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Fiero Brake Upgrades (Let's Make this a Thorogh Review) by chrismclubm
Started on: 10-23-2008 11:39 PM
Replies: 63
Last post by: whodeanie on 11-06-2008 10:31 AM
chrismclubm
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Report this Post10-23-2008 11:39 PM Click Here to See the Profile for chrismclubmSend a Private Message to chrismclubmDirect Link to This Post
Let's compare the Brake system upgrades (Rotors + calipers) that are commonly done to the Fiero. Let's also take into account: reliability, safety, stopping power, brake pedal travel, general improvements, appearance, quality, installation, and most importantly their price (affordability). Some common ones are: Grand Am, Lebaron/Cadallac, wilwood, etc...

I really want my wheels to stand out with some larger slotted rotors but at the same time are easy to install (with minimal modifications). I can't decide what I want to do since brake system discussion are scattered all over the place.

Please provide websites and pictures if you can.

------------------
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For Fiero updates, visit my site and don't forget to click on the ads!
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Report this Post10-24-2008 03:24 AM Click Here to See the Profile for 85fiero_fanatSend a Private Message to 85fiero_fanatDirect Link to This Post
The beretta and grand am upgrades are the same process I believe. I did half of the Beretta upgrade, but if you have a manual transmission I wouldn't suggest it, because you lose your parking break. The rear brakes juts require you to unhook the clip that holds the brake line to the strut, then put the new caliper and rotors on. Very Easy!!! From what I've read, the front require you to either have your front hob/rotor machined down so that it's just a hub. Then the new rotor will fit over and from there it's just as easy as the rear. Put the new calipers and rotors on and you're good to go. I've also been told that if you replace both front and rears with ga or beretta calipers that you'll wanna replace the brake mc with a blazer mc or you'll have soft pedal. After replacing the rears I have no problem, but when I replace the fronts I'll be replacing the mc. Rotors for the GA and Beretta are vented also. New hubs for the front are also available online, but I don't remember where.

Price is like $19-25 per caliper (depending on which you get), vented rotors are $20 each, A set of pads are $19-73 depending on if you want basic or Z-rated.

Total price for all 4 rotors, calipers, and pads= $194 to $326 plus $33 for 1994 Blazer brake mc which hooks right up to the fiero components in the stock location.

http://fierozone.tripod.com/realbrakes/index.html
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Report this Post10-24-2008 05:54 AM Click Here to See the Profile for PeteGTSend a Private Message to PeteGTDirect Link to This Post
Hi Chris,
I am right in the middle of doing a brake upgrade as we speak. The best bang for your buck is the Grand Am. I am doing the Grand Am / Caddy Seville version. (I have a 4 speed & need the E-brake)

Arns85GT has a well written play by play that I am following:
https://www.fiero.nl/forum/Forum2/HTML/083566.html
https://www.fiero.nl/forum/Forum1/HTML/065677.html

I am into it for about 400 bucks but when all is done I should be in very good shape. I have looked long & hard to try to find the application that would best suit me, for install simplicity & economically, and the Caddy version was the best fit.

Here are some others posts that I have found during my search:
http://www.fierofocus.com/a...t-grandambrakes.html
https://www.fiero.nl/forum/Forum2/HTML/080595.html
https://www.fiero.nl/forum/Forum2/HTML/090874.html
https://www.fiero.nl/forum/Forum2/HTML/079787.html
https://www.fiero.nl/forum/Forum2/HTML/094623.html

Let us know what you decide, & Good luck

------------------

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Just like there's no shame in holding your wife's purse for a minute.

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Report this Post10-24-2008 12:17 PM Click Here to See the Profile for chrismclubmSend a Private Message to chrismclubmDirect Link to This Post
 
quote
Originally posted by PeteGT:

Hi Chris,
I am right in the middle of doing a brake upgrade as we speak. The best bang for your buck is the Grand Am. I am doing the Grand Am / Caddy Seville version. (I have a 4 speed & need the E-brake)

Arns85GT has a well written play by play that I am following:
https://www.fiero.nl/forum/Forum2/HTML/083566.html
https://www.fiero.nl/forum/Forum1/HTML/065677.html


I would greatly appriate if you can keep us posted with your work! Thanks!
I am into it for about 400 bucks but when all is done I should be in very good shape. I have looked long & hard to try to find the application that would best suit me, for install simplicity & economically, and the Caddy version was the best fit.

