Original post: Been trying for the past week to find out more about brake upgrades (seems a brake upgrade is a must if you want to use a more powerful engine around here). I've been reading about corvette swaps, grand am swaps, beretta swaps, but I feel that there is something missing: more info on the original brakes. Stopping distances, cut-plane views showing the construction, available off-the-shelf upgrades, etc.
I don't have anything to contribute to this myself yet but hopefully I will get to take a closer look at my front brakes today and if so, I will try to get some good pics of them.
*edit* might be a good idea to put useful links up here and try to summarize the thread somewhat.
Cars using rear calipers with e-brake similar to that of the Fiero:
Cadillac Seville Chevrolet Corvette Ford Focus SVT
Aftermarket calipers and rotors:
Wilwood Brakes one of the most well known brake manufacturers Stainless Steel Brake Company The Force10 Sport R1 and Force10 Super TKR1 feature e-brake mechanisms AP Racing Another well known brake company, seemingly very popular for racing Brembo Brembo brakes are used by Porsche and a few other manufacturers of performance cars
* Most conversions use the old Fiero hub with the rotor cut off. The new rotors are re-drilled with the 5x100 bolt pattern. The calipers are mounted using adapters to get them in the correct position. * The easiest upgrade, and also the least expensive one, is to take a good look at the original system, replacing anything that needs replacing, making sure you change the brake fluid from time to time and making sure you use good brake pads intended for the use you have in mind for your car. * Cross-drilling lessens the mass of the rotor. This means that it heats up and cools down quicker. Cross drilling also means that you get a different wear pattern on you brake pads. There might be stress concentrations around the holes. Adding a radius or a cahmfer should reduce the stress concentration somewhat. Either way, if you use cross-drilled rotors, make sure to inspect them from time to time. * Increasing the diameter of your wheels might have an effect on your braking distance. With a larger wheel, the ground will have more leverage. This can be countered by using a larger diameter rotor. * When doing a brake upgrade, pay attention to your brake bias. For the car to be safe on the road, you want the front brakes to lock the wheels up before the rear brakes. When you lose traction on the rear wheels you're almost certain to have a spin.
[This message has been edited by PerKr (edited 04-06-2007).]
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06:47 AM
PFF
System Bot
FierOmar Member
Posts: 1639 From: Glendale, California, USA Registered: Dec 2001
Originally posted by PerKr: Been trying for the past week to find out more about brake upgrades (seems a brake upgrade is a must if you want to use a more powerful engine around here). I've been reading about corvette swaps, grand am swaps, beretta swaps, but I feel that there is something missing: more info on the original brakes. Stopping distances, cut-plane views showing the construction, available off-the-shelf upgrades, etc.
I don't have anything to contribute to this myself yet but hopefully I will get to take a closer look at my front brakes today and if so, I will try to get some good pics of them.
Since you mentioned the Grand Am and Beretta (as if they were different is some way), I'll try to give you the basics. If I point to a particular vendor, that reference is not intended to mean that the particular vendor is the only one offering a particular item, or that there product is superior, but only to show an example. Please trust the other forum members for their preferences. As for a yardstick for improved braking performance, you have to remember that it is difficult to establish a promised level of performance when the upgrade is being applied to a twenty year old car. Also remember that most of the larger diameter brake systems will require a larger diameter wheel.
First, the options available to you depend on whether you have the early (84-87) chassis, or the late (88) chassis. The 88 has more limited options. However, it may have the simplest upgrade as well. West Coast Fiero ("WCF") offers a relatively inexpensive kit to adapt to the 12" Corvette rotors. It uses the stock 88 calipers and master cylinder. See: http://www.westcoastfiero.com/ [click on Brakes]. WCF also offers a 13" system for the 88.
The early chassis has more options, ranging from the 9.75 (Beretta/Grand Am) system through 13" Corvette upgrades. A sampling of most can be seen at the WCF site. For the early chassis, a front hub needs to be made by "parting off" the rotor from the orginal rotor/hub combination. This is a relatively simple process if you have a lathe, and there is plenty of information on the forum and related sites which details exactly how to do this. Other sites have more detailed information, including some drawings, which document the upgrade. For example, see BubbaJoe's site: http://www.fortunecity.com/...r/switch/67/id20.htm
Which one is best for you depends in part on your budget as well as the availability of parts in your locale.
