Front Bumper and Radiator Aero

[Whittie]

Well I've done some reading and had some discussions and from what I understand, a good method of reducing drag and lift is to block above the front bumper, insert directors to make all the air go through the radiator and avoid air going under the car, something like this photo here:

 

 

 

 

 

 

 

Now, my dilemma, this is how the front of my car looks:

 

 

 

 

 

 

As you can see, below the bumper is blocked, so if I were to block the top of the bumper, there would be no air flow to the radiator. This car is street driven so the number plate must stay!

 

The vents to either side of the bumper are soon to be enclosed and ducted to the front brakes and the front bumpers are going to be vented to allow air to move out from the wheel well down the side of the car.

 

So, if I can't remove the number plate, I can't block the top of the bumper and I will be filling in the gaping holes in the bumper to direct air to the brakes, is there any more I can do to the bumper to increase front aero?

 

I'm also going to, at some stage, seal between the radiator support and the spoiler, stopping air from going below the car in that manner, and also seal all the holes around the radiator, to force all the air into the engine bay through it and not around except for a small amount directed at the carbies.

[AkumaNoZeta]

When I get around doing this with my car I will actually be blocking off the lower portion and blocking off the top half too except for a little bit in the middle of the top half that will have the area of 1/3 the radiator's area. I want to completely block off the bottom because I plan on running 1.5" flares similar to the Subtle Z ones (in fact I want to use Subtle Z fenders with a MSA Type 1 air dam modified to it) with a concave front of the flare and I want to make as much air flow go across that as I can to help pull air out of the wheel wells and it's more concave on the bottom than the top so it would be more effective at the bottom. Purely all theory but I believe it will work.

 

The whole idea is to block unnecessary amounts of air so it doesn't build up in front of the car, it shouldn't matter if you have the bottom or top blocked.

[Whittie]

blocking off the top half too except for a little bit in the middle of the top half that will have the area of 1/3 the radiator's area

 

Is there any maths behind this 1/3rd argument? If so then I might pursue that as something to do.

 

The whole idea is to block unnecessary amounts of air so it doesn't build up in front of the car, it shouldn't matter if you have the bottom or top blocked

 

Cool. I was wondering though if blocking the top or the bottom effects air over the bonnet or around the car? Maybe one is better or worse than the other? It seems to me that people seem to block the upper portion more than the lower.

 

Also, you might want to look into venting the wheel wells like me to achieve air flow out of them. I'm looking to do something like in the following photo, in fact I was thinking of molding these exact vents into some fiberglass front guards:

 

[AkumaNoZeta]

I thought about putting vents behind the wheels but I rather keep as close to the factory look as possible so I won't do it until I feel I need the extra venting and with working the wheel arch correctly and the hood vents I hope I won't need them. My car won't have inside wheel well with tubed front end.

 

The 1/3 thing comes from the other thread in this forum, it states that you only need an opening 1/4 of the area of the radiator to get the proper amount of air flow through it while moving, but should be upped to 1/3 if it's a street car and therefore has to sit in traffic. This is with ducting though, without ducting the air would go around the radiator and cause overheating problems.

[AkumaNoZeta]

If you read the blocking off thread that's in the Sticky section of this aero sub-forum then you'll probably get more information than you need.