Here are some others posts that I have found during my search:
http://www.fierofocus.com/a...t-grandambrakes.html
https://www.fiero.nl/forum/Forum2/HTML/080595.html
https://www.fiero.nl/forum/Forum2/HTML/090874.html
https://www.fiero.nl/forum/Forum2/HTML/079787.html
https://www.fiero.nl/forum/Forum2/HTML/094623.html

Let us know what you decide, & Good luck




------------------
1986 GT Fiero Owner & Enthusiast
For Fiero updates, visit my site and don't forget to click on the ads!
http://educatorstop15.we.bs/fieropage.htm

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Report this Post10-24-2008 12:22 PM Click Here to See the Profile for PyrthianSend a Private Message to PyrthianDirect Link to This Post
I did the Grand Am brakes on the front only.
I ended up with WAY to much front braking. I then removed the spring from the prop valve, and it helped - slightly. the fronts are still overpowered compared to the rear - but the rears now grab quicker - just not any harder.

my future plan is the LeBaron rotors w/camaro front calipers & caddy rear calipers. when I got rims which will fit around them.
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Report this Post10-24-2008 12:55 PM Click Here to See the Profile for Arns85GTSend a Private Message to Arns85GTDirect Link to This Post
Pyrthian, the reason for your lack of balance is that you did half the job.

If you do the Grand Am all way 'round, with the Blazer/S10 booster, you will find it will balance and you won't have a problem. Moreover, it will stop on a dime.

The bracket I designed and DPWood produces (professional tool cut BTW) works with the 85 Seville rear calipers and the Pontiac 6000 driver side cable to produce a perfectly balanced braking system.

I drove a car with the Grand Am rotors only on the front and it was SCARY soft. Mine, on the other hand, is solid and you have confidence you will stop when you put on the brake, and with no fade.

Arn
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Report this Post10-24-2008 01:29 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Direct Link to This Post
 
quote
Originally posted by Arns85GT:

Pyrthian, the reason for your lack of balance is that you did half the job.

If you do the Grand Am all way 'round, with the Blazer/S10 booster, you will find it will balance and you won't have a problem. Moreover, it will stop on a dime.

The bracket I designed and DPWood produces (professional tool cut BTW) works with the 85 Seville rear calipers and the Pontiac 6000 driver side cable to produce a perfectly balanced braking system.

I drove a car with the Grand Am rotors only on the front and it was SCARY soft. Mine, on the other hand, is solid and you have confidence you will stop when you put on the brake, and with no fade.

Arn



By soft, do you mean pedal pressure?

That really has to do with how the system is set up. With a good brake booster and master cyl, as well as steel lines and steel braided connector lines, it should be totally solid if there is no air in the system.

------------------
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Report this Post10-24-2008 01:47 PM Click Here to See the Profile for LitebulbwithaFieroSend a Private Message to LitebulbwithaFieroDirect Link to This Post
When you guys speak of doing this brake swaps, is it for all years or just pre-88?
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Report this Post10-24-2008 01:56 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruDirect Link to This Post
I have 2 88's, one with the 12" Vette rotor upgrade and one stock. They both have the same wheels so you can see the visual difference:




The calipers remain stock, so balance front/rear remain stock as well. Biggest benefit is the increase leverage with the larger rotor diameter. Only downside in my books is they are heavier than stock, but never measured by how much.
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Report this Post10-24-2008 02:04 PM Click Here to See the Profile for PyrthianSend a Private Message to PyrthianDirect Link to This Post
 
quote
Originally posted by Arns85GT:
Pyrthian, the reason for your lack of balance is that you did half the job.

If you do the Grand Am all way 'round, with the Blazer/S10 booster, you will find it will balance and you won't have a problem. Moreover, it will stop on a dime.

The bracket I designed and DPWood produces (professional tool cut BTW) works with the 85 Seville rear calipers and the Pontiac 6000 driver side cable to produce a perfectly balanced braking system.

I drove a car with the Grand Am rotors only on the front and it was SCARY soft. Mine, on the other hand, is solid and you have confidence you will stop when you put on the brake, and with no fade.

Arn


yes, I know. I need/want the handbrake
mine are not anything like "scary soft". yes, I do want to get them brackets - but I thought they were for the 10.25 LeBaron rotors. there is a set which will let me use grand am rotors, and the caddy calipers, and keep my 14" stock rims?
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Report this Post10-24-2008 02:20 PM Click Here to See the Profile for pswayneSend a Private Message to pswayneDirect Link to This Post
I have an 86 on which I put the Grand Am type brakes on the front, and put my old front brakes on the rear. It's an automatic, so I can get by without parking brakes for now. This combination gets rid of the low pedal caused by the rear parking brake mechanism. It stops better than my 88 with stock brakes. But I plan to do the Cadillac brakes on the rear when I get around to it.
ps. The parking brakes on my 88 work wonderfully. Does anybody have first-hand experience on how well the Cadillac parking brakes (as adapted to 84-87 cars) work?
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Report this Post10-24-2008 05:56 PM Click Here to See the Profile for the reverendClick Here to visit the reverend's HomePageSend a Private Message to the reverendDirect Link to This Post
 
quote
Originally posted by 85fiero_fanat:

The rear brakes juts require you to unhook the clip that holds the brake line to the strut, then put the new caliper and rotors on. Very Easy!!!



When I did mine, I didn't have to unhook the clips. 86 notchie. Don't know if they were original lines or not.

The front caliper mounts have to be shaved somewhere around .125 or so to center the caliper to the G/A rotor.

As for using a larger MC. Its a personnel call. One thing I am considering to finish my brake swap is a variable proportioning valve so I can tune the brakes for our driving style.

Nick
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Report this Post10-24-2008 07:02 PM Click Here to See the Profile for Arns85GTSend a Private Message to Arns85GTDirect Link to This Post
 
quote
Originally posted by Pyrthian:


yes, I know. I need/want the handbrake
mine are not anything like "scary soft". yes, I do want to get them brackets - but I thought they were for the 10.25 LeBaron rotors. there is a set which will let me use grand am rotors, and the caddy calipers, and keep my 14" stock rims?


Yes, we made them so you can use your stock 14" rims. The clearance is close, but it's a fit.

BTW, the Caddy calipers have a piston just a hair smaller than the Grand Am fronts, and with the stock proportioning valve it balances right out.

Arn
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Report this Post10-24-2008 07:51 PM Click Here to See the Profile for ErikSend a Private Message to ErikDirect Link to This Post
 
quote
Originally posted by fieroguru:

I have 2 88's, one with the 12" Vette rotor upgrade and one stock. They both have the same wheels so you can see the visual difference:




The calipers remain stock, so balance front/rear remain stock as well. Biggest benefit is the increase leverage with the larger rotor diameter. Only downside in my books is they are heavier than stock, but never measured by how much.


IIRC, when I weighed my 12 corvette rotors and they were 12lbs as compared to about 11lbs for the stock 88 rotors. They made a noticable difference in stopping power with just the front ..I bet all the way around it would be quite a bit better
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Report this Post10-25-2008 01:43 AM Click Here to See the Profile for 85fiero_fanatSend a Private Message to 85fiero_fanatDirect Link to This Post
The most common reason for soft brakes when doing a partial swap is that the fiero mc doesn't put out as much pressure as is required for the grand am or beretta brakes. I did the rear swap on my fiero to get rid of the pesky hand brake all together, and I don't have soft pedal or anything. I do think I'm using my fronts more than I should be (in relation to the rears), but it isn't bad, and I'm actually happy that i am, because my rear cradle is getting bad and rusting through where the passenger side a-arm hooks up. I like the least amount of torque on it as I can get.

Also, the brake upgrades we're all mentioning are for pre 88's. 88 brakes are a whole different monster and from what I hear aren't that bad stock, just tough to find parts for.
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Report this Post10-25-2008 05:30 AM Click Here to See the Profile for Austrian ImportSend a Private Message to Austrian ImportDirect Link to This Post
Please don't forget to add the:

12" Corvette Rotor swap with Corvette Calipers
13" Corvette Rotor swap with Corvette Calipers

Held Motorsports big brake kit
WCF Big brake kits (they have several kinds)

Fieroaddiction:
12" Corvette Rotor swap
13" Wilwood Big Brake kit

Other homebrews.
incl.: Brembo Rotor swap (I think it's from a Porsche)
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Report this Post10-25-2008 06:16 PM Click Here to See the Profile for DandRautoSend a Private Message to DandRautoDirect Link to This Post
I thought the 11 1/4 upgrade with the Lebaron rotors was the most popular. That's what I did.
Brackets have been available from forum members,
GM calipers, GM master cylinder,
Lebaron rear rotors,
and some slightly longer Brake lines.

