running no brake booster???

[Nic19]

hey guys whilst browsing the interwebs i saw an adaptor plate to remove the brake booster on an ae86. what would be the benefit of this and would your brakes still work properlly??

[Dylan]

The ability to run longer velocity stacks?. Just have to push a little harder for the brakes to work

[Nic19]

do u think it would be that hard to push? im only interested as i wanna rmeove as much clutter from the engine bay as possible

[resol]

to see how hard it would be, take the vac line off the booster and go for a drive. i can tell you now i will never run no booster, unless i get some epic leverage action.


-dan

[dustyae86]

usually you up your master cylinder size to compensate. SO it isn't really like driving with your booster hose disconnected, but yes there will be a lot more pedal effort required

[ke70dave]

usually you up your master cylinder size to compensate. SO it isn't really like driving with your booster hose disconnected, but yes there will be a lot more pedal effort required

actually using bigger mastercylinder will make it harder to push.

in order to make it easier to push you would need to use a smaller master cylinder, but then you would need to push it further to make the brakes work.

i dont see a need to not use a brake booster. maybe there is a slim booster you can get off another car to allow for a bit of room for the quad throttle stacks.

[LittleRedSpirit]

Ke55 booster will work and is 1 inch smaller than AE86 in diameter. Make sure you get the one which corresponds to you master cylinder stud pattern as ke30 and ke55 have 2 different patterns that happen to be the same as kouki and zenki ae86 brake boosters.

If you want no clutter you can set up a remote booster and hide it somewhere I guess. lots of cars have remote boosters, Hondas, valiants, its prettyr and om but they are out there. You can buy new aftermarket remote boosters, also.

[takai]

Driving a car with no booster is nothing like driving with one unplugged, that is a load of crap.

Driving sans-booster with an appropriately sized master cylinder gives a much better pedal feel than with a booster, especially if you have a low-vacuum engine.

[Chrisso]

Takai - by a "low-vacuum" engine do you mean one with ITBs? I'd ask about MC sizing but that's obviously specific to brakes and fluid volume. What kind of adaptor plate did you use?

[takai]

This is from my thread on Toymods about it:



All Cars. Custom unboosted setup
Ok, this is the grand daddy of all brake master cylinder upgrades that you can do. It means removing all the booster setup and making a custom plate to fit in its place. The MC which i have found which is extremely good for this setup is suprisingly enough from a Datsun 240K. Basically you need to make up a thick plate with studs on either side to mount the cylinder off. I have done this with an 8mm piece of steel and some hex head studs. 4 will mount back to the pedal box, and another 2 to the cylinder. Like so:
http://gallery2.plebeians.net/d/6395-2/IMG_0019_004.JPG
You will then need to figure out an appropriate length pushrod in order to actuate the cylinder. This takes a bit of testing as you want it to be horizontal for about 95% of the travel of the pedal. I have chosen to put a rose joint into the setup, for a couple of reasons. One so that the pushrod remains captive even if there is a reasonably catastrophic failure. Secondly this allows there to be a fixed pivot point so there can be a vaguely seesawing action in order to locate the pushrod.
On my setup it looks something like this:
http://gallery2.plebeians.net/d/6392-2/IMG_0014_004.JPG
All installed it looks like this:
http://gallery2.plebeians.net/d/6405-2/IMG_0023_004.JPG
*NOTE* This needs to be done at your own risk. Playing with brake parts is reasonably dangerous to begin with, let alone customising mounts and making your own master cylinder mount and actuator. If you are not confident with anything in this guide then DO NOT DO IT.

DISCLAIMER: Usual stuff, you break it, you bought it. Its not my fault if you cant wield a spanner or do simple addition. Crash and die in a fire at your own risk.

ITBs generally only generate a couple of mm less vac than a standard engine, easily enough to actuate a booster. Big cams with massive overlap on the other hand dont. My engine with 272@.50 static cams generates only 5-6mm/Hg vacuum at idle, compared to the standard of around 20mm.

[DRFT]

brake boosters only make it easier to brake gently, when you do an emergency brake or stomp if actually bypasses the booster and it does nothing. so ive been told

[marvis]

Any more discussion on this?

