So I’ve added The beefed up brake booster, thinking about better than stock rotors, etc.... what’s the easiest set up and yet maintains a hand brake for a manual? This is for an 87!
Thanks in advance!

Read about all the brake options in Ogre's cave before you do anything. If you move forward the Grand Am is easiest. If you want to keep the e-brake, you can keep the Fiero rear disks or use '85 Seville calipers on the rear.

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Mike in Sydney

Thanks for the response, eventually I want to do an engine upgrade and whe I do, I want the Fiero to stop safely.

Has anyone tried a line lock on the rear brake line?

quote Originally posted by branger: what’s the easiest set up and yet maintains a hand brake for a manual? This is for an 87! Thanks in advance!

There are no good easy recipes to follow at the moment... hence why my Fiero still has stock brakes.

If factory brakes "have problems" then WTF makes you GA and other "upgrades" are any better?
GA and Seville rears uses same "crap design" parking brakes as Fiero, 6000, Firebird and others.
4W GA is illegal in most palaces regardless doesn't have inspections or can "pass" the lame inspections.
Other "Upgrades" have many of same or worse problems covered in Brake Upgrade because they are "design" by fools that think they can bolt on anything from another car w/o issues. I just only cover the GA because was "popular" at the time, is still sold by TFS and push a lot by others for use on the street.

Calipers and cables "rust/freeze problems" and even "poor performance" issues are mainly cause by DIY and even by so called "Pros" including ASE that might know but cutting corners for doing a job.
Like:

Rear caliper levers and screws get stuck to "weld" in/to the body w/o careful use of Brake Grease to lube and keep out "water."

Sliders need Brake Grease too yet Many install them dry or use wrong grease making rubber swells up. Either makes big problems. Worse, "Old standard" GM sliders are not the only moving part that needs cleaning and lube but nearly all ignores them.

Most use cheapest pads available or use whatever crap on Ebay Amazon etc. While some are good, Ebay Amazon and others have big problems w/ counterfeit and no name parts.
And still wonder why the brake suck on many cars not just Fiero.
Example: Other cars have SS parts as "slider" in different ways but most never clean and lube normal metal parts touching them then wonder why brakes wear out fast. Oh... can't see why? Short answer is polluted water quickly rust normal steel then rust swells making SS parts very tight and pads can't move right or not at all and drag them to death and quick. Often in 1 year or less.

quote Originally posted by creaky78: Has anyone tried a line lock on the rear brake line?

Besides they are Illegal in most places... They don't work as a parking brake and often wreck the hydro system if dumb enough to try. Then add If, more like When, the brake fail to hold when parked and car hurts/kills someone expect to get sued even if you avoid getting change w/ crimes. You can find your Insurance Co won't pay enough or at all when they find out.

I have been unfortunately using my 87 Fiero for the last 4 years as a daily driver. Someone came through a stop sign on my last Fiero and my other daily, was Tboned, someone left turned into my Blazer. Bending the frame enough to pull the drive shaft out of the transmission.
I have put over 35,000 miles on it in that time. When I put the car on the road for daily, rebuilt the front calipers and new hoses all around. Replaced the front and rear pads and rotors. The rotors were Bendix and the pads Raybestes. NOS
In that time, only about 5,000 miles ago did rear brakes.
Now mind you, I am a certified mechanic. Technicians? Mechanics don't mind getting their hands dirty. And have an easier time working on my car if needed. Believe me. The last thing a working mechanic wants to do is work on their own car.
With that.
Unless you are auto crossing or just want the "cool factor", DON'T MODIFY YOUR BRAKES.
As stated here, proper care on the stock system goes a long way. When I did the rear I rebuilt the calipers with new pistons.
I will be doing the front soon and other than mild front rotor pulsation, have had no issues. And this is with stop and go beltway/city driving. With a 2005 vinK 3800 bolted to a 1995 4T60e transmission with a 1993 PCM. With the Fieros I have been driving, it seems that people don't see you or just don't care. So a lot of quick stops/ heavy braking.