Or Archie sells kit as his Big Brake upgrade.
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Report this Post10-26-2008 11:15 AM Click Here to See the Profile for olejoedadSend a Private Message to olejoedadDirect Link to This Post
The 4 wheel GrandAm/Beretta upgrade with an early 90's S-10 Blazer Master Cylinder is a great swap. I have had this on my daily driver for almost 3 years with absolutely no issues and tremendous braking power and excellent modulation at the limits of traction.

A few points:

The early 90's S-10 Blazer master cylinder works better than the stock Fiero Master cylinder - restores lost pedal height and feel when doing all 4 wheels with the GA/B front calipers and rotors.

The brake booster upgrade is not needed, but some people may prefer an "easy" pedal to push rather than a "harder" pedal to push.

The trimming on the front caliper mount does not "center" the caliper, it simply trims back part of the casting that will rub the inside of the thicker GrandAm/Beretta rotor. No machining required, a hand grinder or file will work fine.

The cost for this upgrade is less than rebuilding your stock brakes with Fiero parts.

This upgrade after 3 years outperforms the new stock brakes on my 88 Formula V-8 car.

Don't forget your brake lines and hoses!!!

[This message has been edited by olejoedad (edited 10-26-2008).]

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Report this Post10-26-2008 02:13 PM Click Here to See the Profile for BillSSend a Private Message to BillSDirect Link to This Post
Afraid I've never seen the need for any brake upgrade.

Although I drive an 88 now, which has the better rotors, even the 87 I used to drive had perfectly adequate brakes that never faded despite hard use on the street.

Why do people want to upgrade? Just something to do? Think they might some day have to drive at highly illegal speeds or down mountainsides and might experience some fade? Bragging rights?
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Report this Post10-26-2008 02:19 PM Click Here to See the Profile for Arns85GTSend a Private Message to Arns85GTDirect Link to This Post
 
quote
Originally posted by 82-T/A [At Work]:

By soft, do you mean pedal pressure?

That really has to do with how the system is set up. With a good brake booster and master cyl, as well as steel lines and steel braided connector lines, it should be totally solid if there is no air in the system.


Yes I mean pedal pressure. I was amazed how hard I had to push to make it stop. Having driven both I can tell you that the Grand Am front only swap is definitely inferior to the all way 'round swap with the swapped brake booster.


Arn

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Report this Post10-26-2008 02:21 PM Click Here to See the Profile for Arns85GTSend a Private Message to Arns85GTDirect Link to This Post

Arns85GT

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quote
Originally posted by pswayne:

Does anybody have first-hand experience on how well the Cadillac parking brakes (as adapted to 84-87 cars) work?


Yes, I designed the swap and I use it all the time. The Fiero parking brake lever, the Fiero cables except the driver side cable which is the Pontiac 6000 cable. It works like a charm with the Caddy calipers.

Arn

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Report this Post10-26-2008 03:15 PM Click Here to See the Profile for PerKrClick Here to visit PerKr's HomePageSend a Private Message to PerKrDirect Link to This Post
 
quote
Originally posted by olejoedad:
The early 90's S-10 Blazer master cylinder works better than the stock Fiero Master cylinder - restores lost pedal height and feel when doing all 4 wheels with the GA/B front calipers and rotors.


I don't know the specs of the s-10 master cylinder, but a note of caution: if changing the MC results in a higher pedal, the only logical reason would be an increase in piston diameter, which equals a lowering of the line pressure (which would be offset by an increase in piston diameter and caliper stiffness to increase overall caliper clamping force)
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Report this Post10-26-2008 03:41 PM Click Here to See the Profile for 85fiero_fanatSend a Private Message to 85fiero_fanatDirect Link to This Post
 
quote
Originally posted by BillS:

Afraid I've never seen the need for any brake upgrade.

Although I drive an 88 now, which has the better rotors, even the 87 I used to drive had perfectly adequate brakes that never faded despite hard use on the street.

Why do people want to upgrade? Just something to do? Think they might some day have to drive at highly illegal speeds or down mountainsides and might experience some fade? Bragging rights?