------------------ FierOmar
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12:30 PM
rjblaze Member
Posts: 1159 From: Bethlehem, Pa., United States Registered: May 2006
The basic upgrade is the Grand Am/Beretta upgrade, but no ebrake to date.
You can go to Corvette brakes if you really want to stop hard from 150 mph, however, for street speeds, up to maybe 120 mph the Corvette brakes are overkill.
Take your basic upgrade to Grand Am. The Grand Am car dresses out at 3600 lbs, with a payload of 5 riders (1000lbs) and 200 lbs of cargo. Those brakes will stop almost 5000 lbs to satisfy Transport Safety. So, those brakes applied to a Fiero? Stopping 2700 lbs + 2 riders, 400 Lbs, means you are stopping 3100 lbs with brakes meant to stop 5000 lbs.
It doesn't take a genious to figure out that you will be having to work those brakes very hard and long to heat up those vented rotors past their design heat range.
What is best? It's entirely up to you and your pocket book. I am happy with my Grand Ams and I'm working on the ebrake problem however, the guys with the Lebaron upgrade have the ebrake already worked out.
Hope this helps a little.
Arn
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02:25 PM
typhoon Member
Posts: 1006 From: The Peoples Republic of Wisconsin Registered: Sep 2005
I tried the Grand Am upgrade with little to no improvement. I am in the process of the 12 inch Corvette brake upgrade, and I managed to get all the parts I need for less than $500. And that's with brand new cross drilled and slotted (just for the cool look) zinc plated Vette rotors! Almost a $1,000 savings over Westcoast Fiero prices. The guys over at the corvetteforum will just about give away brake calipers and parts. BUT, you need bigger wheels for this upgrade, I have 17's front and 18's rear.
------------------ ..from beautiful Caledonia, WI 87 GT 5 speed Electron Blue V8 SBC TPI 87 GT 5 speed med red (for sale) 94 BMW 850Ci V12 (for sale)SOLD! 93 GMC Typhoon (for sale)SOLD! 04 Caddy STS 00 Pontiac GTP with GTX package 96 Suburban 92 Dodge Shadow 28K miles
[This message has been edited by typhoon (edited 01-18-2007).]
Looking through the info I've found so far '84 - '87 fieros have the hub integrated into the rotor (everyone probably already knew this, but I haven't seen anyone saying it straight out). Really stupid design from a customer point of view (although it's probably a good economic design for the manufacturers point of view). I'm not sure, but this seems to have changed for the '88 fieros? If they use a separate hub, they might be somewhat easier to upgrade, right? Can an '84-'87 fiero be upgraded to use an '88 hub (if the hub is a separate part from the rotor)?
Anyway, upgrades on an '84-'87 includes making front hubs from the old rotors in addition to the caliper adapters. This means that the offset will change (it's like adding a spacer the same thickness as what ever rotor you intend to use), unless you can remove material from the hub to make it thinner. Does anyone know the thickness of the hub/rotor? How much can we remove and still be safe?
I know the spindles are different on '88s and heard it is just too difficult and expensive, but don't know why.
The material removed from the hub is just enough to fit inside whatever rotor you are using. The absolute limit would be the studs with a 5X100 bolt pattern. Obviously, you want more material around the studs but no one has published any "minimum" that I have read. So far, in the pictures I have seen, removing enough material from the hub to fit inside a rotor has not been an issue.
Anyone have problems with a certain type rotor they want to share?
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08:20 AM
PerKr Member
Posts: 641 From: Mariestad, Sweden Registered: Nov 2006
It would appear that any rotor that is mounted over the stock hub will move the wheel out by the thickness of the rotor "hat". Are you asking if the stock hub can be machined down on its face by that amount to achieve 0 total offset? I'm sure it could, but that would reduce the strength of the hub even more than the machining it gets to fit inside the rotor. Personally, I am not going to be the test mule who finds out where the breaking point is......
I would be interested to find out what other cars thickness is where the wheel studs go through the hub. Anybody doing brake work on another car? Or machined the face of their rotor?
[This message has been edited by Hudini (edited 01-19-2007).]
What about just an upgraded drilled/slotted factory rotor with better pads and braided lines? Seems like that would be a decent improvement over stock?
I did this and rebuilt the calipers and the brakes aren't superb but good enough for Autobahn use...
Looks good, too:
quote
Originally posted by Ryan01228:
What about just an upgraded drilled/slotted factory rotor with better pads and braided lines? Seems like that would be a decent improvement over stock?
