Decided to figure something out after years of talking about it. My mechanic (one of them) is a top notch fab guy. Built the center exhaust and we fashioned the diffuser together. Testing at end of July at Barber motorsports park. The mounting solution for the rear was so simple, just needed the right stuff.

Still in development, but coming along nicely.

 

Looking good. I will be doing something similar over the winter. Should help increase rear down force and decrease drag quite a bit.

 

Very nice Dez. Good job leaving some space underneath it gets hot down there. Make sure there's a lot of air flowing through. I remember a customer years ago that blocked everything off and caused the fire back there. Are you thinking about opening up the license plate area with mesh? Look into making a negative pressure area. You will notice it!

 

Awesome, looks great!

 

We left that part open for cooling and access to suspension eccentrics and boost hoses. Its enough of a pain to have to do that stuff already without having to remove the floor to do so.we may add naca ducts as well but since I only do time trial i decided against it for now. The way we mounted it, there is a lot of space between the floor and engine/headers. 2-3 inches.

 

Really Cool Bro now I'm going to want one.

I wonder if the after market 997 diffuser can be made to fit ?

 

There are some custom ones that will work, but you would have to cut exits for the exhaust. I have seen some cayman ones that just need this mode to fit.

Once we test this in a few different iterations, we will likely make a mold to reproduce in Carbon or fiberglass.

 

Nice!

 

That's awesome. Nice work on the diffuser! Is that alumalite ppaneling? Is the diffuser around 7 degrees?

 

Yep.

 

Could you use the old exhaust exits for cooling the bay at all or would that be just too tight?

 

Cool put me down for the first one

 

Its hard to tell from the pictures but how much angle is there? I cant imagine people with full x-style exhausts would have much room for angle and may only work for those with straight pipes.

 

No, there is a ton of room, and those side are open on both the top and bottom of the diffuser, so there should be lots of air flow. Should cool just fine.

You got it!

There is a good bit of angle on mine, I don't know the exact amount, I was so giddy I forgot to measure it. but if you look at the dividers on it, they pretty much represent how much angle is present. There are nearly level with the rest of the flat floor and the sharp to wide end difference represent the angle.

You are correct though, with a full x-style, you won't get nearly as much angle. The deal breaker for most would be relocating the plate and cutting the bumper. IMO you could still make an effective diffuser inside of the original exits. The best scenario to stay near stock is straight pipes (maybe with cats) and the center portion of the diffuser. I made a homemade Home Depot version of this a couple of years ago and I could actually feel a difference. It have virtually no angle (because I had no clue how to mount it with an angle). But it did reduce parachute effect (I picked up a couple MPH on the back straight at Road Atlanta.

 

As you can see on the 991 GT3 Porsche thought it vital to smooth out the air traveling underneath the engine bay. This has long been left open and was surely a cause of turbulence and lift. Even if you can't get the proper angle, covering up that area makes a difference as it allows smooth passage underneath. Just chassis rake alone can promote faster travel of air beneath the car creating more DF.