Pennock's Fiero Forum
  General Fiero Chat
  better braking (Page 2)

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version

This topic is 5 pages long:  1   2   3   4   5 
Previous Page | Next Page
next newest topic | next oldest topic
better braking by Northwoods2
Started on: 02-01-2015 08:58 AM
Replies: 163 (3254 views)
Last post by: thesameguy on 02-18-2015 06:10 PM
Gall757
Member
Posts: 10760
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 89
Rate this member

Report this Post02-06-2015 12:29 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by theogre:

Sorry I haven't put the info in my cave... I keep forgetting to update the two pages.



As we take your advice pretty seriously around here, I'll be looking forward to the update.
Also, I notice the 88 Fiero is not included in the recall...is it different when it comes to adjustment?

[This message has been edited by Gall757 (edited 02-06-2015).]

IP: Logged
seajai
Member
Posts: 1537
From: Circle Pines, Minnesota
Registered: Feb 2012


Feedback score:    (42)
Leave feedback





Total ratings: 52
Rate this member

Report this Post02-06-2015 12:43 PM Click Here to See the Profile for seajaiSend a Private Message to seajaiEdit/Delete MessageReply w/QuoteDirect Link to This Post
Making sure the braking system is working properly before upgrading anything is definitely the first step. Poor brake performance due to worn, plugged, or failed components will still exist after a larger booster is installed. The only change would be someone's wallet is a little lighter than before.

But I think the other part of the discussion is this. If the system is in proper working condition, will simply increasing the size of the booster make any noticeable difference in braking feel or decrease stopping distance. I haven't done any official testing to measure stopping distance, but I worked the brakes hard right before I did the swap and right after and it certainly felt like it stopped quicker with the bigger booster.

If someone has braking data on the 88's and 84-87's from an old magazine article or something maybe they could post it here. Personally I'd like to do an official stopping distance measurement to see how accurate my butt dyno really is.
IP: Logged
Csjag
Member
Posts: 3170
From: Ocklawaha,Fl, USA
Registered: Dec 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post02-06-2015 01:46 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
I just re-watched the Motorweek road test of the 84 Fiero and they praised the brakes asone of the cars best features with a firm pedal and easy to modulate and a good stopping distance of 125 feet from 55 mph.
IP: Logged
thesameguy
Member
Posts: 1535
From: California
Registered: Dec 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post02-06-2015 02:48 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
125' may have been good in '84, but that was 30 years ago. A Suburban can stop from 55mph in 125'. You could actually find yourself rear-ending a two and a half ton truck in your tiny car because it couldn't stop in time.

Car expectations have changed. I would not consider anything about the stock brake system to be adequate for modern traffic, at least not driving like a normal person.
IP: Logged
seajai
Member
Posts: 1537
From: Circle Pines, Minnesota
Registered: Feb 2012


Feedback score:    (42)
Leave feedback





Total ratings: 52
Rate this member

Report this Post02-06-2015 02:58 PM Click Here to See the Profile for seajaiSend a Private Message to seajaiEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just found this: 1988 Motorweek road tests comparing the Fiero to the MR2. The braking test begins at 7:45. The stopping distance for the 88 Fiero Formula was 118 feet compared to 125 feet for the MR2

[This message has been edited by seajai (edited 02-06-2015).]

IP: Logged
thesameguy
Member
Posts: 1535
From: California
Registered: Dec 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post02-06-2015 03:44 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
That is comparing a 2nd gen Fiero against a 1st gen MR2. Granted, same model year, but still noteworthy. The 2nd gen MR2 got numbers varying from 110' to 116'.

Fun to watch '80s car reviews though - seeing a new Fiero cruise around a track is neat.

Edit: And I guess indicative of what an improvement the '88 was!

[This message has been edited by thesameguy (edited 02-06-2015).]

IP: Logged
Csjag
Member
Posts: 3170
From: Ocklawaha,Fl, USA
Registered: Dec 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post02-06-2015 04:32 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
I just looked at a Car and Driver list of braking distances from 70 mph of 2008 high performance cars and the best was a ZR1 at 142 feet, a Lotus SC was 153 feet. I know the 84 Fiero did 125 feet from 55 mph but that seems to me to compare favorably.
IP: Logged
thesameguy
Member
Posts: 1535
From: California
Registered: Dec 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post02-06-2015 06:18 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
It really doesn't. Speed results in logarithmic increases in stopping distances. The 60-0 of the ZR1 is 110'. Another 10mph adds *30'* to its stopping distance. A Fiero stopping from 70mph could reasonably be in the 160'+ range and I wouldn't be surprised if it was more - small brakes that can't dump heat fast enough? +35' for +15mph is well within reason.