Are there any upgrades that don't add a lot of unsprung weight? The offset doesn't bother me as much, since you can get wheels with a little more positive offset. The weight is a concern, though.
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03:47 PM
Bruce Member
Posts: 2189 From: Ventura, California, USA Registered: May 99
I had new drilled-slotted rotors, brake pads, and brake lines installed in my 86GT, and I didn't notice any significant change over the stock configuration. However, I feel secure that the set-up will last for a while. I kind of agree with Billy Joel: "save your money for a new pair of sneakers." bb
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04:12 PM
rjblaze Member
Posts: 1159 From: Bethlehem, Pa., United States Registered: May 2006
Looking through the info I've found so far '84 - '87 fieros have the hub integrated into the rotor (everyone probably already knew this, but I haven't seen anyone saying it straight out). Really stupid design from a customer point of view (although it's probably a good economic design for the manufacturers point of view). I'm not sure, but this seems to have changed for the '88 fieros? If they use a separate hub, they might be somewhat easier to upgrade, right? Can an '84-'87 fiero be upgraded to use an '88 hub (if the hub is a separate part from the rotor)?
Anyway, upgrades on an '84-'87 includes making front hubs from the old rotors in addition to the caliper adapters. This means that the offset will change (it's like adding a spacer the same thickness as what ever rotor you intend to use), unless you can remove material from the hub to make it thinner. Does anyone know the thickness of the hub/rotor? How much can we remove and still be safe?
I am in agreement with the other guys that recommend NOT thinning down the hub section. You are only talking about 1/8" to 1/4" (about 6mm) change in offset.....hardly noticable at all. There is probably that much deviation in some wheels that are out there.
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05:27 PM
Jan 20th, 2007
FierOmar Member
Posts: 1639 From: Glendale, California, USA Registered: Dec 2001
Originally posted by PerKr: Are there any upgrades that won't change your offset?
I wouldn't worry too much about the offset. The 15x7 Fiero lace wheel has a 30mm offset. Thus for example, if your new rotor is 10mm thick where it mounts to the face of the hub, you can use any 7" wide wheel with a 40mm positive offset, and the centerline of your wheel will be exactly where it was with the original wheel.
Since you will probably want to use a wider wheel and tire on the rear, you can adjust accordingly. Thus, if you were going to use an 8" wide wheel, you could get one with 30mm positive offset, or for example, if 40mm positive offset were the only thing available, add a 10mm spacer. Either way, the centerline of the wheel would be exactly where it was with the original 15x7 lace wheel.
------------------ FierOmar
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12:06 AM
jeffndebrus Member
Posts: 2772 From: Jacksonville, Fl- usa Registered: Aug 2001
I recently got 17-inchers which look excellent on the car. At a great price as well. Don't want to spend another $1000 on new wheels at this time.
So there are no after-market hubs available to allow you to keep the original offset? Noticed fierostores vented front disk upgrade using separate hubs. Anyone know anything about those?
Theoretically, what effect would you get if using drilled/slotted rotors up front with after-market calipers and master cylinder along with upgraded (grand am, corvette, volvo, whatever) rear rotors and calipers?
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03:02 AM
FierOmar Member
Posts: 1639 From: Glendale, California, USA Registered: Dec 2001
Maybe we need more information. What is the width and offset of the 17" wheels that you have? Of course, I am assuming that they are 5x100 bolt pattern since they apparently fit the stock hubs.
------------------ FierOmar
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10:10 AM
Jan 23rd, 2007
PerKr Member
Posts: 641 From: Mariestad, Sweden Registered: Nov 2006
the wheels I'm using are 7x17 et38 (except for one which has an et of 48 which is the reason I got this set so cheap). For legal reasons I will have to buy a cheap set of wheels to go with the new brakes for the yearly inspection, but for normal use I still want to keep the wheels I have now. I'm sure there are others who feel the same way.
Fierostore told me that their vented brake hubs were simply cut from standard fiero rotors, adding 3mm on the track width (on each side I suppose or they are using very thin material compared to the rotors I've seen)
has anyone been looking into the effect of brake swaps? People say that their fieros brake much better after fitting vented disks at the rear, but I haven't seen any figures? what improvements can be had by getting new pads? drilled/slotted rotors? larger vented rears? larger vented on all corners?
