Bosch iBooster Retrofit

[81dmc]

Just to update this

I will be replacing the Tesla master cylinder with one from an Audi A3 e-tron RHD. Bore is smaller at .92” vs Tesla 1” p/n is5QE-611-015-AK. Got a good deal on it, and it’s on its way from Britain. Will report back after testing.

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[81dmc]

So I got the VW/Audi brake master. This master is much more suitable for the DeLorean.
LH is VW and RH is Tesla.
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Bore is in fact smaller and the exit ports are on the correct side (because it is a RHD master). Exit ports are also DIN/Bubble flare but with M12x1.0 fittings.

So it can bolt into the car with just adapters. Of course, my lines are already modified, so I’m choosing to use m12x1.0 line nuts for the 3/16” line.
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Model Y reservoir also fits wonderfully even with outlet orientation (this worried me).
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[81dmc]

Went in beautifully.




Also purchased the brake sensor plug from mouser. Barely has any room, but it works.



Will pressure test when I receive my new iBooster plug (old one was sealed with RTV).

[82DMC12]

DPI sells replacement brake lines which are DOT flex hoses. Josh has a kit that replaces all the hard lines on the entire car with these other hoses that use banjo bolts in some places to connect to the distribution blocks. That would allow you to use a master cylinder of any type no matter where the outlets are located.

[81dmc]

DPI sells replacement brake lines which are DOT flex hoses. Josh has a kit that replaces all the hard lines on the entire car with these other hoses that use banjo bolts in some places to connect to the distribution blocks. That would allow you to use a master cylinder of any type no matter where the outlets are located.

That wasn’t the reason for this change… But I will say, I’m very sure the Model Y reservoir wouldn’t work with the ports on the other side as it would interfere with the level sensor. Also making your own hard lines and flaring them is extremely easy, and they don’t crack, break, or expand like the flex hoses…

Really I only did this swap because this new master has a smaller .92” bore. Tesla is 1” which made braking a little weird. For reference, I think this new master has the same bore as the old crossref Saab master. Factory DeLorean for sure is .81”

[82DMC12]

That wasn’t the reason for this change… But I will say, I’m very sure the Model Y reservoir wouldn’t work with the ports on the other side as it would interfere with the level sensor. Also making your own hard lines and flaring them is extremely easy, and they don’t crack, break, or expand like the flex hoses…

Really I only did this swap because this new master has a smaller .92” bore. Tesla is 1” which made braking a little weird. For reference, I think this new master has the same bore as the old crossref Saab master. Factory DeLorean for sure is .81”

Sorry, when I said Flex hoses I mean they are like the replacement stainless braided fuel lines. They most certainly would not swell or expand under braking or else DPI would not be using them.

[81dmc]

Want to update this again.

After the VW master cyl install, I was having issues with the Tesla iBooster. If I didn't preload the control rod, it would click. If I put just 1mm too much preload pressure, the unit wouldn?t turn on sometimes and would often shut off randomly. Dangerous.


So I bought Honda CRV iBooster and tested it. It doesn't have that preload issue. In fact, the CRV iBooster needs ZERO preload to start. This of course is way better for safety.

First thing is the Tesla iBooster mounting plate must be swapped to the CRV booster. Or just make a spacer for the CRV mount plate. This is necessary as it gives clearance between booster and fuel tank.


One more thing is the CRV master sits 7mm more inside the booster. This means to use a Tesla or VW master on the CRV booster, you need two things.

So first, the control rod must be lengthened. This can be done by unscrewing the CRV control rod to proper setting and adding a jamb nut to be sure it doesn't move, or just find a control rod from a Tesla Booster. Since I had a Tesla booster, I went with the latter.

Next, you need a 43mm ID x 55mm OD x 7mm Wide spacer to place between the master and the booster. This allows the master to push slightly against the iBooster spring. This is required as the clip holding the spring isn't designed to retain it under full compression.




So far, it seems the CRV booster has a better feel to it. Still have yet to test on the road as my car needs a roof...and doors. I believe the function will be better though.

[Reinsch]

here are some photos of Model S, RHD ibooster (gen1) with Model Y reservoir tank. it clears the cover, but the hole is in the wrong place, so need to get a piece of plexiglass and cut it to shape and locate the hole in the correct place.

All works each time I power up the car, really sharp brakes, and so far tested around the block as the car is not yet finished.