[This message has been edited by thesameguy (edited 02-06-2015).]

IP: Logged
theogre
Member
Posts: 29973
From: USA
Registered: Mar 99


Feedback score: N/A
Leave feedback





Total ratings: 558
Rate this member

Report this Post02-06-2015 07:03 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:
As we take your advice pretty seriously around here, I'll be looking forward to the update.
Also, I notice the 88 Fiero is not included in the recall...is it different when it comes to adjustment?

Recall doesn't apply to 87 Fiero too but GM# 88-5-19A does. Many reasons why that can happen...
88 uses same piston design as eary years but the caliper body is different so adjustment method in my cave might change a bit.
You still use same shim but prying out the piston might be harder to do.

 
quote
Originally posted by seajai:
But I think the other part of the discussion is this. If the system is in proper working condition, will simply increasing the size of the booster make any noticeable difference in braking feel or decrease stopping distance. I haven't done any official testing to measure stopping distance, but I worked the brakes hard right before I did the swap and right after and it certainly felt like it stopped quicker with the bigger booster.

If someone has braking data on the 88's and 84-87's from an old magazine article or something maybe they could post it here. Personally I'd like to do an official stopping distance measurement to see how accurate my butt dyno really is.

Closest thing is here...
Rodney's S10 Brake Booster - Review/Evaluation

Bigger Booster does make more Line Pressure for Giving Pedal Load.
More Line Pressure can make the car stop faster. How fast likely depend on tires etc too. Crap tires could just skin more.

Higher line pressure should be safe if the system is in very good condition. I think I've said this in link above because pressure is well bellow FMVSS 106 line/hose test pressure and the Big Booster adds ~300psi average in his charts.

That said... Just 2 Problem:
  • Many saying the Upgrade is Safe and/or Legal. No one have Proof to say either.
    Old lines + Big Booster could = Ouch. While OE line/hoses can fail from rust etc problems at normal working pressure and adding ~300psi can blow out sooner.
  • Many are pushing this upgrade comparing to old booster w/ problems. Even if someone post their stopping distance results, can't really trust the data.
    Can trust link above for pressure chart a bit more because car isn't driving. Engine only at idle and makes constant vacuum so any check valve and vac line problems aren't much of an issue.

    [This message has been edited by theogre (edited 02-06-2015).]

  • IP: Logged
    jscott1
    Member
    Posts: 21674
    From: Houston, TX , USA
    Registered: Dec 2001


    Feedback score:    (15)
    Leave feedback





    Total ratings: 415
    Rate this member

    Report this Post02-07-2015 12:19 AM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by theogre:


    That said... Just 2 Problem:
  • Many saying the Upgrade is Safe and/or Legal. No one have Proof to say either.
    Old lines + Big Booster could = Ouch. While OE line/hoses can fail from rust etc problems at normal working pressure and adding ~300psi can blow out sooner.
  • Many are pushing this upgrade comparing to old booster w/ problems. Even if someone post their stopping distance results, can't really trust the data.
    Can trust link above for pressure chart a bit more because car isn't driving. Engine only at idle and makes constant vacuum so any check valve and vac line problems aren't much of an issue.



  • I've experience several brake line failures over the years. They usually give warning...sometimes not so much. Bottom line is anyone worried about improving brakes should start with a good set of brake flex hoses and if there is rust, replace the hardlines as well.
    IP: Logged
    jscott1
    Member
    Posts: 21674
    From: Houston, TX , USA
    Registered: Dec 2001


    Feedback score:    (15)
    Leave feedback





    Total ratings: 415
    Rate this member

    Report this Post02-07-2015 12:23 AM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post

    jscott1

    21674 posts
    Member since Dec 2001
     
    quote
    Originally posted by thesameguy:

    125' may have been good in '84, but that was 30 years ago. A Suburban can stop from 55mph in 125'. You could actually find yourself rear-ending a two and a half ton truck in your tiny car because it couldn't stop in time.

    Car expectations have changed. I would not consider anything about the stock brake system to be adequate for modern traffic, at least not driving like a normal person.


