Blue_SS

It won't be optimal, but actual problems probably won't surface. The programming for your ABS module was for your OEM calipers and pads. As you dial up the braking capability, you are more likely to lock the brakes up in a skid because the braking ability gets you there (skid) quicker.

Ordinary use won't matter. I would pull the ABS fuse if you want to track it or anything like that. ABS is intrusive anyway, but after this kind of upgrade, it really doesn't know how to act properly in threshold braking situations.

gio89kid

Ok, here comes some thinking...

So having the same brake booster and master cylinder with the new four piston brembo front calipers and factory programmed ABS module will result in potentially dangerous braking situations under heavy pedal use, especially on slippery road surfaces.

TCS and ABS would be at risk.

I currently have the large non brembo SS rotor and caliper bracket. I assume the non brembo SS rotor is the same size for the brembo? And I read on a different post on here that the non brembo SS caliper is actually less pressure than the LS or LT caliper. So this combination gives you equivalent LT/LS higher pressure piston braking over the larger SS rotor which would result in better braking per wheel rotation than both non brembo SS or standard LS/LT options, while still not affecting the ABS algorithm?
(My car brakes normal, how would I test, what MPH do I slam the brakes on?)

Hopefully I have my info correct thus far.

Assuming the rotor size doing the brembo upgrade would be about the same as the non brembo SS bracket upgrade, so now it’s a matter of braking pressure correct?

Four pistons allow for even distribution on the brake pads for smoother braking. But how much pressure are the LT/LS calipers vs. the Brembo calipers.

I don’t know the answer, I am hoping you guys will add to this. But if it is the same or similar piston pressure, the algorithm should still work talking to all the wheel speed sensors?

If not, can a brembo abs be purchased and installed on the car with no modifications?
And will this work for me who still has drums in the back?

firemangeorge

Brembo rotors are bigger than the regular SS rotors. Regular HHR rotors are the smallest. I copied the EBC listed rotor sizes from an old post.

GD7375
Rotor; EBC 3GD Series Sport Slotted Rotors; Set of Two; Front; 10.9 in. Dia.;
GD7265
Rotor; EBC 3GD Series Sport Slotted Rotors; Set of Two; Front; 11.7 in. Dia.;
GD7507
Rotor; EBC 3GD Series Sport Slotted Rotors; Set of Two; Front; 12.4 in. Dia.;

Oldblue

The four piston Brembo calipers provide more clamping force, then the SS non Brembo calipers .
This swap has been done before, I don’t recall any problems resulting from it.

gio89kid

Ok, that is only a 1.5” bigger rotor, split that in half and that’s .75” extra vertical pad area. So far not too bad.

Does anyone know piston force differences between the LS/LT and Brembo?

And what about the ABS module swap?

firemangeorge

Not sure but I don't think it's measured that way. Since the brake master cylinder creates the hydraulic pressure to the calipers, then it would seem that the piston force would be the same if using the same master cylinder.

(OK. Now my head hurts. Too much thinking, way too early in the morning. )

gio89kid

I was thinking the same thing, just more even distribution with four pistons right.

so similar braking forces, just smoother better braking.

So ABS should be good?

Cat Man HHR

What is the total area of all 4 pistons vs the single piston one ? Once that is known then the bore size of the master has to be known.
Being that these cars use a "proportioning valve" Don't know how to give any advice on that.
Here's something to read:
Outlaw Disc Brakes

Blue_SS

Yeah, this is the right idea. The new caliper has additional capability, but the hydraulic pressure will still be the same. You will get more even clamp force as Gio suggested, from 4 pistons instead of 2, but not vastly better braking.

I don't know if the master cylinders are that much different or not, in terms of capacity. I do know that the electronics are the "tuning" for threshold braking. Without running controlled trials with lots of parts, you may never find THE answer.

I don't expect you to run into serious daily issues with your lack of snow and slush in Southern California. Really. One tire on ice, one tire on pavement. Now that's where ABS really matters in keeping you straight.

gio89kid

Ok, crunching numbers from your link CAT MAN HHR.

Brake caliper:
SS non brembo uses a single piston that creates .56sq.in. of piston area.
LS/LT uses a single piston that creates .7sq.in. of piston area.
SS Brembo uses 4 pistons that create 1.12sq.in. of piston area.
That is a .42sq.in. difference in piston area between the the LS/LT and .56sq.in. difference (exactly half) between the non brembo SS.

So you guys are right, equal pressure but more piston area. A .75” taller rotor area plus larger pad size. Thats more friction area, which would result in better braking capability.

But, how much is too much for the LS/LT ABS module algorithm???

Looks like LS/LT models are better off with this upgrade than the non brembo SS guys though based on caliper area.

At least we have done our research, might have to stick to what I have and just paint them for safety concerns.

A good read: https://ebcbrakes.com/how-to-choose-...big-brake-kit/