[Admiral Ackbar]

Removing the booster with no other mods will be shit, because it's not an un-boosted setup, it's a boosted setup with the booster missing :)

The plastic one way valve fell apart while I was driving once...I nearly shit my pants. I drove it like that to a brake place to get a new one way valve...do-able in an emergency but I wouldn't recommend it. It requires massive effort to lock the brakes, as in some people would not be able to get maximum braking effort. I replaced the plastic one way valve with a generic metal one.

[.ady]

braking is over rated. lawlz.

[DRFT]

Removing the booster with no other mods will be shit, because it's not an un-boosted setup, it's a boosted setup with the booster missing :)

The plastic one way valve fell apart while I was driving once...I nearly shit my pants. I drove it like that to a brake place to get a new one way valve...do-able in an emergency but I wouldn't recommend it. It requires massive effort to lock the brakes, as in some people would not be able to get maximum braking effort. I replaced the plastic one way valve with a generic metal one.

Hes right. however it is still doable all you need to do is drop a size in your brake lines, As an old guy ones explained changing the size of your lines is like playing with leverage and fulcrum point. when its smaller its eaiser to push, It gives you more feel. N2 TRD ae86 has no brake booster they run a race pad to compensate and it works miracles

[Javal]

brake boosters only make it easier to brake gently, when you do an emergency brake or stomp if actually bypasses the booster and it does nothing. so ive been told

Wrong.


Hes right. however it is still doable all you need to do is drop a size in your brake lines, As an old guy ones explained changing the size of your lines is like playing with leverage and fulcrum point. when its smaller its eaiser to push, It gives you more feel. N2 TRD ae86 has no brake booster they run a race pad to compensate and it works miracles

Again, wrong. You need to stop posting in this thread and start reading all of takai's posts on the first page.

Seriously, high school physics? Anyone?


Removing the booster with no other mods will be shit, because it's not an un-boosted setup, it's a boosted setup with the booster missing :)

THIS is the answer that most people in this thread are a looking for.

If you want to remove your booster, you need to change your master cylinder to compensate and probably your pedal setup as well. That's the long and short of it.

[ke_70]

yes but does anyone know the basics of building a "boosterless" setup. looking for a ratio of caliper bore size and master bore size. mabey start at takai mc:caliper

changing line size will do nothing.

[marvis]

^ This.


Needs a write up!

[assassin10000]

Not only is the size of the calipers/master cylinder need to be taken into account, but also the brake pads your using. And personal preference on pedal feel/travel.

Andrew

[Celica RA45]

im using AP 4spot calipers on the front and also on the back of my race car front master is .625 and the rear is .700 also have adjustable brake balance to move more front or rear

[ae8zn6]

Removing the booster with no other mods will be shit, because it's not an un-boosted setup, it's a boosted setup with the booster missing :)

The plastic one way valve fell apart while I was driving once...I nearly shit my pants. I drove it like that to a brake place to get a new one way valve...do-able in an emergency but I wouldn't recommend it. It requires massive effort to lock the brakes, as in some people would not be able to get maximum braking effort. I replaced the plastic one way valve with a generic metal one.

Its a trap!








Sorry, I couldnt help myself....

[Sam-Q]

hey DRFT could you downsize your signiture please, it's the size of 3 lines of text.

Another option people should consider is running a remote booster.

[Admiral Ackbar]

I used to have a car (not an AE86) with dual masters+balance bar+remote booster, but only the front master was connected to the booster. Both masters were also the same size. One day I disconnected the booster out of curiosity - locked the rears big time! Which is what I expected because the balance bar was more or less central, so it had roughly equal brake pressure front and rear. When the booster was connected it biased the braking towards the front and also reduced pedal effort. The balance could also be fine tuned using the balance bar.

If you are designing a booster-less system you need to take into account pedal leverage, brake piston area (front and rear), and the pad coefficient of friction when working out master cylinder sizes.

[stahlz_ae86]

Do you know the formula used to calculate it? Do know of this but I'd like too see the formula as I wanna play with some numbers soon.

Cheers,
Paul.

[mikeyee]

http://orangeadvan.blogspot.com/2010/09/new-plate.html

http://1.bp.blogspot.com/_tgQh3YUO5Go/TKVbDAFWRCI/AAAAAAAACXg/dKVueyWmoc0/s1600/bld005.jpg

[Sprinter Freak]

Digging up this thread. What would be the ideal master cylinder size for standard jap ae86 brakes, front and rear. But running them with out the booster?

