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iBooster Electric Brake Booster

I've been scouring my ass off and finding this master cylinder has not yeilded anything yet.
There are a literal TON of theses setups for sale by all the usual suspects, but they are pretty generic, no brand name etc.
Scott Drake sells one already configured for a mustang.
Spent some time trying to find more information and I have yielded the same results. Lots of companies selling the same kit but with it branded in their own name.

I did find ZF makes some master cylinders called "Boosted Master Cylinders". But there's not a lot of information related to price, only to send in inquiries.
Boosted Master Cylinders | ZF MICO

The 3rd gen 2010-2015 Prius uses a similar master cylinder. I believe the master cylinder bore is about 7/8" which isn't huge but might work for a smaller weight vehicle. Hydraulically the master cylinder uses a spool valve to increase master cylinder pressure. Only problem is that the master cylinder is bolted to the ABS unit. It looks like they can be separated but then a machined adapter would have to be made to replace the ABS unit and seal off the master. Next time I'm at the junkyard I would like to grab one for cheap and tear it apart.

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Spent some time trying to find more information and I have yielded the same results. Lots of companies selling the same kit but with it branded in their own name.

I did find ZF makes some master cylinders called "Boosted Master Cylinders". But there's not a lot of information related to price, only to send in inquiries.
Boosted Master Cylinders | ZF MICO

The 3rd gen 2010-2015 Prius uses a similar master cylinder. I believe the master cylinder bore is about 7/8" which isn't huge but might work for a smaller weight vehicle. Hydraulically the master cylinder uses a spool valve to increase master cylinder pressure. Only problem is that the master cylinder is bolted to the ABS unit. It looks like they can be separated but then a machined adapter would have to be made to replace the ABS unit and seal off the master. Next time I'm at the junkyard I would like to grab one for cheap and tear it apart.

1717442048068.png

1717442111696.png
Good info, I was hoping to find something like that just to see exactly how it was working.
I was curious about making a hollow hydraulic cylinder to mount between the master cylinder of choice and the pedal assembly. That would allow you to have a really universal system but obviously there is more to it than just a cylinder...
 
Superduty master update:

I actually ended up going with a plate to rotate the master relative to the booster to get it to package how I wanted. Lots of ways to do that, but I got 3/8" of plate and welded some nuts where the master would clock to, and then the booster side was retained with its normal studs. This is a bit more elegant too than the previous method I outlined earlier.

1717886645005.png


With the position I clocked the master I had to remove the reservoir which is absolutely huge. It would be really easy to make a new reservoir since a large barbed fitting (I think I had some 1/2" or 5/8" ones that seemed like a perfect fit) can slide right into the rubber grommet on the master feed ports. However as a temporary solution I just flipped the reservoir 180deg and then it cleared the big plug which was my clearance issue. There's a roll pin and two clips (one per side) that hold the reservoir down, and annoyingly the clips are barely off center so don't work if you flip it around. With that said, the reservoir is very firmly held in by the rubber grommet and the plastic barbs going into them. For the time being I just ran a zip tie through the plastic clips that no longer engage anything so the reservoir can't come off vertically.

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Onto the good stuff, the brake feel is WAY better. The pushrod off the booster has about 0.75" of motion (out of an available 1.25") before it runs into a wall. I'm not sure what's going on, my wife said the wall would disappear only when we were bleeding the front brakes. In practice you get pretty good braking up to the wall, and then if you really push on it there is more to be had but you really have to shove on it. This is in stark contrast to the car master which had effectively no feel and you could bottom it out very easily.

My brake pedal ratio is around 4:1 currently, braided lines the whole way, no proportioning valve.

