agreed, and yes you are absolutely right on your correction of my sloppy explanation

I think its great that this product exists and actually see it as a great alternative to massively priced BBKs. If you are running real sticky tires, any advantage is a good advantage, especially at the low price.

 

You'll find that as you go faster you'll reach a point at which maximum braking won't overcome the available grip and you won't lock up the fronts or activate the ABS. Increasing the braking power by moving the caliper further out to give it more mechanical advantage against this will increase the speed at which maximum braking can overcome available grip. You can try this for yourself by taking your car somewhere quiet and discovering what speed you need to go to do this. On a 996 it's roughly 60mph, though differs considerably between setups.
For the sake of simplification, if you take the mid point of the pad contact distance from the centre of rotation and move it 18mm further out, you're increasing the mechanical advantage of the pads by roughly 10%. Which in turn should add 10% to the speed at which maximum braking may be applied (momentum = mass x velocity). So in short, this upgrade will stop you slightly quicker, but only from speeds higher than the current maximum brake lock up/ABS activation speed. This doesn't mean your stopping distance will be 10% shorter overall, just that your retardation above roughly 60mph will be enhanced.

Another consideration is that the kinetic energy needing to be absorbed by the braking system rises exponentially with speed (K.E.= 1/2 mass x velocity squared) meaning that even modest increases in speed give proportionately large increases in the amount of heat energy that the braking system need to be capable of dissipating, hence why a bigger disk is a better first step than a bigger caliper when considering a 'stage 1' brake upgrade. This enhanced heat disspation is really the key advantage, as it keeps the brakes working longer and fading later than ones with smaller discs, particularly on the track.

 

@De Jeeper, I've gotten a chance to fully test the BBK with the 18x8.5 ET53 OZ wheels with Michelin Pilot Sport 4S ties in 235/40-R18.
I have a slight rubbing on the front fender liner on the left side only at full right lock.
This is not bad enough to warrant not running the brakes, but it is something that is noticeable in parking lots.
I'm pretty sure if we were running factory width wheels and 225/40/R18 it wouldn't even be an issue.
I'm going to see if this is something that I can easily fix, because it doesn't look like it would take much to remedy.
Here's some pictures of the rubbing:

 

Heat the liner with a heat gun and bend it slightly. You will probably need to heat both sides. I needed to massage the front wheel liners on my Turbo to clear 245/40-18's up front.

 

Thanks!

 

Wont work. The fan bracket is behind where it rubs. My 235s already rub there on the pass side. My sport technos are an 18x8 et of 50 and i have 245s on the apex wheels 18x9 et 46. Probably gonna buy it and try it. Im sure i can get it to work, as i gave gt3 lowers and can adjust camber. Thx for the info.

 

Increasing tyre width whilst keeping the aspect ratio (at 40 in above mentioned cases) increases tyre diameter. That causes the rubbing, not the greater width itself.
More negative camber wont help I reckon

 

Yea im too lazy becsuse it was cold out to look at the aspect ratios and put the numbers into the online calculator. The width does matter(not just diameter) when rubbing while turning because it will be wider on the rim thus closer to the liner. It always rubs at the "corner" of the tire.

 

Is there any way to cut or bend the bracket? I had to cut/bend the rad brackets a bit (Turbo rad brackets are different).
Also the rad brackets can be slid around a little if all the screws are loosened. I pushed mine about 1/8" to the front and gained a tiny bit more space.

 

I got out my heat gun on Sunday and heated the area pretty good and motivated it with a rubber mallet.
When I re-installed it I wondered if it was any different.
Finally got a chance about 30 minutes ago to take my car for a test drive.
That fixed it!
Thanks for the suggestion!

 

Available caliper spaces with 130mm spread in various thickness: 5, 7.5, 12.5, 16.5, 17.5, 25mm for 996/997 front and rear BBK upgrade.

 

Above spacers are applicable to the following models with 130mm spread spindles.


These oversized kits have been offered since 2013 with many happy Porsche owners.
They were bundled with our rotor kits but can be list for purchase if needed.

 

To anybody reading this thread, please be aware that I believe RacingBrake's 996 C2/C4 brake solution to be superior to the one I developed. They use lighter two-piece rotors and give the benefits of the kit I developed, but with a significant advantage in reducing unsprung and rotating mass. I really want to stress that my kit is not intended to compete with their better offering, rather it is to offer a big brake option to a small number of fellow amatuers who would otherwise not be able to afford a more advanced solution.

 

M12x1.5 grade 12.9 steel alloy caliper bolts with the following length are in stock for the required extra length to cover the spacers:

35, 40. 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 125

Please review our brake hardware section and scroll down to the caliper bolts, some popular lengths are listed as 4ea/pack.
https://racingbrake.com/brake-hardware/

 

Is there any worry that these 350mm front and 330mm rear (coming soon) rotors offered within this kit will fit inside stock 996 C2 18" turbo twists?