Why exactly are the Fiero's brake system insufficient?

Has anyone tried :
Larger lines.
Different proportioning valves.
Auxillary brake fluid pressure builder.
Master cylinder mods for more volume or pressure.

What exactly is the problem?

quote Originally posted by cliffw: Why exactly are the Fiero's brake system insufficient? Has anyone tried : Larger lines. Different proportioning valves. Auxillary brake fluid pressure builder. Master cylinder mods for more volume or pressure. What exactly is the problem?

Well I had an 85GT and IMO it's the rotors. The 88's use a vented rotor. The problem I had with the '85 was fade and warped rotors, don't have that problem with the 88........Paul

hi most of it is ok , but it was explianed to me that larger diameter lines do not always equal higher pressure for braking purposes. only higher volume of liquid moved, braking reqiures pressure..............

ps that is why some people, say use blazer cylinder and stay stock otherwise, they have more pedal travel................................................

[This message has been edited by silver86se (edited 06-17-2004).]

I really didn't see a big problem with the original brake system in the Fiero. (After years for racing, taking lessons from professionals, and attending high preformace driving schools) I have a better understand of HOW to get a car to stop. I did replace the the rear rotor on my V6 with crossdrilled rotors, and I do see a improvment, as brakes tend to fade less as they cool quicker, also they shead water quicker the non drilled. When it comes time to replace the fronts, I will do the same as I did for the rears.
Complete rebuild on calipers, powered coat, replace lines with braided steel flex hose.
I do belive that putting on a bigger rotor package, and something with doulble pistons is a good thing, when you start dropping in V8's and things that product over 250hp, probably a good idea at that point to beef up the braking system. But if your just running around town, and keep it off the course,and for the most part a stock Fiero, then the stock braking system should be good, so long as it is maintained correctly.

I'd like to hear from PBJ on this. He is a real expert on this.

He did my brakes.

There are some issues I am aware of though, but I bow to those more knowledgable than me.

1. The rotors are simply small econo rotors.
2. The master cylinder is small and if you add just a bigger one alone it just creates more pedal travel.
3. The rotors are not vented and heat up (ei. hot brakes fade)

I hope this helps.

PS. The Grand Am conversion really is a big improvement and cheaper as well.

Arn

quote Originally posted by Arns85GT: 2. The master cylinder is small and if you add just a bigger one alone it just creates more pedal travel.

I haven't done any mods to Fiero brakes. I think they work well.

I don't know exactly how the Blazer MC dimensions compare with the Fiero MC, but I think if the diameter is bigger, you should get less pedal travel, not more. This is because for a given length of pedal stroke, you are forcing more fluid through the lines and out to the wheel cylinders.

Or am I on crack?

That exactly is the problem with the Blazer MC. It requires more effort but it moves more fluid. You are speading the load over a larger surface so you loose mechanical advantage.

If you have stock Fiero brakes and have never had them fade, either you don't drive it or never go over 50MPH.
I'm doing portfields all around, sloted rotors, steel lines and high temp fliud. Total cost, about $450. If that setup don't stop it, I'll install an anchor dropping system off the rear wing. Not really, but did heard a lot of good things about the setup I'll be doing when everything gets here.

I've driven my "new" Fiero enough to know now that the little thing just needs some bigger and/or vented rotors. The stock system is ok...its not the worst. If you want bad...try driving any 96-99 non-SHO Taurus. Why it had ABS I couldn't tell you because the system wasn't strong enough to lock up anyway....and mine had 4 wheel disks. I could not imagine those brakes with drums on the rear...which is what most of them had. You get warped rotors turned every few thousand miles if you're lucky for them to last that long between turning. Be thankful you have decent, balanced brakes on the Fiero.....they're not on every car.

After driving my old Taurus I have not had much of a problem with my Fiero brakes. They have not faded or warped....and it is due for new pads at that.

* Edited cause I can't spell worth a flip today. *
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I have the precious gift of patience.....it just takes too long to use it!

[This message has been edited by Key Of David (edited 06-17-2004).]

quote Originally posted by Paul Prince: The problem I had with the '85 was fade and warped rotors,The 88's use a vented rotor.don't have that problem with the 88........Paul

By fade, you mean the brakes weaken with use ? Warped rotors could be caused by overtightened lug nuts. Vented rotors help brake fade by cooling warmer than normal rotors due to heavy / hard braking. Not my issue. I do not feel comfortable knowing a panic stop may be necessary at any time.

quote Originally posted by silver86se: ps that is why some people, say use blazer cylinder and stay stock otherwise, they have more pedal travel

This also seems to provide more fluid. Into the same size lines it may raise pressure, maybe not. What pressures are normal? Now this is a good mod. Did I think of a brake fluid pressure guage system first. Yippie, I am going to be rich ! Still, if blazer mc satisfied the users it is a consideration. Which do I look for? Easy swap?

quote Originally posted by CYNFIERO:Complete rebuild on calipers, powered coat, replace lines with braided steel flex hose. I do belive that putting on a bigger rotor package, and something with doulble pistons is a good thing,.

