Ferrari F150 – Starter Motor Hole – Blown Diffuser

Ferrari are amongst many teams that have placed their exhausts down low close the cars centreline. In doing this they are passing some of the exhaust gas through the starter motor hole in the diffuser to create more downforce. This solution was likely given the cars exhaust and diffuser layout, but was proven when Felipe Massa’s fire on the third day of testing showed the flames passing not only over, but also through diffuser via the starter hole. Given the rule changes this year, this solution is surprisingly legal.

Teams were using this legal opening in the diffuser last year for aiding their double diffusers. Using the opening as an extra slot to make the diffuser more aggressive, just as rear wings use more slots to allow them more angle-of-attack. Mid season in 2010 the FIA issued a clarification to reduce the size of the slot. This formally made it into the technical regulations for 2011 as article 3.12.7.

3.12.7 An aperture for the purpose of allowing access for the device referred to in Article 5.16 is permitted in this surface. However, no such aperture may have an area greater than 3500mm2 when projected onto the surface itself and no point on the aperture may be more than 100mm from any other point on the aperture.

It doesn’t state or prohibit what else the aperture can be used for, just its maximum surface area and width can be. A rectangular slot would be 10cm wide and 3.5 cm tall, a simple round hole would be a 66mm in diameter.

As the FIA moved to prevent double diffuser, the loophole allowing opening the floor was also closed to the kind of open fronted diffuser as used by Red bull and latterly many of the top teams. With this change in the rules teams are limited in how they can blow the exhaust into the diffuser. Aside from Red Bulls exploitation of the outer 5cm of floor, the only other option is to blow some of the gas through the starter motor hole.

By pointing the exhausts along the sides of the gearbox the fast moving gas flow will pass over the top of the diffuser, when it hits the trailing edge and gurney flap it will help draw more flow underneath the diffuser.

http://scarbsf1.wordpress.com/2011/02/03/ferrari-f150-starter-motor-hole-blown-diffuser/

 

What would you like us to talk about Lorca, your ability to cut and paste? Do you have any personal views?

 

Does Lorca even understand half of what he has plagiarised?

 

I doubt it. Thats ScarbsF1 guy writes fantastic stuff, and he's spent years around the sport. This is pure copy and paste, if I want F1 news I check a news site, if I want to discuss it I do it on a forum. All this really needed was a post saying, "Hey guys, anyone noticed that the starter motor hole is being used for aero benefits?, Have a look here. Thoughts?" Kind of thing

On topic, the teams are obviously going to extract the most performance they can out of the car. Because there are rules designating the size of the hole, its almost tantamount to saying you can use it for aero. As a hole, air will go through it anyway, so it effects the aerodynamics of the car, why not use it positively? I imagine most teams will use it, unless they have a more creative solution.

 

I think it was last year canary that the teams were coming up with innovative shapes for their starter motors to do just this hence the specifics around the measurements. They use every nook and cranny. Very clever.