Anyone try using an S10 Master cylinder- Results? (Page 2/2)
fieroguru SEP 20, 02:22 PM

quote
Originally posted by pmbrunelle:
...assuming that braking_force/pedal_force is the metric you wish to maximize.

There's a range of workable gains; I wouldn't set the factory gain as a hard lower bound.



I am merely stating that if you swap in a large master assuming all other things being equal the car will stop better with the same pedal effort, you will be woefully disappointed. The car will either take longer to stop or require more pedal effort to stop the same.
darkhorizon SEP 22, 11:32 PM
During my quest for superior braking performance, i tossed a S10 master in my fiero because my buddy had a autozone warranty for them. I can still easily lock up all 4 at any speed, and I get a little better modulation now. I'd say it was an upgrade although it did slightly increase my pedal effort and shorten my throw which makes for a little better heal toe braking.
edfiero SEP 23, 12:07 PM
Dennis, post up your results once you complete the swap.
theogre SEP 23, 05:43 PM

quote
Originally posted by fieroguru:
I am merely stating that if you swap in a large master assuming all other things being equal the car will stop better with the same pedal effort, you will be woefully disappointed. The car will either take longer to stop or require more pedal effort to stop the same.

Yes, is Basic Hydraulic 101.
"Big MC" puts out Higher Volume and Lower PSI vs Fiero Factory Installed MC And will to this w/ stock And any "upgrades."

You install "big MC" to address Bigger Pistons that need More Fluid Volume on GA and other "Upgrade." Not to give you a big boost in line pressure.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

0z SEP 23, 07:42 PM
All I know is that I have 2 88s, One previous owner installed the S-10 Booster and slotted rotors, the other is completely bone stock except for the new pads and rotors I put on it.
The one with the S-10 booster locks the wheels up with ease.
The stock system takes a LOT of effort to do the same.

[This message has been edited by 0z (edited 09-24-2020).]

Mike in Sydney SEP 23, 08:20 PM

quote
Originally posted by 0z:

All I know is that I have 2 88s, One previous owner installed the S-10 Booster and slotted rotors, the other is completely bone stock except for the new pads and rotors I put on it.
The one with the S-10 booster looks the wheels up with ease.



Does your car have the S-10 Booster with the S-10 MC?

Like Ogre says, larger bore = lower line pressure which means you have to use higher brake pedal effort to get the same pressure as you get with the OEM MC and brake booster. The S-10 Booster provides a good bit of additional "oompf" with the original master cylinder. Using it and a S-10 master cylinder may help with the pedal effort. Maybe Ogre has an opinion about use to the S-10 booster / MC combination on Brake upgrades.

BTW, I've got and S-10 Booster and Wagner TQ pads on my one of my '86 GTs and it stops a lot faster than the one with the stock booster.

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Mike in Sydney

0z SEP 23, 09:11 PM

quote
Originally posted by Mike in Sydney:


Does your car have the S-10 Booster with the S-10 MC?





That I am not sure of. The MCs in both cars look the same. I'll have to see if the PO knows.

**** It is just the booster. Stock MC

[This message has been edited by 0z (edited 09-24-2020).]

theogre SEP 24, 02:46 AM

quote
Originally posted by 0z:
All I know is that I have 2 88s, One previous owner installed the S-10 Booster and slotted rotors, the other is completely bone stock except for the new pads and rotors I put on it.
The one with the S-10 booster looks the wheels up with ease.
The stock system takes a LOT of effort to do the same.

Very Likely something is wrong w/ you "all stock" car.
Any Vacuum booster can have 1 or more problem affecting brake performance on top of whatever else maybe wrong and w/o a clue saying use big booster means bloody little.

No-one should compare non-ABS to ABS.
ABS systems often way over boost the brakes to the point that even small kids can push the brake and let ABS box to handle wheel skid problems. Problem is many ABS systems still have problem even on Dry Pavement like ABS "trips" when brake and turn and even at low speeds.
Dennis LaGrua SEP 24, 08:07 PM
Just a heads up . After all the discussion I decided to play it safe and just replace the master cylinder with a stock part. I went with a new AC Delco unit and I purchased it from Summit Racing Equipment, a reputable dealer, so I'd get the real Delco part and not the counterfeits that are sold on eBay. I paid a premium price $130 shipped but when it comes to brakes whats your life worth?. The best part is that this master cylinder is Made in the USA and its stamped right on the bottom of the unit. If you decide to buy this master cylinder it is sturdy cast iron not aluminum. Installation was a 30 minute job. Pedal is no longer spongy but I will again bleed the calipers to insure best braking action..

[This message has been edited by Dennis LaGrua (edited 09-26-2020).]

Mike in Sydney SEP 24, 09:13 PM
Post deleted. Posted in error. Oops!
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Mike in Sydney

[This message has been edited by Mike in Sydney (edited 09-24-2020).]