Like above, if you missed the gist of it, the Grand Am/Beretta rotors are vented. If you replace all 4, with the Blazer or S10 booster, and with a new master cylinder (bigger is good), the car is going to stop WAY better. it is cheaper than messing around with specialty drilled and slotted rotors. (they do work and look nicer BTW)
We'll have a design for an ebrake using Caddy calipers and the Grand Am rotors in the spring.
If you want the ebrake now and have larger wheels already, (16" and up) the Lebaron conversion is your ticket. It does what the Grand Am conversion does only better.
Arn
Typo
[This message has been edited by Arns85GT (edited 01-23-2007).]
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11:17 AM
Jan 24th, 2007
midengineracer Member
Posts: 196 From: Kaiserslautern, GE Registered: Dec 2006
Isn't the et number your offset (I thought it matched in mm)? If that is the case, you do not need to worry about the slight increase in track from doing a brake swap, you have bigger issues with the one rim of the wrong offset. I also do not think that they will be able to notice the increased track during an inspection and it may be within factory deviance still (things were sloppy in the 80s...)
------------------ Another Fiero some day... 2005 Smart ForTwo 1991 BMW 520 1986 Austin Mini 1989 Toyota *** (You know what it is...) (now sold) 1986 Fiero GT 5-speed
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02:58 PM
Jan 25th, 2007
PerKr Member
Posts: 641 From: Mariestad, Sweden Registered: Nov 2006
Maybe you're right and they won't notice. Then again, maybe they will. Either way, I want to know as much as possible about the brakes.
A few questions I still do not have an answer for:
1) what deceleration rate do we achieve with standard brakes (solid rotors)?
2) what is the weak spot of the system (are the calipers not clamping the rotor hard enough, are the pads simply not up to the task or is it the main cylinder? something else?)?
3) Where do we have the center of gravity of a fiero (and I'm talking about a measured CoG, not a perceived one, as this info is needed to calculate the loads on the hub)?
Like above, if you missed the gist of it, the Grand Am/Beretta rotors are vented. If you replace all 4, with the Blazer or S10 booster, and with a new master cylinder (bigger is good), the car is going to stop WAY better. it is cheaper than messing around with specialty drilled and slotted rotors. (they do work and look nicer BTW)
We'll have a design for an ebrake using Caddy calipers and the Grand Am rotors in the spring.
If you want the ebrake now and have larger wheels already, (16" and up) the Lebaron conversion is your ticket. It does what the Grand Am conversion does only better.
Arn
Typo
Have any preliminary ideas of how much said adaptors will cost?
Maybe you're right and they won't notice. Then again, maybe they will. Either way, I want to know as much as possible about the brakes.
A few questions I still do not have an answer for:
1) what deceleration rate do we achieve with standard brakes (solid rotors)?
2) what is the weak spot of the system (are the calipers not clamping the rotor hard enough, are the pads simply not up to the task or is it the main cylinder? something else?)?
3) Where do we have the center of gravity of a fiero (and I'm talking about a measured CoG, not a perceived one, as this info is needed to calculate the loads on the hub)?
1: Good question 2: The brakes are fairly good until you start racing. The pre-88 rotors arent vented so they easilly overheat and the brake pads stop gripping. 3: Weight distribution is supposedly 44/56 for the 84.
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04:11 AM
midengineracer Member
Posts: 196 From: Kaiserslautern, GE Registered: Dec 2006
Maybe you're right and they won't notice. Then again, maybe they will. Either way, I want to know as much as possible about the brakes.
A few questions I still do not have an answer for:
1) what deceleration rate do we achieve with standard brakes (solid rotors)?
2) what is the weak spot of the system (are the calipers not clamping the rotor hard enough, are the pads simply not up to the task or is it the main cylinder? something else?)?
3) Where do we have the center of gravity of a fiero (and I'm talking about a measured CoG, not a perceived one, as this info is needed to calculate the loads on the hub)?
OK, I agee, these are good questions. It seems like you are doing good research and asking good questions. I am stock right now, if I can find my G-tech pro, I will get the results of a few 60-0 stops, distance and hopefully max G pulled.
My feelings are that the brakes are adequate to start with but, as mentioned, they will fade. There is enough force available to lock up the wheels but the feel (bite, consistency, etc.) isn't the greatest. The most important step is getting the heat disipated. I will be doing the lebaron 11 1/2" upgrade for this end. I am currently able to run on the autobahn but I haven't pushed the brakes to the limit (currently, the car pulls to the right unsettlingly at speed). This means, as far as I understand it, the weak spot is the rotor, it can't dissipate the heat fast enough. The cures, in order of effectiveness, are: cross-drilling/slotting, vented, up-sizing.