If you compare fiero braking distance to that of modern family cars it is highly inadequate. That is the main reason for the swap. The other reason is cost. Pre 88 calipers are $50 a piece, and the rotors are more than most other rotors (ie cav/ga rotors) and aren't even vented. I replaced my rear calipers with the beretta calipers because my brake lines are seized up and I was missing one of the hand brake brackets, which I was told was needed or the brakes wouldn't re-adjust themselves right. I saved $60 replacing my rear calipers (which were already leaking) with beretta ones.
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Report this Post10-26-2008 04:46 PM Click Here to See the Profile for Arns85GTSend a Private Message to Arns85GTDirect Link to This Post
 
quote
Originally posted by PerKr:


I don't know the specs of the s-10 master cylinder, but a note of caution: if changing the MC results in a higher pedal, the only logical reason would be an increase in piston diameter, which equals a lowering of the line pressure (which would be offset by an increase in piston diameter and caliper stiffness to increase overall caliper clamping force)


I've got an 85 Blazer booster and my pedal isn't higher. It is rock solid so it doesn't depress as much. It also doesn't take any more pressure than my Oldsmobile.

Arn
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Report this Post10-26-2008 04:58 PM Click Here to See the Profile for PrimarisClick Here to visit Primaris's HomePageSend a Private Message to PrimarisDirect Link to This Post
 
quote
Originally posted by 85fiero_fanat:


If you compare fiero braking distance to that of modern family cars it is highly inadequate. That is the main reason for the swap. The other reason is cost. Pre 88 calipers are $50 a piece, and the rotors are more than most other rotors (ie cav/ga rotors) and aren't even vented. I replaced my rear calipers with the beretta calipers because my brake lines are seized up and I was missing one of the hand brake brackets, which I was told was needed or the brakes wouldn't re-adjust themselves right. I saved $60 replacing my rear calipers (which were already leaking) with beretta ones.


http://www.teamscr.com/grmbrakes.htm

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Report this Post10-26-2008 07:30 PM Click Here to See the Profile for olejoedadSend a Private Message to olejoedadDirect Link to This Post
Perker - I should really have said "firmness" rather than "height", actually, "effort" would be a good description of what the S-10 Blazer M/C does for the 4 wheel GA/B swap.

In any case, I've been using it with excellent results for the past 35,000 miles.
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Report this Post10-26-2008 10:13 PM Click Here to See the Profile for 85fiero_fanatSend a Private Message to 85fiero_fanatDirect Link to This Post
 
quote
Originally posted by Primaris:


http://www.teamscr.com/grmbrakes.htm



Okay, how's this for reasoning then. The blazer brake mc allows for less pressure to create more pressure, because it has a smaller piston diameter than the Fiero's MC. The beretta/ga brake calipers need this, because they have a bigger piston diameter than those of the Fiero. The beretta/GA rotors are better than that of the fiero because they're slotted which allows for better heat dissipation and less warping. After making all of these changes the fiero still has a good compliance and doesn't run out of fluid when applying pressure.

As far as tires go...The fiero (or atleast my fiero), pre-88, with factory calipers couldn't even produce enough pressure on dry pavement to induce loss of traction. Therefor the problem with the system isn't the tires it's the braking system's ability to stop those tires. Also, brand new it might have been able to induce sliding, but tires have improved over the years and you can get much better traction (friction/resistance) with new ones.

I understand the concepts of how it's really energy that you look at when talking about braking systems and stopping, and that the wheels are what stop the car, but from what I said you should have had a decent understanding of why we do the brake upgrades. My braking has improved drastically by replacing only the rear calipers. I can't imagine what it would be like with new front calipers as well.
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Report this Post10-27-2008 02:57 AM Click Here to See the Profile for PrimarisClick Here to visit Primaris's HomePageSend a Private Message to PrimarisDirect Link to This Post
If your brakes were not able to lock up your tires then yes you need a bigger lever.

I don't know enough about the specifics about your upgrade to do the math, sorry. But, if you have the measurements you can plug in the numbers just like they did on that link.

The reason I posted the link is to help dispel the thinking that bigger brakes make you stop faster. The only thing that does make the car stop faster is more stick from your tires.

