Best After Market Brakes - Front and Rear

The Wilwood set up for the front can accommodate 13" rims and is well accepted as a significant upgrade both in performance and even easier pad replacement.

Going to Fiat 125 rear calipers has been shown to significantly improve general braking as it moves the brake bias more to the rear. There are not a lot of choices for rear brakes.
 
I guess there is "best" and there's "best value".

On my car, I have rear calipers with the larger 38mm piston. I have Tarox braided stainless flexi hoses, I have Tarox discs on front and back, and I have EBC Green Stuff pads all round. I also replaced the rubber lines that run from the reservoir to the master cylinder.

When things are tip-top, it all works a treat! But you have to keep an eye on the sliders for the caliper mounts. Regular greasing (at least annually) is a must. Also, getting all the air out of the system is time consuming, and seems to take more than one or two attempts. But it works very well once you get there!

Regards,

Mickey
 
What are the expectations for brake performance improvements? What will this exxe chassis be used for?

*Stopping power.

*Pedal effort.

*Pedal feel.

*Heat dissipation.

*Front to rear brake bias.


???

There is no simple or blanket "best Brakes" which of these factors needs improvement, why and what the budget for brake performance improvements?


Bernice


Is there anything worth buying for 13 inch rims?
 
Nothing stops like a wall

Red-brick-wall-texture.jpg
 
The reason for no rear brakes:
Rear brakes do much less of the overall braking on most cars due to significant front brake bias (generally 80% front and 20% rear). Its generally bad form for your rear brakes to lock up as it is a recipe for a quick spin into the block not around the block, not something you want

Rear brakes are much more complex than are front brakes. The complexity is due to the actuation of a mechanical emergency brake, many of which are quite different from each other.

The biggest reason is the first one: people pay for upgrades which have significant improvements in performance. Generally there is little performance to be gained by upgrading rear brakes.

As we all know the emergency/parking brake isn't something to write home about so a more modern upgrade would be welcome without a doubt.
 
Weight bias has a very significant effect..

On FWD chassis that are front heavy, they need MUCH larger braking capacity in the front due to the inherent weight at the front. For a rear engine, rear RWD chassis the rear brakes are larger due the weight over the rear wheels and lower weight over the front wheels.

In all daily driver road cars, they have brake biased towards the front to prevent rear wheel lock up in nearly all conditions as rear wheel lock up can indeed result in a spin. This is considered a serious safety hazard for road cars.

Performance or race cars often do not follow this convention. It is based on different demands placed on the braking. It is common for a race or performance driver to use the brakes to "point" the chassis into a turn which often means far less front brake bias and this brake balance changes with fuel load and tire conditions. Very, very different than a street or road driven daily driver.


Bernice





The reason for no rear brakes:
Rear brakes do much less of the overall braking on most cars due to significant front brake bias (generally 80% front and 20% rear). Its generally bad form for your rear brakes to lock up as it is a recipe for a quick spin into the block not around the block, not something you want

Rear brakes are much more complex than are front brakes. The complexity is due to the actuation of a mechanical emergency brake, many of which are quite different from each other.

The biggest reason is the first one: people pay for upgrades which have significant improvements in performance. Generally there is little performance to be gained by upgrading rear brakes.

As we all know the emergency/parking brake isn't something to write home about so a more modern upgrade would be welcome without a doubt.
 
rear brakes

Berenice
the rear brake adjustment is achieved with the e brake setup, hence the helical center pin???? was playing with the idea of front calipers on the rear
all those years with fiat and I have forgotten.
I don't want to run a brake bias valve, nor the e/b cables and thought a "line lock" that is used to keep the front wheels at the line locked until it's time to boogie as a e/b setup letting the hydraulics hold the car on a hill. I hate to think of getting under a car that sits in the weeds, so to speak, and manually move the pivot to compensate for pad wear.
you are one of the most knowledgeable here ....uhhhh....except papa tony.....

HA
sorry tony:whistle:
mikemo90*aol.com
 
Balance

Bernice got it right. Brake performance is ALL about balance. Our X's are typically weight biased to the rear. That means you can maximize front brake performance, then still have the option of adding more stopping power for the rear, than a front heavy car will have. That equals more overall brake performance is possible for a rear heavy car. If you maximize front perfomance, without maximizing rear performance, you leave a little on the table, but it's safe.

