iBooster Electric Brake Booster

[Grendel]

I am getting one soon for my CJ8

 

[JNHEscher]

Got mine. Turns out the mounting dims are identical to my '01 Outback. Pulled the vac booster gasket off and it sat right on the ibooster studs.

 

[JNHEscher]

Didn't find the pushrod specs in here. I'm measuring mine tonight and will confirm them at the hardware store tomorrow to post here. I need to extend mine about an inch with a thread adapter.

Mine came from a 20-22 Honda CR-V 1.5 turbo.

 

[snivilous]

I tried to find a tail light signal output but there's no straight 12V or GND coming off any wires when the brakes are applied. Maybe it's tied into the CAN data. Guess a normal pedal switch will still be needed

 

[JNHEscher]

8-1.25 stud on my ibooster pushrod.

 

[snivilous]

I've been starting to look at larger master options or if people have done conversions and came across this thread:

iBooster retrofit

I've been playing with these lately and had really good luck on a First Gen and C10 install. It works really well, big improvement over vacuum. If you're thinking about taking a run at it I'm glad to talk you through it and help you source the parts.

nastyz28.com

In the thread the guy mentions a conversion adapter from a company but I can't find it looking on their website. I have essentially the same wildwood master (that I was running before the ibooster), so I'll look at what's needed to adapt an off the shelf wilwood setup to the ibooster and that will open up any size master. I haven't read the whole thread but it looks like just a plate and pushrod adapter for the wilwood.

 

[JNHEscher]

All I'm lacking to get mine operational is the upper res and wiring. I can't seem to find a '20-'22 upper res anywhere without buying another MC. Anybody happen to have quick access to the hose between the upper and lower reservoirs for measuring?

 

[snivilous]

All I'm lacking to get mine operational is the upper res and wiring. I can't seem to find a '20-'22 upper res anywhere without buying another MC. Anybody happen to have quick access to the hose between the upper and lower reservoirs for measuring?

What about the hose do you need measured? I have the hose and reservoir I think from the buggy I could send you too, assuming I didn't throw it out. I don't know what year it's from but can get pictures.

 

[JNHEscher]

What about the hose do you need measured? I have the hose and reservoir I think from the buggy I could send you too, assuming I didn't throw it out. I don't know what year it's from but can get pictures.

Just the ID. I want to run either the OE upper res for the booster I got or pick an aluminum res off Summit. Didn't think to measure it today and can't get to my car for a couple days.

 

[snivilous]

Just the ID. I want to run either the OE upper res for the booster I got or pick an aluminum res off Summit. Didn't think to measure it today and can't get to my car for a couple days.

I'll try to remember in the morning. This is the reservoir I'm using for two of my setups, need to screw a barb into it but it works like a champ and is pretty cheap and nice quality.

Amazon.com

 

[snivilous]

Just the ID. I want to run either the OE upper res for the booster I got or pick an aluminum res off Summit. Didn't think to measure it today and can't get to my car for a couple days.

 

[HYDRODYNAMIC]

Have an Accord Gen2 on the way for $100 shipped off FleaBay. Worth trying out this technology for the price.

Research is still ongoing but here is what I'm thinking.
Stock Ibooster stroke is 1.25" with a 4:1 pedal traveling 5", correct me if I'm wrong.
The Wilwood High Volume MC 260-6766 1", 260-6765 7/8", 260-6764 3/4" has a 3.82" stroke.
With a 7:1 pedal the 3/4" or 7/8" have acceptable performance for manual brakes.

"Enter in some old brake calculations intended for future reference."

Two qty one sided 2-Piston calipers with 1.75" dia. pistons = 9.6 sq. in. effective area per axle.
Recommended working pressure 1200 PSI.
75 lbs foot force on a 7:1 pedal = 1200 PSI with one qty 3/4" master cylinder.
150 lbs foot force on a 7:1 pedal = 1200 PSI with two qty 3/4" master cylinders, one per axle.
Master Cylinder Displacement (1.25" Stroke) = 0.75 cubic in. per axle

1200 PSI x 4.8 sq. in. piston area on each caliper = 5,760 lbs clamping force x .375 friction coefficient = 2160 lbs on half of rotor dia. 5.59" = 12,074 in. lbs. / half of tire dia. 19" = 635 lbs per tire
2 tires = 1270 lbs of total braking force front axle

1200 PSI x 5.52 sq. in. piston area on each caliper = 6624 lbs clamping force x .375 friction coefficient = 2484 lbs on half of rotor dia. 5.59" = 13,885 in. lbs. / half of tire dia. 19" = 730 lbs per tire
2 tires = 1461 lbs of total braking force rear axle