CoG I can't help with but I am pleased to hear you consider this aspect...
My favorite brake upgrades are the cross-drilled brake lines. They really keep the fluid cool during hard braking. This also reduces the force required to push the brake pedal.
My favorite brake upgrades are the cross-drilled brake lines. They really keep the fluid cool during hard braking. This also reduces the force required to push the brake pedal.
-L
I realize this also helps reduce the amount of grimy old brake fluid in the system but I think it is more worth my time to just flush my brakes every couple of years...
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05:23 PM
Jan 28th, 2007
typhoon Member
Posts: 1006 From: The Peoples Republic of Wisconsin Registered: Sep 2005
My favorite brake upgrades are the cross-drilled brake lines. They really keep the fluid cool during hard braking. This also reduces the force required to push the brake pedal.
-L
Cross-drilled brake lines???? How about some prop wash to go with that?
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10:06 AM
Primaris Member
Posts: 550 From: Oak Grove, KY USA Registered: Aug 2001
Originally posted by midengineracer: OK, I agee, these are good questions. It seems like you are doing good research and asking good questions. I am stock right now, if I can find my G-tech pro, I will get the results of a few 60-0 stops, distance and hopefully max G pulled.
My feelings are that the brakes are adequate to start with but, as mentioned, they will fade. There is enough force available to lock up the wheels but the feel (bite, consistency, etc.) isn't the greatest. The most important step is getting the heat disipated. I will be doing the lebaron 11 1/2" upgrade for this end. I am currently able to run on the autobahn but I haven't pushed the brakes to the limit (currently, the car pulls to the right unsettlingly at speed). This means, as far as I understand it, the weak spot is the rotor, it can't dissipate the heat fast enough. The cures, in order of effectiveness, are: cross-drilling/slotting, vented, up-sizing.
CoG I can't help with but I am pleased to hear you consider this aspect...
Has anyone looked into 2-piece rotors? As someone mentioned in the porsche brakes thread, it might be possible to convert the old hub/rotor in order to mount a separate rotor from companies such as ap racing or wilwood. Anyone tried this?
Sure it is possible IF you have enough money. Every brake upgrade I have read (I did the GA upgrade) has the underlying assumption of saving money over the big brand names like wilwood, et al.
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08:24 AM
Feb 26th, 2007
PerKr Member
Posts: 641 From: Mariestad, Sweden Registered: Nov 2006
Money is an issue, even though it shouldn't be when it comes to brakes. If money was not an issue for me, I'd be going with Held Motorsports big brake kit with new spindles, but that would cost more than the whole car...
Anyway, what about spindle and hub upgrades? With new front spindles and separate hubs from a different car (maybe an Opel Manta), maybe a brake upgrade could be done without changing the offset?
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04:25 PM
DRA Member
Posts: 4543 From: Martinez, Ga, USA Registered: Oct 1999
I would love to see some brake upgrade shoot outs! It seems actual documented improvements are few and far between. It would be nice to see some actual documented testing and comparisons.
In this thread, https://www.fiero.nl/forum/Forum2/HTML/080463.html , I posted a question about actual tests and data but didn't really get any response. The following is a cut and paste of my original post:
**************************************************************************** I've driven a lot of cars in my day, never been particularly easy on any of them, and I will say sometimes seat of the pants feel can be deceiving (even on braking!). I tried to find some actual brake tests on the Fiero (specifically the 85 - 87 V6 models) and it seems the data is not real easy to find. Can someone confirm or rebuke the following data? 1986 Pontiac Fiero GT General Performance
New Price: $14,800 Options on test car: air conditioning, rear spoiler, optional subwoofer, cruise control, rear defroster, power door locks Engine: 2.8 liter Multi Port Fuel Injected V-6, iron block and heads Engine management system: Pontiac/Delco electronic Power: 140 bhp @ 5200 rpm 170 lb-ft @ 3600 rpm Redline: 6000 rpm
These posted numbers show an 86 Fiero braking from 70 – 0 mph in 190ft Compared to these numbers from October 2004 Car and Driver the Fiero seems to have held up well when compared to newer cars unless the data above is total BS. Acura TSX 70 – 0 mph in 194ft Audi A4 1.8T 70 – 0 mph in 180ft Subaru Legacy 2.5GT 70 – 0 mph in 196ft Volvo S40 T5 70 – 0 mph in 166ft
It does seem that motorweek had the braking on the Fiero at around 125 ft from 55 – 0 mph where the above data says 118 ft. Seems like a big descrepency.
