New booster option for e30 - Bosch iBooster

[e30mclow]

I'll throw my hat into the ring here, as I've just finished what appears to be successfully getting the iBooster going.

I have been booster-less for about 4 years since going 1JZ, then subsequently 1.5jz. I was using the Massive booster delete and a VW Fox dual circuit master cylinder to compliment by e46 325i brakes front and rear.
Pedal feel was actually very nice, as I had spent quite some time playing with cylinder sizes. It has been years, but I think I ended up with a 19mm master and it gave great pedal travel and worked awesome with track pads and race fluid.

Not until going to a 2jz block could I really look at the iBooster, as with the shorter 1jz block, the inlet manifold would absolutely conflict with it.

SO, here is what I used.

Tesla/Bosch iBooster, which came with a cut harness. I scored it locally for only $150. As mentioned several times in the thread, it is the same bolt pattern as the e30 pedal box.


I knew the 25mm master wouldn't work for me, given the port locations and the bore is a little big. I wanted a 23mm master that has the ports on the opposite side, but had as close to the Tesla proportions as possible. After probably 3hrs of opening almost every master cylinder tab in RockAuto, I took a gamble on a 2017 Mini Cooper master cylinder, specifically the "Sport Brake" option.

Part Number: CENTRIC 13034123


Before you get your hopes up, it DOES NOT FIT. The RHD Tesla 25mm may be a better option for you, but with my brakes, it seemed 23mm was going to be worth the effort.

Issue 1: The mounting points (bolt holes) are spaced differently to the Tesla. You need to oval pot the holes in the Mini master with a dremel/file so as to bolt it up.

Issue 2: The offset from the mounting face of the master cylinder, to the start point of the piston is different. Meaning, once you do the above and bolt it up, you will end up compressing the piston by about 6-7mm. No good. You need to made a spacer to avoid drastic preload on the master. I bought some 1/4" aluminum plate off of Amazon and cut out a simple spacer. There is some adjustment on the pushrod in the iBooster, so I was able to set the thing with the same verrry minor preload as the original master, which is only about 1-1.5mm.







To set the same preload, I just popped an oring on the tesla unit, bolted it up, and then measured the stroke through which the ring was displaced when bolted. Like the rear shock of a mountain bike.


Issues 3: The bore of the Mini master external casting doesn't sit hubcetricly (word?) within the iBooster housing. Meaning you need to find some sort of hubcentric ring. I did, and it worked out perfect. I used a sleeve from a hydraulic ram. I searched and came up with this and it makes a very snug fit. https://www.oringsandmore.com/ and search for part # MWBP50552025. It just snaps on over the casting of the master that slides into the iBooster.




Issue 4: There is a little nubbin on the Mini master that conflicts with the inside of the iBooster. I just ground it down.

So with that, I was able to put it all on the car. Tiiiight.


For a reservoir, I used an bmw 2002Tii reservoir, some hose from CIP1,com, and bungs from a VW master that took small nipples/ports.
To hold the bungs down, I made a clamp or sorts.



I've since put some washers under the clamp to get 360 degree force down on the bungs.

For the lines, I just got some new ends and flared my own copper lines.
I only got the car back driving yesterday as I had a bunch of other stuff ripped apart.


The pedal feels perfect while driving! Nice gradual assistance, but can brake wayyyy harder than before.
Prior to driving it, and while statically feeling the assisted pedal, I thought I'd have a case of over-assistance, but it is great.

Wiring has been covered before so I didn't get into that.

So far, so good!



EDIT!

The clevis! An e30 clevis threads directly onto the booster, but it too short by about 7-8mm (measure for yourself).
I just got a coupler nut, some threaded rod from a bolt, and welded something up that adjusts easily.

[Striker01]

If you are planning on using the Chevy Bolt master the lines are different from what was posted for the Tesla master cylinder. Best I can tell they are M12 x 1.5. I couldn't find any info online so I ordered a stock line from the dealer.