    I agree. I want to keep my Indy mostly stock, but the stock 84 brakes (in excellent condition) are still outright dangerous in my opinion. I have a set of Grand Am calipers, vented rotorrs, big bore master cylinder and will add the big booster as well. In the back I'm going to do the Seville/Lebaron upgrade.
    IP: Logged
    PFF
    System Bot
    Northwoods2
    Member
    Posts: 21
    From:
    Registered: Jun 2011


    Feedback score: N/A
    Leave feedback

    Rate this member

    Report this Post02-07-2015 07:29 AM Click Here to See the Profile for Northwoods2Click Here to Email Northwoods2Send a Private Message to Northwoods2Edit/Delete MessageReply w/QuoteDirect Link to This Post
    Boy I really opened a can of worms here with a question. I'm not totally new to this. I'm an electrical troubleshooter for a company with a hydraulics back ground. Was an electrician for the U.S. Navy too so I got some age and understanding under my belt. The thing is, I have had 4 Fieros. I love them, but realistically, how can all of the brakes feel identically the same. It is not a new feel to me period. I do appreciate the comments and will give my feed back after I do what I'm gonna do now. The first is, I just bought cross cut and drilled rotors. I have been thru this car of mine. It's a pretty white 85 that I was hoping to make a calendar contest with too. Yes, the hydraulics in a braking system are touchy, and at the same out come, can last decades with crap in them. At any rate, I will give my feed back. It may be a while. I'm from the top of Wisc. She's a cold one up here and no Fieros in site. I however ran into people up here that can't get over how good the car looks. So it's all good. It's my baby, just want to treat it good, learn more, have fun with it and you folks. Thank yous.
    IP: Logged
    seajai
    Member
    Posts: 1537
    From: Circle Pines, Minnesota
    Registered: Feb 2012


    Feedback score:    (42)
    Leave feedback





    Total ratings: 52
    Rate this member

    Report this Post02-07-2015 10:00 AM Click Here to See the Profile for seajaiSend a Private Message to seajaiEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by jscott1:


    I've experience several brake line failures over the years. They usually give warning...sometimes not so much. Bottom line is anyone worried about improving brakes should start with a good set of brake flex hoses and if there is rust, replace the hardlines as well.


    I recently had a hard line failure with my 1-ton chev pickup during a panic stop to avoid a flock of deer running across the road. I got no warning on that one, definitely gets your attention though.

    I did my booster swap in early 2012, I remember reading Guru's thread on the subject. I took the s-10 booster apart and swapped over the Fiero brake pedal push rod and apply pin when I did mine. My hard lines were rust free but I didn't trust the 25 year old rubber hoses so those were replaced with new braided steel ones. IMO, a braided hose upgrade should accompany a booster upgrade.

     
    quote
    Originally posted by theogre:

    That said... Just 2 Problem:
  • Many saying the Upgrade is Safe and/or Legal. No one have Proof to say either.



  • Is it legal? Has anybody done this mod and then taken their car through a state inspection? Minnesota doesn't have private vehicle inspections, only commercial, so I can't say here.

    Is it safe? Realistically, the safety of any deviation from stock comes down to the skill level of the person performing the work, and how thorough they are with inspecting and replacing suspect parts. A 400+HP Fiero is far more dangerous in the hands of an unskilled driver than any booster upgrade would be. Yet the safety of more HP is never questioned. Hydraulically speaking,( IF all components are in good condition) it's safe. Guru's tests show that it only ups the pressure at the caliper by a few hundred pounds, well within the safety ratings of the parts. The only proof I have as to safety is 12,000 miles of real world driving without brake line / hose / MC failure, and I work the brakes just as hard as the accelerator.

    [This message has been edited by seajai (edited 02-07-2015).]

    IP: Logged
    JohnWPB
    Member
    Posts: 5175
    From: West Palm Beach, Florida
    Registered: May 2009


    Feedback score:    (21)
    Leave feedback





    Total ratings: 144
    Rate this member

    Report this Post02-07-2015 12:47 PM Click Here to See the Profile for JohnWPBClick Here to visit JohnWPB's HomePageSend a Private Message to JohnWPBEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by Northwoods2:
    The thing is, I have had 4 Fieros. I love them, but realistically, how can all of the brakes feel identically the same.


    Sounds to me like you have bad tires, bad calipers, a faulty valve, or a plugged filter on all four Fieros. That sounds like a pretty stupid argument doesn't it LOL!

    So many people have commented that after installing the S-10 booster, that the brakes feel and work easier. Then immediately a few people keep making the same stupid statement; "That is only because you had a bad brake system in the first place".

    So, just to be clear here. Around 30-50 Fiero owners have done the S-10 booster upgrade that I have seen. All have commented on how well it has worked for them, and the pedal is softer, much like a more modern car. I personally have driven many, many stock Fieros and all the brakes felt pretty much the same, stiff. Northwoods himself had 4 Fieros and states that all his cars "brakes feel identically the same" Now, after installing the S-10 booster, the only reason it works better for everyone is because ALL of these cars had bad braking systems or components in the braking system in the first place? Does anyone else here see just how insanely ridiculous this sounds?


