They have a fixed bracket.

Uhm, no. It is a sliding bracket with a grommet, you can even see it in one of the pictures on the CSG page you linked. The fit is pretty tight though and it takes some force for the brake line to slide.

From Essex (emphasis mine):

All Spiegler Stainless Steel Lines come with an abrasion resistant coating. On the standard parts (non-custom colors), that coating is clear so you’re able to see the underlying stainless weave. The abrasion resistant coating prevents the line from snagging, protects the stainless weave from debris, and also allows the line to slide smoothly through any required retainers or brackets [...]

[CSG Mike]

Originally Posted by Code Monkey

Uhm, no. It is a sliding bracket with a grommet, you can even see it in one of the pictures on the CSG page you linked. The fit is pretty tight though and it takes some force for the brake line to slide.

From Essex (emphasis mine):

All Spiegler Stainless Steel Lines come with an abrasion resistant coating. On the standard parts (non-custom colors), that coating is clear so you’re able to see the underlying stainless weave. The abrasion resistant coating prevents the line from snagging, protects the stainless weave from debris, and also allows the line to slide smoothly through any required retainers or brackets [...]

Well see, here's the thing. I've actually used these lines.

The lines will *swivel* yes (with a lot of effort), but actually slide in the grommet? Good luck. It's precisely why I make this recommendation. For all intents and purposes, the location of the bracket is fixed, and is pre-positioned out of the box precisely because it's... not going to move.