Brakes, Manual vs Booster Opinions Wanted

My old buggy had a single manual wilwood MC. I think it was 1" and it did very well. My new buggy had dual Wilwood 1" when I got it and would not stop on level ground. I change them to 3/4 and it's only okay now. I wish I could get dual 1/2". I may eventually switch to a single 1" and see how that does.

I have dual MC and dual pedal, 7/8 bore. Not great but works. But y'all are saying a single MC will do better?

So why do smaller bores work better? ???
Seems so backwards but heard that more than once.

pholmann said:

So why do smaller bores work better? ???
Seems so backwards but heard that more than once.

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Higher pressure and less volume is what I have been told.

Smaller bore = less surface area = more psi from applied force (your leg)

Also moves less fluid so there is more stroke required, so more variable feel.


To answer the above question about single vs dual mc, they will work the same if the overall piston surface area is the same, but usually the duals will have more combined size than a larger single. Dual 3/4 = single 1 1/16"

Also most people use the 7:1 wilwood swing pedals, intended for drag cars and dune buggies. Building a longer pedal to gain more motion ratio would help a lot.





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Re:

Its all about volume vs pressure vs pedal force.

A large master might be able to deliver more fluid, but it takes more pedal force to generate the same pressure, or braking force. If you are boosted, this assists the force applied, uping the pressure. With a manual setup the smaller master allows more pressure without a super stiff pedal, but might need residual valves to keep some of the fluid at the caliper.

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Re:

Billvista has a calc thats good.

To get the best setup start at the wheels and work backwards to the master/pedal. It might mean you need a custom pedal setup, or boosted.

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TBItoy said:

Also most people use the 7:1 wilwood swing pedals, intended for drag cars and dune buggies. Building a longer pedal to gain more motion ratio would help a lot.

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This.

I built my pedal on my samurai when I switched to manual brakes.

What a difference going up 1 point of ratio makes, I couldn't believe it.

I'd start by figuring out the pedal throw you want (packaging) and the pressure you need at your calipers (performance) and engineer the system to both match. Like paradisepwoffrd said, it might end up meaning you need a custom pedal ratio or boosted MC.

I have 3/4 ton front calipers on all 4 corners with a 74 I think corvette master cylinder and a toyota dual plane booster with stock toyota pedal. with the booster UNhooked the truck stops ok, with the booster connected the you have to push the gas pedal harder than the brakes. slamming on the brakes the truck will almost do a stopie

I took my jeep apart to build a buggy the plan was to use a wilwood pedal/dual mc. After doing readings here and there I've decided to go back with a tj booster and ram 2500 mc. My brakes were awesome before. 1t front 3/4t rear on 43s I could lock them easily with very little effort. It will be harder to fit but worth it. Electric brakes would be handy when the motor is off but not for the extra $1100.

I don't think packaging would be very difficult while building a buggy as long as you plan on running a booster from the start. I think most people (like me) figured the dual mc's would be fine. I haven't driven mine yet but I can't imagine it being much different than anyone else's experience since I'm running a very common setup.

slravenel said:

I was in the same boat...super unhappy with manual brakes (CNC pedal and masters, 1/2 chevy rotors and calipers) until I just ponied up and bought good brakes. Spidertrax 14" rotors, wilwood 4 piston calipers on all 4 corners and the same CNC pedal and masters. 60/14 bolt

It will stop great now...and I am not even using the "nice" wilwood 6 piston calipers.

If you can fit the stock booster setups they are cheaper - but there are issues that can arise from them too for some folks.

I like simple...it just so happens that in this case, simple wasnt the cheapest option...but its still really simple.

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What pedal ratio and size MC's are you running?

Thanks for the info. I don't plan on changing mine on the new buggy unless it horrible, as long as I don't drive a buggy with a booster, I won't ever know the difference

Really appreciate all the info from you guys!! I did a lot of ready on the different types of systems mentioned. I learned a lot!!!

Over the weekend the Unlimited Off Road Expo came to Dallas. I think it has been a long running event in Kentucky, first time here. It was a really good chance to talk to vendors and to individuals and race teams that were displaying their vehicles. The most popular system I saw on rigs was hydroboost. Many of the guys I talked to said brakes were no longer an issue for them. If it can hold up to those KOH cars, must be ok for me. So I think this will be the route I go.

Price isn't to bad. I have an Oreilly's and NAPA near me so I started punching in vehicles. An early 90's 1 ton K series Chevy pick up or Suburban runs this system with some engines. Plus it was designed for the front calipers I am running. The rear might need a 2lb residual pressure valve or a proportioning valve to fine tune. No big deal.

Booster can be had for $175 plus a $30 core charge and the master cylinder for $50 no core. I'm ok with that.

Oh the off road show!! Super cool. Big thanks to the guys in the WOD booth. Super helpful, super nice, I bought some parts from them. Show special!! They had one of their chassis on display. pure sex!!! So nice. Compact, great welds, clean, simple, the panels were fitted so nice. Want one of those bad!! Maybe next time.

Tom at PSC gave me the run down on pump and reservoir options. Thanks!! I have run their systems on both my prior rigs with no issues. Great product and awesome customer service.

The owner of Radflo was there, nice conversation about shocks. Explained un-sprung weights and angles and what he needs to build me a set that is in the ballpark to start with.

BJ Allen of Barco Motorsports. He runs a WOD chassis and has a UTV parts biz. Super nice guy and lives the next town over from me. Had some great input on parts and pieces that he likes.

Unfortunately their was only a small percentage of hardcore rigs there, but, if you wanted a giant lift and low profile tires on your tow rig they had you covered, plenty of those there.

For those that have run manual brakes and a LSx based engine, how did you block off the brake booster vacuum port on the rear of the intake? Anyone have a part number for this? I know some came with hydroboost, so there should be a plug from the factory.

Im running a TBSS intake manifold.

Pic?

the_white_shadow said:

For those that have run manual brakes and a LSx based engine, how did you block off the brake booster vacuum port on the rear of the intake? Anyone have a part number for this? I know some came with hydroboost, so there should be a plug from the factory.

Im running a TBSS intake manifold.

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It is just a 1/2 tube plug.



https://www.fastenal.com/products/details/0441576

random internet pic attached.

The trucks that came with hydroboost had a dummy plug on the back. There isn't a standard plug to go in it since there is no hole. Im sure you could just epoxy up the insert for vacuum so it cant leak vacuum out and it would be pretty clean looking.

pholmann said:

The trucks that came with hydroboost had a dummy plug on the back. There isn't a standard plug to go in it since there is no hole. Im sure you could just epoxy up the insert for vacuum so it cant leak vacuum out and it would be pretty clean looking.

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No need for epoxy. I gave him a link to exactly what he needs. It is just a air line fitting.