Good explanation!

When I did mine last year (and my GF's last month), I cut out all the flat plastic between the plastic buttresses on the outside of the back side of the airbox, and as much as I could get at with the Dremel on the curved portions between the buttresses and the sides of the airbox. I even smoothed up the Dremel cuts as much as possible to allow for smoother airflow. It adds lots of area for air to get in, and adds minimal turbulence from the couple of plastic bits still left supporting the top rear rail of the airbox.

HTH!

C ya,
Dutch

 

Dremel goood

 

this is my theory:


having 4 holes in place of one holes end up with twice the area. your link shows a poor attempt to reproduce this effect. was kinda hoping this idea wuold decrease wind turbulence.

offering constructive debate.

 

I think your math is a bit off.
785 sq. in. would give you a radius of 125
392 sq. in. would give you a radius of 62.4, or 1/2 that of the above.
In order to fit in the same space, the radius of four holes would have to be 1/4 the radius of the big hole, which equates to 31.2*2*3.14, which gets you the same 785.

Given the width of the divider is ~7in, the biggest circular hole would be ~22 sq. in.

 

Using a Dremel, you can remove the entire rectangular area easily.

More area = more airflow.

Wear long sleeves and gloves, though. Those hot, molten bits of plastic sting a bit....

C ya,
Dutch

 

If A=πr2 then 3.14x3.5x3.5=38.465 in.sq.
Using that 7" number then the biggest each the 4 holes could be is just under 3.5". Since D=2r then r=1.75.
3.14x1.75x1.75=9.61625. So 9.61625x4= ta dah! 38.465 in. sq.
Of course if they were truly that size then there would be zero material between the holes and your center section would just fall out. Leaving? One giant hole
Also as I referenced earlier you will have a slightly higher incidence of turbulence, proportionally, around 4 small holes than you will one large one.

I agree with joe_bfstplk. Just cut a bigass hole. IMO that area is such an airflow mess you can't smooth it out.
I tested and posted info on this on MINI2 and maybe here years ago. The only real advantage to this hole is cooler air. The closed box traps in the heat. This vent to the cowl evacuates the hotter air more readily when the car is in motion. Stuck at a stop light everything is equal.

Fun stuff. I haven't thought this hard in a while lol

 

the smaller holes are 1/2 the radius. i make the box 500inches. larger hole has 250 radius, the smaller holes have 125. which make double size. just reflecting how more holes end up with more area. 8 make more then 4, 16.

anyways, i never understood why we are making all these holes vrs the big cutout. i wish somebody wuold get some measurements to see if any of this stuff works. maybe its better to reroute air from the front. i see lots of stuff in the way. neat idea thou.

 

Measure what?
Probably old posts here or on MINI2 about the statements below. Too lazy to look.

Measurements I made in the past. Pressure difference with and without the cut out wall. If I recall it wasn't even measurable below 55Mph. After that it was minuscule.
Temperature I did as well.Your induction chamber evacuates heat quicker with the cowl wall cut out, when in motion. At a standstill there was no statistical difference in heat rise time or min/max temps with the cowl open.
Speeds as low as 15Mph demonstrated faster temp drops with the cowl mod.
At cruising speed there's no significant difference.
I never did test any of the cowl vent scoops on the market but I'll go out on a limb and say in the real world they're good for appearance only.

 

think this works?

http://new.minimania.com/web/Item/NMA1151/InvDetail.cfm


cowl scoop for mini.

 

Never tested them TBH so I can do nothing more than speculate along every one else.
My nickel has always been they will probable help at highway speeds but the help would be almost immeasurable.
The trade off is maybe more air at speed but mildly likely to trap heat when stopped in traffic.

I do like the way the look though. I've seen them body color and black. I prefer the black. Looks like swipes of anti-glare black under a football players eyes lol.
My nickel.

For half the price I'd go with this: http://www.madnessmotorworks.com/omp...tress-bar.aspx
Don't now the specs on your car but the best mod for quickness and handling is light wheels. I went from 18lb R84s to 11.5lb SSRs and lighter tires. Been a few years but I think it was around 11lbs per corner. Probably some of the best money I've ever spent modding the car.

 

link to pics of your car and the 11.5lbs wheels? and specs?

 

Company site with specs
Pic is almost 7 years old now. Company went out of business for a while I think a couple times. I autocrossed on them for a couple seasons before buying something cheaper that I worried less about They held up well.
It looks like they don't make them with the machined lip any more. 16x7
I now run them for my street wheels.
I run these on the rare track day. 12.4lbs but they're 15x8

 

Hello fellow motorors! I'm sorry to bump this very old thread, but I'm planning to drill the airbox holes as described and would love to see the photos! Is that possible in some way?