Overall it feels a lot better, though I must admit I expected it to be easier to lock up the brakes. The car master would lock the tires up in a discomfortingly easy manner, where as this will also lock them up but requires a lot more effort to do that. The braking zone before lockup feels great, and lockup I wouldn't say is hard, but a kid for example couldn't lock the tires up where as they could with the car master no doubt. I've only done one test drive for ~30 miles, but I like it a lot, and even though it requires a bit more effort than expected to lock up the brakes the flip side is it's a noticeable force increase required to do it so it doesn't sneak up on you. For going fast I like that, for crawling I could see a higher pedal ratio being nice to not have to work so hard, we'll see if I continue that philosophy once I get it out in Sand Hollow.
 
Superduty master update:

I actually ended up going with a plate to rotate the master relative to the booster to get it to package how I wanted. Lots of ways to do that, but I got 3/8" of plate and welded some nuts where the master would clock to, and then the booster side was retained with its normal studs. This is a bit more elegant too than the previous method I outlined earlier.

1717886645005.png


With the position I clocked the master I had to remove the reservoir which is absolutely huge. It would be really easy to make a new reservoir since a large barbed fitting (I think I had some 1/2" or 5/8" ones that seemed like a perfect fit) can slide right into the rubber grommet on the master feed ports. However as a temporary solution I just flipped the reservoir 180deg and then it cleared the big plug which was my clearance issue. There's a roll pin and two clips (one per side) that hold the reservoir down, and annoyingly the clips are barely off center so don't work if you flip it around. With that said, the reservoir is very firmly held in by the rubber grommet and the plastic barbs going into them. For the time being I just ran a zip tie through the plastic clips that no longer engage anything so the reservoir can't come off vertically.

1717886908092.png


Onto the good stuff, the brake feel is WAY better. The pushrod off the booster has about 0.75" of motion (out of an available 1.25") before it runs into a wall. I'm not sure what's going on, my wife said the wall would disappear only when we were bleeding the front brakes. In practice you get pretty good braking up to the wall, and then if you really push on it there is more to be had but you really have to shove on it. This is in stark contrast to the car master which had effectively no feel and you could bottom it out very easily.

My brake pedal ratio is around 4:1 currently, braided lines the whole way, no proportioning valve.

Overall it feels a lot better, though I must admit I expected it to be easier to lock up the brakes. The car master would lock the tires up in a discomfortingly easy manner, where as this will also lock them up but requires a lot more effort to do that. The braking zone before lockup feels great, and lockup I wouldn't say is hard, but a kid for example couldn't lock the tires up where as they could with the car master no doubt. I've only done one test drive for ~30 miles, but I like it a lot, and even though it requires a bit more effort than expected to lock up the brakes the flip side is it's a noticeable force increase required to do it so it doesn't sneak up on you. For going fast I like that, for crawling I could see a higher pedal ratio being nice to not have to work so hard, we'll see if I continue that philosophy once I get it out in Sand Hollow.
Thanks for the update.
I look forward to you getting this dialed in. And I’ll likely copy your setup.
 
Spent some time trying to find more information and I have yielded the same results. Lots of companies selling the same kit but with it branded in their own name.

I did find ZF makes some master cylinders called "Boosted Master Cylinders". But there's not a lot of information related to price, only to send in inquiries.
Boosted Master Cylinders | ZF MICO

The 3rd gen 2010-2015 Prius uses a similar master cylinder. I believe the master cylinder bore is about 7/8" which isn't huge but might work for a smaller weight vehicle. Hydraulically the master cylinder uses a spool valve to increase master cylinder pressure. Only problem is that the master cylinder is bolted to the ABS unit. It looks like they can be separated but then a machined adapter would have to be made to replace the ABS unit and seal off the master. Next time I'm at the junkyard I would like to grab one for cheap and tear it apart.

1717442048068.png

1717442111696.png
Noticed this setup on a NV3500 Nissan van, seems similar in design with "servo" name call out. 2017-2020 maybe.

