Braking system upgrades

cdavie2002

cdavie2002

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Looking to start from scratch and go for wilwoods or brembo calipers. The hard part however is the actual hydraulics, has anyone upgraded the MC and/or booster set up?

What did the racing csl have?
 
When my e34 conversion was done the brake booster was swapped to a hydrualic one.
I think the only issue was that the entire pedal setup had to be removed to shorten something.

Parts are a mix of E34 and E28 but has worked well for 10+ years. I am pretty sure my problem in the posts below do not stem from that

I can supply some pics and so if you like.
 
Im obviously not up to speed, hydraulic brakes, is that not normal? Pictures would be appreciated, yes please.

Plus this is new to me, what is it?
Powerbrakeunitdepression.png

22.png
 
There are two main systems used in BMWs over the last 40 years for power braking: engine vacuum and hydraulic pressure. The most common system uses a device called a brake booster, which uses the engine vacuum pressure in the intake manifold to create a pressure gradient over a large membrane, increasing the force exerted on the master cylinder when you press the brake pedal. The other system is purely hydraulic, and uses a pressure accumulator (usually called the "brake bomb") driven by the power steering pump, which has 4 feeds in/out as a result. (2 for steering, 2 for brakes) The pressure accumulator is connected to a valving system which exerts additional pressure (from the accumulator) on the master cylinder when the brake pedal is pressed.

The pictures you are showing are of two separate braking systems: a brake booster-actuated one (shown in Figure 34/7) and a system using two smaller master cylinders with smaller brake boosters shown in Figure 34/18 and 34/7. I have never seen this dual system in person before, but it was apparently used only in Europe. The vast majority of BMWs use the system shown in Figure 34/7.
 
Good info, cheers! I understand the vacuum booster setup as i have that in my e21.

Not sure which system the e9 has as the engine bay is empty and i have not looked through all the spare parts yet.

Just had another upgrade thought: ABS, has anyone retrofitted an ABS system or knows how to go about it?

Chris
 
cdavie2002 said:
Good info, cheers! I understand the vacuum booster setup as i have that in my e21.

Not sure which system the e9 has as the engine bay is empty and i have not looked through all the spare parts yet.

Just had another upgrade thought: ABS, has anyone retrofitted an ABS system or knows how to go about it?

Chris
Click to expand...

Are you talking about an aftermarket ABS system, or an OEM one? Any ABS system will require significant work, as the car was never designed to have individual wheel speed sensors. Also, systems that are easiest to retrofit will also have the worst performance, as they will lack the information processing and additional inputs more modern systems have.

In general, given the weight of the car and how "overbraked" it is already, a retrofitted ABS would be inferior to better driver skill.
 
So is the diagram 34/7 of two seperate systems or do they join together somehow? My car is a RHD.

With regard to ABS, it wasjust a thought.
 
cdavie2002 said:
So is the diagram 34/7 of two seperate systems or do they join together somehow? My car is a RHD.

With regard to ABS, it wasjust a thought.
Click to expand...

The two systems shown in Figure 34/7 are completely separate. They would not be in the same car at the same time. They share the same hookups to the rubber brake lines, which is why they are shown on the same diagram for those part numbers.
 
cdavie2002 said:
Anybody fitted a pedal box and gone boosterless?
Click to expand...

My track car is "boosterless" and although RHD now, was originally LHD so none of the servos (thats what the big strange-looking chunks are in your fotos) Often the track cars were boosterless, but for longer events would have a booster or even PS added (???!?!?)

If you're over "there" with an RHD car, and want the stocker RHD setup, call Munich Legends, I cannot imagine where else you'll be able to find servos today, seems they were all being "blown out" price-wise a few years ago by many of the other "usual sources"

Good luck!
 
Im just thinking out loud about all my options regards brake upgrades.

I was curious about a racing pedal box giving me seperate front and rear circuits, and ofcourse then running with no booster. Would this be suitable for road use or just track? What are the differences?

Thoughts/ideas all welcome?

Chris
 
brake upgrade

I'm using 840 calipers and rotors up front and 540 rotors and boxter rear calipers on the back. I switched to 530 hubs on the front and also used 530 axles on the back. I had to make centering rings for the front hubs to hold the rotors centered and then modified the rear swingarms to accept some 535 backing plates, because the parking brakes are bigger on the 540 rotors. I built caliper adaptors for both the front and rear. I'm going to use the Tilton dual master cylinder balance bar assembly, and Tilton worked out the sizing and said that I need a .700 inch front master cylinder for the front and a .825 inch master cylinder for the rear. This setup gives lots of clearance for installing my M5 engine and should put some real stopping power in this car. Good luck with your project. Leroy
 
Hi Leroy.

To post pictures i use www.photobucket.com

You set up a free account, follow the instructions to upload the pics you have from your computer to the website. Once uploaded the pic will be given an (image code). You simply copy and paste that code into the post.

Hope this helps, id love to see some pics of your brake upgrade!

Chris
 
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