I suspect, only suspect, if a Fiero can't lock up its brakes it is from these issues:
-Air in the lines. The DS rear line is level with the MC, who knows why?
-There is a problem with the Combination Valve (aka proportioning valve)
-The self adjusting rear calipers are not working correctly

BTW according to this Motor Week road test: http://www.youtube.com/watch?v=-Ib-jB58GEg The Fiero stopped from 55mph in 118ft. That seems to be right in line with modern cars.

Here are some more brake myth busting links:
http://www.teamscr.com/rotors.html
http://www.stoptech.com/tec...rped_brakedisk.shtml

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Pyrthian
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Report this Post10-27-2008 08:13 AM Click Here to See the Profile for PyrthianSend a Private Message to PyrthianDirect Link to This Post
 
quote
Originally posted by BillS:
Afraid I've never seen the need for any brake upgrade.

Although I drive an 88 now, which has the better rotors, even the 87 I used to drive had perfectly adequate brakes that never faded despite hard use on the street.

Why do people want to upgrade? Just something to do? Think they might some day have to drive at highly illegal speeds or down mountainsides and might experience some fade? Bragging rights?


the most basic reason is larger rims/tires. when you have larger circle rolling, you need a larger circle to stop it as well.

and, then solid disks of the 84-87 just will not do if you do ANY type of driving, where you need braking events within 3 seconds of each other.

and, back to the original reason: the larger rims - not only is it needed - it also looks WAY batter if that large rim is open to see a nice shiney rotor & polished painted caliper.

and, finally - a larger disk gives you more control of the pressure. you can more accurately apply pressure. as mentioned above - all you really need is to be able to lock the brakes. obviously, locking the brakes is NOT a desired result. but, being able to more accurately reach the point just before lockup is MUCH easier with a larger rotor. "leverage" is the actual force being used - and a larger rotor is a larger lever.

so, yes - it is a mixed bag of need & brag - but dont for a second think it is 100% brag. it is always better to have a car that wont start - than a car that wont stop.

[This message has been edited by Pyrthian (edited 10-27-2008).]

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Arns85GT
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Report this Post10-27-2008 08:26 AM Click Here to See the Profile for Arns85GTSend a Private Message to Arns85GTDirect Link to This Post
I agree. I don't really want to lock up when in a panic stop. My Fiero doesn't generally lock (although I haven't hammered the brakes at 70mph) unless going down hill. In that application the fronts will lock a wee bit just before it comes to a stop. The important thing to me is that when I step on the brake the car stops hard and straight and doesn't slide. Having ridden a motorcycle for a number of years I can say that a Fiero or any other street car is unlikely to be able to stop in as short a distance as a well equipped motorcycle. That said, the Fiero with the Grand Am rotor conversion is much safer and more secure in stopping with less effort. That, is confidence for me. BTW, I think the Corvette rotor conversion is way cool and if I was racing that is the route I would go.

Arn
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Report this Post10-27-2008 11:38 AM Click Here to See the Profile for 85fiero_fanatSend a Private Message to 85fiero_fanatDirect Link to This Post
 
quote
Originally posted by Primaris:

If your brakes were not able to lock up your tires then yes you need a bigger lever.

I don't know enough about the specifics about your upgrade to do the math, sorry. But, if you have the measurements you can plug in the numbers just like they did on that link.

The reason I posted the link is to help dispel the thinking that bigger brakes make you stop faster. The only thing that does make the car stop faster is more stick from your tires.

I suspect, only suspect, if a Fiero can't lock up its brakes it is from these issues:
-Air in the lines. The DS rear line is level with the MC, who knows why?
-There is a problem with the Combination Valve (aka proportioning valve)
-The self adjusting rear calipers are not working correctly

BTW according to this Motor Week road test: http://www.youtube.com/watch?v=-Ib-jB58GEg The Fiero stopped from 55mph in 118ft. That seems to be right in line with modern cars.

Here are some more brake myth busting links:
http://www.teamscr.com/rotors.html
http://www.stoptech.com/tec...rped_brakedisk.shtml



Yeah, I know. I don't feel like searching everything up, but I've talked to many people who did the conversion years ago and have never had problems. That was my initial reason for doing it (aside from the price of fiero calipers, and the parking brake problem).

