I hear "early model 90s" big booster and MC form the S10 works good on the Fiero, but exactly what year? Is there any options out there that doesn't require smashing the fiero inner fender wall?
Originally posted by Blacktree: Are you installing bigger calipers? If not, then a bigger master cylinder will actually reduce braking power. The S10 booster will increase braking power, but requires "percussive adjustment" of the sheet metal.
Wouldn't installing a bigger M/C decrease the amount of brake pedal travel and increase response? Maybe I'll try just the boster first.
I installed Bretta Calipers & Rotors on the Front about a decade ago. Not sure if the are large than the OEM pre-88 Fiero.
I'm just really tired of almost crashing when I change form my daily BMW driver and take the Fireo out for a drive. The difference is like night and day. I almost rear ended someone today while driving through a yellow light. The car in front of me decided to stop suddenly. I'm know comparing the Fiero to a BMW is not fair, but I'd like to make it as close as possible.
Have you fixed the mismatch in caliper piston size yet? That is your primary problem, it must be fixed before you do anything else to your brake system. Members here have (some anyway) given you very good advice to get your brake system back to good performance, you should heed their advice.
Originally posted by SP1200: Wouldn't installing a bigger M/C decrease the amount of brake pedal travel and increase response?
It will reduce pedal travel, at the expense of increased pedal effort.
Since you have Beretta calipers in the front and Fiero calipers in the back, you're in a weird place where you need more fluid volume for the front calipers, but up-sizing the master cylinder will weaken the rear brakes.
That said, a bigger booster can't hurt. It will give you more vacuum assist.
Originally posted by SP1200: I'm just really tired of almost crashing when I change form my daily BMW driver and take the Fireo out for a drive. The difference is like night and day. I almost rear ended someone today while driving through a yellow light. The car in front of me decided to stop suddenly. I'm know comparing the Fiero to a BMW is not fair, but I'd like to make it as close as possible.
Just put a bit of muscle into it. Stock Fiero brakes should be able to lock the tires.
Manhandle the Fiero; it's not a fragile iPhone that you touch with your fingertips.
I would suggest returning the front to stock. The others have mentioned this already, but if you hear it from another person, you may believe it more.
Have you fixed the mismatch in caliper piston size yet? That is your primary problem, it must be fixed before you do anything else to your brake system. Members here have (some anyway) given you very good advice to get your brake system back to good performance, you should heed their advice.
Thanks Ole, and I understand what your saying. Someone will give me some advice, I will feel on track...then it will spark a debate and other members will chime in with what they do/dont do...and I feel just overwhelmed. I'm considering manufacturing some lines, and installing a jegs/summit replacement adjustable prop valve.
I also wanted to get the part number info on the booster and MC so I can order all the parts. I think with a jegs prop valve and a good boster, it should give me the results I'm looking for.
[This message has been edited by SP1200 (edited 04-27-2018).]
It will reduce pedal travel, at the expense of increased pedal effort.
Since you have Beretta calipers in the front and Fiero calipers in the back, you're in a weird place where you need more fluid volume for the front calipers, but up-sizing the master cylinder will weaken the rear brakes.
That said, a bigger booster can't hurt. It will give you more vacuum assist.
OhhI see. Good explanation. Thanks. I will just go with he booster for now.
Just put a bit of muscle into it. Stock Fiero brakes should be able to lock the tires.
Manhandle the Fiero; it's not a fragile iPhone that you touch with your fingertips.
I would suggest returning the front to stock. The others have mentioned this already, but if you hear it from another person, you may believe it more.
Maybe I'd go back to OEM if I can get some decent vented or cross drilled rotors. I remember the brake fade issue was just to much for me back in them old days. Would hate to go back in time.
Originally posted by SP1200: Maybe I'd go back to OEM if I can get some decent vented or cross drilled rotors. I remember the brake fade issue was just to much for me back in them old days. Would hate to go back in time.
Stock rotors and calipers, a properly functioning E-brake, and good quality pads will give you good brakes.
For the booster, I went with one from Summit Racing, Tuff Stuff TFF-2232NB, along with an Adapter from Rodney that was made specifically for this swap. Worked out great, and with buying a new booster, I got a warranty that came in handy about a year later. Makes a huge difference in braking ability vs my previous setup ( 1 foot vs 2 on the brake pedal!!). I have the Grand Am's on the front, and Seville's on the rear, but I tried the booster after the front swap only, and it was a really nice difference. Not much change once I added the rears.
I am happy that someone mentioned quality of parts. Pads and everything else add up to a well thought out system.
My well kept 87GT locks them up with VERY sticky tires. Good pads, braided lines, and vented and drilled rotors. Over 30,000miles and still a ton of pad life left. Going to change out pads here in a few only due to age. I will not buy the least expensive pads.
Originally posted by SP1200: PS. I still don't have an answer to my OG question of what year S10. So I guess I go with the Tuff Stuff Performance Brake Booster 2232NB
The original swap used a 1996 S10 booster. //www.fiero.nl/forum/Forum2/HTML/072173.html Over the years, people have found a wide variety of different year boosters will work, the only significant difference is the design of the banjo rod and they all need some type of modification to fit the Fiero (unless you use Rodney's banjo and the booster he specifies, then they just bolt together).
.. they all need some type of modification to fit the Fiero (unless you use Rodney's banjo and the booster he specifies, then they just bolt together).
Ahh ok so thats why people are going with the Tuff Stuff Performance Brake Booster?
It will reduce pedal travel, at the expense of increased pedal effort.
[b]Since you have Beretta calipers in the front and Fiero calipers in the back, you're in a weird place where you need more fluid volume for the front calipers, but up-sizing the master cylinder wieaken the rear brakes.[/b] l w That said, a bigger booster can't hurt. It will give you more vacuum assist.
You need to compensate for that mismatch in volume between the front & back calipers. That is what proportioning valves are for. Some are adjustable, some are not. You need to be careful upsizing the booster unless you have a bigger engine that will make more boost. And hot cams cost you because of valve timing overlap. You can get buy with it if you're not on the brakes all the time.
Use this larger brake booster Larger Brake Booster Then purchase the brake booster rod end adapter from Rodney Dickman ,reuse the Fiero brake booster bracket to attach and you're in business. I have read all the comments like this booster won't work right with the stock Fiero brakes but my experience proves otherwise. By just changing to this brake booster the braking action on my 87GT has improved 100% . I just installed one on my 85GT with similar results.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 01-31-2020).]
Foot travel distance to lockup point. Pressure needed to reach that point. Rears not locking up at all. Fronts locking up too much.
The stock brake proportioning valve has a significant front bias. Putting larger bore calipers in front, while keeping stock calipers in back, exaggerates that bias. Also, the larger bore master cylinder can push more fluid through the system, which is good for larger calipers. But it comes at the expense of reduced line pressure, which is bad for the stock calipers. All those things combined create a worst-case scenario for rear brake performance.
There are a couple ways to approach that problem:
1) Tinker with the prop valve (at your own risk), to adjust the brake bias. 2) Install rear calipers that match the front calipers.