Anyone have some different sources for this kind of actual brake performance comparision?
I haven't tried searching the forum yet but it seems some in depth performance comparisons must have been done to show actual performance improvements for brake upgrades.
Edited to add a few more statistics I've run across, still not having much luck finding any independent tests on the Fiero.
From Car and Driver showdown 1994 CHEVROLET CAMARO Z28 70 - 0 mph 167ft 1994 FORD MUSTANG GT 70 - 0 mph 179ft
From Motor Trend 2003 Infiniti G35 Sport Sedan 60 - 0 mph 114ft 2003 Infiniti G35 Sport Coupe 60 - 0 mph 112ft
Edited one more time to add:
Been searching the forum and reading threads for a while now, getting tired. I can't seem to find any actual comparison testing of any brake "upgrades" against the original brake system in "like-new" condition. All I seem to be able to find are seat of the pants comparisons with no details on the condition of the components/system replaced. Would be nice to see some actual statistics and test results.
I would be willing to put my GA upgrade to the test. I'm just not sure how to go about it so that it would mean anything to anyone. I have seen the TV tests where they brake from 60 to 0 and measure using cones. I am guessing they have their foot on the brake so they mash down passing the first cone (as opposed to lifting off the gas, then mashing the brake at the cone because that would involve reaction time too)
If you want to setup some ground rules, I will help.
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07:41 PM
DRA Member
Posts: 4543 From: Martinez, Ga, USA Registered: Oct 1999
I would be willing to put my GA upgrade to the test. I'm just not sure how to go about it so that it would mean anything to anyone. I have seen the TV tests where they brake from 60 to 0 and measure using cones. I am guessing they have their foot on the brake so they mash down passing the first cone (as opposed to lifting off the gas, then mashing the brake at the cone because that would involve reaction time too)
If you want to setup some ground rules, I will help.
I was thinking further about some of the descrepncies in some of the numbers I have found, for a real comparison test it would almost have to be done on the same surface/weather/time of day/etc. That may be why some of the numbers from one test to the other on the same stock cars differ. The tough part would be to get the cars together in one place and insure all the different options being tested were in tip top shape, what are the odds of that happening! LOL With the ideal situation being very unlikely I guess guys could include conditions along with their numbers. Not sure how you would grade the test surface, new asphault, worn asphault, concrete, are all going to give different results I'm sure along with tire/wheel combo's and suspension upgrades/condition. Also cycling, I've seen tests where they repeatadly accelerate to 60 and then brake to 0 to measure fade, without a closed course I'm not sure how the average guy is gonna accomplish that. It would be nice to know though, would you want to spend $600 on a brake upgrade the gets you down from 60 - 0 in 113ft as opposed to keeping a stock system that will get you from 60 - 0 in 118ft? Maybe one or more of the clubs could organize a shoot out and at least come up with some averages.
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10:35 PM
Feb 27th, 2007
Whuffo Member
Posts: 3000 From: San Jose, CA Registered: Jul 2003
Maybe you're right and they won't notice. Then again, maybe they will. Either way, I want to know as much as possible about the brakes.
A few questions I still do not have an answer for:
1) what deceleration rate do we achieve with standard brakes (solid rotors)?
2) what is the weak spot of the system (are the calipers not clamping the rotor hard enough, are the pads simply not up to the task or is it the main cylinder? something else?)?
3) Where do we have the center of gravity of a fiero (and I'm talking about a measured CoG, not a perceived one, as this info is needed to calculate the loads on the hub)?
I think you're asking the wrong questions. The stock Fiero brakes are very good when in good working condition. The only problem is that brakes work by converting kinetic energy to thermal energy (heat). As long as the brake rotors can radiate / dissipate the heat faster than it's generated there's no problem. But when you work the brakes hard - on the race track, on a long twisty downhill grade, etc. - the heat builds up. Once the temperature exceeds the vaporization point of the adhesives / binders in the brake pads - or the brake fluid gets heated above its boiling point - your brakes fade out.
