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GT3 or Other 6 Pot Calipers on a C2

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Old 05-13-2019, 07:27 AM
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Evil Bunny
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Default GT3 or Other 6 Pot Calipers on a C2

Has anyone successfully fitted the 996 GT3 / 997 Turbo 6 pot calipers to the front of a 996 C2, without changing the upright/knuckle?

Is it possible to use an adapter? Has anyone done this?

Do any other 6 pot calipers exist in the Porsche foodchain that can be made to work with the standard C2 knuckle?

Any info appreciated!
Old 05-13-2019, 03:40 PM
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Capt. Obvious
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Most any Brembo caliper should bolt right up I believe. I'm pretty sure (but not 100% confident) that the bolt spacing is standard on their calipers.
Old 05-13-2019, 04:30 PM
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The Radium King
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https://www.design911.co.uk/fu/prod1...C2S---997-C4S/
Old 05-13-2019, 07:03 PM
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Evil Bunny
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The challenge is that the front mounting centres are 130mm most callipers that have a 130mm centre are 4 pot.

The Cayenne callipers Mount differently they are not radial, as such they need to be machined and have a bracket added to make them work.

The adapter in the link is for cars that already have a larger calliper, the spacing is not 130mm and as such these would not work, however, this is the type of thing I am looking for.

Keep the suggestions coming!!
Old 05-13-2019, 07:13 PM
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Quaz
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I have been interested in this as well. The Macans come with the lighter weight 6 piston calipers that mount from the top and they are becoming pretty cheap on the used market. Apparently Brembo makes an adapter to put those calipers on, but they only are available as part of their “kit”. So it must be possible to make an adapter which spaces out the mounting holes and moves the caliper out for a larger rotor. The question is does someone else sell the adapter and if not can who is willing to be a test mule to make the adapters. I did this for my early 911 years back to mount boxster calipers and even offer to sell the sets, but there was not much interest so I dropped it. But between materials and machine time I had about $500 into the first 10 sets made. I think I could have sold a complete kit with hardware for about $150 per kit. Thoughts?
Old 05-14-2019, 12:16 AM
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dan_189
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Subscribed - would love a 6 pot option for the C2! Something about the look and performance of a big set of brakes... mmmm
Old 05-14-2019, 06:12 AM
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Evil Bunny
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Guys, take a look at this

http://www.911uk.com/viewtopic.php?t...493c7b95bccc5c

Cayenne 6 pots can be made to work but it requires machining of the caliper and a bracket.

The 997 turbo calipers (Same as on 996.2 GT3) are already radial mount, as are the 958 Turbo calipers, as are the Macan front 6 pots as identified by Quaz.

In the Audi/VW/BMW work there are about a million caliper adapters that allow the mounting of what seem like virtually any caliper to any model, however there is very little in the Porsche world.

Looking at the included thread I see no reason why a bracket/adapter cannot be made to fit to a 997/958/Macan 6 pot to a 996 C2, in the same way that a bracket has been made up to get the Cayenne 18Z caliper to fit a 996 once the lugs have been machined off.

I was hoping someone had already made/identified something.

Quaz, if you can make an adapter for a specific Porsche caliper to make this happen, I would be interested in purchasing.
Old 05-14-2019, 08:51 AM
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Quaz
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I don’t mind going down this road, but it does take some time. This should be a little easier then last time I did it since I don’t have to engineer a rotor to fit either. What makes the process easiest is if everything can be take off the car and put on a bench for fitment and measuring. So I would need to acquire a hub spindle assembly (about $100 used), desired target rotor (probably $80-150), and a macan caliper ( $300). The aluminum for the the brackets is trivial (probably $200 for 10 sets), but then there is the design and machine time. I had a buddy do it last time and he only charged me a couple hundred dollars. So just for development of this I will be into for $1k. If there is some genuine interest or potential partners to chip in I am willing to go down this road again. Here are some pics of the kit I put together for early non-S air cooled 911s. I think had I done that kit 20 years ago everyone would have used it, but hot rodding early 911s has gone out the windows since they are now worth so much more put back together stock.


Old 05-14-2019, 10:08 AM
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Batteaux
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My 2001 has 997 GT3 calipers and rotors. Don't know how the PO did it but I'll go through the service records and see if I can figure it out. The car stops really well!
Old 05-14-2019, 10:18 AM
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Quadcammer
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what are you hoping to achieve? Are your stock brakes boiling the fluid or are you unable to lock up the tires?
Old 05-14-2019, 10:40 AM
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dan_189
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Out of curiosity when upgrading to larger brakes should the booster + master cylinder be upgraded as well? Or is it enough to just upgrade the calipers and rotors?
Old 05-14-2019, 11:40 AM
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Quaz
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That is an it depends answer. I have not checked caliper piston total volume displacement from old to new calipers yet. If the total volume doesn't change much then it really isn't needed. However in general when going to a larger caliper piston volume it is helpful to increase the master cylinder size to reduce pedal travel. If you don't mind a slightly longer pedal travel then you don't necessarily have to upgrade the master cylinder. So for street driving it probably isn't necessary, but if you track the car then you will want the larger master cylinder for sure.
Old 05-14-2019, 11:46 AM
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The Radium King
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sorry, i missed the 's' on the listing i posted. i know it has been done but couldn't remember the name of the company. oddly, founding it again by searching 'cayenne brakes porsche 996'. go figgure.

http://www.goingsuperfast.com/Porsche-996.html

big $.
Old 05-14-2019, 12:35 PM
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Quaz
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Yeah the Cayanne kit isn't overly desirable for a couple of reasons. First the calipers are very heavy, so you put quite a bit of unsprung weight on the front. They are meant for a truck. Second the pad size is not appreciably bigger than the standard C2 caliper pad. You can accomplish much of the same thing by just putting 330mm rotors with the stock calipers. The GT3/Macan 6pots have a much larger swept area and a pretty light weight caliper. Overall it just makes for a better solution. Not to mention you don't have to machine the calipers to make them fit, so off the shelf calipers will bolt right on. The ideal kit is a set of 350mm GT3 rotors, set of adapters and Macan calipers/pads. All bolt on and a true upgrade. Master cylinder is optional if you plan to track it. At least that is what I am thinking. I need to do some math on all this when I get some time maybe this weekend.
Old 05-14-2019, 06:17 PM
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dan_189
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Thanks someone on here did write up installing a 997 GT3 master cylinder (I think).

Looking forward to your calculations! Thanks


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