$100 brake upgrade (Page 41/43)
longjonsilver OCT 14, 08:55 PM

quote
Originally posted by Patrick:

I don't know how else it could've been interpreted. Did you not get the connection between weak legs and the need for a larger power brake booster? It was just a joke, and I thought the picture was perfect.



i guess i can be quite dense at times. Anyway, the correct length of the Fiero rod to cut and thread for my 84 Fiero and for the 95 GMC Sonoma power booster was 5 1/8". i did some welding and now its the correct length and the pedal height is the same as the clutch, and the brake light is off, unless i tap on the brakes and the light comes on immediatly. Just what i want.

Lets do some math (maybe i have weak legs, but hey, i'm getting old and my brain functions fine)
Force=Pressure * Area
lbs force = lbs/in^2 * in^2

the ratio of lbs force new booster/lbs force old booster = Pressure of Vacuum * Area of new booster / Pressure of Vacuum * Area old booster

Since the pressure of the vacuum for both booster is equal, the pressure terms drop out (anything divided by itself is 1)

so we are left with

the ratio of lbs force new booster/lbs force old booster = Area of new booster / area of old booster

Area = Pi * radius ^2 . so Pi divided by Pi drops out ( anything divided by itself is 1) . So we have

the ratio of lbs force new booster/lbs force old booster = Area new booster/ Area of old booster = r^2 new booster/r^2 old booster

Old booster is 9" and new booster is 10 3/4" so R of old booster is 4.5" and R of new booster is 5 3/8"

R^2 of old booster is 20.25 and R^2 of new booster is 28.89

So the ratio of lbs force new booster/lbs force old booster = 28.89/20.25 = 1.427 . But i can't measure that accurately with my equipment so rounding off we get a ratio of 1.4

In other terms the S10 booster is 40% more powerful than the old booster. But you knew that didn't you?

jon

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Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

Patrick OCT 14, 09:49 PM

quote
Originally posted by longjonsilver:

Lets do some math (maybe i have weak legs, but hey, i'm getting old and my brain functions fine)



I'm 62 and my legs are strong from cycling, yoga and playing hockey... but my math sucks. So I guess we're even.

longjonsilver OCT 16, 02:10 PM
i've been enjoying my "new" brakes, but one thing that i don't remember anyone else mentioning was the different size vacuum hose between the 84 Fiero and the 95 GMC Sonoma



i had to reuse the Fiero banjo fitting and shorten the hose to fit the larger booster.
Would the smaller diameter Fiero hose (and the longer run from the engine) make the recovery time longer ?

hmmmmmmmmmmmmm

jon
longjonsilver OCT 16, 02:11 PM
duplicate post

[This message has been edited by longjonsilver (edited 10-16-2018).]

Red98422 OCT 18, 03:21 PM
Are you referring to the little plastic one way valve? If so I just swapped them over from fiero to the s-10 and have seen no ill effects. As for the recovery time, sure it’ll take a little bit longer but not by that much at all, once the booster sees vacuum the likelihood that you will be able to drain it faster than it builds is near non-existent (assuming everything is functioning properly)
Dennis LaGrua OCT 22, 05:10 PM

quote
Originally posted by Red98422:

Are you referring to the little plastic one way valve? If so I just swapped them over from fiero to the s-10 and have seen no ill effects. As for the recovery time, sure it’ll take a little bit longer but not by that much at all, once the booster sees vacuum the likelihood that you will be able to drain it faster than it builds is near non-existent (assuming everything is functioning properly)



On my 87GT, I also had to swap the old check valve to the new brake booster as well. I used the Tuff Stuff booster with the Rodney Dickman end. Actually two screw on ends come with the Tuff Stuff (Hurst) booster but they are too short. They could be extended with a long nut and a small length of threaded rod but I thought that keeping only one attachment point was beneficial. BTW by tightening with some Red Locktite on the threads I cannot see the end coming off. If I was that worried I would tack with mig welds there. Best brake upgrade ever.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

liv4God JAN 26, 12:44 PM
I've put together a before and after test comparison video for anyone who is wondering what affect the big brake booster actually has on their Fiero:
Tony Kania JAN 26, 02:59 PM
Cool review.
wftb JAN 26, 05:01 PM
That is a great video. Funny the Motor Week guys got the rears to lock up on a stock Fiero, I have never seen that happen. Nice to see a video that clearly shows the kind of results a mod can give you.

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86 GT built 2.2 ecotec turbo
rear SLA suspension
QA1 coilovers on tube arms

liv4God JAN 27, 03:05 PM
Thanks for the positive words guys!
I would like to find a way to adjust my brake bias to add a little more in the back. I think it could stop even faster if the bigger back tires are pulling their weight.

[This message has been edited by liv4God (edited 01-27-2020).]