e30 m3 S52 swap Brake upgrade question

[Lakis]

1991 E30 M3 now with S52 1999 M3 engine (OBD1)

potentially idiotic question but here goes:

My question is, I am upgrading the front brakes to a Brembo 13'' setup with the 4 piston calipers etc-

I am leaving the rear brakes as is.

Will the ABS system adjust to such a difference; in other words, will I still even get action from my rear brakes.

thanks

JOHN

[gobuffs]

No, the ABS will not "adjust". But, it depends on the size difference in the calipers per swap to that post swap. You may need to install a brake bias adjuster.

[flyboyx]

i can't remember if the e30 m3 has the larger diameter master cylinder, but if it is the little one, it will help you out a lot to upgrade.

[asubimmer]

iirc the m3 has the larger master

[Dominic49]

what would the abs have to adjust to? all it looks for is if a wheel stops moving in relation to the other 3 wheels. it will pulse the single channel it sees lockup occur at regardless of the brake size.

[erik325i]

No, the ABS will not "adjust". But, it depends on the size difference in the calipers per swap to that post swap. You may need to install a brake bias adjuster.

Isn't it frowned upon to install a brake proportioning valve in the front brakes?
I thought they were only supposed to be used in the rear.

Erik

[z31maniac]

Isn't it frowned upon to install a brake proportioning valve in the front brakes?
I thought they were only supposed to be used in the rear.

Erik

This is correct. You never want to decrease front braking power, only be able to adjust rear.

[gobuffs]

iirc the m3 has the larger master

M3 has a 23mm brake master. A common upgrade is the 25mm from a 7 series.

Isn't it frowned upon to install a brake proportioning valve in the front brakes?
I thought they were only supposed to be used in the rear.

Erik

Never said to put a brake porportioning valve on the fronts. A brake porportioning valve controls the bias front to rear.