New booster option for e30 - Bosch iBooster

[kristov]

https://www.ebay.co.uk/itm/Tesla-Model-S-70D-2016-Brake-Master-Cylinder-J121/383277652321?hash=item593d20d961:g:y9IAAOSw8Q5d1h2w

RHD MC if someone needs one.

[nando]

Yeah, I saw that one yesterday, but it seems pretty crusty. Wish we could read the part numbers on it - I doubt it's very expensive new.

Really thinking about one of those CRV boosters though. Could always swap out to the Tesla RHD MC later on. What I like is I could get this put in long before doing a swap... keeping my E30 operable is one of the reasons I've been able to hang onto it through marriage and two kids. :p

[kristov]

Is there any technical documentation on the MC sizes?

[nando]

It looks like the castings are identical, but the flanges are different (the CR-V's is thinner). However, it does unbolt from the main booster housing:

[nando]

You know honestly, the flange isn't that much different on the Model-3 booster. It seems like it would be relatively trivial to move the bolt centerlines less than 3mm over:


I think the pictures are deceiving too. It looks like the connector sticks out to the side, but I think it goes pretty much straight down. Should easily fit within the huge envelope of the original E30 booster, no?

[nando]

Is there any technical documentation on the MC sizes?

If you dig through enough pictures, you'll see stampings of "25" on them.

[hubcapboy]

I want to say I found a RHD photo showing the part number and it was the same as the LHD... it might just be a casting number and it gets a part number when it gets cut one side or the other and assembled with a booster.

...a Tesla part number doesn’t do us much good because we can’t order from Tesla.

I think the model 3 (ibooster gen 2) would absolutely fit anywhere a normal booster would fit. The challenge I have with the n52 intake is extreme, and I don’t think it would fit with that constraint.

[nando]

I'm pretty sure in reality it's no wider than the gen-1 booster. It's possibly shorter?

I have a line on a Honda booster for a song. I'm having a hard time not buying it on a whim.. there's a Model 3 MC for pretty cheap too. for a RHD booster, you're looking at least $500, plus the connectors. I feel like moving some bolts around at less than half that cost could be worth it?

Looking at it again, the ix is kind of oddball, everything is in a different position relative to the RWD E30. I think for sure, the Gen 1 will fit easily. I'm not certain about Gen 2. I think it's a "maybe".

[FredK]

Whoa, this is pretty cool! That test video of the guy in the Delorean was pretty convincing too!

[nando]

Holy cow! FredK in da house!

To give some color to my discussion with hubcapboy - the N52 three stage manifold takes up a shit ton of room. Basically, if the Model S booster clears that by a finger width, it's going to clear pretty much everything else by a mile. IMO, it makes swaps of all kinds a much simpler and cheaper proposition.

I'm still not sure about the model 3 / honda booster. It probably clears a lot of typical swaps (certainly M5X). It could clear the S54. Clearing the N52 is a bigger hurdle.

[hoveringuy]

I just got to try it. Compared to my current brakes, it feels much smoother. No delay.
it feels like when you're riding a nice e-bike, it doesn't feel like the motor is helping but you just have a lot of wind at your back.
The true test will be if it feels uncommunicative or overboosted on the road

[FredK]

Holy cow! FredK in da house!

To give some color to my discussion with hubcapboy - the N52 three stage manifold takes up a shit ton of room. Basically, if the Model S booster clears that by a finger width, it's going to clear pretty much everything else by a mile. IMO, it makes swaps of all kinds a much simpler and cheaper proposition.

I'm still not sure about the model 3 / honda booster. It probably clears a lot of typical swaps (certainly M5X). It could clear the S54. Clearing the N52 is a bigger hurdle.

Yeah, the N52 manifold is huge! I actually went back to boosted brakes, I'm using a Smart ForTwo brake booster, and it rubs on just one protrusion of the S54 intake plenum and can easily be clearanced. Given the size of the N52 plenum, I do not think the ForTwo booster will work, but is an inexpensive alternative for folks looking to retain boosted brakes with an S54.

[FredK]

I just got to try it. Compared to my current brakes, it feels much smoother. No delay.
it feels like when you're riding a nice e-bike, it doesn't feel like the motor is helping but you just have a lot of wind at your back.
The true test will be if it feels uncommunicative or overboosted on the road

Nice! I wouldn't expect much delay as it's a modern electromechanical system. I think especially on an E30 with relatively small F/R caliper pistons, it won't feel that overboosted, but time will tell! I'll def be checking in on this thread, this is a pretty exciting development.

[hubcapboy]

It looks like the castings are identical, but the flanges are different (the CR-V's is thinner). However, it does unbolt from the main booster housing:

This made me realize I didn't mention it earlier: the Gen 1 firewall housing bolts on with two bolts from the firewall side. You can see the bulges where they thread in.

It looks like the Honda just has a steel flange instead of aluminum.

The Gen2 doesn’t seem to have swappable flanges

[nando]

Well, the flange *does* unbolt, it's just a much larger stamped piece, and there are more bolts. But I'll bet the Honda Accord and Model 3 bolt patterns are the same, potentially a cheaper option for other E30 swaps.

Funny enough, there are about as many Model 3s sold a year now as Accords. So really, choices should be plentiful. Who knew the EV revolution would benefit our old car hobby..