Average total braking 150 lbs input = 2731 lbs

1.25" Master cylinder travel x 7:1 pedal ratio = 8.75" of foot travel

Not pushing through the brakes at idle in low gear is a torque converter, gearing, and leg strength/comfort equation.
The average adult male can exert roughly 300 pounds of force (maximum) with one leg.
Wilwood says not to exceed 1200 psi on their calipers. This calculated with cyclic rate failure in mind. Destructive testing by a college FSAE report shows a single max failure pressure to be 5000 psi.
With a 7:1 pedal and 3/4" master cylinder and 300 lbs at the foot = 2378 PSI which is over Wilwood rating and below the failure point.
Hydroboost valves can produce around 2000 psi which is well over the 1200 psi rating.

These calcs are for 1.75" dia. 4 piston or 2 single sided pistons = 4.8 sq. in. which is a common size.
F250 2000 rear calipers are 1.75" dia = 4.8 sq. in. which I am using in the front.
F250 2005 rear calipers are 1.875" dia = 5.52 sq. in. which I am using in the rear.
Many Wilwoods four pistons go up to 4.8" sq. in.
Wilwoods AT6 is their off road race caliper at 5.4 sq. in.
GM one ton single sided pistons are 2.375" dia. = 4.43 sq. in.


If 5" of travel on a 4:1 pedal is enough for a grandma then the 1.25" MC travel with a 1" MC x 2 QTY can generate enough to brake.
If 8.75" of travel on a 7:1 pedal is enough for a crossfitter then the 1.25" MC travel with a 3/4" MC x 2 QTY can generate enough to brake.
Keep in mind the Wilwood can travel 3.82" that is way more than the 1.25"
Rather than attach a stock or large Wilwood MC directly to the end of the Ibooster, attach a linkage to a lever arm.
Say the lever arm is 2:1
The 1.25" of Ibooster travel turns into 2.5" of travel using twice the amount of Wilwood MC travel.
Now the single 3/4" MC is traveling twice the distance generating enough oil for all four calipers. This would help with running out of oil if the linkage had some slop or soft lines were expanding.
Not suggesting to use only one MC and hydraulic circuit.
Somewhere I posted about the importance of having equal braking at all four corners to releave the drivetrain of brake related torque spikes when locked in 4X4. This was a Wilwood tech talking about the Miller cars.
The added benefit of using a lever arm is now the MC can be mounted in reverse next to the Ibooster, this decreases the over all length and opens up more mounting options.
It also allows for tuning with different lever arm ratios and lengths.
It allows for use of the more common size 3/4" , 7/8", 1" MC that people already have.
You can still run dual MC on a single lever arm or a single tandem MC. Not sure a balance bar would be needed if all calipers and MC were the same displacement.
If you dont like the 8.75" of pedal travel with a 7:1 pedal then make a 2:1 ratio lever arm and be at 4.375" of pedal travel.

 

[Bebop]

I suggest staying around 75lbs pedal force.
300lbs is completely insane and definitely not a usable number.

I also hate the idea of a single MC for the whole car. That’s a single point of failure I don’t want to deal with.

 

[HYDRODYNAMIC]

I suggest staying around 75lbs pedal force.
300lbs is completely insane and definitely not a usable number.

I also hate the idea of a single MC for the whole car. That’s a single point of failure I don’t want to deal with.

300lbs plus safety factor was max force that the system should be able to handle without breaking the pedal, linkage, blowing a seal or line. This was more so brought up because the 1200 psi rating for Wilwood is bogus, when it is going to see close to double this pressure at times to avoid crashes.
150LBS is doable for short bursts, but not sustainable.
75LBS starts to burn after awhile, but is sustainable, figuring eventually the drivetrain will be shifted to take off the load and give a break.
75LBS would be a lot for a kid or small driver.

Agree on redundant MC and hydraulic circuits front and rear is worth it. Chances of ripping a line or breaking a fitting is high.
I am more of a fan of two separate MC off a common lever arm than the tandem factory MC or the Wilwood tandem units. As of now I am thinking the dual 3/4” MC with a 2:1 lever arm will have plenty of volume and generate enough pressure with hopefully half the input force with half the pedal travel.

I wonder what the force multiplier is for the iBooster? 4:1?
It would also help with over pressurization of the system as the electrical motor would stop multiplying force beyond what the OEM system was designed to handle. In other words if you pushed with 300LBS of force in a crash, it would not turn into 1200LBS of force and blow up the system or break something.
Would be cool to see someone put a psi gauge on the system with power on and off to measure the added pressure boost. There must be a service tech bulletin related to testing of the pressure to make sure it is working.