I have a 7/8" wilwood master at the moment and i think its a bit too big, takes a fair bit of force to lock up the brakes.

i was thinking either a 3/4" or 5/8" bore master cylinder?

[drift kid]

I did a booster delete and used a wilwood 7/8" master. I did a bit of research too, I found quite a few people running then with sucess. I really like the pedal feel

[Sam-Q]

I would think the stock 13/16" size?

[Sprinter Freak]

I would think the stock 13/16" size?

yea stock size is 13/16"

Have been doing a bit of research and what people have been saying is to go a smaller brake master, which increases the pedal travel but makes it easier to brake.

But how much smaller do you go from standard? :S

The 7/8" still works you just have to use a bit of force, maybe i just need to get used to it. But could imaging it would be a bit sketch with emergency braking

[jonesy3194]

Essentially it's the volume of liquid you have to move in the master cylinder, if you decrease the diameter of the master by half you have to move the pedal 4 times further to get the same braking effect also the effort required would he 1/4 of that of the larger cylinder


From a purely theoretical point of view

[Sprinter Freak]

Essentially it's the volume of liquid you have to move in the master cylinder, if you decrease the diameter of the master by half you have to move the pedal 4 times further to get the same braking effect also the effort required would he 1/4 of that of the larger cylinder


From a purely theoretical point of view

yea i get what you mean, but I'm not sure how much pedal travel i have at the moment. will have to measure it and see. Just don't want to go down to a 5/8" bore master and the brake pedal to be an inch off the floor before it starts working :right:

[Sam-Q]

yea stock size is 13/16"

Have been doing a bit of research and what people have been saying is to go a smaller brake master, which increases the pedal travel but makes it easier to brake.

But how much smaller do you go from standard? :S

The 7/8" still works you just have to use a bit of force, maybe i just need to get used to it. But could imaging it would be a bit sketch with emergency braking

I asked the exact same question a while ago and was told to watch out for running out of brake travel. I can't see a 3/4" master being an issue though.

[Javal]

yea i get what you mean, but I'm not sure how much pedal travel i have at the moment. will have to measure it and see. Just don't want to go down to a 5/8" bore master and the brake pedal to be an inch off the floor before it starts working :right:

Spot on mate, a smaller master gives greater hydraulic advantage but requires more travel to do so. As sam has said above, running out of travel can he an issue - it will be just as progressive as normal but over a longer pedal travel. Moving the clevis for the master further down on the pedal (somehow) would assist in reducing the travel but you'd lose some of the mehanical advantage on the master you get through the leverage of the pedal just to help overcome havin too much hydraulic advantage. So sizing it correctly is important - i'm unable to help you choose a master size for a boosterless setup but a good way to do is to look at an already working boosterless setup, and calculate the ratio between the surface area of the caliper pistons (or wheel cylinders) at all 4 corners and the surface area of the master cylinder. That'll give you a good indication of how to size your master - worked an absolute treat for my boosted setup - then you just have to get the travel right!

[LittleRedSpirit]

As I understand it, the master cylinder you use must be hydraulically correct for the system over the desired pedal travel. The rest is down to the leverage ratio of the pedal to overcome the lack of a booster. If you change mc to reduce effort, Id be looking at moving the pedal pivot up more and lengthen the pedal to enhance the leverage ratio and also the travel of the mc piston since, being smaller it will require more travel to move the right amount of fluid.

Have you seen this (http://www.motorsport-tools.com/toyota-corolla-rwd-ae86-brake-balance-bar-bias-pedal-box-wilwood-mc.html).?

[tottacrolla]

Have you seen this (http://www.motorsport-tools.com/toyota-corolla-rwd-ae86-brake-balance-bar-bias-pedal-box-wilwood-mc.html).?

Make absolutely sure it fits an AE86 if you are thinking of buying one.
There is probably a good reason why it is out of stock.....

[LittleRedSpirit]

Yeah, its probably popular. They list them for almost all popular cars in the uk market. The listing is specifically for ae86, if it didnt bolt in Id be pretty disgusted, but then theres still the issue of the leverage ratio and whether its correct or not with those mcs and the brake calipers youre running.