Porsche Brembo 996 BBK conversion

[SWRT_M3]

what car does the Pad D738 come off of? I plan to buy my pads off FCP Euro as well.

996 Carrera (non turbo models) and 986 Boxster S, if you don't want a rust ring, go with the D737 front pads from the 986 Boxster

[Tonggi]

996 Carrera (non turbo models) and 986 Boxster S, if you don't want a rust ring, go with the D737 front pads from the 986 Boxster

are those both front pads of carrera non turbo?

I'm currently looking up "Front Pads off 2000 Boxster 2.7L Non S" That is what im using to find the pads for the rear, I believe those are D737. If no rust ring with D737 then im in, I was under impression D738 had better pad surface?

[Sergmann]

D737 is the pad shape you are looking for for no "rust ring"

[selm3]

So what track oriented pad is everyone buying from fcp euro now a days?

[mrgizmo04]

does anyone run any type of aftermarket master cylinder with this setup or strictly OEM E46? I am not very impressed with this setup on the track (Ds1.1 pads) and am wondering if going to a different master cylinder could help? would 996 GT3 even be a possibility? It has a 27mm piston vs our stock 25.4mm

What you are experiencing with this kit is the lower clamping force generated by the front caliper...
The rears with 30/28mm pistons generate about the same clamping force as stock. The fronts (I was actually surprised how small the calipers and the 2 pairs of pistons were when I was rebuilding a set), with the 40/36mm pistons, generate about 16% less clamping force that stock fronts. This naturally moves the bias backwards, but also front+rear of the 996 kit is overall less than front+rear of stock. Using more foot/pedal force as was suggested...is a solution, but remember that also locks up the rear sooner...
I won't go into too much calc/detail here, but due to pi*r^2 (mainly r^2) term when calculating surface area of pistons, a stock single 60mm piston has a much larger area (and more clamping force for same brake pedal travel) vs 40/36mm pistons.

Regarding the master cylinder...I posted in some other thread, but depending on what threads folks read, good to post again so we as a community grow and learn. Somewhat counter intuitive, but you would want the master cylinder diameter to be smaller that stock to generate more force at the calipers. Per Pascal's law, the force difference is proportional to areas of the pistons - master cyl vs caliper pistons (the circular area, not total volume which takes into account the length/height of the piston or travel of the piston). Think of how your hydrolic jack works, same principle. You pump a handle connected to a small cylinder (equiv of brake pedal/master cyl) which converts the hydrolic pressure to a much larger force via the big piston that allows you to raise the car (equiv of hydrolic pressure in the brake lines pushing against the caliper piston areas).

Doing calculations as well as talking to folks who run 996 kit on track, to enjoy it more...You have to "cheat" the fact that fronts have lower clamping force by putting a higher mu pad there vs the rear (friction coefficient also incorporates into total clamping force on top of piston areas, disc diameter, etc, but not pad size that's more for handling heat). Folks who run same pad front/rear find it a bit underwhelming. Folks who run DTC70 front and DTC60 rear, or I think Radek settled on PFC pads and runs PFC11 front and PFC08 rear, LOVE it.

I will be testing out several setups in terms of BBK. I've run the full ST40 355 front and rear. I felt that rear was overkill (it does have nice benefits of swapping rings and pads front to rear as things wear). Funny enough, I discovered the rear ST40 kit has both pistons which are 28mm. I was actually surprised by this, as ST is well known for making BBK setups, and normally with multi piston setups you want the trailing piston to be larger to counter gas/debri/material buildup as the disc rotates to get even pad wear. The rear having same pistons was a bit annoying with pedal feel and pad wear - pad wear was tapered which also pushes out one of the pistons more so each piston is not handling the same volume of fluid. I've sold off the rear 355 kit. As quick side note in terms of piston sizes, front pair is 42/38 on ST40, which brings the bias and overall clamping force back toward what stock feel is.
Now on the car I have the front ST40 355 and rear 996 kit. I also have the front 996 kit sitting in the garage. I don't know in what order I will run my combo testing ST40 front vs 996 front with the 996 rear. I have same for same pads for 996 front/rear, I don't currently for the ST40 front and 996 rear. For 996 I do have have DTC60 for both front and rear, and I also have a DTC70 for the front, so I can test those combos. When I switch to ST40, I have PFC08 pads (which I love and run all the time), I might need to get a set of PFC08 for the rear 996 kit to run same pad test.

