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Hydro Boost and Wilwood Calipers

Blase said:
I agree with Patooyee. ......I think. From what i've read you need two 3/4" master cylinders with 2lbs residual pressure valves for the calipers that you are running. wether you run them on two pedals is up to you.

I know I had 1 7/8 and 1 1" master on 1/2 ton chevy calipers when I first built my buggy and I had a hard time stopping it. after some reading I switched to two 3/4" masters and 2 lbs pressure valves I was MUCH happier!! still not BJ hydro boost good but almost twice as good as they were with less leg effort. I had a little longer stroke on the brake pedal but not too bad.

For the cost of new master cylinders and some residual pressure valves I'd give that a shot before you junk all those new calipers and rotors that you bought!!

If you do decide hydro boost is the way to go can you put a thicker rotor on those new hubs that you bought? And would you need to? I know Bjs set up uses a "thin" rotor but i'm not sure how thick it is.

yeah, Andrew Dobosh (sp?) "redneckengineered" was having the same problem with his brakes (masters too big, pedal too stiff) and switched to dual 3/4" and made his brakes much better (he was/is running the big ford dual piston calipers all the way around).

the 3/4 masters will generate more pressure at the caliper with the same applied foot pressure.

but, power brakes are nice... but come with a couple "catches" like that they can limit flow to the steering system (ported versions are available)

or you can run a seperate ps pump just for the brakes

BJ isn't that how your buggy is setup? (stand alone pump for brakes)
 
Elliott said:
Hydro may make more pressure, but I had an old dually that leaked out some power steering fluid going down the road while I was pulling my 20 ft gooseneck loaded, a person stopped in front of me and when I went to slow down didn't have a stitch of brakes. I would never put hydro boost on anything because of that.It prob works fine on a Buggie but it gave me a bad taste about it.And cole wonder why it changed your brake pedal so much, just not moving enough fluid?

So you would prefer to tow a 20' loaded trailer without boosted brakes??? And what do you mean by it leaked some fluid out while you were driving? If it leaked enough to make the brakes stop working then the pump wasn't working either and your steering was affected also. Unless the system just explodes this isn't something that happens quickly as you drive. They don't just randomly expel fluid y design. The leak was probably there beforehand resulting in the fluid level being low. But obviously something very rare happened to you that doesn't happen to 99.999999% of properly operating HB setups.

HB has a small pressure accumulator built in to give you one or two assisted pushes of the pedal before completely going dead in the event of pump failure, that's more than vacuum boost gives you. And if the pump does die the brakes still act as manual brakes. So its not like you have no brakes.

I've never met anyone who switched to HB and didn't love it. But the added pressure does require more beef at the caliper which most aftermarket caliper companies do not build for that I am aware of.
 
I say screw it, put ya some pinion breaks on it and be did with it! It would be original for sure
 
My Jim's Garage has a standalone pump that only runs the brakes. It is a very small displacement pump PSC built for me.

My WOD buggy runs a 2nd pump for the brakes and rear steer. It is a standard CBR pump.

A P Pump or CBR running through the hydroboost had never caused me am issue in the past. I run PSCs humongo pump and it is too much to run through the hydroboost IMO.
 
i'm running 4 piston wilwood's all around with two wilwood 3/4 MC's, 2 psi residual valves and -4 line. very pleased with my brakes, I got my hats and caliper brackets from EZ Rick and he suggested the 3/4 MC's.

IMO, the 1" MC is your issue for sure, even with my stock brake setup, I had to mess with MC size to get it performing better. i'd go to two 3/4 MC's, residual valves will help some too
 
Thanks for all the good info, definitely gonna try the MC change since they are pretty cheap.
 
wizzo said:
i'm running 4 piston wilwood's all around with two wilwood 3/4 MC's, 2 psi residual valves and -4 line. very pleased with my brakes, I got my hats and caliper brackets from EZ Rick and he suggested the 3/4 MC's.

IMO, the 1" MC is your issue for sure, even with my stock brake setup, I had to mess with MC size to get it performing better. i'd go to two 3/4 MC's, residual valves will help some too

I am a believer in -4 lines on manual brakes. I can go into the physics, fluid movement is what I do for a living. It makes total sense for gains in clamping force.
 
Re: Re: Re: Hydro Boost and Wilwood Calipers

crawlin85cj said:
I am a believer in -4 lines on manual brakes. I can go into the physics, fluid movement is what I do for a living. It makes total sense for gains in clamping force.

I would like to hear your reasoning for this. If you think others will find it boring feel free to pm me. Thanks.

Sent from my DROID BIONIC using Tapatalk 2
 
Re: Re: Re: Hydro Boost and Wilwood Calipers

crawlin85cj said:
I am a believer in -4 lines on manual brakes. I can go into the physics, fluid movement is what I do for a living. It makes total sense for gains in clamping force.

