RacingBrake's kit is for 996s and 997s that have the 142mm front caliper bolt spacing. The kit I have devised is for the 130mm bolt spacing that is used on the 996 C2/C4 and the 997 non 'S' models. For clarity, the 996 C4S, GT2/3 and Turbo have 142mm front caliper bolt spacing and upgrading the rotors from 330 to 350mm on them is simply a case of longer caliper bolts with spacers under the caliper, and replacing the 330 rotor with the 350 one. I'm the only engineer to have devised this solution to cheap bigger brakes on the Carreras, I've created only a handful of kits, and I'm a backyard mechanic trying to keep the wolf from the door whilst I'm too sick to work. I'll happily give the owners of Rennlist a cut from each sale if that's what they want. I'm certainly not a full blown commercial enterprise that's competing with site sponsors, I can't be because I'm the only person offering this upgrade path.

 

Thanks for the info. I really appreciate the clarification.

 

So, I just want to make sure - run through this with me like I'm an idiot (because I'm not a technical guy):

1) The stock calipers (the things that press the pads to the braking surface, the rotor) still fit using this system by way of longer bolts - correct?
2) The diameter of the rotor has increased - however, since the pads/calipers remain unchanged, braking won't change much, correct? Is the main benefit then JUST the better cooling because it's similar heat over a larger rotor?

So, does that mean to get truly enhanced brake performance (decreased stopping distance), one would want to increase both caliper size AND rotor size? However, this will give the cooling edge?

I'm genuinely curious because I was thinking of doing a "big" brake kit setup, but I wasn't sure what I wanted yet. This could be a great intermediate solution.

 

Braking should also get better because the caliper is farther away from the centerline of the wheel. Im not sure by how much and if i wasnt so lazy i could look up the formula to figure it out.

 

You're pretty much spot on with all of your points. The stock calipers are retained and are secured using longer bolts. The diameter of the rotor has increased, and the caliper is further from the centre of rotation, giving it a greater mechanical advantage. However, the braking power increase this confers is modest, perhaps around 15%. (I did the calculations way back and don't have that notepad to hand, otherwise I'd give the calculation used). The bigger rotor does give a significant advantage in cooling, fending off fade for longer, and in many systems preventing it entirely. Feedback from other users of the kit is that the performance increase is noticeable and worthwhile. You also get to use much more aggressive pads that generate more friction and therefore heat, with more of the heat dissipated by the larger rotor, and therefore less heat going into your brake fluid to boil it.

The other advantage is aethetic in that the 350mm rotor 'fits' the wheel much better and is the size that any car person would expect to see behind the spokes of your wheels, rather than the somewhat small stock rotors.

This setup isn't intended to give the performance increase achievable by using a $3000 big brake kit with six pot monoblock calipers and 350mm floating rotors. It's intended to create a new, much more affordable way to put 350mm OE spec rotors from elsewhere in the Porsche range on any of the lesser Porsches that normally use the 318mm rotor and 130mm bolt spacing calipers. As you note, it's definitely an intermediate level upgrade rather than a full monty. It's perfectly doable to install this kit for $600 all-in, if you shop around for cheaper discs. Please note I haven't so far found any of the cheaper discs to give a sub-standard performance, so please don't assume that in this area paying cheap means paying twice.

 

I spent $664 for everything including shipping.

I recently noticed another advantage.
I think the 350mm rotor itself has introduced some additional offset.
The extra offset has created extra space between the caliper and the wheel.
This makes cleaning the front caliper easier...more like the rear wheel.

Hopefully I'll get a chance soon to measure to see what total offset difference I see with the Dynamic Friction 350mm rotors over the Pagid 317mm rotors.

 

Not to get too far off the intial topic but is there a direct replacement 6 pot caliper for the front of the c2/c4 stock application? (Brembo, Wilwood) My thought is, if there is one it may work with this kit???

 

Brembo makes a BBK with 6-pot fronts compatible with the 996 wheel carriers. I believe list is somewhere in the $5-6k range. I did a bunch or research thinking about this lat year as there was a used set of front calipers in the classifieds for $3500.

There’s also a BBK available from Stoptech that gets you 355mm front rotors, but the calipers are still 4-piston and IIRC the pistons are not any bigger than the stock fronts. List was still about $3k, so I was considering just moving to Girodisc rotors instead. Martin’s kit now has me rethinking that.

I also have a GT3 MC sitting around which is supposed to stiffen up the pedal and is a must if increasing piston volume.

 

Well im not nearly a good enough driver to need $6k worth of front calipers, thx.

 

Same thing for me, but move the cost down to $3000.
That's why Martin's kits attracted me.
I'll spend $600 for slightly better braking and a lot better heat dissipation, but I won't spend $3000.(typical BBK starting prices)
If the factory brakes sucked, then yeah $3K would be a no brainer.
But the factory brakes are really good...but for $600 why not improve them a little more?
The 350mm rotors do look better behind the wheel, but that was not a huge concern to me.
The improved heat dissipation was my first priority.
The increased braking ability, and the better looks, were bonuses.

 

Martin and Tex, great points. I pretty much feel exactly the same - I've been shopping for BBK, but at those 3-5k prices, I've basically been pushing it off, especially since I track the car once a year, or less. I had the GT3 brake cooling ducts installed because I didn't know about this package, but I may consider doing this. I also had the GT3 master cylinder and SS brake lines installed for better feel, so I think I'll see if my shop can install the upgrade (since I live in an apartment, not allowed to do the work in my parking stall :/

 

It shouldn't cost much to have done.
It's just brake rotor R&R labor +2 minutes.
I can both sides in under 30 minutes once the car is up in the air.
You could do it in any parking lot and most people would think you're just changing a tire.

 

U agree that these cars stops great even better with pagid yellows and ss lines on mine, so the 6 pots wont happen 4 me.

Im pretty sure ill be buying the kit by the end of week. Seems to be a solid cost/reward upgrade.

 

how will you get "better braking" with the bigger kit if the stock brakes will lock up the stock tires at will?

Basically, the larger diameter gives you a touch more braking torque, so perhaps slightly less pedal pressure is needed at light braking, but if you can lock the wheel, a bigger disk will do nothing but lock it up slightly sooner.

If you run slicks/hoosiers, maybe thats not a problem, but I can lock up 235 NT01s easily with stock 996 front brakes and pfc 08 pads.

 

True (and Martin himself said as much).
To be nitpicky the bigger disk wont lock up 'sooner' just at a lower pedal force, i.e. Master cylinder pressure than with a smaller disk.
The braking force at which the wheel locks is identical (I'm aware you, Quadcammer know that).

The benefit and performance increase is the greater thermal capacity of the increased mass of the bigger diameter disk as well as the greater cooling rate because of the greater surface area that both radiates the heat and is cooled by the air passing over it.

I like the set-up that Martin came up with very much. It is a solidly engineered solution in my opinion.