$100 brake upgrade (Page 3/43)
Blacktree APR 04, 01:24 PM
Actually, the formula is F=PA.
fierogt88 APR 04, 01:27 PM

quote
Originally posted by Blacktree:

Actually, the formula is F=PA.


No, it's not.

edit: or maybe it is. Regardless, it's a matter of ratio to the pressure and the value of F can vary widely depending on the mechanical leverage available from the pedal design. I'm looking now for verification of the formula either way...

[This message has been edited by fierogt88 (edited 04-04-2006).]

fieroman_5000 APR 04, 01:30 PM
think units...say F is in lbs, P is in psi, and A in2 so with F=P/A you get psi/in^2 which gives you lbs.
Blacktree APR 04, 01:42 PM
Think for a minute. What units do we use to measure pressure? In the Imperial system it's Pounds per Square Inch, i.e. force/area. So obviously, P=F/A. Multiply both sides by A and you get F=PA.

BTW, here's confirmation from Wikipedia.org.

But back on topic... the big question is the size difference between the S10 booster's bladder and that of the Fiero booster. The force increase will be directly proportional to the bladder area increase.

[This message has been edited by Blacktree (edited 04-04-2006).]

fierogt88 APR 04, 01:51 PM
You are correct on the formula. (so you can ignore my previous post where I relied on the false formula)

However, you are still neglecting the importance of the correct level of vacuum.
The check valve and the amount of vacuum the engine can pull are the other half of the equation.

Pyrthian APR 04, 02:02 PM
the same vacuum in a larger area = more force - its basicly like useing a larger wrench
now, on the other side, many aftermarket cams do lower the manifold vacuum, and canisters are used to store vacuum peaks, and even vacuum pumps are used for extreme applications.
while I understand this is brakes, and its important to be careful, but its not like this is an overwhelming brake assist that will lock up the brakes with the slightest tap of the pedal, its just a slightly larger assist to help with slightly larger bore MC, which needs slightly more assist.
fieroman_5000 APR 04, 02:02 PM
Yes Blacktree, but that just means that instead os ponds per squar inch in the line I was thinking pounds force at the calipers...either way. Though about the vaccum and volume of the booster...I thought the bosster was sealed, ie, no check valve? I thought once it got to the correct vaccum it would hold there, though saying this now in my head makes no sence as if that happened the vacuum would continue to rise, untille the sys gets air from somewhere (leak) so in that case I can definately see that if the check valves were indeed differant (open sooner for the *bigger* booster) this would be a problem. All in all Phil said the results are great so the detail don't really matter to me, except what year S-10 the booster is out of?
Blacktree APR 04, 02:03 PM
I'm not neglecting anything. As I already stated, the bigger booster will take longer to pressurize.

Do you have an air compressor? If you use it to fill a 10 gallon tank, does the pressure somehow end up being lesser than a 2 gallon tank? If the compressor is capable of 100PSI, it will fill both tanks to 100PSI. The difference is time.

fieroman_5000 APR 04, 02:04 PM

quote
Originally posted by Pyrthian:
its just a slightly larger assist to help with slightly larger bore MC

Or for us who have to apply excessive amounts of force to the pedal to get the brakes to lock-up

[This message has been edited by fieroman_5000 (edited 04-04-2006).]

fierogt88 APR 04, 02:14 PM

quote
Originally posted by Pyrthian:

the same vacuum in a larger area = more force - its basicly like useing a larger wrench


And, again, until you can show me that a 2.8 and 4.3 pull the same vacuum and that the check valve from a fiero booster and the check valve from an s10 maintain the same vacuum then no global statement that uses the term "same vacuum" is even remotely valid.



quote

now, on the other side, many aftermarket cams do lower the manifold vacuum, and canisters are used to store vacuum peaks, and even vacuum pumps are used for extreme applications.

So changing cams can change how much vacuum is pulled but changing engines doesn't?


quote

while I understand this is brakes, and its important to be careful, but its not like this is an overwhelming brake assist that will lock up the brakes with the slightest tap of the pedal, its just a slightly larger assist to help with slightly larger bore MC, which needs slightly more assist.

Yes, I think once we verify how much vacuum is being pulled inside the booster with a 2.8 engine (and honestly I really really really do think it will come up fine - but nobody has offered to hook up a vacuum guage yet...) and once we have some comparable measurements for the pedal assemblies, this may actually allow the use of the bigger cylinder with more force applied at the calipers and less pedal effort at the foot. But again, if the proper vacuum can't be generated/maintained then it's a little early to be telling everybody it's a safe upgrade.

[This message has been edited by fierogt88 (edited 04-04-2006).]