[dylhaus]

I was able to purchase the RHD model S brake master from a place in the UK, but it's pretty expensive all-in-all. I think it ended up being ~$150USD for the brake booster, ~$200USD for the RHD master after needing to use a courier to pick up, and ~$80USD for the connector kit from Tulay's. I expect to need to make a longer clevis fork as well, and get the threading adapters for the current lines (or make new lines). Based on the placement, I am not sure if I will need to change my intake from the M50 manifold since the S50 is sitting at the same angle as the M20, but I'll check on the install

EDIT: part arrived and they didn't include the reservoir ffs

[dylhaus]

This is what I have been wondering, how to "talk" to the booster to get it the information it need to function right. I am sure you can just turn it on and it would work in a fail safe mode. But to truly tune it in terms of pedal effort or brake bias, it probably needs more information from other sensors. I would like to help if needed, I am a embedded software engineer and could hopefully put my skills to use in this endeavor.

I would love for failsafe mode to be good enough to use, but I'm not holding my breath. I believe we'll need to work in CANoe, CANalyzer, or CANape, and I'll have access to each of them through my job, as well as a CAN case to interface with the module. I'm going to probably mock it up on a bench before installing it into the car if I have the time. The site I was thinking of was EVcreate but I was mistaken and they just reference the .dbc files, and not the .cfg

EDIT: reading through that link above, I found someone who makes an ECU for the ibooster here. I haven't read all of the documentation but it looks pretty good

[jbontke]

Purchased a tesla iBooster without a MC today and trying to work with a parts supplier in the UK for a RHD MC to put this in my s50 325ix. Will also be messing around with CAN when it arrives and updating here and on my build thread. I ordered a Chevy bolt iBooster, and it looks like more of a headache than this route so I'm sending that back to LKQ. Harness components and diagrams are available through Tulays Wire Werks, and I think there's a small repository of .cfg files I have saved somewhere for the Tesla braking CAN setup.

This is what I have been wondering, how to "talk" to the booster to get it the information it need to function right. I am sure you can just turn it on and it would work in a fail safe mode. But to truly tune it in terms of pedal effort or brake bias, it probably needs more information from other sensors. I would like to help if needed, I am a embedded software engineer and could hopefully put my skills to use in this endeavor.

[dylhaus]

Purchased a tesla iBooster without a MC today and trying to work with a parts supplier in the UK for a RHD MC to put this in my s50 325ix. Will also be messing around with CAN when it arrives and updating here and on my build thread. I ordered a Chevy bolt iBooster, and it looks like more of a headache than this route so I'm sending that back to LKQ. Harness components and diagrams are available through Tulays Wire Werks, and I think there's a small repository of .cfg files I have saved somewhere for the Tesla braking CAN setup.

[Striker01]

I bought a unit out of a 22 Chevy bolt for about $130, the Tesla ones are expensive for the same thing and the Bolt master will provide more room unless you can get a RHD Tesla one, I'll just come up with something like warzywko did for the reservoir. The firewall pattern is different but the studs and input threads are the same as an e30. I had a local shop fill and drill the flange to match the e30 firewall and pedal box.

They can CNC a new billet flange but the first one would be about $300, then I'd be right back to Tesla prices. I had them fill and drill but if enough guys are looking for one of these I will have them draw it up and it should get cheaper if enough of us want a pretty one.



The input shaft is about an inch shorter than the e30 booster and the threaded portion is shorter as well so I had them make a new clevis. It's about 1/16" too long but on the firewall it should be perfect. It's threaded all the way just like my original so I can shorten it a little if needed.

[Markus]

Hi,

I have not tested it, and its possibly unsafe, but in theory throwing in a restistance in the series for main power for a electric motor should reduce its power output.

Its more likely a master/caliper ratio problem: smaller master will give you longer throw, however, it will also allow a small force on the pedal to give a higher force output of the calipers. 23mm is for small calipers. Its even smaller than the e-golf one which is 23.81.

I suggest trying the master from the Tesla s. Its 26mm. Tesla has both gen 1 and 2 iboosters, so try and get the correct one in case they are not same.

You can calculate the ratio of the tesla or other cars master/calipers, and check if its going to somewhat match your setup first. Bosch produce masters for a bunch of cars, its possible there are other ones out there we dont know about that fit or can be made to fit, but check tesla one first.