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For going fast I like that, for crawling I could see a higher pedal ratio being nice to not have to work so hard, we'll see if I continue that philosophy once I get it out in Sand Hollow.
if you were only concerned about crawling, you’re saying you’d step up to a higher pedal ratio on the SD master instead of just going back to the car master?
 
if you were only concerned about crawling, you’re saying you’d step up to a higher pedal ratio on the SD master instead of just going back to the car master?
Yes, possibly. I haven't taken it crawling yet to see if the pedal ratio I have is too low, I was just thinking if you're parked on a steep incline for a couple minutes is the effort required annoyingly high.

I like the SD master a lot more than the car master no doubt, for a small buggy though just crawling it's a toss up. I have a buddies rock lizard in my shop with Toyota axles, I would think the car master on that would be perfect. The super duty brakes are kind of on the border for the car master, it was able to brake but felt like it was on the limit of pushing enough fluid sometimes. But if packaging is a problem, I would be hard pressed to use anything besides the car master since it's so tiny and I ran it for a year without issue.

Also keep in mind I run soft lines the entire way.
 
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Yes, possibly. I haven't taken it crawling yet to see if the pedal ratio I have is too low, I was just thinking if you're parked on a steep incline for a couple minutes is the effort required annoyingly high.

I like the SD master a lot more than the car master no doubt, for a small buggy though just crawling it's a toss up. I have a buddies rock lizard in my shop with Toyota axles, I would think the car master on that would be perfect. The super duty brakes are kind of on the border for the car master, it was able to brake but felt like it was on the limit of pushing enough fluid sometimes. But if packaging is a problem, I would be hard pressed to use anything besides the car master since it's so tiny and I ran it for a year without issue.

Also keep in mind I run soft lines the entire way.
How is the comparison between the two with no power. Is the SD MC too big for the 4:1 pedal?
 
How is the comparison between the two with no power. Is the SD MC too big for the 4:1 pedal?
Just pushing on it in the shop I think it'd be hard if not impossible for a normal person to stop/hold the brakes on much of an incline at 4:1

Which makes sense, for a brief time I had a 1.125" Wildwood master at 7 or 8:1 and I didn't like that enough that I went down the ibooster route, so 1.250" at 4:1 gut checks from that of being extremely hard to do.
 
Working on installing this in my Willys.. having a weird issue with the pedal not returning. Once powered and I push down, it just stays down. Any ideas?



GEN 1 booster off a CRV.
 
So, is there a ready made wiring kit by now? I am going to buy one for my CJ8.
 
also, these gents make a stand alone CANBUS controller:


These gents reverse engineered CANBUS for iBooster:


Then it looks like someone raided our CAD library, a resevoir leveler:

 
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Figured I would share my progress with all the info I have read in this thread and some other things found during all my research. I really appreciate everyone for doing all the leg work to get this ball rolling because it should be an awesome option once its dialed in.

My parts list so far:

2022 Accord Gen 2 IBooster with the oem reservoirs.

I also grabbed a 2020 F350 MC and reservoir, in case I want to upgrade to the larger master cylinder, hoping I don't need it because its BIG!

The brake pedal is a Wilwood reverse mount pedal, 340-13574 that I had and was planning on using for my remote mount configuration.

The original plan was to run a Wilwood slave cylinder, and mount the iboost remotely somewhere in the belly of the chassis due to space issues. However, once I got the booster in my hands it was smaller than I planned so I changed my mind. I have almost no room out the front of the firewall to mount anything yet plenty of room inside the cab with how the chassis is set up. I cut up the Wilwood pedal assembly and built a bracket to mount the pedal and ibooster with. I will go back in and add another gusset or two to firm it up some more but for proof of concept im happy with it.

I couldn't find a readily available clevis with an 8mm thread that would fit the wilwood pedal, so I just built one. I got everything tacked in and it feels good. The brackets don't flex when manually pushing the pedal. Pedal ratio is 4:1 is comfortable and the pedal throw is acceptable.

I am running a 05 f250 dana 60 with stock calipers up front and an older 14 bolt, with stock front calipers on it. I am hoping the smaller MC is going to do the trick because the F350 MC is huge and I don't have a solution for that size constraint yet but Ill tackle it one problem at a time.