 

[Bebop]

75LBS starts to burn after awhile, but is sustainable, figuring eventually the drivetrain will be shifted to take off the load and give a break.
75LBS would be a lot for a kid or small driver.

Agreed, I was talking about max force.
"Normal" force is much much lower. I can move my buggy in the shop while walking next to it and stop with 1 finger on the break pedal.

I am more of a fan of two separate MC off a common lever arm than the tandem factory MC or the Wilwood tandem units. As of now I am thinking the dual 3/4” MC with a 2:1 lever arm will have plenty of volume and generate enough pressure with hopefully half the input force with half the pedal travel.

I like the tandem units from GM from the 70s. Cheap, can get one at autozone anywhere and various bore sizes are available.

Rather than attach a stock or large Wilwood MC directly to the end of the Ibooster, attach a linkage to a lever arm.

I like that idea. A lot.

 

[HYDRODYNAMIC]

iBooster is in, don’t know how well it will work, but reviews say it makes for a much more comfortable drive. One of the biggest advantages is when my boys drive, they will have a much easier time working the brakes.
I wanted it to be a direct bolt in to the Wilwood MC/pedal combo. So for whatever reason, it can be switched out without fab work.
This was one of the more difficult designs for the buggy as far as time goes. Making sure everything cleared and shoehorned in.

Ratio is 4:1
Travel is 1.25” at MC
MC is around 1” metric
Travel is 5” at pedal
Geometry is very close to OEM
iBooster is a Gen2 Honda Accord
M12-1.0 banjo bolts to -3AN banjos
Still need to add a brake light switch, probably a mil spec toggle momentary NC contact that closes on first pedal movement

 

[Tech Tim]

Looks good!

 

[HYDRODYNAMIC]

Found this researching:

Still Same Brake Problem 9 months later - Ford Truck Enthusiasts Forums

1999 to 2016 Super Duty - Still Same Brake Problem 9 months later - Still the same problems with brakes. I bought this truck in Nov of 2017 a 2011 F-250 Super Duty Super Cab XL 4WD 6.2L flex fuel gas engine, and the brakes are still the same only worse. Here is the problem. When I first press...

www.ford-trucks.com

Every vehicle sold in the USA has to pass the brake test procedures in the Federal Register, which are under the regulation of NHTSA. They are FMVSS 105 and 135 for stopping ability. Superdutys fall under 105, lighter vehicles 135. The stopping distance changes based on the GVW of the vehicle.

Part of the procedure is failed system tests, each side of the master cylinder circuit, and when equipped with a booster (vac or hydro), failed booster. The brake suppliers (me), the vehicle manufacturer, and NHTSA will all test the vehicles under the procedure in that order. The same brake system was used on 1999 to 2004 Superduty pickups and the Excursion. It's not fun having NHTSA find a vehicle platform out of compliance.

I'll show the procedure, and how the OE front brake only test performed at GVW, along with the second fade section of the same test as that graphic includes the maximum pedal travel until hitting the firewall or floorboard. The test vehicle, built up with new brakes and new brake fluid, fully bled so there was no air.

In service air can get entrained in the system, brake pads can wear unevenly and require a higher brake fluid volume, and old brake hoses can expand taking up the volume that would require a long pedal travel. Aftermarket floor mats or misplaced floor mats can take up travel too. And aftermarket pads, which by the way do not have to comply with any of this, can fade or go soft and use up the travel when pushed into service as a front or rear brake only situation.

The vehicle was designed for being able to stop on one master cylinder channel using 5.5 inches of travel at 150lbs pedal effort out of the total 7.1" available travel. What NHTSA has found over the years is that consumers typically don't press all the way. It's a long way down. Just saying, it could be any of the items mentioned that alter brake travel.

 

[HYDRODYNAMIC]

Accord 2020 front caliper piston size is 2.249” x 1= 3.97” area
Accord 2017 rear caliper piston size is 1.5” x 1=1.76” area, no data for 2020
The front and rear MC are isolated
So regardless of rear piston size, the front MC has enough volume for a 3.97” area
Ford SD rear calipers are 1.75” x 2 = 4.8” area
4.8” vs 3.97” = 20% needed increase in oil volume
The Accord MC should have more than a 20% safety factor built in to provide the extra fluid for 4.8” brakes

 

[JNHEscher]

Coming back to this to see if anyone has come up with OE plastic reservoirs that will plug directly into the OE MC. I've had no luck finding a basic res to connect to the ibooster lower res, and happened to lose my lower res at the salvage yard yesterday.

