How to: Convert to boosterless/manual brakes

From the tranny down to wheel bearings.
User avatar
Yoshi
Site Admin
Posts: 9087
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

How to: Convert to boosterless/manual brakes

Postby Yoshi » Fri Dec 11, 2015 5:57 pm

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!


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.

Image
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

Image
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.

Image
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

Image
Here's waht my bay looks like after that.

Image
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.

Image
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.

Image
For the PS lines, install the adapters to the rack.

Image
Image
Now install the high pressure line loosely so it's still movable.

Image
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).

Image
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.
Image
Status: HG repair. 488wtq though!
User avatar
M20_fever
Größter Vorsitzender
Posts: 11026
Joined: Fri Feb 27, 2009 1:28 pm
AntiSpam: No
Location: Northern IL

Re: How to: Convert to boosterless/manual brakes

Postby M20_fever » Fri Dec 11, 2015 6:02 pm

I've driven cars with manual brakes, it sucks ass.
Image
Midwestern Councel C Prepared class champion 2012
North Suburban Sports Car Club C Prepared class champion 2012
HSAX Instructor

GET YOUR E3P GEAR HERE: http://www.cafepress.com/e3pgearshop
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Convert to boosterless/manual brakes

Postby ten2doyle102 » Mon May 23, 2016 2:39 am

My buddy Jermey and I were just discussing this earlier since I was having issues with my booster today. I'd have to assume they'd be better than what I have going on in mine with now! lol!
Image
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Convert to boosterless/manual brakes

Postby ten2doyle102 » Mon May 23, 2016 2:40 am

Oh crap.... wow, I just awoke this from the grave.... my bad. I guess I need to get on here more often. :(
Image
User avatar
Yoshi
Site Admin
Posts: 9087
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: How to: Convert to boosterless/manual brakes

Postby Yoshi » Mon May 23, 2016 12:08 pm

Even with the increased pedal ratio, I wouldn't recommend the manual swap with everything else being factory. I do have my VW master swap but the pedal is spongy and has to be to make up for the lack of assist. IMO, the only way to do a good non assisted brake setup is to also upgrade your brake calipers at the same time.

Don't worry about waking old threads. They're all old threads here lol.
Image
Status: HG repair. 488wtq though!
User avatar
M20_fever
Größter Vorsitzender
Posts: 11026
Joined: Fri Feb 27, 2009 1:28 pm
AntiSpam: No
Location: Northern IL

Re: How to: Convert to boosterless/manual brakes

Postby M20_fever » Mon May 23, 2016 1:08 pm

even with the rx7 brakes I wouldn't want manual only. I have some plans for the e30, keeping that to myself for now, but options for brake assist are on my list of things to investigate.
Image
Midwestern Councel C Prepared class champion 2012
North Suburban Sports Car Club C Prepared class champion 2012
HSAX Instructor

GET YOUR E3P GEAR HERE: http://www.cafepress.com/e3pgearshop
User avatar
Yoshi
Site Admin
Posts: 9087
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: How to: Convert to boosterless/manual brakes

Postby Yoshi » Mon May 23, 2016 2:50 pm

The nice thing about the RX7 upgrade is the larger disk. Really, increasing rotor diameter exponentially raises braking power. If I were to look into braking options for my E30, I'd do the E36 M3 or E46 330 brake swap and retain the factory E30 master. That's just a ton of money just for brakes. I'd have to redo my secondary caliper system and get new front coilovers. That's easily in the $1500 range just to get back to factory feeling brakes.
Image
Status: HG repair. 488wtq though!
User avatar
M20_fever
Größter Vorsitzender
Posts: 11026
Joined: Fri Feb 27, 2009 1:28 pm
AntiSpam: No
Location: Northern IL

Re: How to: Convert to boosterless/manual brakes

Postby M20_fever » Thu May 26, 2016 2:16 pm

For that much you could just get a legit BBK from Lee and not deal with all the BS.
Image
Midwestern Councel C Prepared class champion 2012
North Suburban Sports Car Club C Prepared class champion 2012
HSAX Instructor

GET YOUR E3P GEAR HERE: http://www.cafepress.com/e3pgearshop
User avatar
Yoshi
Site Admin
Posts: 9087
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: How to: Convert to boosterless/manual brakes

Postby Yoshi » Fri May 27, 2016 3:44 pm

Yea. all options wind up being about the same amount in the end. Not really feeling it honestly. F it.
Image
Status: HG repair. 488wtq though!

Return to “Drive Line”

Who is online

Users browsing this forum: No registered users and 4 guests