Well, now.... that is an issue, isn't it? I guess the cars I've seen it on vent radiator heat upward out the forward edge of the hood, out the sides of the front fenders in front of the doors, or run rear mounted radiators and/or engines and draw air in mid-car and dump it out the back, now that I think about it.

I thought there was an after market firm that supplied full underbody panels for the S2000. I can't remember who they are but perhaps they have an answer.

I can think of a few ways to solve the problem, but all involve some or a lot of fabrication work and IMO would be beyond the scope of what is normally done in these forums (close off the front of the car completely, run radiators for all three, engine, tranny, and diff., in the trunk feeding air from under the car and exhausting it through a grill above the bumper in back, for instance).

But thanks for the heads up!

Jim

 

An undertray (ie ground effects) is the best way to get downforce without the penalty of a wing. Sport racers and race cars make most of their downforce this way, they are high-downforce cars. Doing this on a street car is a complex problem because it's expensive, complicated and requires a fair amount of thermal engineering.

You not only need to install a tray and a diffuser you have to replace that tray every time it breaks. You need to install a front splitter and close in the sides with skirts. You need to offer some sort of extra cooling with an oil cooler, transmission and differential coolers. You goal is to reduce airflow under the car and that by definition means less air for cooling the moving parts.

It's definitely the best way to get cheap downforce but short of a full-on racecar c/w budget it's beyond the scope of most. Not impossible but difficult and expensive. A lower front fascia with splitter and side skirts would definitely help.

 

Would cutting off the lower half of my rear bumper improve air flow/downforce (or make it worse)?

 

Try it and see. My guess is you won't be able to tell the difference.

 

I imagine there might not be enough air flowing there now, esp. with a front splitter, to make a difference, esp. to create any downsforce.

 

As far as I can see it couldn't hurt. If you're not that attached to your bumper hack it off. Another option would be to cut some slots in it to vent any trapped air and maybe fill with some mesh grill material for aesthetic purposes if you'd like

 

Absolutely the wrong thing to do. Trapped air does not have any drag. Air that is moving and trying to squeeze through some mesh does have drag.

 

^If that were true wouldn't a parachute be rendered useless?

 

Nope. The drag on a parachute is not from the air trapped inside it, it is from the air than moves around the edges of it and tries to fill in the huge void behind it. More or less. The air trapped in the parachute serves mostly to hold the parachute in the proper shape.

In the case of the bumper cover, the stagnant air trapped there just forms a bubble which the moving air goes past.

For similar reasons, pickup trucks usually have less drag with their tailgates up than they do with the tailgates down or removed. Worst of all is a pickup truck with one of those net tailgates.

I don't know for sure what would happen to drag if the bumper cover were removed or modified, but I am pretty certain that cutting holes in the bumper "to vent trapped air" would be among the worst options.

 

I appreciate all the input. I'll start with the basic adjustments on the wing starting with just a neutral setting.

What side skirts and front splitter are people running? Krazik, I've seen the custom fabbed razor splitter on your car.

Yanked out the soft top and motors today ... it was a LOT easier than I imagined. I was tempted to just start gutting the car when I had it all ripped apart, but I decided I did not have the time to start that process.

Is anyone other than Bitterman planning on coming out to Miller Motorsports Park for the NASA event this month?