    Sounds like a nice Fiero you have there. The booster swap is simple. It took myself and a friend all of about 30 minutes to do. Grant it, it was not -10 degrees outside int he snow when we did it though

    By the way, you should try to make it to the Tyler Shipman car show at the end of July this year. It is in Frazee MN about 4 hours North-West of Minneapolis St. Paul.

    [This message has been edited by JohnWPB (edited 02-07-2015).]

    IP: Logged
    jscott1
    Member
    Posts: 21674
    From: Houston, TX , USA
    Registered: Dec 2001


    Feedback score:    (15)
    Leave feedback





    Total ratings: 415
    Rate this member

    Report this Post02-07-2015 01:43 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
    How many people here that daily drive a Fiero get in a brand new rental car and nearly launch themselves through the windshield the first time they touch the brakes? Yes newness feels better than 30 year old brakes, but your average grocery getter today has at least twice the brakes of the 84-87 Fiero. I promise you they don't have tiny calipers on solid rotors that's for sure.

    IP: Logged
    theogre
    Member
    Posts: 29973
    From: USA
    Registered: Mar 99


    Feedback score: N/A
    Leave feedback





    Total ratings: 558
    Rate this member

    Report this Post02-07-2015 02:17 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by jscott1:
    I've experience several brake line failures over the years. They usually give warning...sometimes not so much. Bottom line is anyone worried about improving brakes should start with a good set of brake flex hoses and if there is rust, replace the hardlines as well.

    Hoses might weep before leaking/failing. Most cases a dead hose or hard line gives no warning. Brakes can work ok and next you push the pedal you have big problems.

    Having new hoses and often hard lines before you add more pressure is good.
    New SAE J1401 hoses are much better then Stock/OE replacement w/o SS issues/problems.
    see //www.fiero.nl/forum/F...HTML/129208.html#p27
    You can find hoses w/o J1401 but don't buy them. Raybestos PG Plus and others use J1401 hose. The hose itself is label w/ DOT and SAE J1401

     
    quote
    Originally posted by seajai:
    Is it legal? Has anybody done this mod and then taken their car through a state inspection? Minnesota doesn't have private vehicle inspections, only commercial, so I can't say here.

    Most with inspections don't mater because most just don't look at the booster.
    Some states, like DE, actually test the brake system using brake "skid" dyno. Short Story... Mainly that test looks for each wheel brake output. If a wheel has less/no brake on same axle then the test will fail.

    Laws/Regulations can depend on state... Any mod/upgrade might be legal in all states, some or none.
    Even if you don't break any Laws/Regulations, you could be in civil court after a wreck.
    IP: Logged
    E.Furgal
    Member
    Posts: 11708
    From: LAND OF CONFUSION
    Registered: Mar 2012


    Feedback score:    (23)
    Leave feedback





    Total ratings: 278
    User Banned

    Report this Post02-07-2015 06:45 PM Click Here to See the Profile for E.FurgalSend a Private Message to E.FurgalEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by jscott1:

    How many people here that daily drive a Fiero get in a brand new rental car and nearly launch themselves through the windshield the first time they touch the brakes? Yes newness feels better than 30 year old brakes, but your average grocery getter today has at least twice the brakes of the 84-87 Fiero. I promise you they don't have tiny calipers on solid rotors that's for sure.


    i'll take old car brakes over the newer car systems that think they know more than the driver..
    IP: Logged
    jscott1
    Member
    Posts: 21674
    From: Houston, TX , USA
    Registered: Dec 2001


    Feedback score:    (15)
    Leave feedback





    Total ratings: 415
    Rate this member

    Report this Post02-07-2015 08:52 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by E.Furgal:


    i'll take old car brakes over the newer car systems that think they know more than the driver..


    If you mean ABS... my 2007 does not have it and the brakes are still twice as good as a stock Fiero ever was.
    IP: Logged
    JohnWPB
    Member
    Posts: 5175
    From: West Palm Beach, Florida
    Registered: May 2009


    Feedback score:    (21)
    Leave feedback





    Total ratings: 144
    Rate this member

    Report this Post02-08-2015 01:41 AM Click Here to See the Profile for JohnWPBClick Here to visit JohnWPB's HomePageSend a Private Message to JohnWPBEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by jscott1:
    How many people here that daily drive a Fiero get in a brand new rental car and nearly launch themselves through the windshield the first time they touch the brakes?


    I did that in a new Impala. I pulled up to the gate so he could check my rental agreement, and let me out. I went to stop and bounced the car.... needless to say I felt pretty stupid....


     
    quote
    Originally posted by jscott1:


    If you mean ABS... my 2007 does not have it and the brakes are still twice as good as a stock Fiero ever was.