I'm interested also. I like tech
 
patooyee said:
Wilwood calipers were designed to stop light little sprint cars on the street, not heavy 4x4's with 40"+ tires trying to cling to a mountain.

This is pretty much what I'm thinking too... I ridden with a guy who had wilwoods on a 3500 lb street car and they sucked... To the point of being scary
 
I know when I used to race MX going to a larger brake line had the same effect as going to a larger MC. A smaller line would increase pressure and lessen the firmness at the lever
 
I'm driving and can't really type it all out but I will ASAP.

In the meantime, if -4 is questionably a good move, why not use -2? If going larger seemingly causes ill effects it stands to reason smaller would correct the issue. Wilwood even taps the caliper for 1/8"
 
I was under the impression that most people that converted the Wilwood calipers and master cylinders to AN went from 1/8"npt to -3 AN.
 
My hydraulic rendition of braking.

MC bore and stroke determines displacement. The amount of fluid the MC pushes out on a pedal stroke should match the displacement required to force each caliper piston out of its bore, creating the clamping force of the pad against the rotor prior to the pedal reaching full stroke. I shoot for 1/4 stroke leaving pedal travel to create pressure required to clap the pad against the rotor.

Pedal ratio, caliper piston displacement and MC displacement all affect the amount of fluid delivered to the caliper and the foot force to deliver such. We all have varying level of strength and desire in our left legs to accommodate such work and we all have various room for pedal length. All variables

Brake fluid is not compressible. The amount of fluid put into the brake line via the mc equals the amount of fluid that leaves the line into the caliper. The line will gobble up pressure in friction loss as it moves through the line.

The desired result of the braking system is to build pressure at the caliper to force as much fluid as needed into the caliper to stop the vehicle. If the energy is being spent to get the fluid through the smaller line there is less energy available to move the caliper pistons.

Line size is a compromise of physics, amount of space and economics. The remaining factor is that braided line will swell to some degree during under pressure. This increase in line diameter will rob volume needed at the caliper and become wasted energy in the system, causing an increase in input energy for no gain in stopping power. Nylon lines are even worse IMO.

Now introduce hydroboost into the equation, or any type booster for that matter. Wilwood MCs create approx 1000psi of pressure when the displacements are correct. Hydroboost can create as much as 2500psi of pressure.

This increase in pressure does a couple things for us. It helps overcome the friction losses in the line as well as decreasing the amount of energy put on the pedal by supplementing it with an alternate energy source. The net effects of losses are less prevalent because of the reduced effort applied at the pedal.

-4 lines are certainly not the fix all but in my mind and per what I know about fluid movement, hydraulic engineering and application as well as energy efficiency a larger line size can not hurt a thing post bleeding process.

The cons to a larger line...cost, room, more difficult to bleed and increased risk of line swell.

I was successful in having great manual brakes with Wilwood 4 piston dynalites, a 3/4" MC for each axle and -4 line. After 3 left knee surgeries my leg looks like a science fair project and is weak. I simply can't apply an abundance of pressure to the pedal which is why I use hydroboost on everything. I went with manual brakes on my Jimmy's car because that's what all the cool kids do. I fell victim to the same follow the pack that brake line size is grouped into. They were good but they were no hydroboost setup! I won't ever go back especially since someone took the time to design a nice clean and small unit that works great in a buggy.

Check this out, I have it in my new buggy and it flat works awesome. Minimal effort and it drives a small and cheap OEM 4 piston caliper that can also be provided.

http://www.wideopendesign.com/Product/10872/Hydroboost-Brake-Assembly.aspx

Here is a picture of it in my buggy
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The caliper on the WOD scalloped rotor
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The brake pads can be changed without removing the caliper from the buggy.

I'm no brake system expert but I do have a fair amount of hydraulic and fluid energy knowledge. This is what I know and how I translate it to stoping a buggy. I've been pretty successful at having good brakes on every rig I've owned whether it be manual, vacuum boosted or hydroboost.
 
Re: Re: Hydro Boost and Wilwood Calipers

Which toy calipers are you referring to?

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Re: Re: Re: Re: Hydro Boost and Wilwood Calipers

patooyee said:
Which toy calipers are you referring to?

Sent from my DROID BIONIC using Tapatalk 2

Factory solid axle calipers 79-86 for the non-vented plate style rotors, 86-95 for vented rotors. These are "narrow mount" calipers and will swap with the narrow mount wilwood calipers.

96+ Tacoma/4runner/FJ Cruiser/6 lug Tundra all have interchangeable calipers which match the wide mount wilwood calipers. These yota calipers have different hose connections (either flare or banjo) and mounting ear height according to application (taller ears for bigger rotors)
 

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