Hood vent placement

Hi everyone

I currently have a 2011 Mini Cooper S R56 that I am using as my track car. There aren't many motorsport focused hood vent kits out there for these cars, and afaik only 1 kit made specifically for these cars but it is made out of FRP and has no aero testing. My question is if I were to install hood vents to help with underhood temps and not create lift, should I go with a kit similar to this (http://hoodlouvers.com/shop/size-medium-hood-louvershood-vents/powder-coated-black-hi-flow/) from runcool and put the vents on the sides of the hood but still behind the hood scoop, or if I should put a vent sideways towards the back of the hood behind the hood scoop like this kit (http://hoodlouvers.com/shop/in-or-out-small-utility-vents/in-or-out-utility-vents-8-12-x-5/), or even if both would be best theoritically. Any feedback is appreciated, TIA!

Without any relevant pressure test data it looks to me like both locations would work. Make sure the forward ones are behind the core support to hood rubber seal. The rear ones might need to be farther forward than in your pic. They should be placed ahead of the cowl to hood rubber seal.

In reply to NOT A TA :

Sounds good, do you think a combination of them both would hurt aero or not? I'll probably start with the blue ones and if I feel like I need more cooling I'll add the red ones

The red areas in your picture are going to have the opposite effect of what you want.  The base of the windshield is a high pressure area.  The blue areas should work well though. 

If you moved the red vents up to where the leading edge is touching the back edge of the radiator it would probably show the most benefit.

In reply to Patientzero :

I studied engine compartment pics of '11 Mini's before making my suggestions. If the rear vents are placed forward of the rubber cowl/hood seal they'll be far enough forward to not be in the high pressure area at the base of the windshield. And as previously mentioned the forward vents need to be behind the core support to hood seal.

Based on the testing I've done on various cars and simply looking at the pressures across a hood, the blue vents are going to be much more effective. That being said, I'm not sure what effect the bulges behind the headlights will have. Might even make them more effective.

The red ones are not going to work well if they're in the location in that picture, and even if they're moved forward they're still going to be in a less desirable position.

The blue outline/vents are your only option here and a good one for drawing hot air out of the engine compartment. Placement as suggested above of course but maybe craft a slight lip at the front. Think of the lip that pops up when opening a sun roof. It prevents turbulence and helps create nice a flow over the open sunroof hole to draw air out rather than for air in. Bernoulli's principle I guess? This would work the same for your hood vents.

The red ones could [i]possibly[/i] pull air in.  Vents in that area, especially cowls, can be touchy. Those vents might act like a stock cars cowl induction.

In reply to tekshteint :

It appears that both locations would work without any relevant pressure test data. To properly align the forward ones, ensure the rubber seals for the core support are behind the hood rubber seals. Those at the back might need to be positioned farther forward than on your picture. In general, they should be installed ahead of the rubber seal between the cowl and hood.

I took some pictures of the hood and under hood on my car to see where vents might be placed. I don't think I have enough clearance under the hood for any kind of ducting and wonder about the efficacy without them.

Thoughts?

Several people(myself included) thought my vents extended too far back toward the high pressure zone at the base of the windshield but I am happy to report after my track day last week that my coolant temps are actually lower at the end of a 20 minute session than they are during normal street or highway driving.  Never went over 195°.  I do have some additional things done; radiator is layed forward 20°, upper grill is blocked, lower grill is ducted to the bumper, and the splitter extends back to the front edge of the engine.

Patientzero said:

Several people(myself included) thought my vents extended too far back toward the high pressure zone at the base of the windshield but I am happy to report after my track day last week that my coolant temps are actually lower at the end of a 20 minute session than they are during normal street or highway driving.  Never went over 195°.  I do have some additional things done; radiator is layed forward 20°, upper grill is blocked, lower grill is ducted to the bumper, and the splitter extends back to the front edge of the engine.

Great results! Do you have any other pics? Of the hood and the new radiator layout.

In reply to 67LS1 :

There are tons of pictures in my build thread.

Another Mustang, LS3 power