Brake Booster (Page 4/6)
fieroguru AUG 20, 08:30 PM

quote
Originally posted by Xenoblast:
What is the actual effect of the s10 brake booster mod on pedal feel? My friends miata brake pedal feels like pressing on a solid block of rubber, which to me is more desirable then the stock squishy feeling.



With additional boost assist, for a given pedal force, adding the S10 booster will provide more clamp load to the calipers, so the car will stop faster (up to a point).
Additionally, if you want the car to stop at the same rate, the additional boost assist means less pedal effort is needed.



quote
Originally posted by olejoedad:
How much extra clamping force does the S-10 booster provide over the OEM Fiero?



It isn't linear, nor is it the same front/rear.

[This message has been edited by fieroguru (edited 08-20-2023).]

jelly2m8 AUG 21, 02:40 AM
I also have done the brake booster that Phil mentioned in his / the original swap. What I found was this, and to me the beauty and best feature of the S10 Booster is that now My Fiero feels like a modern car when applying the brakes. many of us are upgrading our 35 plus year old Fiero's with modern equipment, be it drivetrains, electronics, suspension, why not make the braking feel modern also.


My car has new Raybestos pads front and rear, new Raybestos rubber hoses all around, Calipers that have been gone through with new dust boots, ceramic grease on the sliders and a master Cylinder. I do have 12 inch rotors on the car. It still felt like a Fiero braking. After I did the S10 booster I said WOW! I don't know if it will brake harder as I do not drive like a complete idiot but slowing down from a bit above posted speed limits I do not have to go APE on the brake pedal, the car slows down and stops quickly without feeling any drama. Driving it normal the brake pedal feels about as normal as any car built within the past 5 years.

I guess I could say I find more modulation, not the all or nothing of Stock Fiero Braking system. And Yes, I drove Fiero's when they were still selling them new.

[This message has been edited by jelly2m8 (edited 08-21-2023).]

longjonsilver AUG 21, 07:24 AM

quote
Originally posted by olejoedad:

How much extra clamping force does the S-10 booster provide over the OEM Fiero?




Given the same vacuum, i estimate the S10 booster has 40% more surface area. Therefore 40% more clamping force.


quote
Originally posted by theogre:

3. 84-86 Fiero has vac filter in engine bay that can plug up and small line that restrict air flow with long line. The small size (3/8") work w/ front engine vehicles because only 1 to 2 feet to reach the booster. GM "fix" this for 87-88 Fiero w/ 1/2" vac line and related fitting and deleted the filter. (Warning: FSM and 22P has no data for this and many parts stores don't list correct booster vac parts for 87/88 Fiero.)



Interesting what the Ogre posted about the bigger vac lines on an 87-88 car vs the earlier ones. Anyone done this mod?

------------------
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, 3800SC, 4-wheel drifts are fun!

Wichita AUG 21, 09:29 AM
Has anyone ever thought in putting in an ibooster?
https://www.bosch-mobility....ing-safety/ibooster/

I know that there have been several classic car builds on Youtube that have put these in their builds, instead of a traditional diaphragm booster.

Originally people where snagging these off of wreck Teslas, but Honda puts it in theirs and they are a lot cheaper to find. But you can also buy them brand new from Bosch.
82-T/A [At Work] AUG 21, 11:18 AM
Not to detract from Wichita's question above...

But I keep hearing people say that you need to use a hammer.

In my 1987 Fiero SE / V6, I installed an S-10 Brake Booster and it fit perfectly without any clearance issues. I'm just curious what models everyone here has installed that required modification?
Vintage-Nut AUG 21, 12:57 PM

quote
Originally posted by 82-T/A [At Work]
But I keep hearing people say that you need to use a hammer. In my 1987 Fiero SE / V6, I installed an S-10 Brake Booster and it fit perfectly without any clearance issues.



Really?

The major drawback to me which requires "percussive adjustment" or "massaging" of the sheet metal (hammer) to make a depression in the steel inner fender for this larger booster to fit.

I didn't want to modify the frame.....
NW-Fiero AUG 21, 02:26 PM

quote
Originally posted by 82-T/A [At Work]:
In my 1987 Fiero SE / V6, I installed an S-10 Brake Booster and it fit perfectly without any clearance issues. I'm just curious what models everyone here has installed that required modification?



Without knowing the Year/Model/Size of Booster you installed it is hard to determine your situation

There were several size of Boosters used on the S10. You may have installed the CARDONE 501268 which had a diaphram size of 9.11"

While the larger S-10 Size, most appear to have installed, was 10.4"

.

------------------
Mark
' 85 2m6 3.4PR
In the Great Northwest!

[This message has been edited by NW-Fiero (edited 08-21-2023).]

jelly2m8 AUG 21, 06:28 PM

quote
Originally posted by Vintage-Nut:


Really?

The major drawback to me which requires "percussive adjustment" or "massaging" of the sheet metal (hammer) to make a depression in the steel inner fender for this larger booster to fit.

I didn't want to modify the frame.....



Your not really modifying the frame, It's just a subtle reshaping of one small area that if you don't go too crazy it's not really even noticeable with the Booster not even in place. It's not an area that shows from the underside. I too did not want to ' beat on my chassis', I looked at several options, angling the booster, off setting it inboard but both of those options left the same issues, incorrect pushrod angle and it was alot of work for zero gain.

10.4in booster in place before subtle modification Notice the gap at the bottom of the bracket.


The modification done to allow booster to seat properly


Booster mounted.
Vintage-Nut AUG 21, 11:07 PM
Thanks for the photos jelly2m8, I didn't find any photos of "massaging" the sheet metal.

I’m still working on the complete brake system service and when I’m finished, of course I’ll see if I really ‘need’ a bigger booster....

Edit to Add "Thanks" to NW-Fiero for Rodney's S10 Brake Booster - Review/Evaluation Link!

[This message has been edited by Vintage-Nut (edited 08-22-2023).]

Patrick AUG 22, 03:49 AM

Maybe you guys wouldn't require a larger brake booster if you quit skipping leg day at the gym. lol




Just kidding, just kidding... please don't neg me.