Alcon BBK or just OEM calipers ?

[1MOREMOD]

Originally Posted by Sleeper519

OP, If I could afford only one track mod it would be the BBK. Some folks go with just the front kit and use oem on rear, that seems to work ok and saves money (don't tell 1MOREMOD), but I say just do the full monty. You won't regret it.

why all the pearls of wisdom after i already went full monty? i dont regret it yet and wont unless they stop worse which would be about impossible. im one of those that couldnt deal with different rotors and caliper design front and back.

[FormulaMMM]

Originally Posted by Sleeper519

^ Agree.

I DID try the "poor man's brake upgrade" with fluids, lines, and race pads on stock calipers. it is an improvement BUT the problem is with repeatability and thermal capacity, as has been said. Heavy cars need big brakes. I had fade, shimmy, rotor deposits (despite proper bedding), and poor pad life. Just didn't inspire confidence. And, if you upgrade tires to r-comps or slicks then you will completely overwhelm a stock setup, no question about it. They will melt down.

Interesting that you report the shimmy and deposits even with race pads. I swear this is a stock BMW caliper/rotor specialty. Suffered from deposits with my old M5, then when it happened with the E90 I decided that was enough and went with the Stoptech kit. Wheel jumping out of your hands into every brake zone gets old.

[Sleeper519]

Originally Posted by 1MOREMOD

its really frowned upon here to be sensible and try to save money.

Originally Posted by 1MOREMOD

why all the pearls of wisdom after i already went full monty? i dont regret it yet and wont unless they stop worse which would be about impossible. im one of those that couldnt deal with different rotors and caliper design front and back.

I only referenced you because of the money saving thing, not the front-only thing.

Now go help that man with the women's clothing thread.

[1MOREMOD]

Originally Posted by Sleeper519

I only referenced you because of the money saving thing, not the front-only thing.

Now go help that man with the women's clothing thread.

what we have a cross dresser section?

[Sleeper519]

Originally Posted by 1MOREMOD

what we have a cross dresser section?

yeah, haven't you heard of competitive Auto-Cross-dressing? its a new CCA event.

[MaxL]

I went through all iterations:

1. Stock brakes - mad pad deposits on day 2. No-go
2. Got street-friendly track pads & higher temp fluid. Lasted me half a season till I got confident in a new car. Eventually lost brakes in Turn 9 on Watkins Glen - pads got too slippery. Got back to pits - 1/3 of pad material lost in one session... So I figured trying to run street-friendly track pads would be to dangerous and expensive.
3. Got the highest-temp pads I could find that were reasonably rotor-friendly (managing costs) - supposedly good till 850C or so - much higher temps than, for example RS29s. Of course no-go for street. Those were holding up very well but were pain in the ass because the heat was still not getting anywhere, just pads were holding up better. So as a result, rotors were getting red hot and cracking badly, plus I has to do more than one cooldown lap before pitting in, or otherwise heat from rotors boiled calipers as soon as the car was stopped. Way too much heat. So I was bleeding brakes every couple of weeks, and doing multiple cooldown laps or even driving around in the pits and stuff like that - not fun, but workable. But one day I lost brakes again and almost launched myself up the hill in Turn 5A at mostport. So I got Alcons.
4. Alcons - regret that I did not get them sooner. Brake feel is sublime. Never overheated them on track and only once when parked without cooldown after a dude crashed and blocked the track in front of me. Braking distances are the same but repeatability is much higher - the distance does not change over the course of the session. Also, no noise, and can run same pads street and track because no need to run super-aggressive pads on the track (RS-29 are all you need). Pads are expensive, but rotors are very reasonable for how long they last - the size and construction, and maybe metal, make them not crack at all, and they look great all the way till minimal thickness. I wish pads were cheaper though. Rears are common shape, but fronts are rare (no pun intended :-)). Also, BBKs hold value well for resale.

So in the end, knowing what I know now, I wish I would have gotten the BBK right away and saved myself a lot of time and unpleasantness.

[1MOREMOD]

Originally Posted by Sleeper519

yeah, haven't you heard of competitive Auto-Cross-dressing? its a new CCA event.

i knew i didnt like BMWCCA for a reason. i will abstain and only do this in the comfort of my home thank you. i hate driving in heels as well.

[sawzall]

Originally Posted by 1MOREMOD

i hate driving in heels as well.

you really should try doing it more! i think you might find it quite liberating!

[JAJ]

Originally Posted by MaxL

... no need to run super-aggressive pads on the track (RS-29 are all you need) ...

You do know that RS29's are a full-race pad, right? That they win championships, right? RS-29's are all you need because, like PFC-01's, they're in the very top tier of brake pads.

That's why they're expensive.

[1MOREMOD]

Originally Posted by sawzall

you really should try doing it more! i think you might find it quite liberating!

might help my driving. kind of like practice with a blindfold or a cougar in the car?

[MaxL]

Originally Posted by JAJ

You do know that RS29's are a full-race pad, right? That they win championships, right? RS-29's are all you need because, like PFC-01's, they're in the very top tier of brake pads.

That's why they're expensive.

Yes, they are "good" . But there is more to pads than that. RS-29 is endurance pad - it works from cold, lasts a long time and is easy on rotors, and can be used on the street with no discomfort, but at expense of top-end performance. This is intentional and by design - not a deficiency. But but if you run them in stock calipers and go just a notch above beginner, you may run into those top-end performance limitations. With a good BBK, you will have enough headroom so that RS29 will still work.

Just for comparison: the yellow line here are RS-29s - peak at 500C and drop off rapidly after 600C, with 700C being max recommended: http://www.braketechnology.com/techinfo.html

A full-on non-endurance race pad will go to 850C-1050C operating temp (here is similar to what I used with 1000C working temp: http://www.project-mu.co.jp/en/products/pad_sin.html). Jump from 600 to 1000 basically means that you can dissipate twice as much heat with the same rotor size (assuming 200C ambient, which is typical around rotors at peak temps). Of course, that all comes with a cost - nightmare on streets (lots of noise, no friction when cold and then sudden friction jerking the car) and eating through rotors.

I'm not an expert on pads, but what I spend on pads for this car is rapidly closing in on the price of the car, so I had to do some research and testing :-)