Brake BOOSTER - How necessary for street use ?

[abently]

Ok, I've heard from some circuit racers, its plausible........ then I've heard from others, more so auto brake businesses that it'll be impossible.....

So some facts, remove Brake booster (4.1 ratio) but increase Master Cylinder cylinder ID area by 25% whilst keeping same internal volumes of the Front and rear disc calipers. (Front discs 276mm, Rears 266mm)

Plausible or too dangerous to really use correctly if need be in an emergency ?

Vehicle does not have ABS, so brake control may actually be better than a boosted System in a High-speed braking emergency..... unsure on low-speed / instant braking emergency... ?

And yes, I know the legalities of it all as well......

Peoples experiences ?

[merc-blue]

Keep the booster, if its causing any negative affects get its recoed, its probly leaking

Most race cars dont use them but most use a dual cuircut system so they have 2MCs which both are quite big, in the 3/4-1inch range.

You will have a very stiff pedal and will require alot of effort to drive, if you wont be able to get smooth braking transisions and will probly lock wheels quite abit more. if you jump the pedal you are quite likly to lock it all up

There is no benefit gained from removing a properly functioning booster, if you have a squishy pedal get it recoed

[allencr]

... increase Master Cylinder cylinder ID area by 25% ... same internal volumes ...

How about 'decrease' & 'area' instead of increase & volume!
Just do it, there's no magic in it, just leverage.

[MRMOPARMAN]

^^ exactly. increasing the size of your master will make your pedal harder and work quicker. keep the booster for the simple fact that the car will be much easier to drive, less of a tire.

[The Real Roadrunner]

to do it properly on a single maso system and still have good feel with reasonable pedal effort required you need to increase the leverage ratio to 6-1.

but as has been said its better to keep a booster there if it came with 1 and only remove it if you go to dual maso setup.

cheers
linden

[roadsailing]

I drove a car with no booster for a few months, it was fine (old civic)

i think a sprinter would be fine too, but i'd only remove it for a real reason, like fitting in a bigger inlet plenum etc for quads, and even then i'd look at smaller boosters first.

main problem is when you get in a car that does have boosted brakes, brake and then stick your head through the windscreen!

[lexsmaz]

Its far from being impossible but why do it ??? Also if you but a larger m/cyl on, as has been said it would require more pedal effort again on top of the fact that you have no booster ... Stupid idea .... if its room you are after you could hook up a remote booster like a VH44 set up ...

[harolto]

my old 1200 had no booster and i hated it, was alright for daily driving, but once you were giving it abit of stick, stopping became a problem without locking up,
also stopping with a car load down a hill was a B*tch, had to put my while weight onto the brake pedal.
sure it had small brakes and was 4wheel drum, but driving without a booster honestly sucked,
-Jake

[30psi 4agte]

I dont run a booster and use a single master setup and love it.

Yes you will need to apply more pedal pressure but thats about it...The only thing having no booster will effect is the force YOU need to apply to the pedal.

The only drama i can see with it is what road runner mentioned......The leverage ratio causing the brakes to be just unusable. My car came from factory with no booster so the pedal setup and leverage ratio are designed accordingly.

Forgive me.but what car are we talking about here ?---I take it its a sprinter..
If you are dead keen on giving it ago you may need to modify your pedal setup to try and gain some leverage if the pedal is too hard.


If you ask me ..... you will have far better pedal feel and brake control with no booster than you will with one.
It will be a pretty hard pedal and have minimal travel with no booster but you soon get used to it
I would have no booster over boosted brakes any day on a tuff street/ racer!... If the car was supposed to be a comfy cruiser than i would have a booster.

If it is a sprinter i recon you will be ok to get rid of the booster

[The Real Roadrunner]

profile says sw20 but who knows he hasn't been overly specific.

cheers
linden

[abently]

Yes, its not the SW20.

Does anyone by any chance have an internal contact at PBR to get the list of various M/Cyl ID's and lengths ? (First and last time I called them, I walked straight into their internal brick wall ) As I will be either going smaller or changing my pedal leverage.

[Mos]

Have you driven the car without brake assistance? Did you like it?
Mos.

[Rodger]

Brakes only need to work and be biased front to rear so the fronts lock first. There is no legal requirement for a car to use a booster. Of course a car that was ADR'd with a booster would need to be tested to confirm that the braking ability has not decreased and the bias is ok.

If the car has a booster now and you want to feel what the brakes are like without it, disconnect the vacuum line from the booster, and block the line.

Then find a quiet safe street and try to lock the brakes at various speeds.

Then if you can, take the car to an RTA testing station and ask if you can run it on the brake test machine. If you can meet the required brake force readings without the booster connected then it will be roadworthy.

Then let us know how it went.

Regards

Rodger

[The Real Roadrunner]

If the car has a booster now and you want to feel what the brakes are like without it, disconnect the vacuum line from the booster, and block the line.

Then find a quiet safe street and try to lock the brakes at various speeds.

Regards

Rodger

this i don't recommend, as i stated earlier the leverage ratio will need to be increased and chances are a smaller maso fitted.
just disconecting the vac line wont give any indication of what it will feel like if done correctly, it will just feel like pushing against a brick wall.

abently, how bout you tell us what car its for and we may be able to help (if you want good info you need to let us know what car we are talking about)

cheers
linden

[Rodger]

Yes exactly linden,

abently will not know until he tries. If it is like pushing against a brick wall then that is what his boosterless brakes will be like using the M/C size he has now.

Then he can try smaller M/Cs or more leaverage.

I know just how hard it is to push when the engine is not running and I am rolling in my Landcruiser. It has a 1 inch M/C and I need to grab hold of the steering wheel and push but the brakes bite just as well and there is no less pressure exerted on the pads.