    That could only be do to the fact that the brakes on your Fiero have been neglected and something is bad
    IP: Logged
    RayOtton
    Member
    Posts: 3459
    From: Cape Charles, VA, USA
    Registered: Jul 2012


    Feedback score: N/A
    Leave feedback





    Total ratings: 54
    Rate this member

    Report this Post02-08-2015 06:21 AM Click Here to See the Profile for RayOttonClick Here to Email RayOttonSend a Private Message to RayOttonEdit/Delete MessageReply w/QuoteDirect Link to This Post
    I duuno, maybe I'm just lucky.

    I have an '88 Fiero, '98 F-150, '02 Civic, '04 Bravada and an "06 Lincoln LS.

    The brakes feel pretty much the same on all of them.
    IP: Logged
    Csjag
    Member
    Posts: 3170
    From: Ocklawaha,Fl, USA
    Registered: Dec 2013


    Feedback score: N/A
    Leave feedback

    Rate this member

    Report this Post02-08-2015 08:42 AM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
    I have read several posts on here in the past that said the brake pads used make a difference in stopping power, each person said the wagner thermoquiet pads are better. I think what I will do is get a set of Wagner thermoquiet pads and replace my booster with a rebuilt oem style and see what it does. I really don't mind having to use more pedal pressure, I am concerned that using a brake booster not designed for the car will result in locking up the brakes more easily. I don't race or autocross my car and most roads I travel on have a 55 mph speed limit so I drive no faster than 65 and I don't tailgate.
    IP: Logged
    PFF
    System Bot
    olejoedad
    Member
    Posts: 14738
    From: Clarendon Twp., MI
    Registered: May 2004


    Feedback score: (5)
    Leave feedback





    Total ratings: 193
    Rate this member

    Report this Post02-08-2015 10:38 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
    Wagner QuickStop is also a good choice.
    IP: Logged
    Csjag
    Member
    Posts: 3170
    From: Ocklawaha,Fl, USA
    Registered: Dec 2013


    Feedback score: N/A
    Leave feedback

    Rate this member

    Report this Post02-08-2015 11:47 AM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
    okay thanks, I think rock auto carries those
    IP: Logged
    E.Furgal
    Member
    Posts: 11708
    From: LAND OF CONFUSION
    Registered: Mar 2012


    Feedback score:    (23)
    Leave feedback





    Total ratings: 278
    User Banned

    Report this Post02-08-2015 11:48 AM Click Here to See the Profile for E.FurgalSend a Private Message to E.FurgalEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by jscott1:


    If you mean ABS... my 2007 does not have it and the brakes are still twice as good as a stock Fiero ever was.

    but that 2007 stops no better than an 1984 caprice..

    the fiero only had/has brakes that it needs, and in good working order, are just as good as a small econo box..from today.

    Everyone has said that Pontiac told the brass it was "only" a commuter car, with their fingers cross behind their back.. knowing they were going in a more sports car, route, but needed to get the ball rolling.
    I'd love to have a road course pro driver, drive one fiero with the stock set up, same brand rotors and pads, tires,alignment and another with the only change the s-10 booster, and comment on what set up gives the driver the better "feedback" .
    A road test above listed the fiero with a stopping of 116 feet,, IIRC the 2002 f body test got 110 feet.. with much bigger brakes, and was class leading at that time..
    I think much of the issue is that drivers have been used to set up's with very light touch needed, designed so the weakest person can push on the brakes, without effort.. taking the "feedback" to the driver out of the design needs, ABS only made that even worse.

    [This message has been edited by E.Furgal (edited 02-08-2015).]

    IP: Logged
    theogre
    Member
    Posts: 29973
    From: USA
    Registered: Mar 99


    Feedback score: N/A
    Leave feedback





    Total ratings: 558
    Rate this member

    Report this Post02-08-2015 12:24 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by Csjag:
    I have read several posts on here in the past that said the brake pads used make a difference in stopping power, each person said the wagner thermoquiet pads are better. I think what I will do is get a set of Wagner thermoquiet pads and replace my booster with a rebuilt oem style and see what it does. I really don't mind having to use more pedal pressure, I am concerned that using a brake booster not designed for the car will result in locking up the brakes more easily. I don't race or autocross my car and most roads I travel on have a 55 mph speed limit so I drive no faster than 65 and I don't tailgate.

    Try Wagner TQ first and check, replace if needed, all calipers.
    Note: ANY pads will take a long time to "bed" w/o good surface on rotors. Ceramic pads can take longer...
    Depending how bad the rotors... Can try turning them. Spec in my cave.

