Black Ops for the '04 Open Track Challenge

[Jack Olsen]

Well, we don't need to be too sneaky, since none of the M3s dared to show up this year. We're pretty much assured of a first place finish in our class, even without any clever tricks.

But the TRE Motorsports team of Jack Olsen and Tyson Schmidt is testing out a new idea of Tyson's this year, which is to improve the aerodynamics of the part of the car not covered in smooth paint.



It's an 8-foot-long sheet of .90-mil ABS (technically: Acrylonitrile Butadiene Styrene, I learned from the salesgal at the plastics warehouse), and it runs from the back of the front condenser all the way to the rear swaybar. It undoes some of the aerodynamic damage done by the pre-964 underbelly design, and -- in my particular case -- the big AC condenser I keep down there.

Weather forecasts call for 70-degree highs for most of the week, so sacrificing some AC functionality is a minor concern. And in a pinch, the thing unscrews and rolls up for storage.

[CHILI]

You have A/C in that thing? I never knew that. What a panzy!

That's a cool trick. Let's see how it helps.

[Rot 911]

Looks good but I would think a screw at each corner by the front torsion bar covers might be some added insurance to make sure those corners don't catch air and bend down at high speeds.

[speeder]

BB2 has A/C, a cup holder, and 9 second delay dome lights. It's a true pimpmobile.

[Jack Olsen]

Don't forget the full leather interior.

[ZAMIRZ]

Look very clean and should smooth out some of the turbulence under there.

I have a question, where the ABS ends, it seems as though something is dropping down below the sheet, is that just the bottom of the motor or an optical illusion caused by the exhaust or rear bumper???

[ZCAT3]

Originally posted by JackOlsen
Well, we don't need to be too sneaky, since none of the M3s dared to show up this year. We're pretty much assured of a first place finish in our class, even without any clever tricks.

Wow - I hope you knocked on wood about a hundred times as you wrote this. Talk about tempting fate -



Bill

[Dantilla]

Every time I think I have a really cool car, Jack posts something to put me back in my place.

I like it!

[chrisp]

Any worry about high tranny temps? Can't see back that far but it looks like you may be far enough back to block air from circulating around it and letting the cooling fins do their work. Maybe you have a tranny cooler somewhere and I'm barking up the wrong tree or the plastic doesn't reach as far back as it looks.

I commend you on your creativity and thinking outside the box.

You should shave those tires too. I bet all those tread blocks create a ton of drag

Good luck out there!

[BURN-BROS]

Jack, what is going to happen when you are at speed and air gets trapped between the floor and the abs? I would think that there would be enough force to rip the sheet away from the fastners. Imagine this flapping abs getting caught up in the frear wheels while in a turn no less. Just a thought for safety. Best, Aaron

[masraum]

Hmm, lots of valid points, I wonder how this is going to work out.

I've wondered about trying to smooth out the bottom of the car myself, some of the tricks that I have heard of (primarily from either Porsche or Ruf) is 1) a lip spoiler in front of the engine area (Ruf CTR), 2) deflectors in front of each rear tire (used, I think, on stock GT2's), and 3) an underbody tray kind of like Jacks, but I was thinking thin Al, not ABS and possibly something near the engine (ala 964, CGT, several other cars Porsche and not).

[masraum]

Too, what about a deeper rubber front lip like you see on so many track cars?

[BURN-BROS]

Maybe, f/g or carbon fiber sheet epoxied to 1/8 inch alluminum flat bar for reinforcement.

[chrisp]

Is it a safe assumption that this will help the overall aerodynamic package? Agreed that well designed cars have flat bottoms. Is it a stand alone improvement or does it require/allow for additional changes to other areas (wings, splitters, overall top side profile) to get necessary benefits while keeping the chassis dynamics as you expect (mechanical grip)?

I guess I am thinkng along the lines of the front lip and the rear wing. Front lip is okay alone. Rear wing is okay with front lip. Rear wing alone is BAD. Could this have a similar effect?

Still worth testing for sure.....

[}{arlequin]

You should shave those tires too. I bet all those tread blocks create a ton of drag

Jack, do you use street tires or DOT approved ones? Hoosiers?

[masraum]

Actually, I think, yes just smoothing out the bottom of the car (or side, or top, etc...) will improve aerodynamics. I guess just the right kind of non-smooth surface would be better (think golf ball), but I don't think the bottom of our cars is that surface.

That will make the car more slippery, it may or may not reduce lift, but at higher speeds it should be a good thing.

[}{arlequin]

well it WILL make the airflow smoother, therefore faster, under the car... the quicker the air from under the car exits, the more efficient the "push" from above (downforce) becomes

[Eric Coffey]

One thing that might be of minor concern is if it increases the amount of air "spilling" out the sides. You might try experimenting with side skirts (rocker extensions) and/or vanes.


This reminds me of a spiffy front under-tray I saw on an ebay car recently:

[masraum]

what are the two naca ducts for?? Cooling the steering rack?

[JeremyD]

Look under a 964 and you'll get the idea! Next TRE/jlmpro product is a true one piece bolt on bottom with venturis to induce downforce. See it here in 90 days! Be the first on your block with a smooth bottom! The'll market it as the concrete terminator for Nostatic.

I know the f1 cars used to have enough downforce with their wings/underbelly to be able to run inverted at 100 mph.