My setup is also quite sensitive which is fine for the streets, but not like you are describing. It took some getting used to. This is running on the e32 740i brakes

If you try it, please keep me updated.



Also, do you have some info on brake bias? im running the original 2-door rear brake bias valve, and i feel like i almost dont have rear brakes. What are people running?

[warzywko]

Hey every one I've been a lurker for a long time so this is my first post. I'm on my 3rd E30 , previously both were 20V swaps .
Currently I have a 2JZGTE VVTI swap with a PMC adapter with a GS6-53BZ 6mt out of a 335i.

I'm currently running the Model S booster . I was unable to clear the Model S master so I got a Chevy Bolt Ibooster as the outlets are rotated 90*. The Bolt Ibooster does not straight bolt on to the fire wall but the Iboosters of this gen are all the same physically , as in the mounting flange for the master is the same and so is the mounting flange for the Fire wall adapter.
I still had to run it upside down.
Model S master

Bolt master

I've Managed to make it work with 1/4" of clearance but had to make a custom reservoir and use barb adapters with custom retainer plate to keep it from popping out







Anyway I'm kinda dealing with an issue of Over performance if you can call it that.

I'm running Willwood BBK 6 piston front and 4 piston rear.
when I lightly tap the brakes rolling 5-10mph you can knock your teeth out on the steering wheel that's how hard the car stops.
The brakes are super sensitive , not sure if this is due to the different master or the BBK or the combination of both.

I Know there's not that many people run this kit but does anyone have any suggestions?
I wonder if the module is programed different for the Model S vs the chevy bolt as in More assistance for the much heavier car.

I do have the whole Chevy bolt Ibooster and I'm planning to swap that in in place of the Model S booster and hope that its programmed for less assistance for the lighter car.

Also the Chevy bolt master has a marking on the body P and S I'm assuming that's Primary and Secondary cylinder , so I have the P connected to the front and the S to the rear brakes. Maybe that is backwards , I could not find any info on the master.

Any info is appreciated

[almostacrayon]

where are ya'll tapping into for 12v switch?

[spiDmang]

S54/iBooster update: It is NOT possible to run an iBooster with a CSL style CF airbox. The master cylinder comes into contact with the airbox. The next option is to use the Race German Booster relocation template to slot the booster over 1/2 inch. But from eye balling it, it doesnt seem like that solution will work either.

[tyeler18]

So your post reminded me that I've been meaning to buy these for my E90 booster (except M10 bubble to M12 bubble).
While doing so, I noticed that the bubble-bubble version have A = 16mm instead of 12mm. Not sure why these are so much shorter, but maybe there's a longer set?

They don't show any in their catalog. At this point though I don't think it matters. I think im scrapping this project. I tried to test fit this yesterday and the sikky mounts put the engine way too close to the firewall and centered in the bay to make this work safely. Ryan's offset firewall mount is the only way I can see this even fitting in it's space and even then it's so close to the head and headers that I'm fairly certain the pedal travel sensor would melt down during an HPDE run if it even lasted beyond some spirited street driving. I have no problem cutting the car up to make it work but I don't see any way to do that without an extensive amount of work to the firewall.

[Northern]

So your post reminded me that I've been meaning to buy these for my E90 booster (except M10 bubble to M12 bubble).
While doing so, I noticed that the bubble-bubble version have A = 16mm instead of 12mm. Not sure why these are so much shorter, but maybe there's a longer set?

[tyeler18]

Here's the right-hand-drive master with some adapters that I believe will work. I haven't had the e30 lines connected, but I believe I have the fittings correct on either end.

Is anyone using these adapters successfully? I picked these up since theyre one of the few 12mm inverter to 10mm bubble adapters out there but they seem to short to seat. I actually cut the flare off the tesla line to put in as a fake flare fitting and they still seem to be tightening up on the threads not on the flare. Planning to bolt the booster in this week and I feel like these are going to leak at the threads.

[hozzziii]

Has anyone undertaken the project to understand the CAN signals so that the booster response can be adjusted? It's just in fail-safe mode by default.

Well Lars, being the genius he is, again, has done some digging into it on his blog:

https://www.evcreate.nl/ibooster-can-bus/