Good advice. Flush and new fluid was a help. Replace lines? You mean hoses, yeah? What will powder coating do? Bigger rotor package, same wheels ? I would like double pistons. If at all possible I want to make my system acceptable, I want to keep my emergency brake. Any Grand Am caliper mods to allow this?

quote Originally posted by pollock: II don't know exactly how the Blazer MC dimensions compare with the Fiero MC, but I think if the diameter is bigger, you should get less pedal travel, not more. This is because for a given length of pedal stroke, you are forcing more fluid through the lines and out to the wheel cylinders.

Not sure but you are on the Forum. When you say for a given length it has to be the same pedal travel. A bigger mc could be diameter and length. May not expell any more fluid. I seem to remember using smaller sized piston and liners in pumps to increase pressure. I believe this was accomplished by the length of travel forcing liquid into a smaller hole. Quantity doesn't matter. The hole has to be full before pressure will build. A hole can only be so full reguardless of the size hole.

I think you should head to Ogres cave because he beats the crap out of the brake topic and its a good read. It has lots of good info and can create a base for a new brake idea with those variables in mine. I will do my own sort of brake up grade once I am out of AIT and basic training. This will be on an 88 fiero once I get that far, the car will be raced on the track so thats why..

quote Originally posted by Psychosis39:. I think you should head to Ogres cave .

Your right ! I am a dumba**

Thanks

In my opinion, the problem with the '84-87 Fiero brakes is the rotors. They're not vented, and they're mostly covered by the splash guards. So when they get hot, they don't cool down very quickly. If you live in a hot climate like I do, things can get downright scary sometimes.

quote Originally posted by cliffw: This also seems to provide more fluid. Into the same size lines it may raise pressure, maybe not...

Not. Your right leg supplies the power to actuate the brakes. If you supply 100 lbs of force into a MC piston that has 1 square inch of surface area then the brake fluid sees 100 lbs/sq in (100/1=100). If you double the MC piston surface area then the brake fluid sees 50 lbs/sq in (100/2=50).

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RickN
White 88GT 5spd - Grey Interior
White 85GT Auto - Grey Interior

The real problem with Fiero brakes is that the newest (non '88) ones are 17+ years old and probably haven't been maintained well. Other than that they're quite adequate with good pads.

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Doug Chase
Chase Race
Custom roll cage and exhaust fabrication

quote Originally posted by Doug Chase: The real problem with Fiero brakes is that the newest (non '88) ones are 17+ years old and probably haven't been maintained well. Other than that they're quite adequate with good pads.

i agree with that statement. my brakes were not so great, my brothers crown victoria stopped better. i put on all new calipers and just a good set of pads (the ones that guy was selling in the mall for $7 a set or whatever) and now i can lock up the wheels on a 45 to 0 stop. the brakes are 50 times better than they were

now i dont know much about brakes (or car mechanics in general) but i think that the rotors heat up so much wouldnt that cause the pads to glaze over? maybe we should just change our brake pads every so often?

quote Originally posted by RickN: Not. Your right leg supplies the power to actuate the brakes. If you supply 100 lbs of force into a MC piston that has 1 square inch of surface area then the brake fluid sees 100 lbs/sq in (100/1=100). If you double the MC piston surface area then the brake fluid sees 50 lbs/sq in (100/2=50).

Read theorges write-up. Still thinking about it to fully understand. Will need to read again, think more, read more. I am seeing errors in my logic.

The municiple water system (average 40psi ) is the master cylinder. Your water hose is the brake line. The pressure can not exceed the supplied pressure. Pinch the flow down with a nozzle, the water shoots further. This has to result from a pressure increase. I guess I am comparing apples to oranges. Sealed system versus open system.

As with sailing, a small amount of wind can move a boat. The air (pressure) is magnified because it covers a large area (sail). Again, apples to oranges. Air pressure to hydraulic pressure. But why wouldn't a caliper piston be more conical? Still would be spreading the same pressure over a larger area.