I need to figure out/work on a low profile remote mounting option because the stock reservoir is too tall to have the remote reservoir not oddly high on the front of the chassis.

I took note of the two lower profile options posted here and probably will try to copy something similar. I also found a really slick reservoir option from BBT Fab, just not in love with the price tag. Figured I would share that option incase someone is interested in their reservoir mount. But they also have a couple nice adapters for the iboost stuff.


I also found an adapter from this place that will adjust the pitch on the tesla reservoir, if anyone should choose to find one of those and run it.

 

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^

This clevis screwed right on to my 2018 Accord iBooster. I had to drill out the clevis just a sliver to fit a 3/8 pin that my 78 F150 uses to retain it to the pedal.

Because the rod from the booster sticks out so much more than my stock vacuum booster I have to make some spacers between the booster and the stock mounting bracket on my truck. Will post up more as I get further along. Waiting for the Accord MC and Tulay Wiring harness.
 

^

This clevis screwed right on to my 2018 Accord iBooster. I had to drill out the clevis just a sliver to fit a 3/8 pin that my 78 F150 uses to retain it to the pedal.

Because the rod from the booster sticks out so much more than my stock vacuum booster I have to make some spacers between the booster and the stock mounting bracket on my truck. Will post up more as I get further along. Waiting for the Accord MC and Tulay Wiring harness.
Just cut the rod and rethread it. That's what I did on Hydrobooster.

I'm contemplating this electric booster over the GM hydroboost I've got on as I'm having issues when the oil gets warm/hot I'm loosing steering response. (all PSC setup, dual return reservoir) swepco 715.

I've got their single pass cooler in front of my radiator and it don't seem to work that well.
 
I don't think there's enough here to really cut and re-thread unfortunately. Otherwise I agree that would be the best route. There's JUST enough room for me to add a 3/4" spacer and still be able to get a nut on the threads of the booster. If there wasn't I think I would be in for a lot more work with the pedal set-up/stock booster bracket.

IMG_5717.jpg
 
I don't think there's enough here to really cut and re-thread unfortunately. Otherwise I agree that would be the best route. There's JUST enough room for me to add a 3/4" spacer and still be able to get a nut on the threads of the booster. If there wasn't I think I would be in for a lot more work with the pedal set-up/stock booster bracket.

IMG_5717.jpg
Oh shit ya that's real short.

I'd have to add length to it.
 
Couple photos for future reference of how the reservoir seals with the master.

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A 1/2" nipple (or tube) slides into it. The bottom of the nipple would need to be sanded about flush for it to fully seat back into the master.

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An easy low profile remote reservoir mount would be some 90deg fittings. Or one step sexier would be a tube with fittings welded to it similar to a fuel rail. The F350 master uses the same sealing approach. And then something to keep the nipple from backing out since the seal doesn't actually lock into anything on the master, which is why the roll pin exists on the reservoirs.
 
Any of these boosters smaller than the others? Or, maybe I should ask, what is the smallest of these electric boosters that people have seen?

I'm planning a new buggy build and would love to have some form of boosted brake pedal. I want to stuff one in the subframe of the new buggy to get it off the firewall, but space is pretty limited. I could probably fit a hydroboost unit in the subframe, but that adds another thing to an already overworked steering pump and I worry about hydraulic leaks. I like the fact that these units will also provide boost with the engine shut off. Maybe if I can figure out a linkage system I can stick it above the bellhousing.
 
Any of these boosters smaller than the others? Or, maybe I should ask, what is the smallest of these electric boosters that people have seen?

I'm planning a new buggy build and would love to have some form of boosted brake pedal. I want to stuff one in the subframe of the new buggy to get it off the firewall, but space is pretty limited. I could probably fit a hydroboost unit in the subframe, but that adds another thing to an already overworked steering pump and I worry about hydraulic leaks. I like the fact that these units will also provide boost with the engine shut off. Maybe if I can figure out a linkage system I can stick it above the bellhousing.

