For starters, this article is written with complete elimination of the booster in mind. No other forms of assist. Just straight up you and that pedal.
Fair warning: I'm not 100% done with research on this topic. My solution works but leaves something to desire.
Video supplement!
No worky? https://www.youtube.com/watch?v=Q28U_iDB6Vg
Why would you want manual brakes?
Some people will say that it's because race car drivers prefer it. Really, 99% of the time I've seen it for an E30, it's to clear space for a motor swap. My personal preference is to retain vacuum assisted brakes if at all possible. Sometimes, you just have to work with what you have.
What am I losing by deleting the booster?
Pushing a lot of hydraulic fluid to the calipers takes a good amount of force. By removing the booster, you are removing all assistance to help you press harder on the pedal. A 100% pure delete with no other modifications would make a car nearly impossible to slow down in regular day to day driving.
How do I fix this?
Move the clevis mounting point to the pedal to give more leverage (stock IIRC is a 4:1 ratio)
Higher friction brake pads
Upgraded calipers (rx7 fronts, wilwood calipers, etc)
Smaller bore master cylinder
Just one of these may or may not be enough to get back to factory feeling brakes. It's best to consider all of these options and find what works best for you. I'm currently researching options while retaining factory brake calipers as this would be the most costly "fix".
How to do the swap
This writeup is written with the Sikky delete kit in mind (comes with the LS power lines in my case). If you have questions about the kit, email me at (yoshi at sikky.com) and I'll help you out.
Parts list:
LS high and low pressure PS lines (regular E30s will not use this)
AN lines with adapters from the master to the ABS unit
Steering rack stock to AN line adapter fittings with crush washers
Adjustable plunger for the pedal
CNCed aluminum adapter bracket
First step is to go ahead and mount the master to the adapter bracket. The relocation is to the top right most of the firewall without needing body modifications. The 4 bolts for the adapter to the firewall are already pressed in so you won't have to hold the other side when bolting this sucker to the firewall.
Next step is to attach the lines themselves. The longer line goes to the back of the ABS unit (closest to the headlights) then to the front most of the master cylinder ports (closest to the headlights). The shorter line goes to the back of the ABS unit and the plug on the master cylinder closest to the firewall. There should be plenty of room for the lines to wiggle around. The AN lines are 13mm but I think the adapter itself is 15 or 16mm
Here's waht my bay looks like after that.
Next is to put all 4 (13mm) nuts to connect the bracket to the firewall. A good tip is that there is already a hole in the brake pedal to allow an extension through for the top left most nut.
Next step is to attach the supplied plunger to the clevis. Image is there to show what parts go where. You'll need to take the clevis off first and spin it on before putting everything in.
If you aren't LS, you can basically stop here. Just fill the system with fluid and bleed the brakes. I've been driving around like this for a week now.
For the PS lines, install the adapters to the rack.
Now install the high pressure line loosely so it's still movable.
Install the high pressure line (18mm) that goes to the top port FIRST and tighten it down to spec. Then install the lower hose (18mm again).
Finally connect the low pressure back to the res. Mine goes to a cooler first so it looks different in this picture. Refill with fluid and enjoy!
More to come on the manual brakes. I'm swapping to a smaller master cylinder to try to get back to factory feel. The quicker solution is to likely pick up some spec E30 brake pads.
Fair warning: I'm not 100% done with research on this topic. My solution works but leaves something to desire.
Video supplement!
No worky? https://www.youtube.com/watch?v=Q28U_iDB6Vg
Why would you want manual brakes?
Some people will say that it's because race car drivers prefer it. Really, 99% of the time I've seen it for an E30, it's to clear space for a motor swap. My personal preference is to retain vacuum assisted brakes if at all possible. Sometimes, you just have to work with what you have.
What am I losing by deleting the booster?
Pushing a lot of hydraulic fluid to the calipers takes a good amount of force. By removing the booster, you are removing all assistance to help you press harder on the pedal. A 100% pure delete with no other modifications would make a car nearly impossible to slow down in regular day to day driving.
How do I fix this?
Move the clevis mounting point to the pedal to give more leverage (stock IIRC is a 4:1 ratio)
Higher friction brake pads
Upgraded calipers (rx7 fronts, wilwood calipers, etc)
Smaller bore master cylinder
Just one of these may or may not be enough to get back to factory feeling brakes. It's best to consider all of these options and find what works best for you. I'm currently researching options while retaining factory brake calipers as this would be the most costly "fix".
How to do the swap
This writeup is written with the Sikky delete kit in mind (comes with the LS power lines in my case). If you have questions about the kit, email me at (yoshi at sikky.com) and I'll help you out.
Parts list:
LS high and low pressure PS lines (regular E30s will not use this)
AN lines with adapters from the master to the ABS unit
Steering rack stock to AN line adapter fittings with crush washers
Adjustable plunger for the pedal
CNCed aluminum adapter bracket
First step is to go ahead and mount the master to the adapter bracket. The relocation is to the top right most of the firewall without needing body modifications. The 4 bolts for the adapter to the firewall are already pressed in so you won't have to hold the other side when bolting this sucker to the firewall.
Next step is to attach the lines themselves. The longer line goes to the back of the ABS unit (closest to the headlights) then to the front most of the master cylinder ports (closest to the headlights). The shorter line goes to the back of the ABS unit and the plug on the master cylinder closest to the firewall. There should be plenty of room for the lines to wiggle around. The AN lines are 13mm but I think the adapter itself is 15 or 16mm
Here's waht my bay looks like after that.
Next is to put all 4 (13mm) nuts to connect the bracket to the firewall. A good tip is that there is already a hole in the brake pedal to allow an extension through for the top left most nut.
Next step is to attach the supplied plunger to the clevis. Image is there to show what parts go where. You'll need to take the clevis off first and spin it on before putting everything in.
If you aren't LS, you can basically stop here. Just fill the system with fluid and bleed the brakes. I've been driving around like this for a week now.
For the PS lines, install the adapters to the rack.
Now install the high pressure line loosely so it's still movable.
Install the high pressure line (18mm) that goes to the top port FIRST and tighten it down to spec. Then install the lower hose (18mm again).
Finally connect the low pressure back to the res. Mine goes to a cooler first so it looks different in this picture. Refill with fluid and enjoy!
More to come on the manual brakes. I'm swapping to a smaller master cylinder to try to get back to factory feel. The quicker solution is to likely pick up some spec E30 brake pads.
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