However to maximize brake performance you HAVE to get the bias right. And, it HAS to be right for the road conditions you're driving in. If you have your brake bias set for ultimate dry performance, and drive in the rain, you'll find the rears will lock up on you before the fronts and - wooops - the rear of the car tries to pass the front. That's why easy brake bias adjustment is important.
 
During the pre-ABS era, manufactures did most all they can to prevent rear brake lock-up in most every road and vehicle load condition possible.

They knew well if the rear brakes were to lock-up, the risk of a spin under braking goes up a lot resulting in a very un-safe road condition.

One other factor is brake modulation which was important back then as it gave the driver the ability to lock-un-lock the brakes as required to lower stopping distances. Most all of this has gone as ABS did way with the need for good pedal feel and ability for the driver to modulate the brakes since the ABS system will do that automatically. Once this design concept stuck, work was done to lower pedal effort as there was little reason to have high effort at the brake pedal since the ABS system will prevent brake lock-up.. why have high brake pedal effort? It was not necessary in a brake system that basically cannot lock up the brakes and the system will allow steering under braking even if the car was in a slide.

This is why the brakes on the exxe is so very different than brakes on a modern car with power assist and ABS. They are essentially from different planets and places in time. It is also why the exxe has brakes that are biased towards the front and less in the rear, done to prevent rear wheel lock up under hard braking. In the extreme case, the Lancia Scorpion-MonteCarlo has power assisted front brakes with no power assist in the rear. This is an example of extreme front brake bias which resulted in a number of other problems including a reputation for poor braking performance. The brakes on the Scorpion-MonteCarlo was one of the sources of major grief that gave this design a ever-lasting reputation for being AWFUL beyond being under powered.

Braking performance in the exxe can be improved by increasing the brake caliper piston diameter in the rear thus increasing the amount of braking force in the rear of the chassis. This increases the risk of rear brake lock-up at the trade-off of lowering stopping distances by making all four brake calipers work in better sync. I don't believe this alteration is for every driver, road condition and more. It is a performance related modification that will increase the risk of rear brake lock up.. In ways, it is much like reducing the amount of understeer in the chassis. Cornering speeds and control goes up at the trade-off of less benign chassis behavior near or at the tire adhesion limits.

Brake pressure limiting valves work by limiting brake fluid pressure once that set limit is reached. Below that the valve does little to nothing. This is why the manufactures of these valves does not recommend these valves being used on the front brakes as it would limit front brake stopping power.

Using two independent brake master cylinders with a "Bias Bar" results in a linear brake pressure adjustment since the change in force remains much the same over the adjustment range due to essentially moving the brake pedal's point of applied force, not limiting brake fluid pressure.

Brake setups that are designed for FWD or front engine-rear wheel drive cars often do not directly transplant to a mid-engine chassis due to chassis weight bias or where the weight is located. FWD chassis often have much larger brake caliper pistons compared to the rear while a mid-engine chassis can have nearly the same brake caliper piston diameters front and rear.


Bernice


Bernice got it right. Brake performance is ALL about balance. Our X's are typically weight biased to the rear. That means you can maximize front brake performance, then still have the option of adding more stopping power for the rear, than a front heavy car will have. That equals more overall brake performance is possible for a rear heavy car. If you maximize front perfomance, without maximizing rear performance, you leave a little on the table, but it's safe.

However to maximize brake performance you HAVE to get the bias right. And, it HAS to be right for the road conditions you're driving in. If you have your brake bias set for ultimate dry performance, and drive in the rain, you'll find the rears will lock up on you before the fronts and - wooops - the rear of the car tries to pass the front. That's why easy brake bias adjustment is important.
 
Wilwood for 13"?

I've heard of a setup that uses Wilwood calipers but needs 15" wheels. Do you know where I can find information on the setup for 13" wheels? Thanks!
 
Never Mind

I found the Wilwood kit for 13" wheels on the Midwest Bayless site. Not sure why I missed it before...
 
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