I know I don't have air in my lines, because I've bleed quite a few times (with changing calipers), and every time it feels the same. The brakes feel solid, but when coming to a stop it just feels like you're trying to put your foot through the floor to stop the car (almost feels like you're going to brake the pedal). I've had two times where I had to lock them up and they didn't lose traction until the very end of braking (like 5-0mph). I feel a lot safer with the beretta brakes in my car and feel that they grab a lot better than the fiero ones did (feels like I have a lot more control).
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Report this Post10-27-2008 11:39 AM Click Here to See the Profile for 85fiero_fanatSend a Private Message to 85fiero_fanatDirect Link to This Post

85fiero_fanat

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quote
Originally posted by Arns85GT:

I agree. I don't really want to lock up when in a panic stop. My Fiero doesn't generally lock (although I haven't hammered the brakes at 70mph) unless going down hill. In that application the fronts will lock a wee bit just before it comes to a stop. The important thing to me is that when I step on the brake the car stops hard and straight and doesn't slide. Having ridden a motorcycle for a number of years I can say that a Fiero or any other street car is unlikely to be able to stop in as short a distance as a well equipped motorcycle. That said, the Fiero with the Grand Am rotor conversion is much safer and more secure in stopping with less effort. That, is confidence for me. BTW, I think the Corvette rotor conversion is way cool and if I was racing that is the route I would go.

Arn


I agree on the locking up, but I feel that if your brakes don't grab hard enough to induce minor slip then how sure are you that they're grabbing as much as they can without inducing sliding?
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Report this Post10-27-2008 01:40 PM Click Here to See the Profile for PerKrClick Here to visit PerKr's HomePageSend a Private Message to PerKrDirect Link to This Post
 
quote
Originally posted by 85fiero_fanat:


Okay, how's this for reasoning then. The blazer brake mc allows for less pressure to create more pressure, because it has a smaller piston diameter than the Fiero's MC. The beretta/ga brake calipers need this, because they have a bigger piston diameter than those of the Fiero. The beretta/GA rotors are better than that of the fiero because they're slotted which allows for better heat dissipation and less warping. After making all of these changes the fiero still has a good compliance and doesn't run out of fluid when applying pressure.



The larger caliper pistons do not require a smaller MC piston. A smaller MC piston increases line pressure. Larger caliper pistons increase clamping force. If you keep increasing the caliper piston size, sooner or later you will need to increase MC piston size in order to move enough fluid to apply the brakes. That said, from the information I have been given, the fiero MC is relatively large compared to the caliper pistons, compared to other cars (my daily driver has a 23mm MC piston and 57mm caliper pistons), so I doubt we would need to worry about our master cylinders being too small (if it is indeed 1" diameter as I've been told).

I'll go back to just watching this thread now
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Report this Post10-27-2008 02:06 PM Click Here to See the Profile for PerKrClick Here to visit PerKr's HomePageSend a Private Message to PerKrDirect Link to This Post

PerKr

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quote
Originally posted by Primaris:The reason I posted the link is to help dispel the thinking that bigger brakes make you stop faster. The only thing that does make the car stop faster is more stick from your tires.


This is only true if you're already at the limit of your current tires. You have to keep an eye out for the weakest link, and if you're driving an 84-87 with wider-than-original tires, the tires are probably not it.

 
quote

BTW according to this Motor Week road test: http://www.youtube.com/watch?v=-Ib-jB58GEg The Fiero stopped from 55mph in 118ft. That seems to be right in line with modern cars.


that's an '88. I haven't found anything to suggest the 84-87 cars stopping sooner than 183ft (which was pretty poor even back then), but maybe someone else knows better (and can tell us exactly what the difference is between the 84-87 and 88 brake systems).

[This message has been edited by PerKr (edited 10-27-2008).]

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Report this Post10-27-2008 02:36 PM Click Here to See the Profile for PrimarisClick Here to visit Primaris's HomePageSend a Private Message to PrimarisDirect Link to This Post
 
quote
Originally posted by PerKr:
This is only true if you're already at the limit of your current tires. You have to keep an eye out for the weakest link, and if you're driving an 84-87 with wider-than-original tires, the tires are probably not it.


Yes. If your current brake system can lock up your tires, then putting larger rotors on it will not lower the stopping distance. WhooHoo, the truth spreads!!!
LOL

Seriously, though ask any drag racer who has horsepower induced wheel spin and they talk about adding traction via tires. So why don't people realize the same thing applies to stopping? Stopping is just negative acceleration after all.

I own an '86 too, purchased in '88. Back in the day it use to be able to lock up the brakes. The issue I had with the brakes was a delay of caliper release upon locking them. This made it very, very hard to keep the car at impending lock up.