    If you think booster is bad... First check Vac Line/filter. Try bypassing the filter. (Not all Fiero came w/ vac filter...) New check valve are ~$5.00. Get thru Dorman HELP! at many stores.
    IP: Logged
    Raydar
    Member
    Posts: 38922
    From: Carrollton GA. Out in the... country.
    Registered: Oct 1999


    Feedback score:    (12)
    Leave feedback





    Total ratings: 455
    Rate this member

    Report this Post02-08-2015 02:10 PM Click Here to See the Profile for RaydarClick Here to Email RaydarSend a Private Message to RaydarEdit/Delete MessageReply w/QuoteDirect Link to This Post
    Gall757 suggested that I check out this thread.

    My situation is that my 88 has a heavy front bias to the brakes. Always has.
    From conversations with people who are in a position to know, I understand that it's a common complaint. My other 88 was the same way.
    I should add that my brakes work fine, otherwise. This includes the parking brake. I use it all the time, usually leaving the tranny in neutral.
    I have fieroguru's 13" brakes, and am quite happy with the setup.

    I was attempting to purchase aaron88's adjustable proportioning valve, but he seems to have fallen off the earth. Others who have purchased this valve have high praise for it.
    I started another thread in "tech" looking for another solution. Might as well ask here, too.

    (And yes... my front tires are slightly narrower than the rears - 215s vs 235s - but I'm told that adding wider tires to the front won't make that much of a difference. It would just be a bandaid to address a poorly balanced system. Aside from that, the stock 88 GT and Formula also have staggered tire sizes.)

    Anyone have any positive means to adjust the bias to the rear?
    IP: Logged
    olejoedad
    Member
    Posts: 14738
    From: Clarendon Twp., MI
    Registered: May 2004


    Feedback score: (5)
    Leave feedback





    Total ratings: 193
    Rate this member

    Report this Post02-08-2015 02:48 PM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
    Wilwood sells proportioning valves.
    IP: Logged
    tshark
    Member
    Posts: 4388
    From:
    Registered: Feb 2014


    Feedback score:    (6)
    Leave feedback





    Total ratings: 68
    Rate this member

    Report this Post02-08-2015 03:19 PM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
    The adjustable one like aaron88 had? I don't find such a user on here.

    [This message has been edited by tshark (edited 02-08-2015).]

    IP: Logged
    Raydar
    Member
    Posts: 38922
    From: Carrollton GA. Out in the... country.
    Registered: Oct 1999


    Feedback score:    (12)
    Leave feedback





    Total ratings: 455
    Rate this member

    Report this Post02-08-2015 04:00 PM Click Here to See the Profile for RaydarClick Here to Email RaydarSend a Private Message to RaydarEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by tshark:

    The adjustable one like aaron88 had? I don't find such a user on here.



    //www.fiero.nl/forum/Forum4/HTML/064690.html
    IP: Logged
    jscott1
    Member
    Posts: 21674
    From: Houston, TX , USA
    Registered: Dec 2001


    Feedback score:    (15)
    Leave feedback





    Total ratings: 415
    Rate this member

    Report this Post02-08-2015 05:43 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by JohnWPB:


    That could only be do to the fact that the brakes on your Fiero have been neglected and something is bad


    I guess you missed the part about "ever was" meaning Fiero brakes were never as good as your average grocery getter today. Show me any production car with a solid rotor on the front and I'll show you a dodo bird.

    [This message has been edited by jscott1 (edited 02-08-2015).]

    IP: Logged
    jscott1
    Member
    Posts: 21674
    From: Houston, TX , USA
    Registered: Dec 2001


    Feedback score:    (15)
    Leave feedback





    Total ratings: 415
    Rate this member

    Report this Post02-08-2015 05:49 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Edit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by E.Furgal:

    I think much of the issue is that drivers have been used to set up's with very light touch needed, designed so the weakest person can push on the brakes, without effort.. taking the "feedback" to the driver out of the design needs, ABS only made that even worse.



    This is a good point... where is it chiseled in stone that to stop quickly one must apply hundreds of pounds of force to the brake pedal? New cars are able to apply the brakes all by themselves with no input from the human. Even cars without automatic brake systems stop with far less pedal input from the human which leads to a more confident driving situation even if stopping distance is the same form the 80s.

    Even if the bigger booster does not shorten stopping distance if it reduces pedal input needed from the human it's a good thing.
    IP: Logged
    PFF
    System Bot
    fieroguru
    Member
    Posts: 11555
    From: Champaign, IL
    Registered: Aug 2003


    Feedback score:    (45)
    Leave feedback





    Total ratings: 257
    Rate this member

    Report this Post02-08-2015 09:25 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
    I am pretty sure the main difference for the brake pedal "feel" between Fieros and newer cars is caused by one (or both) of these two things...