As has been said before the stock brakes are fine as long as they are in perfect condition and you drive normaly. If everything is not in perfect condition and or you drive hard they arn't worth a darn. I am working on a upgrade of my own. More details will come after I get some things worked out.

About a year ago, several of the folks in the Bluegrass Fieros Group went out and bought the C4 Corvette (Rotors) brake upgrade for their 88's, I was so impressed with the improvement on my 4.9 Formula that I decided to do the same conversion on two of my other 88 Formulas. I agree that if you maintain your braking system, it is very adequate for normal driving, but I will also state that the change in stopping power is tremendous with this upgrade. I know this doesn't do anyone that driving 84 through 87 any good and I suppose the Grand Am upgrade is about as close as you'll get to this, but that ain't all bad. My understanding is that it's not as expensive. I have installed Brimbo 12" on the front and rear of two of my Formulas and have a set of slotted Brimbos to put on my Pantero when it's ready to go public. Just my two cents worth.

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Ron
02 Dodge Ram Diesel with 32 foot Gooseneck Fiero Transport.
If you can read this, thank a teacher. Since it's in english, thank a soldier.

[This message has been edited by blackrams (edited 06-17-2004).]

I'm working on an "Upgrade" that, on paper, offers better performance then the full grand am conversion, and for less $$, while still retaining near stock proportioning. I'm waiting to release it till I get it all together and get it on the car for real world testing...

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My Cardomain page
www.FFDET.com
Please rate me if I've been helpful...

I'll agree, stock brakes, in good condition, are ok for day-to-day driving. also, the vented Grand Am front brakes do wonders for the brake fade. to me, if you can lock up the tires, you CANT get any more braking power than that. now, braking power is not everything. controllablity. the vented brakes give you better control. but, if you really want more brake control - LARGER diameter rotors. this gives you finer control. you can apply finer pressure & control lock-up much better. also, the larger rotors cool quicker, and have enough power to lock up much wider tires. and tires do affect braking. even your suspension affects braking. I got the Grand Am brakes on the front on mine. I like the braking. could use a little more rear braking (bias?), but its probably cuz the rears aren't adjusted right...

quote Originally posted by Pyrthian: I got the Grand Am brakes on the front on mine. I like the braking. could use a little more rear braking (bias?), but its probably cuz the rears aren't adjusted right...

If you changed to the Blazer M/C then you LOST rear piston ratio, by about 20%.... If you are still using the stock M/C, then it's because you gained about 20% more piston ratio on the front, making your front brakes do almost 80% of the work, you also have the possibility of not having enough volume, and bottoming out the master Cylinder... Either way your proportioning is way off, due to difference in piston diameter between the front and rear brakes....

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My Cardomain page
www.FFDET.com
Please rate me if I've been helpful...

[This message has been edited by Freshj (edited 06-18-2004).]

Man I love this topic....
Ok here we go...
I am not an engineer.. but i do have the GA brake upgrade.. and it works.. Simply put the things work and have been working for others as well..

heres a theory ( midn you I'm an idiot Network admin BS in computer science, MCSA & RHCE)
If GM put those shabby parts from a chevette (the rack, the rotors and other parts) .. it's obvious that the brake system has been "skimped" out on too.. the car was originaly designed to be an econobox.. with econobox brake performance. I have to say that the work that Ogre put into the fiero brake system is more work that GM put into it...
Perhaps one might want to rely on intuition and being SAFE instead of theory's that do not account for the amount of flex an aliminum caliper has... and the expansion of hot metals (even cheaper metals if it's an aftermarket part). I guess that it's part of my job to think outside the box... so I do.. sorry for the rant.

quote Originally posted by NY_FIERO: Man I love this topic.... Ok here we go... I am not an engineer.. but i do have the GA brake upgrade.. and it works.. Simply put the things work and have been working for others as well.. heres a theory ( midn you I'm an idiot Network admin BS in computer science, MCSA & RHCE) If GM put those shabby parts from a chevette (the rack, the rotors and other parts) .. it's obvious that the brake system has been "skimped" out on too.. the car was originaly designed to be an econobox.. with econobox brake performance. I have to say that the work that Ogre put into the fiero brake system is more work that GM put into it... Perhaps one might want to rely on intuition and being SAFE instead of theory's that do not account for the amount of flex an aliminum caliper has... and the expansion of hot metals (even cheaper metals if it's an aftermarket part). I guess that it's part of my job to think outside the box... so I do.. sorry for the rant.