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Report this Post10-27-2008 02:42 PM Click Here to See the Profile for PyrthianSend a Private Message to PyrthianDirect Link to This Post
 
quote
Originally posted by Primaris:
Yes. If your current brake system can lock up your tires, then putting larger rotors on it will not lower the stopping distance. WhooHoo, the truth spreads!!!
LOL

Seriously, though ask any drag racer who has horsepower induced wheel spin and they talk about adding traction via tires. So why don't people realize the same thing applies to stopping? Stopping is just negative acceleration after all.

I own an '86 too, purchased in '88. Back in the day it use to be able to lock up the brakes. The issue I had with the brakes was a delay of caliper release upon locking them. This made it very, very hard to keep the car at impending lock up.


because "locking it up" is not how most people come to a stop.
larger rotors allow more control of braking. and, yes - this WILL decrease your stopping distance.

and, again - larger wheel/tire combos need larger brakes for the exact same reason.
leverage.

there ARE valid reasons for brake upgrades. but, I agree 100% that most do so because they want to, not because they need to. and, that is 100% fine too.
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Report this Post10-27-2008 04:09 PM Click Here to See the Profile for PerKrClick Here to visit PerKr's HomePageSend a Private Message to PerKrDirect Link to This Post
 
quote
Originally posted by Primaris:

Yes. If your current brake system can lock up your tires, then putting larger rotors on it will not lower the stopping distance. WhooHoo, the truth spreads!!!
LOL

Seriously, though ask any drag racer who has horsepower induced wheel spin and they talk about adding traction via tires. So why don't people realize the same thing applies to stopping? Stopping is just negative acceleration after all.


I agree, if your current brakes can lock up your current tires you do not need to increase clamping force. But if you can't lock your tires up (and I'm not talking about the last few feet of braking where even my shoddy brakes manage to lock my cold front tires), you should benefit from increased leverage or clamping force. As I said (I think I did, or maybe I didn't?), the braking system is only as good as it's weakest link, and that includes the tires. end of discussion?
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Report this Post10-27-2008 07:55 PM Click Here to See the Profile for 85fiero_fanatSend a Private Message to 85fiero_fanatDirect Link to This Post
 
quote
Originally posted by PerKr:


The larger caliper pistons do not require a smaller MC piston. A smaller MC piston increases line pressure. Larger caliper pistons increase clamping force. If you keep increasing the caliper piston size, sooner or later you will need to increase MC piston size in order to move enough fluid to apply the brakes. That said, from the information I have been given, the fiero MC is relatively large compared to the caliper pistons, compared to other cars (my daily driver has a 23mm MC piston and 57mm caliper pistons), so I doubt we would need to worry about our master cylinders being too small (if it is indeed 1" diameter as I've been told).

I'll go back to just watching this thread now


the smaller bore mc would allow higher pressure to those calipers though wouldn't it? According to the web page that was presented the only problem with getting a smaller mc was that it might not move enough fluid and that causes problems. The fact that the fiero's mc is very large vs other cars means that a smaller mc should be very feasible, and by the looks of things, it is.
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Report this Post10-27-2008 08:14 PM Click Here to See the Profile for Steven SnyderClick Here to visit Steven Snyder's HomePageSend a Private Message to Steven SnyderDirect Link to This Post
88 stock rotors are 10 lbs, the Corvette 12" rotors I have are 14 lbs.
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Report this Post10-28-2008 04:02 PM Click Here to See the Profile for PerKrClick Here to visit PerKr's HomePageSend a Private Message to PerKrDirect Link to This Post
 
quote
Originally posted by 85fiero_fanat:


the smaller bore mc would allow higher pressure to those calipers though wouldn't it? According to the web page that was presented the only problem with getting a smaller mc was that it might not move enough fluid and that causes problems. The fact that the fiero's mc is very large vs other cars means that a smaller mc should be very feasible, and by the looks of things, it is.


not so much "allow" as "result in", but yeah, you're right.
The Ferrari 308 has a 22mm MC and the same size caliper pistons as the fiero (though on the ferrari they are fixed 2-pots instead of floating single-pots). The porsche 911 at one point used a 20mm (well, 20.something mm) MC with the same size calipers as the ferrari 308.
But there is probably a reason why GM decided to use a larger MC, though it's sort of unclear.
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