i have an 89 civic si and i recently upgraded my brake system with the following:

91 crx si rear trailing arm
99 si rear caliper's and rotor's
front 10.5' 99 si caliper's and rotor's and knuckles
91 crx si mastercill
91 crx siperportioning valve
nuspeed stainless lines

i dodnt touch the brake booster is the 89 si any diff from the 90-91 booster? and if so should i get an integra booster because of my integra sized brakes on all 4 corner's?
thanks just didnt think about the booster till today.
i never hear people talk about doing the upgrade so i hope there the same.

-larry

 

you should get the integra booster. it'll match your integra altezzas on your hatch.

 

4gsicivichatch, I don't think you'll need it. I would try the current setup first, and see how it handles. But I don't see you having any problem with that setup.
I am currently using the CRX HF MC, and BB with the Teg front brakes with no problem.

 

You don't need the booster, but you should look into taking out that Si master cylinder and swapping out for a 4 door EX unit. Master cylinders from the DX/LX/... were all 13/16", the Si's with the rear disc brakes were supposedly 7/8", and the EX had a 15/16" because it has the large front brakes.

The EX MC will bolt directly to your booster (and is the same part number from honda as far as I know).

 

you shouldn't need the booster, all that does is assist you through vaccum.