    1. Quick take-up master cylinders (dual stage 23.8/36mm). The 36mm is the quick take up portion and while larger master cylinder bores move more fluid, they also contribute to a harder pedal.

    2. Fiero combo valve significantly restricts rear brake line pressure. Fieros use the same size caliper piston size front/rear, so all bias comes from rear line pressure reduction. Most other cars create reduce rear braking with smaller diameter rear caliper pistons, so their combo valves don't need to restrict rear brake line pressure as much.

    Its not from mechanical leverage on the pedal - because they activate with limited pedal movement (like the fiero).
    Its not from the brake booster as most are the same size or smaller than stock fiero.

    So its likely in the master/combo/caliper diameters.

    88 Fiero:
    Brake booster: 9.04" dual diaphragm
    Master Cylinder: 23.4/36mm
    Calipers F/R: 48mm/48mm (1809 mm^2/1809 mm^2)
    Rear brake pressure is ~56% of the fronts past the knee point (measured) - with same caliper and rotor size F/R this is a measurement of the actual bias.

    2011 Nissan Murano (wife's car with touchy brakes)
    Brake booster: 9.1" dual diaphragm
    Master Cylinder: 1" (not quick take up)
    Calipers F/R: dual 45mm/single 43mm (3179 mm^2/1451 mm^2)
    Rear caliper area is 45.6% of the front - so with the SAME line pressure F/R, the rears will see 45.5% of the caliper clamp load (approximate braking force) of the fronts... so the combo valve doesn't have to make huge (35%) pressure reductions to the rear brakes.

    If you compare more other newer cars, most are NOT using quick take up master cylinders and have the rear calipers significantly smaller than the front (so the rear brake pressure is less restricted).

    One of these days when the wife isn't looking, I may take the wheels off her car and measure the caliper line pressure directly. My guess is the front/rear line pressure will be much closer than what is seen with the Fiero.

    [This message has been edited by fieroguru (edited 02-08-2015).]

    IP: Logged
    fieroguru
    Member
    Posts: 11555
    From: Champaign, IL
    Registered: Aug 2003


    Feedback score:    (45)
    Leave feedback





    Total ratings: 257
    Rate this member

    Report this Post02-08-2015 09:49 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
    The 88 Fiero has a 23.8/36mm master, but the 84-87 uses a 25.4/36mm one according to Centric. All Fieros have caliper diameters of 48mm (or within 1mm depending on reference). So the 88 master is about 12% smaller and should have a softer pedal and more clamp load at the calipers for a given pedal force.

    Since the S10 booster installs before the master, it will be more effective (higher caliper clamp load for fixed pedal force) on the 88's. The 88's also benefit from more mechanical leverage at the caliper (slightly larger rotor diameter) as well as the vented rotors to better resist brake fade.

    For the record, I am not a fan of adding the S10 booster on an otherwise stock 84-87. It will stop with less pedal effort and could give you a false sense of security. If you interpret the lower pedal effort as "better braking" and drive more aggressively (especially with good tires), you could more easily induce brake fade... where braking significantly declines.
    IP: Logged
    tshark
    Member
    Posts: 4388
    From:
    Registered: Feb 2014


    Feedback score:    (6)
    Leave feedback





    Total ratings: 68
    Rate this member

    Report this Post02-08-2015 10:58 PM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by Raydar:
    //www.fiero.nl/forum/Forum4/HTML/064690.html


    I've seen that thread, but am looking for wilwood...or any user that can build these.
    IP: Logged
    Csjag
    Member
    Posts: 3170
    From: Ocklawaha,Fl, USA
    Registered: Dec 2013


    Feedback score: N/A
    Leave feedback

    Rate this member

    Report this Post02-09-2015 07:59 AM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
    I was just looking at the vented front rotor kit with the larger caliper piston from the Fiero store. Has anyone installed that? It purports to give shorter stopping distances.
    IP: Logged
    theogre
    Member
    Posts: 29973
    From: USA
    Registered: Mar 99


    Feedback score: N/A
    Leave feedback





    Total ratings: 558
    Rate this member

    Report this Post02-09-2015 11:38 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by Csjag:
    I was just looking at the vented front rotor kit with the larger caliper piston from the Fiero store. Has anyone installed that? It purports to give shorter stopping distances.

    Is same "upgrade" GA front brakes for sale as a package. I'm surprise no-one sued them yet for this and big MC. Only recently TFS says big MC goes with the GA upgrade.
    See my Cave, Brake Upgrade
    IP: Logged
    thesameguy
    Member
    Posts: 1535
    From: California
    Registered: Dec 2012


    Feedback score: N/A
    Leave feedback

    Rate this member

    Report this Post02-09-2015 02:36 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by E.Furgal:
    IIRC the 2002 f body test got 110 feet.. with much bigger brakes, and was class leading at that time..