But if you have to.
The booster mod is not that bad of an idea. Your not screwing with the hydraulic balance.
I have been working on a front mod. Have been toying with it for about 2 years and still don't have it down.
That was to use S10 rear calipers with the same piston diameter pistons. The pads are about 93% the same surface area. With Cavalier vented rotors 10.15". The mod is almost bolt on other than drilling the threads out on the spindles for bolts and cut off Fiero rotor hubs. The bolts, bolt into the caliper bracket instead of the spindle. The same way the Isuzu Impulse used. By the way are the same spindles except for the threads for the caliper bracket. I would have to use 10mm spacer between the caliper bracket and spindle, but this is becoming common on OE applications. I haven't put this together for 2 reasons. I don't like the cut off Fiero rotor as a spindle. and would rather use a different hub to decrease the spacers. I have been researching a few hubs but haven't put all the numbers together yet. This is some of my standards for this. Have to be a SAE approved hub used on car sold in the US. For the same or more GVW for that axle.
First one. 1994-1998 VW VR6 5 lug rear hub. Uses the same outer bearing races, but the distance between bearings may be too narrow.
Second. 1992-1997 Plymouth Acclaim and Dodge twins rear drum hub, But the right bearings may be hard to find.
And finally even harder to find Subaru 2wd rear hubs with 5 bolt. And the center opening is 1mm different.
If all of the specs don't come together, it is not going on my car.

[This message has been edited by cmechmann (edited 12-04-2019).]

I have stock rear brakes and modified front brakes. If you get your stock rear brakes working like new they work quite well, even on track days. The Fiero really does not weigh enough to need huge vented rear brakes so why bother? Big rear brakes are just for looks unless you are driving a 4000 lb car.

That being said, the braking distance for stock 84-87 fiero's from 70 mph is 200 feet. There are very few modern cars, even minivans and large SUV's that take more than 170 feet to come to a stop from 70 mph. Most new sedans will do it in 160 feet or less. That means you have to realize something when driving along: everybody in front of you has better brakes than you do.

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

Thanks gang! This is a very interesting topic as we all want good brakes, and don’t want to screw up our cars in the process of getting better. I think at this point, I will make no other changes besides my brake booster (mind you when I did the bigger brake booster, I replaced the rubber brake hoses with threaded steel cables, thinking increased booster may increase hydronic pressure in the lines, but I’m no mechanic).

quote Originally posted by wftb: That being said, the braking distance for stock 84-87 fiero's from 70 mph is 200 feet. There are very few modern cars, even minivans and large SUV's that take more than 170 feet to come to a stop from 70 mph. Most new sedans will do it in 160 feet or less. That means you have to realize something when driving along: everybody in front of you has better brakes than you do.

Because many run Higher hydro system pressure and other "mods" and let ABS to limit brake power to hopefully stop on crap/wet roads.
Many vehicles have Hydro or Electric PB that puts higher pressure input to the MC.

I don't know where you get brake data... Many Owners Manuals and other OEM are wrong for many reasons.
GM and other also publish under rated HP and Torque # for many cars and other vehicles. Many are done to fake numbers for insurance and feds. Other are done so one model far weaker then their high dollar car(s). Don't believe "Car & Driver" rags either that gets Huge $ from GM etc.

Fiero w/ better brake and suspension parts or even change tires can reduce braking distance way lower then data in OM.
If you replace w/ cheapest parts or tires then very possibly you get same or even worse then OM said.

This just just Hype that Michelin etc use this to sell Tires and other parts that can help you stop better.

Stopping distances are from actual tests done when the cars were new. I saved all my old magazines that had articles about Fiero's in them. One test has a graph comparing the Fiero to test data from other cars deemed similar : Toyota MR2 stopped from 70 in 175', Subaru XT turbo and Honda CRX SI both had worse stopping distances than the Fiero at about 208'.

I read a lot of automobile magazines and one thing I have noticed lately is production cars have almost reached maximum braking force. Stops from 70 mph are routinely in the 145' range for sports cars and even a lot of sedans are achieving this number. But very few vehicles of any kind are getting below this figure. Brakes have gotten as good as they can get.

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

quote Originally posted by wftb: I read a lot of automobile magazines and one thing I have noticed lately is production cars have almost reached maximum braking force. Stops from 70 mph are routinely in the 145' range for sports cars and even a lot of sedans are achieving this number. But very few vehicles of any kind are getting below this figure. Brakes have gotten as good as they can get.

If you're threshold braking at all four tires, you can't decelerate any harder than that... so cars having no downforce, and similar rubber, and passably-tuned ABS are going to be comparable.

