Brakes - stay stock or upgrade?

[shaman1204]

Originally Posted by j.fro

Do it yourself...it's an easy job. Search around and you'll find complete instructions along with photos. Here's one suggestion: buy a Motive Power Bleeder and change the fluid. ATE blue is a good choice. If you are interested in a firmer pedal feel, stainless steel brake lines make a big difference, and they're an easy swap while you are doing the rest of the brake work.

I agree totally. I changed the pads and flushed the brakes on my 01 base and I've never even witnessed a brake job before. I went with Mintex redbox and ordered the Motive power bleeder, brake fluid and pads from Pelican. Not a bad price and got free shipping on the whole deal. Just make sure before you order the brake fluid you check the master cylinder to see what color fluid your are currently using and buy the opposite or you won't be able to tell when the old stuff is flushed out. IIRC the rotors aren't that difficult either, but I didn't have to do mine because they only had 35k on them. Just read and re-read the instructions before proceeding and you'll do fine. Took me a total of 3 hours for all four corners.

[TriGem2k]

986 to 987 FRONT parts ARE a straight parts only swap. Double check your references Bob. I'm on my second round of 987 Discs and Pads on my 2001 986. AGAIN FRONT ONLY ARE A STRAIGHT SWAP.

23109 - If you end up buying zimmerman discs make sure you paint the hats on the disc. The coating from the factory suck and they will rust VERY fast.

[Bob O]

[QUOTE=TriGem2k]986 to 987 FRONT parts ARE a straight parts only swap. Double check your references Bob. I'm on my second round of 987 Discs and Pads on my 2001 986. AGAIN FRONT ONLY ARE A STRAIGHT SWAP.

Glad to know that. As I said, I could be wrong.

[TriGem2k]

Just making it clear for everyone so they don't go buying both front and then find out the rears wont fit.

[Lil bastard]

It's a falacy that more power requires bigger brakes.

More power will get you 0-60 faster, but the car is still going to stop in the same distance from 60 (or any other speed) as before. The Boxster brakes are some of the best in the business and are more than sufficient for any modding a DIYer would do short of doing a lot of track or auto-x work. People are either misinformed, or they simply like the peacock effect of larger brakes, drilled and slotted rotors, etc.

If you substantially increase the weight, say by 500 or more lbs. then bigger brakes may be in order to maintain the same stopping distance.

[JackG]

Originally Posted by Lil bastard

It's a falacy that more power requires bigger brakes.

Blanket statements like that are rarely true. In the Boxster's case, the brakes are already about as good as they get for its normal performance use, like DE or AX.

However, it's a fact that more horsepower on the track will provide higher entry speeds into the corners. With higher entry speeds, you will need more braking to haul the car down to the speed the corner requires. Even if you brake earlier, you'll still be requiring the brakes to absorb more energy. If they are already near their limits, adding more horsepower *will* overcome your brake's capabilities. Brake fade will result.

In that case, it would be a trueism that "More power requires bigger brakes."

[Topless]

Originally Posted by JackG

Blanket statements like that are rarely true. In the Boxster's case, the brakes are already about as good as they get for its normal performance use, like DE or AX.

However, it's a fact that more horsepower on the track will provide higher entry speeds into the corners. With higher entry speeds, you will need more braking to haul the car down to the speed the corner requires. Even if you brake earlier, you'll still be requiring the brakes to absorb more energy. If they are already near their limits, adding more horsepower *will* overcome your brake's capabilities. Brake fade will result.

In that case, it would be a trueism that "More power requires bigger brakes."

Confirmed.

Stopping distance is mostly a function of weight and tire grip. If you want to stop faster, drop some car weight or add some fat sticky tires or both. A stock base Boxster already has a shorter stopping distance than a Ferrari 575 Maranello. It's no slouch to be sure.

Brake pad/rotor fade and overheat is mostly a function of weight, driving style and brake components. If you often overheat your brakes something is probably wrong: sticking caliper, lost cooling ducts, poor braking technique etc. Find the problem and fix it for 1/20th the cost of all new upgraded brake components.

Spongy, imprecise brake feel at the end of a long track session on a hot day is most likely brake fluid approaching it's boiling point. A well known Porsche problem. This is often misdiagnosed as brake pad fade. If you do a lot of track days just use a good high temp brake fluid and change it once a year.

If you add a bunch of horsepower should you upgrade your brake components? Maybe. For spirited street driving it is probably still overkill. If you are a fire breathing track hound the answer is probably yes.

For example: An 80hp 914 enters turn one at Streets of Willow at around 90mph. My 200hp 986 enters the same turn at 115mph. A well known 295hp 987S enters at 125mph. The 987S is carrying greater speeds into each turn and weighs a little more. He needs to scrub a lot more energy every turn and is more likely to overheat his brakes. The larger 987S brakes are matched to his higher corner entry speeds and higher heat generated.

So if you track you car a lot and drop in a 3.6L motor, bigger brake components are probably in your future. Otherwise you will probably never notice the difference between well maintained stock brakes and "upgraded" brakes... Except perhaps for that all important "Peacock" factor.

[Kirk]

Originally Posted by Lil bastard

It's a falacy that more power requires bigger brakes.

Bleh! I took my Boxster S for a spirited drive this weekend and the brakes performed wonderfully. I could not imagine though having the weak brakes from my Honduh CRX on the Boxster. There is NO WAY I could have enjoyed the car as much with weak brakes like that. It's all about balance - matching the engine performance with appropriate suspension tuning and braking performance. With my Boxster those performance limits are pretty high and I need brakes to match them. I guess I could have driven it okay with the weak CRX brakes, but I would have had to use half of the available power.

Likewise my weak CRX brakes are okay for that car as it's barely even pushing 100 HP and only has to stop 1850 lbs, but even then they are maybe marginal. I already have a full suspension in the CRX (roll cage, bracing, torsion bars, springs, adjustable shocks, etc.). If I added 200 more horsepower, no weight, and left the brakes the same I'd have to throttle it back and either still drive it the same as I do now or end up dead from overrunning the brakes....

Just for grins... here's my CRX daily driver:



Kirk

[Lil bastard]

It's about weight, or more specifically momentum. Adding power does increase momentum, but only if you use the right foot. A 3000 lb. car with X brake setup will stop in X feet from X Speed. If that same car gets a more powerful engine, it will get to X speed faster than before, but the rest of the variables remain the same.

If tracking the car, where the brakes are applied more fully, and frequently, the larger brakes are an improvement because they shed heat faster and so don't fade as soon. But on the street, where's there's rarely seconds between brake applications, enough time exists between braking for the brakes to cool and not fade.

Don't forget, the difference in stopping distance between the 'S' brakes and Base brakes is only 4' @ 60MPH. Could that 4' make the difference in some rare circumstance? Of course. But that's an endless debate, what if the needed improvement was 5'? Than neither brake setup would have an advantage over the other (for street).