$100 brake upgrade (Page 1/43)
Phil APR 04, 08:37 AM
As some of the folks from the chat room and at Daytona already know, I stumbled upon a cheap and effective brake upgrade. There is also a writup of this in the current Fiero Pride newsletter. Although I've only done this on a 88 I see no reason why it wouldn't work for any year Fiero. While I had the hood open on my Chevy S10 pickup (dead battery) I noticed that the power brake booster had a bit larger diameter than that of the Fiero. After taking a few rough measurements I determined that the S10 booster would fit in the Fiero. The installation turned out to be rather easy.
# 1 - Unbolt the master cyl from the Fiero booster and just move it out of the way( no need to disconnect any brake lines) and disconnect the pushrod from the pedal
# 2 -Remove the Fiero booster and then file/cut/ grind the 4 rivets that attach the bracket to the Fiero booster and bolt the bracket to the S10 booster

# 3- You now have to extend the pushrod from the booster to the pedal. I made a threaded coupling but it's really not needed. Cut the end off othe S10 booster ( it's the wrong size hole) you can get a piece of steel rod and drill a hole in one end to fit over the rod and then cut the Fiero rod insert the proper length onto another drilled hole in your coupling. Seeing that this extended rod will only be in compression you could get away with JB welding the ends into the coupling but electric welding may be better.

# 4- A slight bit of BFH work is needed to give the needed clearence for the new setup

# 5- Reinstall the new setup and you're finished

I used a booster from a 96 S10
I will be doing this conversion at a NEFA Tech Session at my house o n Apr. 23 . Let me know if you want to attend
Pedal modulation is excellant and I can lock up all 4 at any speed ( if I realy really wanted too)

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

3800superfast APR 04, 08:44 AM
Pretty Cool Phil... Thanks for posting it....
Phil APR 04, 08:53 AM
Just as a side note , I did have the 12" Vette rotor setup on my car before but I didn't like having to carry a 16" spare in the front ( sunroof glass wouldn't fit in the front anymore) and I think that I now have better braking with the stock rotors and the bigger booster than with the Vette setup. I don't know if I would do both conversions at the same time - brakes might get a little too touchy.
dguy APR 04, 09:20 AM
How much of a performance increase do you get out of that bottle-fed hamster?
Formula88 APR 04, 09:31 AM
Great idea, Phil!! I may have to give this one a try.



quote
Originally posted by dguy:

How much of a performance increase do you get out of that bottle-fed hamster?


Don't you recognize a Nitroused Mouse Motor when you see one?

[This message has been edited by Formula88 (edited 04-04-2006).]

fierogt88 APR 04, 10:09 AM
This has a lot of potential...

But I'd really like to hear from some people who know how a brake booster works - with the math. I think we all know that sometimes bigger doesn't mean better - as in the case of big-bore master brake cylinders. Does a bigger brake booster automatically mean more brake assist? Can the stock engine supply the vacuum necessary?

avengador1 APR 04, 10:43 AM
As the area increases the amount of force created will be bigger, even if the pressure stays the same, or in this case vacuum. So going to a physically bigger booster should increase the braking force.
The big bore master cylinders work the opposite of this because of the way the force is applied. You are applying the same force over a large area and generating less pressure, so it would take more force to generate the same pressure of the normal sized master cylinder.

Here the formula to use for calculations P=F/A and a link to a calculator: http://hyperphysics.phy-ast...edu/hbase/prcal.html

[This message has been edited by avengador1 (edited 07-29-2007).]

NorthFloridaFiero APR 04, 11:04 AM
Cool.
Would be awesome if you got it on video.
Looking forward to other peoples thoughts on it.
fierogt88 APR 04, 11:15 AM

quote
Originally posted by avengador1:

So going to a physically bigger booster should increase the braking force.


But only if the vacuum stays the same. And I know from personal experience with one of my secret projects, that increasing volume of a vacuum canister has a tendency to reduce vacuum given the same source of the vacuum. In other words, my compressor running a venturi valve to vacuum a tank produces a lesser rate of vacuum with a bigger tank. Imagine trying to suck one breath out of a 20oz pop bottle... enough vacuum to crush the bottle. Now imagine trying to suck one breath out of a tanker truck. Your vacuum won't even register....

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

GT40 Kit 3.8 SC APR 04, 12:01 PM
Fiero88GT,
If your vacuum drops, you have a leak. Regaurdless of the size tank you're using. The only difference that the size of the tank will make is in recovery time. Keep in mind that the S-10 booster is only slightly larger, the recovery time to make up for this size is negligable.
Your engine produces a near constant vacuum. (sucking on a water bottle does not). Replace, "you sucking on the bottle", with a vacuum cleaner. Both bottles will colapse.
Kevin

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85 Fiero-based ASPP GT-40 MarkII. 3800 S/C, Auto, Held suspension all around with 2" drop spindles and sport fr. end. RCC bump-steer correction. Mr. Mike's interior.