 

[snivilous]

Coming back to this to see if anyone has come up with OE plastic reservoirs that will plug directly into the OE MC. I've had no luck finding a basic res to connect to the ibooster lower res, and happened to lose my lower res at the salvage yard yesterday.

Is there a reason you want a OE reservoir so badly? There's nothing special about the OE ones besides that mine have a brake fluid level sensor in them. Shit I can probably mail you one since I haven't used the OE reservoir on any of my ibooster swaps since they're so ugly lol

 

[JNHEscher]

Is there a reason you want a OE reservoir so badly? There's nothing special about the OE ones besides that mine have a brake fluid level sensor in them. Shit I can probably mail you one since I haven't used the OE reservoir on any of my ibooster swaps since they're so ugly lol

The OE res isn't what I'm after. Just need a res to put on it so that I may finish this up. I was just going to use an aftermarket res with a cap to connect to the ibooster lower res, then I lost my lower res


Found a possibility, but nobody lists the port dims. I was able to open your adapter CAD file to get the low res port dims. If I can find somebody local with some options in stock, I can check them out with a caliper.

More Information for GM GENUINE 23496820

'12-'15 Chevy Captiva

 

[HYDRODYNAMIC]

If anyone has a good lower reservoir for an Accord let me know. Mine looks like it was dropped in shipping and what was clearish is now white so I'm assuming the plastic is stressed and will crack at the wrong time.
Any metal lower reservoirs out there for the Gen2?

 

[JNHEscher]

If anyone has a good lower reservoir for an Accord let me know. Mine looks like it was dropped in shipping and what was clearish is now white so I'm assuming the plastic is stressed and will crack at the wrong time.
Any metal lower reservoirs out there for the Gen2?

That's the part that I just lost at the salvage yard. Went around looking for an OE res that would plug in place of it and I set it down somewhere. I also broke the barb while trying to get the hose off, hence the search. I'm open to metal as well, as long as it fits right on. Don't have the place or the power to set up fabbing an aluminum res.

 

[snivilous]

The OE res isn't what I'm after. Just need a res to put on it so that I may finish this up. I was just going to use an aftermarket res with a cap to connect to the ibooster lower res, then I lost my lower res


Found a possibility, but nobody lists the port dims. I was able to open your adapter CAD file to get the low res port dims. If I can find somebody local with some options in stock, I can check them out with a caliper.

More Information for GM GENUINE 23496820

'12-'15 Chevy Captiva

If anyone has a good lower reservoir for an Accord let me know. Mine looks like it was dropped in shipping and what was clearish is now white so I'm assuming the plastic is stressed and will crack at the wrong time.
Any metal lower reservoirs out there for the Gen2?

I machined a low profile lower reservoir for one of mine, I uploaded the CAD here so might be of use:

iBooster Gen2 Low Profile Reservoir Adapter

iBooster Gen2 Low Profile Reservoir Adapter

irate4x4.com

I don't know of any other lower reservoir options than the OE ones though.

 

[snivilous]

 

[snivilous]

That's the part that I just lost at the salvage yard. Went around looking for an OE res that would plug in place of it and I set it down somewhere. I also broke the barb while trying to get the hose off, hence the search. I'm open to metal as well, as long as it fits right on. Don't have the place or the power to set up fabbing an aluminum res.

Actually! Since I made my own lower resi I probably have the OE style laying around too that I could send you. I could send you the lower and a factory upper since I should have spare of both from my Hilux pictured above. I'm traveling this week but can confirm this weekend if I have them.

 

[JNHEscher]

Actually! Since I made my own lower resi I probably have the OE style laying around too that I could send you. I could send you the lower and a factory upper since I should have spare of both from my Hilux pictured above. I'm traveling this week but can confirm this weekend if I have them.

Wouldn't mind that at all, man. I can shoot you some fundage. Just wanna get mine up and going.

I was looking at the OE res pics, trying to figure out what was what and saw two barbs on the upper res. Diagrams showed another hose leading off along the firewall or something. What kind of convoluted fluid containment are these iboosters running?

 

[snivilous]

Wouldn't mind that at all, man. I can shoot you some fundage. Just wanna get mine up and going.

I was looking at the OE res pics, trying to figure out what was what and saw two barbs on the upper res. Diagrams showed another hose leading off along the firewall or something. What kind of convoluted fluid containment are these iboosters running?

I'll let you know this weekend and then just send me your address.

I havent seen any of the shit you're talking about, the three I've picked up all just have the mini reservoir off the master with a hose to a bigger conventional reservoir that's remote mounted. And the mini reservoir isn't really needed so not entirely sure of its purpose besides redundant capacity.

 

[SMI17]

How much shipped to 50265?