I am looking to add downforce for the track to a 2005 987S. I have read the best thing and least expensive is a GT3 Cup splitter. Checking with Sunset Imports they can get one for a 997 GT3 Cup car or a 996 GT3 Cup car for $220-$240. Anyone know which one fits best? Again, black is fine, this is not for looks, just for track. I might remove it for street so I can get in the driveway.

Neither will fit without serious modification to your bumper and/or the splitter. You would need to updgrade to a full 997 nose and fenders for the perfect solution. Otherwise there are some aftermarket splitters out there for the Cayman bumper. Do a search here for the options.

I put the 996 GT-3 splitter on my car and it fits well, not perfect but pretty good. I had to put some double sided automotive foam tape and the plastic anchors to attach it to the bumper. I started by removing the bumper and placing it upside down on a work bench covered with a furniture blanket. Place the splitter on the bumper and align the first holes on the ends of the splitter with the first holes on the ends of the bumper (nearest the wheels). Mark the outline and holes from the splitter on the bumper. Note the area in the center that is a little lower than the sides where the spoiler lips are. Cut the foam tape to fit in the area that is lower and place it. Carefully place the splitter back on the bumper and drill the holes with a drill bit the size of the anchors.
There is a strip of tape on the splitter that is covered with an orange plastic strip, remove it and replace the splitter and carefully align the holes and put the anchors in. I put black tape over the piece of tape that was not covered by the bumper in the center area. That's it.
I need to re-do the black tape a little better, you can see it was not even.
I will be at Homestead Speedway on 4/19-20. I'll report after how it went.
Here's a link to some pictures: .Mac Web Gallery

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Thanks, I did send an email to The Collection Motorsports, The Collection - The Collection - Audi, Porsche, Ferrari, Maserati, Aston Martin, Jaguar, Lotus - New and Pre-Owned, and got a reply. The splitter they sold you is for the 996 GT3, not the 996 GT3 Cup. I am not sure that matters. It is $237 with Cayman Club special discount. He said it includes the 11 plastics rivits for install and notes it was done successfully on a Cayman with no problems (that would be Alejo's car)

If you add the splitter in front and get reduced lift, wouldnt that make teh car tail happy unless you added a wing in back to balance it?

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AFRIDI
Cayman S 2007

That could be the case, so you need to be prepared for that possibility.
I had more down force in the rear and started to feel the front end getting loose on high speed turns. (On slower speed turns, it was perfect.)
Now it should be more balanced, if it starts getting loose in the rear,
I'll add a little more wing. lol...

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I remember reading an article on the Manthey Cayman where they measured asomething like 30-40 kg lift at the front and about 19kg at the
back which would explain what you experienced stock.

I have no idea what the factory upgrade splitter/wing actually does except Porsche says it was wind tunnel tested. If someone has the figures for that I would be much obliged. The idea of a fixed wing (no motors/reduced weight) appeals to me.

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AFRIDI
Cayman S 2007