I'm not saying the FULL Grand Am upgrade doesn't offer better performance. But doing just the rear is really bad, and doing just the front can pose other problems, if not set-up correctly. The full upgrade does offer about 20% better braking, and vented rotors. The only real problem with this is that it is at a near 50-50 proportioning, and the lack of E-brake. Which, unless 50-50 is exactly what you want, can be quite the suprise in a high speed corner, or on slippery surfaces.

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My Cardomain page
www.FFDET.com
Please rate me if I've been helpful...

[This message has been edited by Freshj (edited 06-18-2004).]

quote Originally posted by cliffw: Read theorges write-up. Still thinking about it to fully understand. Will need to read again, think more, read more. I am seeing errors in my logic. The municiple water system (average 40psi ) is the master cylinder. Your water hose is the brake line. The pressure can not exceed the supplied pressure. Pinch the flow down with a nozzle, the water shoots further. This has to result from a pressure increase. I guess I am comparing apples to oranges. Sealed system versus open system. As with sailing, a small amount of wind can move a boat. The air (pressure) is magnified because it covers a large area (sail). Again, apples to oranges. Air pressure to hydraulic pressure. But why wouldn't a caliper piston be more conical? Still would be spreading the same pressure over a larger area.

"The municiple water system (average 40psi ) is the master cylinder. Your water hose is the brake line. The pressure can not exceed the supplied pressure. Pinch the flow down with a nozzle, the water shoots further. This has to result from a pressure increase."

You were doing so good at start, but ended up wrong. The pressure stays the same after you pinch down. In fact it could go down if the supply line is too small. And in the sail it is volume of air (area), nothing is magnified. The pressure against a small sail is the same per inch as a large sail. PSI is PSI is PSI
A small piston will move less fluid per inch but will have a higher PSI as a larger piston moving the same distance with the same force against it. Just remember that in a braking system you are supplying the initial force against a piston that is transfering its fluid to another piston that is doing the work (braking).

quote Originally posted by Freshj: If you changed to the Blazer M/C then you LOST rear piston ratio, by about 20%.... If you are still using the stock M/C, then it's because you gained about 20% more piston ratio on the front, making your front brakes do almost 80% of the work, you also have the possibility of not having enough volume, and bottoming out the master Cylinder... Either way your proportioning is way off, due to difference in piston diameter between the front and rear brakes....

no, havent changed the MC (yet). and yes, thats exactly how it feels. I want to keep my e-brake, that's why I left the rear stock. what is a reasonable solution? are proportioning valves any way adjustable? but, I dont think I'd want to mess with it. are there any e-brake calipers that would work? can the existing ones be re-bored & re-pistoned? maybe just a better brake pad on the back? no, dont think mixing pad compunds would be good. Maybe a stock prop. valve from another car with a better (or more rearward) split? what is the stock front/rear bias?

quote Originally posted by blackrams: About a year ago, several of the folks in the Bluegrass Fieros Group went out and bought the C4 Corvette (Rotors) brake upgrade for their 88's, I was so impressed with the improvement on my 4.9 Formula that I decided to do the same conversion on two of my other 88 Formulas.

sorry, but what kit is this ?
it sounds really interesting, I don't know about it & have an 88, planning a SBC swap.
thx in advance,
Philippe

quote Originally posted by blackrams: About a year ago, several of the folks in the Bluegrass Fieros Group went out and bought the C4 Corvette (Rotors) brake upgrade for their 88's, I was so impressed with the improvement on my 4.9 Formula that I decided to do the same conversion on two of my other 88 Formulas.

How did you go about getting your parts/is there a kit available?

quote Originally posted by gumert: How did you go about getting your parts/is there a kit available?

Gumert and Kwez,
West Coast Fieros does make a kit for this conversion, but we didn't use their kit. I think Archie makes one also. Ours is very similar to WCF's, haven't seen Archies. If you're interested, send me your email addresses and I'll tell you what our group did. We are considering doing another run at the machine shop if we can get 10 or more folks interested. Your costs would be exactly production and shipping costs, there is no profit in it for us.

Ron
blackrams@insightbb.com

doing just the rear Grand Am upgrade eliminates your parking/emergency brake, making your car ILLEGAL for street use. Period. I don't care if you have an automatic, if your brakes fail, what's your back-up? This should be a dead issue, but it's not. If all you do is race, and your car doesn't see street driving, then go ahead and do the grand am thing if you wish.

There is a website somewhere that shows an upgrade with custom brackets to mount LeBaron rotors and Camaro-Firebird calipers up front and same Lebaron rotors and calipers from a Cadillac Eldorado with the spring and lever parking/emergency brake system like that of the fiero somewhere.