I think what I will find through my unscientific testing, is that, running DTC70 on 996 front and DTC60 rear will actually feel relatively good. This might be a good compromise... I do run brake ducts, so I will need to see how the fronts last/behave. This setup (with higher mu pads in front) would be loosely equivalent to running front ST40 355 kit with same pad mu front/rear (in terms of feel/clamping forces, but we'll see). What might push me toward running ST40 in front instead of the 996 with higher mu pad is if I need more heat capacity (which with brake ducts I should not), but I do run sessions that are much longer than 20-30mins. 355x32 has a lot more meat to handle temp deltas vs 345x28. I will also need to see how swiss cheese front rotors do/last in terms of cracking/longevity and what that will mean in term of change intervals (even with FCP "free" warranty, swapping discs once a year or several times a year might get a bit old), if I can run ST40 meats for several years between changes.

I am excited by having FCP warranty, they do have Hawk pads back in, I know the downside is that dust is corrosive...I'll need to see what feels good for my driving and then decide. This will be multi month period of testing, so don't expect results next month. I'm also not super active here these days, but I'll try to update impressions/findings here and on youtube.

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[eljay]

Sorry to ask a newb question, but given that the 996 kit has less braking torque, are there any advantages over stock ZCP setup?
Are they really just for looks?

I ask because I have ZCP brakes now and need new rotors very soon (and I'll change pads too), so naturally, I'm looking at "upgrades" and the 996 kit option is tempting. Sadly, my car doesn't see regular track duty, meaning I hope "one day" to get back on track, but if that happens, it will be light duty unlike many of you track warriors.
Any recommendation for my situation?

[Tbonem3]

Heat capacity, modulation/feel

If you're not going to be stopping hard repeatedly, you're better off with stock brakes.

[eljay]

Heat capacity, modulation/feel

If you're not going to be stopping hard repeatedly, you're better off with stock brakes.

Got it! Thank you.
They do look good though and from what I've read, the front/rear bias remains very close to stock ZCP.
Is there any info on weight differences of 996 calipers with brackets vs stock?

edit:
I think another benefit worth mentioning that I can see with the 996 calipers is how easily the pads can be changed. No need to remove the caliper, correct?

[Tbonem3]

No need to remove caliper to swap pads as long as you don't employ the damper inserts.

Weight loss is one of the best qualities of the kit. Looks is good too ofc, compared to stock.

[Thoglan]

Getting quite hard to source a set of these for a decent price. Especially in my area. Twice I thought I'd found a set for a good price before they disappeared/price changed before I could get them. Shipping them anywhere is pretty much prohibitively expensive as well given the weight of the calipers.

[eljay]

What's the going rate for a set these days?

P.S. What a mistake clicking on this thread was!! It's gonna cost me.

[DvSkD4]

I absolutely LOVE how easy it is to do brake pad changes. Any time I do it at the track it makes people around me jealous.


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[heinzboehmer]

I absolutely LOVE how easy it is to do brake pad changes. Any time I do it at the track it makes people around me jealous.


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You're making me jealous

I've been passively looking for used calipers recently for exactly this reason. Yeah sure, all the other things would be nice, but what I really want is to be able to do pad changes with basically zero effort.

[Arith2]

I really prefer the more rear bias braking from using the same pads. The Porsche OE Textars do alright. I've seen plenty of Porsches tracking them as well. There is a huge difference in the Textar brand and Porsche OE pads, contrary to popular belief. They don't grip as well and are glazed very easily. Get the Porsche ones because in this case, you get what you pay for.

Just an FYI for those not reading the entirety of the 34 pages, this swap will work with stocks 18s but ONLY with at least 12.5mm spacers. They can't be 12mm or they're touch. I did the math and measurements on the Brembo website about checking for rim clearance. My math turned out to be correct. I think I came to needing 11.9mm extra. I offset the rear with 10mm spacers just to balance out the width increase.

The calipers for the Carrera 4S are larger so don't get those. Also, 997 started in 2005 and 996 ended in 2006. 987 Cayman and Boxster S have the same part numbers on the calipers so those should be good post 2005. Be careful on what you order. Pelican couldn't send me the right pins and springs after a few tries. They kept sending Cayenne/997 ones. There is also an update in pins and springs which front pads for the 986 boxster actually changed. I grinded off the pins off the pads (wear a full faceshield) and they fit. One did hit my faceshield pretty hard so I was thankful to be wearing it over just safety glasses.

[t44tq]

Heat capacity, modulation/feel

If you're not going to be stopping hard repeatedly, you're better off with stock brakes.

The 996 Brembo setup discussed here is using OE BMW rotors- there is no improvement in heat capacity, as the rotors have not changed. There is a difference between the base rotors and the ZCP rotors, but if you already have the ZCP rotors, there is no difference.