    A 2002 F-body weighs nearly 1000lbs more than a Fiero, and still manages to stop in 6' less space from 5mph faster. Do you not see how that suggests a performance and/or safety issue with the stock Fiero brakes? A heavier car taking less time to stop from a greater speed? Also, that F-body was doing that 12 years ago - the Fiero's brakes were inadequate over a decade ago.

    [This message has been edited by thesameguy (edited 02-09-2015).]

    IP: Logged
    Formula Owner
    Member
    Posts: 1053
    From: Madison, AL
    Registered: May 2001


    Feedback score: N/A
    Leave feedback

    Rate this member

    Report this Post02-09-2015 05:50 PM Click Here to See the Profile for Formula OwnerSend a Private Message to Formula OwnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
    All of you who are claiming that Fiero brakes are crappy based on magazine test results... should realize that all these modern 4-wheeled wonders... are using modern rubber. Tires can MORE than make up the difference seen in these results. Go test a modern car against a Fiero with properly working brakes, and modern tires. Tires will make a big difference. Enough of a difference? I don't know, but if you're going to compare, make the comparison as equal as possible.

    Also, modern vehicles benefit from ABS. Not necessarily because ABS is better, but it allows the mfrs to dial in more rear bias without the risk of the rears locking up first. THAT is the biggest advantage of ABS. Whenever you see a brake upgrade article in a magazine, it ALWAYS includes an adjustable proportioning valve. Then they proceed to adjust it for optimum braking on whatever surface their test systems have. Of COURSE they're going to show huge improvements, but it's all due to the change in F/R bias.

    Many don't like the Fiero's stiff brake pedal. Different strokes. I love it. I can stab the brake pedal in a panic, and still have control. Modern cars with sensitive brakes... I can't stop smoothly to save my life. However... I learned threshold braking in racing karts, which have very stiff brakes. I MUCH prefer a stiff pedal.

    [This message has been edited by Formula Owner (edited 02-09-2015).]

    IP: Logged
    E.Furgal
    Member
    Posts: 11708
    From: LAND OF CONFUSION
    Registered: Mar 2012


    Feedback score:    (23)
    Leave feedback





    Total ratings: 278
    User Banned

    Report this Post02-09-2015 06:39 PM Click Here to See the Profile for E.FurgalSend a Private Message to E.FurgalEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by theogre:

    Is same "upgrade" GA front brakes for sale as a package. I'm surprise no-one sued them yet for this and big MC. Only recently TFS says big MC goes with the GA upgrade.
    See my Cave, Brake Upgrade


    Nice write up..
    IP: Logged
    E.Furgal
    Member
    Posts: 11708
    From: LAND OF CONFUSION
    Registered: Mar 2012


    Feedback score:    (23)
    Leave feedback





    Total ratings: 278
    User Banned

    Report this Post02-09-2015 06:57 PM Click Here to See the Profile for E.FurgalSend a Private Message to E.FurgalEdit/Delete MessageReply w/QuoteDirect Link to This Post
     
    quote
    Originally posted by thesameguy:


    the Fiero's brakes were inadequate over a decade ago.



    if you say so, It's called knowing what you are driving, I guess all old cars should be taken off the road as they ALL, have the same issue the brakes are not as good as todays cars..
    Would you tailgate with a 4 drum brake 71 chevelle? or a 1986 f-150? knowing that there are cars that can stop in half the space..
    heck there are cars new ones that some stop much faster than most, that if the two panic stopped one would eat the others trunk?
    Some drive within the vehicles limits.. I'd not tailgate a new zr1 in an accent and expect the accent to stop as fast as the vette, so I'd leave space..
    nothing wrong with the fiero's brakes.. other than some think all cars can stop in the same space.. or should be able to..
    if you want a sports car that stops on a dime you buy a one that it's limits are higher than your talent .
    The good part is using the fiero stock parts you can get it to stop as good as most cars made today.. just have to use the correct parts, not the chain store pads engineered for vented, soft iron rotors, and pads designed for solid rotors, There is a difference.
    IP: Logged
    Previous Page | Next Page

    This topic is 5 pages long:  1   2   3   4   5 
    next newest topic | next oldest topic

    All times are ET (US)

    Post New Topic  Post A Reply
    Hop to:

    Contact Us | Back To Main Page

    Advertizing on PFF | Fiero Parts Vendors
    PFF Merchandise | Fiero Gallery | Ogre's Cave
    Real-Time Chat | Fiero Related Auctions on eBay



    Copyright (c) 1999, C. Pennock