October last year I searched for a silent vacuum pump. The Mes Dea pump I found was relatively quit, but in the end it’s still noisy. I really did not like the idea that once you enable the car, the first thing you hear is prrrrr from the pump building up vacuum.
Searching for power brakes without vacuum
Therefore I conducted a search for power brakes without the need for a vacuum pump.
In the US at ABS Powerbrakes you can buy an “Electric High Power Electric Brake System” with a master cylinder, hydraulic accummulator and a pump. Is around 1500 euro’s so not an option for me.
Furthermore there are various ‘hydroboost’ systems in which oil pressure from the steering pump is being used for power braking. Since I do not have an electric equivalent of that onboard already it is not really an option for me.
Henri (thanks!) suggested that the first type Ford Scorpio (1985-1994) had an electric brake booster. I found a page where someone started implementing that system in his Taunus. Advantage is that it is quite a stand alone system and I could even also implement the ABS.
In terms of weight of the car that could match quite nice. However I could not find any of the components new. And searching for and using 25 years old parts was not really an option.
I also looked at the systems used in a Lexus since they have a ‘drive by wire’ philosophy. I found interesting offerings of parts advertised as ‘brake booster‘ which upon request were told to be 100% electric. However after looking at the Lexus part manuals it turned out to be only a small part of a larger system. In the end I concluded the part from the Lexus RX 450H was only a sensor so also not an option.
Finally the iBooster made by Bosch. I found it before and it’s an impressive piece of engineering.
It is being used in later Tesla Model S cars with Autopilot, in the model X, Chevrolet Bolt and Malibu and the Honda CR-V. After some more research the below video’s made me decide on the iBooster:
iBooster Bench test by Jeff
He will be using the iBooster in his Teslorean project (Delorean with Tesla technology).
iBooster in a Delorean
And a Delorean with combustion engine with a modern brake feel while using an iBooster from a Tesla.
So in the end I decided to use an iBooster. The one from a RHD Tesla model S would be the best fit since the brake lines are in that case not at the battery box side.
Bosch iBooster from Tesla model S
So I searched for a brake booster from a 2014+ Tesla model S. I could not easily find a complete unit from a RHD car so bought a LHD instead. It will replace the original single master brake cilinder, the Lockheed brake booster and the vacuum pump and vacuum tank.
Identical to the way Tesla used it with the ECU towards the battery box did not fit.
From other applications I know that the orientation of the iBooster itself is not important. Therefore I rotated the master cilinder by 180 degrees and that fits a whole lot better.
He needs to be a bit further towards the front to create enough room for the steering rod and I need to create some space near the inner wing for the ECU. So I designed an adapter.
I had the two flanges cut at 24/7 Tailorsteel and the large tube I shopped at AJ Speedshop.
The large tube is 3″ exhaust pipe and I bought some more 1 3/4″ for the heater as well.
The front flange from the original master brake cylinder will be used. Modified it a bit in the lathe.
Which made it flat and perpendicular and exactly fit within the small tube.
The make sure it’s not only being supported by the pedal box but also in the front I designed a flange.
As soon as the parts arrived I could continue.
Cut the tube and stitch welded it to be able to do a test fit.
Worked out nice.
Checked the clearance with the hood, also good to go.
So I finalised the welds from the adapter and added the front support.
Made an extended push rod.
An that one also fits.
Another part is ready to be mounted.