I was just about to ask the same. I had a buddy 3D print the ibooster from the docs on irate... way too big for my application... I need something tiny due to shock tower location in the tacoma.
 
Any of these boosters smaller than the others? Or, maybe I should ask, what is the smallest of these electric boosters that people have seen?

I'm planning a new buggy build and would love to have some form of boosted brake pedal. I want to stuff one in the subframe of the new buggy to get it off the firewall, but space is pretty limited. I could probably fit a hydroboost unit in the subframe, but that adds another thing to an already overworked steering pump and I worry about hydraulic leaks. I like the fact that these units will also provide boost with the engine shut off. Maybe if I can figure out a linkage system I can stick it above the bellhousing.
Deleted my reply, thought you were talking about masters.

There's only the Gen 1 and Gen 2 booster, not sure if the Gen 1 is any (or even noticably) smaller than the Gen 2. The Gen 2 are all effectively the same.

You could get pretty creative with mounting if you wanted since it's really just a linear motor. You could have a normal brake pedal run to a piston on the booster and remote mount the booster/master anywhere, like a clutch setup feeding it essentially. Or do the linkages.
 
Deleted my reply, thought you were talking about masters.

There's only the Gen 1 and Gen 2 booster, not sure if the Gen 1 is any (or even noticably) smaller than the Gen 2. The Gen 2 are all effectively the same.

You could get pretty creative with mounting if you wanted since it's really just a linear motor. You could have a normal brake pedal run to a piston on the booster and remote mount the booster/master anywhere, like a clutch setup feeding it essentially. Or do the linkages.
Ok, thats good to know at least. Maybe I'll have to get creative. I was just thinking I could mount it on the other side of the steering column more towards the middle of the firewall. Length would then become a problem, but at least its in the same line of sight as the motor. It would need to be mounted above the pivot point of the brake pedal to make it work right with the master setup being mounted on the inside of the firewall.
 
A push pull cable would also work for remote mounting.
That an interesting idea too.

Do you feel like you have too much break leverage in your system? From reading your thread it almost seems like you could use a bit less from your driving experiences you posted. Wondering if a 3-1 pedal would work better. I kinda feel like running the large Ford SD MC might be too much though. Maybe a 1.125 bore master would be better. Dunno.
 
Any of these boosters smaller than the others? Or, maybe I should ask, what is the smallest of these electric boosters that people have seen?

I'm planning a new buggy build and would love to have some form of boosted brake pedal. I want to stuff one in the subframe of the new buggy to get it off the firewall, but space is pretty limited. I could probably fit a hydroboost unit in the subframe, but that adds another thing to an already overworked steering pump and I worry about hydraulic leaks. I like the fact that these units will also provide boost with the engine shut off. Maybe if I can figure out a linkage system I can stick it above the bellhousing.

manual clutch/slave would do the trick as weel
 
That an interesting idea too.

Do you feel like you have too much break leverage in your system? From reading your thread it almost seems like you could use a bit less from your driving experiences you posted. Wondering if a 3-1 pedal would work better. I kinda feel like running the large Ford SD MC might be too much though. Maybe a 1.125 bore master would be better. Dunno.
Pedal ratio really comes down to power on vs power off.
I can learn to have a lighter foot. But when the power dies for whatever reason, I want the higher ratio pedal so I have a chance at slowing things down.
I think a matched caliper and rotor front to rear is even more important with boosted pressure when locked 4x4 so braking force is not transferred through the drivetrain. If you are running large piston area in the front and low piston area in the rear and locked in 4x4, the front braking force is going to hold the rotor and shafts and drivelines and t case and send it all the way to the back tires since the back rotors are holding with a lower force. The closer each tire gets to equal braking force, the lower the drivetrain stress. Add an iBooster and the importance multiplies.
 
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