New booster option for e30 - Bosch iBooster

[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.

[almostacrayon]

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

[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

[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?

[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.