To stop in the shortest distance possible, one should first get sticky rubber (removing the first performance bottleneck) before thinking about brake modification.

quote Originally posted by cmechmann: The booster mod is not that bad of an idea. Your not screwing with the hydraulic balance.

Actual data doesn't support that statement.
Since the force gain is in front of the combo valve, it alters the gain between the front and rear.
The front starts at 41% improvement at light pedal pressures and reduces to 14% as pedal pressure increases.
The rear starts at 0% improvement at light pedal pressures and increases to 17% as pedal pressure increases.

https://www.fiero.nl/cgi-bin...1747&style=printable

code:

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Caliper Pressure Comparison Stock 88 Booster vs. Rodney S10 Prototype:
All Tests with Engine On, but there is data from two 88 Fieros - 3.4TDC and 2.5L

		3.4TDC	2.5L	Stock	3.4TDC	3.4TDC	2.5L	3.4TDC	 
		Front	Front	3.4TDC	Front		Rear	Rear	
  		Stock 	Stock	vs.	S10   	Front	Stock	S10	Rear
Input Air	Booster	Booster	2.5L	Booster	Gain	Booster	Booster	Gain		
		(psi)	(psi)	(psi)	(psi)	(%)	(psi) 	(psi)	(%)
5		135	n/a	n/a	<200 	n/a	n/a	n/a	n/a
10		320	400	-80	450	41%	300	300	0%
15		550	600	-50	700	27%	400	400	0%
20		675	800	-125	950	41%	500	550	10%
25		975	925	+50	1275	31%	600	675	13%
30		1150	1200	-50	1475	28%	675	775	15%
35		1200	1225	-25	1500	25%	700	775	11%
40		1200	1250	-50	1550	29%	700	775	11%
45		1275	1300	-25	1575	24%	725	850	17%
50		1325	1325	0	1600	21%	725	850	17%
55		1475	1375	+100	1675	14%	775	900	16%	
60		1475	1400	+75	1700	15%	775	900	16%

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quote Originally posted by fieroguru: Actual data doesn't support that statement. Since the force gain is in front of the combo valve, it alters the gain between the front and rear. The front starts at 41% improvement at light pedal pressures and reduces to 14% as pedal pressure increases. The rear starts at 0% improvement at light pedal pressures and increases to 17% as pedal pressure increases.

You're thinking about the bias as a function of pedal force. From that standpoint, everything you've said is coherent.

However, I disagree that studying bias as a function of pedal force leads to correct conclusions when discussing what happens during braking.

I submit that a driver will initiate braking with some certain deceleration value in mind (as measured on the ass meter). The driver then modulates the pedal force such that the car's actual deceleration matches the desired deceleration.

For a given vehicle deceleration (and vehicle configuration), there is only one possible master cylinder pushrod force that could induce said deceleration.
As I expect you would agree, front/rear bias is completely defined once the master cylinder pushrod force is known.
It follows that front/rear bias depends only on vehicle deceleration.

Hence, how the master cylinder pushrod force was generated (driver muscle force versus booster force) is irrelevant to the subject of front/rear bias.

[This message has been edited by pmbrunelle (edited 12-05-2019).]

[QUOTE]Originally posted by fieroguru:


Actual data doesn't support that statement.
Since the force gain is in front of the combo valve, it alters the gain between the front and rear.
The front starts at 41% improvement at light pedal pressures and reduces to 14% as pedal pressure increases.
The rear starts at 0% improvement at light pedal pressures and increases to 17% as pedal pressure increases.

Most people that have put the brake booster mod on stock brakes do report better braking. With the rears improving more than the fronts at higher pedal pressures it makes sense to me why there is an improvement. 84 to 87's have such weak rear bakes that the only function they serve is to keep the car in a straight line under heavy braking. And from my own experience, putting a big brake kit front and rear will cause the right front tire to lock up in a panic stop. I cured that problem by putting smaller 2 piston Wilwood calipers on the front, going stock in the rear and adding an aftermarket brake control valve with a disabled stock prop valve. If I ever get one of these : https://www.fiero.nl/forum/Forum4/HTML/064690.html I will put it on the stock prop valve I have in a drawer and get rid of the aftermarket control valve.

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