The trick is to keep things cool. Ventilated rotors are a good idea - as are wheels with lots of open space between the spokes, and vents to duct cooling air towards the rotors. Easiest is changing to alloy wheels with a small number of thin spokes; this allows the rotor to radiate heat into open air. Changing to ventilated rotors is a good idea IF DONE CORRECTLY. The brakes on a Fiero are a system - and if you're going to re-engineer any part of the system you need to consider the effect upon the whole system. Please try to avoid just sticking whatever fits on there and calling it good; you may well have better braking in some conditions when you're done - but under different conditions the car may become unstable or just plain dangerous. Chances are you're *not* smarter than the team of automotive engineers that designed the system to start with.
To do these sort of mods safely and have predictable results, you really need to have access to a brake dynamometer. Really. Do you want to test that 100-0 stopping distance on a brake dyno, or would you rather take your chances some night on the freeway and hope for the best? I'm sure you wouldn't want to just hit the road and hope the brakes work - would you?
I'm not saying that the brakes couldn't be better designed - we've got 20 years of improvements in materials and design to draw upon. They could - and it'd be a worthwhile improvement for hard-driven Fieros. But there's something else that needs to be considered: if you have an accident and your brakes are found to be modified in (what they'd call) an unsafe way - it doesn't take a rocket scientist to calculate who'd be liable.
So anyway, when you're looking at these third-party brake kits - it might be worth asking some questions of the vendor. Was an engineer involved? Can I see the brake dyno results?
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02:20 AM
DRA Member
Posts: 4543 From: Martinez, Ga, USA Registered: Oct 1999
I think you're asking the wrong questions. The stock Fiero brakes are very good when in good working condition. The only problem is that brakes work by converting kinetic energy to thermal energy (heat). As long as the brake rotors can radiate / dissipate the heat faster than it's generated there's no problem. But when you work the brakes hard - on the race track, on a long twisty downhill grade, etc. - the heat builds up. Once the temperature exceeds the vaporization point of the adhesives / binders in the brake pads - or the brake fluid gets heated above its boiling point - your brakes fade out.
The trick is to keep things cool. Ventilated rotors are a good idea - as are wheels with lots of open space between the spokes, and vents to duct cooling air towards the rotors. Easiest is changing to alloy wheels with a small number of thin spokes; this allows the rotor to radiate heat into open air. Changing to ventilated rotors is a good idea IF DONE CORRECTLY. The brakes on a Fiero are a system - and if you're going to re-engineer any part of the system you need to consider the effect upon the whole system. Please try to avoid just sticking whatever fits on there and calling it good; you may well have better braking in some conditions when you're done - but under different conditions the car may become unstable or just plain dangerous. Chances are you're *not* smarter than the team of automotive engineers that designed the system to start with.
To do these sort of mods safely and have predictable results, you really need to have access to a brake dynamometer. Really. Do you want to test that 100-0 stopping distance on a brake dyno, or would you rather take your chances some night on the freeway and hope for the best? I'm sure you wouldn't want to just hit the road and hope the brakes work - would you?
I'm not saying that the brakes couldn't be better designed - we've got 20 years of improvements in materials and design to draw upon. They could - and it'd be a worthwhile improvement for hard-driven Fieros. But there's something else that needs to be considered: if you have an accident and your brakes are found to be modified in (what they'd call) an unsafe way - it doesn't take a rocket scientist to calculate who'd be liable.
So anyway, when you're looking at these third-party brake kits - it might be worth asking some questions of the vendor. Was an engineer involved? Can I see the brake dyno results?
This is what I've been wondering for years, where's the data and what were the test methods. It's easy to say bigger rotors and dual pistons = better braking, vented rotors = better cooling, different pad compounds = better stopping, etc, etc, but it would be nice to see some data to show what kind of difference these changes make. I drive my car hard on occasion but I doubt I would ever need the same brakes as someone who is spending 4 hours balls out on Road Atlanta. I have heard (actually seen data) different pad compounds actually decrease your brake performance in day to day driving, some of these need to be heated up to reach their optimum performance. For any person that is looking for improved performance usually we want to see documented dyno results, who here would spend $1000 or even $500 for a performance upgrade based solely on someones "seat of the pants" opinion? Maybe we could get some folks to actually test some of the well documented brake mods and vendor offerings in a controlled enviroment (brake dynamometer), this would give folks a real baseline to make the decision on which mod or package meets their needs. For me, I defineately don't have the funds to spend on a brake upgrade, but even if I did, I'll stick with the stock system in proper working order till I see some real numbers.
