What are the Pros and Cons of switching to a bigger set of Brakes?

[OrbitalEllipses]

For those wondering....those ZX brakes are actually the same units as the Subaru (FHI) units, except for the mounting ears. You can find adapters if you try hard enough, though the Subaru units are really easy to source albeit a bit pricey (for no real upgrade aside from looks).

[Jordo!]

Originally Posted by STi88

As much as I want the cosmetics improvement

Better brakes are a performance improvement. If the goal is purely enhanced cosmetics, just stop right there...

Start with pads that have better stopping power and get up to temp quickly so you can use them for a DD.

SS brake lines will also improve braking feel. No need to invest in a bigger set of calipers just yet.

[dirk_diggler]

Originally Posted by ZDan

Adding 40%(!) more piston area will KILL the bias (WAY too much front bias) and give you longer pedal travel for a given level of braking. Seems like an exceedingly bad idea to me...

Researching this, I noticed that the highlander rear piston diameter is 41mm and the Camry was 38mm, which is not a huge difference. This is why I thought that if I were to do this poor man's bbk, I would leave the rears alone. This assumes everything else being equal, which may not be the case.

Also, maybe someone with actual experience in doing this can chime in, but I figured that even IF there was a bias change, stopping in DD scenarios will be largely unaffected.

[der_rainman]

One problem with measuring pistons is where you are actually measuring. You can't just take a caliper to the exposed face of the "piston" underneath the pad. Oftentimes the actual piston diameter is different (within the actual bore) than what you see up top/exposed. Best way to measure is to actually remove the piston from the caliper. Especially if you are trying to accurately calculate brake bias.

[dirk_diggler]

Originally Posted by der_rainman

One problem with measuring pistons is where you are actually measuring. You can't just take a caliper to the exposed face of the "piston" underneath the pad. Oftentimes the actual piston diameter is different (within the actual bore) than what you see up top/exposed. Best way to measure is to actually remove the piston from the caliper. Especially if you are trying to accurately calculate brake bias.

Good point. I have no clue how the diameters were measured. These were the diameters shown in catalogs for rebuilt calipers.

Several people have done this upgrade with good results if I were to believe them. Since none of those people were on the standard issue 17" SE wheels, I didn't want to take the risk to find out. The Brembo rotors eliminated the shimmy when hot (and only when hot), so problem was solved half way. The other half was to pass the Camry down to the wifey.

[ZDan]

Originally Posted by dirk_diggler

Researching this, I noticed that the highlander rear piston diameter is 41mm and the Camry was 38mm, which is not a huge difference. This is why I thought that if I were to do this poor man's bbk, I would leave the rears alone. This assumes everything else being equal, which may not be the case.

The Highlander has a *different* braking system. Probably has different master cylinder, different proportioning valve and different rotor diameters. You shouldn't change *anything* without knowing what the front/rear bias ramifications are.

Also, maybe someone with actual experience in doing this can chime in, but I figured that even IF there was a bias change, stopping in DD scenarios will be largely unaffected.

If you put front calipers with significantly more piston area up front, you will TREMENDOUSLY affect stopping distances for the worse. At the point where ABS engages to reign in the overbiased fronts, the rears won't be contributing anything like as much braking as they would be with proper bias. In most instances, people won't continue to apply more and more brake pressure once they feel the ABS pulsing.

This mod sounds like a BAD idea to me. Basically, you'll engage ABS at much lower braking g's, and have to "push through" a fair amount more to fully utilize the rear brakes. Stock should already be a bit front-biased. Adding a ton more front bias? Bad idea...

[der_rainman]

And to continue what Dan is saying, the big problem is this type of "upgrade" feels great! You get serious nose dive from an overly front biased "upgrade" that you get from improperly biased components (leading to more brake torque up front). That serious nose dive is often interpreted as an improvement in braking. But its not! its usually just the opposite.