Brake stopping distance

[lousava]

Does anyone have the stopping distances for stock 1980 spider brakes vs the up grades from, whoa, the 500 conversion or just new rotors ( solid,vented) and ceramic pads?

I've been told to go to the wilwood 4 piston caliper and 10.25" rotors I can expect about 1-1.5" more pedal travel.

Thanks,
Lou

[707kevin]

Big brakes will hold temperature better, therefore fade less, and stop hard over and over, but it's the tires job to reduce stopping distance. If the tires lock up, there isn't enough traction. Even the stock brakes will lock up tires. You will get better modulation with larger brakes typically. but the end of the day, it's tires tires tires that will shorten stopping distances. Better brakes just do what they do under more extreme conditions without failing.

If you're getting fade on a high speed stop, you might have moisture in the fluid or contaminated rotors/pads, or very cheap pads?

Sorry, I know it doesn't directly answer the question, but stopping distance is a factor of rubber on road, assuming a functional braking system.

[So Cal Mark]

well, that's not exactly true unless your tires are not adequate for the vehicle. We're seeing stopping distance reduced about 30% with the 500 conversion using the same tires as before the conversion

[707kevin]

Sure, I oversimplified things. A brake system is a complex beast with many variables. I guess what I mean is that bigger brakes don't magically make the tires adhere better. And the tires ability to adhere during braking is the theoretical braking limit regardless of brake system. 30% is a MASSIVE reduction in stopping distance - is that comparison with identical fluid and pad compounds too? I;m guessing a large part of that comes from being able to modulate more accurately and avoid lockup?

With my skinny tires, I can lock up all four rather easy in the fiat with a healthy stock brake system. Now my wrx with pilot SS, it stops in less distance than the factory tires, and the brake components did not change. Again thought, too many variables, and now I'm bringing and ABS system into the conversation also.

Anyways, the stock fiat brakes are cool for their age, but a little silly compared to modern stuff and a brake upgrade is going to be a good thing no matter which way you go.

[vandor]

> I've been told to go to the wilwood 4 piston caliper and 10.25" rotors I can expect about 1-1.5" more pedal travel.

More piston area does increase pedal travel, but I don't think by that much. I have driven 124s with the Wilwood calipers many times, and I have not noticed the increased pedal travel compared to my Spider. I'm not saying it's not there, but I did not notice it, so I really don't think it's as much as 1-1.5".

[lousava]

Thanks Guys,
I actually forgot I posted my question on brakes. I finally got around to ordering my 500 big brake conversion from Mark Allison.
I have to tell you these guys are terrific. Very helpful and willing to discuss options without being salesmen like. You can tell they love what they are doing.

Thanks Allison Automotive

Lou

[jon8christine]

I know this is an old thread, but how is your experience with the 500 big brake conversion? My 76 has always had soft mushy brakes compared to a modern sporty car. Looking to autocross it and brakes wheels and tires are first.

[SteinOnkel]

I know this is an old thread, but how is your experience with the 500 big brake conversion? My 76 has always had soft mushy brakes compared to a modern sporty car. Looking to autocross it and brakes wheels and tires are first.

That would suggest there is something wrong with your current setup.

My brakes feel the exact same in my '78 as they do in my '14 Focus. Not that I'm implying any of those are modern or sporty

You sure you want to autox a vintage 124? The chassis is so so soft, it might get torn to pieces.