Looks to me like that isn't NACA ducts for the purpose of getting the air above the diffuser, that's literally two diffusers, one in front of the other. Moving air to the top of the second diffuser is a byproduct of having the first one in front of it, but it's not the goal, the goal is to have two diffusers (awesome)

-Ryan

 

Ha! That's my photo!

 

My neighbor who works on vintage formula one cars suggested that I slightly ark up the splitter where it passes under the empty cavity between the sub frame and bumper. He said that ark would help create downforce.

 

.

 

That would be a front diffuser.

 

K24 - from that description I'm picturing a bubble that arcs up and then drops back down when it reaches the front subframe. Or was he suggesting a regular diffuser that would arc up and basically send air at/over the front subframe rather than below it?

I have diffusers in my front splitter, I just haven't put pictures of it out there

-Ryan

 

Sounds to me like the neighbor's describing what's in the picture. Merge the splitter up to the front subframe, or to the level of the flat floor if one's been implemented.

 

From what I posted up on the page before. They talk about equaling the rear wing out with active aero under the front. I am guessing in saying that it prob is the 2 front diffusers in front of the Front Tires.

 

On our cars at least, the splitter height is roughly the same as the bottom of the front subframe, and the height of the flat bottom (if one were present), so any front diffusers will go above that level.

-Ryan

 

I think we all agree, and should now consume significant numbers of pints together. Come to Portland bitches! I'll buy the first round.

The active underbody aero part of the P1 is fascinating - and is what makes this truly a supercar in my humble opinion. As evidenced numerous times on this forum, anybody can slap a powerful engine into a responsive chassis and add some home-grown aero and embarrass Very Expensive Cars on track. True active aero management requires tools beyond those available to us DIY'ers. To do it in such a way that it is seamless to the driver is impressive.

 

Very much agree indeed.

 

That's the way I understood it. He said the air will have to accelerate to follow the ark thus giving more down force.

It's amazing to see some of the aero designs of the formula one cars over the years. The tunnel cars were the coolest IMHO.

 

This is the splitter made for the Catfish. The two rear mounting bolts connect to the Miata K-member. Without spacers at the K-member--at least on the Catfish--the splitter angles upward slightly. I use spacers to flatten it out, and regardless feel a noticeable difference in down force, especially on the brakes.

Anyone with basic skills could make this part, or trace it and have a local shop plasma cut it from a sheet of aluminum.

 

How thick of an aluminum did you go with?

 

If you're talking about the Catfish, the floor is .090. It's made so a racing splitter can be installed under it that would extend forward of the nose, and there are plenty of discussions as to the best and most cost effective material types for that structure.

 

I wasn't saying I wanted active aero, but to see if anyone knew how the front aero being so small works so much to off set the rear wing. I tried to find pics anywhere on the internet with no success. So I went down to look at the car again and take pics.

McLaren P1 Under Diffuser Looking Forward





McLaren P1 Under Front Splitter Looking back towards the right front tire





McLaren P1 Underbody



McLaren P1 Under Front Left Tire



McLaren P1 Rear Cooling Fans with Carbon Blades and Shroud





McLaren P1 Back





Love That Paint

 

 

The more pictures I see, the better and better the McLaren aero gets. Fantastic.

There is an article in Racecar Engineering this month on the Porsche 919 LMP, but it does not show much on the aerodynamics unfortunately. They do however have an article on testing the effects of rake and ride height on the Praga R1 in a wind tunnel. The testing showed what generally applies to undertray aerodynamics. Downforce is sensitive to ride height, and the bias of the undertray downforce shifts fore and aft with rake; increasing rear ride height (or decreasing the front) shifts the undertray downforce balance (center of effort) forward.

Here is the Praga R1
http://www.roadandtrack.com/car-revi...-on-our-shores

There is also a good article about the effects of yaw on wing downforce and what happens when you add intermediate spill plates.

 

Woah. Never heard of the Praga before. Looks awesome.

 

Thought I'd share this one: