Road Racing - Going to take part in top speed event, how to prepare? Would undertray help?

This would be my first time in such event with F-body. What should I do to be safe and possibly get better top speed? This will be 1km race. I'm thinking of maybe covering some parts of underbody with aluminium sheets. Or is it not so important? I plan to do around 140-150mph in 1km.
Has anyone here any experience with top speed events?

This would be a good starting point....
http://www.texasmile.net/pdf/TexasMileRRTS_2012_4Edition.pdf

And no I wouldn't recommend putting sheet metal under your car unless you want it flying off at 150mph

Didn't think forces underneath are enough to rip off metal sheets... But underbody of my TA is horrible form aero point of view. And rear bumper is even worse, looks like a parachute :)

I did this

http://i143.photobucket.com/albums/r136/HioSSilver/IMAG0055.jpg

http://i143.photobucket.com/albums/r136/HioSSilver/IMAG0334.jpg

http://i143.photobucket.com/albums/r136/HioSSilver/IMAG0333.jpg

http://i143.photobucket.com/albums/r136/HioSSilver/20120305_151836.jpg

I did this

http://i143.photobucket.com/albums/r136/HioSSilver/20120305_151836.jpg

Good stuff... thanks for posting.

Did you purchase that chin spoiler or make it? What's it made out of?

Also, any cooling issues? What type of driving do you do with the car in this config?

Any feedback on the differences these mods made to the way the car handles at high speeds?

Also, I very much want to do an undertray in the rear similar to yours, however I've been reluctant since I'd be trapping all that heat from the muffler in with the gas tank. Still thinking of a simple solution that'll put my mind at ease. Until then, I've got plenty of other stuff to do :)

Mark.

I made the chin spoiler. I made it out of 2 Mach1 chin spoilers. I had some cooling issues until I extended the airdam under the car, but only with the ac on.

I can't tell any real differences in handling, but I think it helped my trap speed at the drag strip. The car has trapped 130 now. with the front and rear done.

There is no heat issues for the gas tank, but if you noticed I am running a single straight threw muffler. Which is about the only way to make the rear pan work. If you was looking for down force out it you could put some verticle elements on it but I was just looking to smooth up the back.

Didn't think forces underneath are enough to rip off metal sheets... But underbody of my TA is horrible form aero point of view. And rear bumper is even worse, looks like a parachute :)

Try some "Custom Bumper Speed Holes!!

I think Pep_Boys is having a sale on them

:gruffy:

If you are only planning on going 150mph just remove your mirrors. The aero drag doesn't really get bad until much higher than that speed. Run small front tires to reduce drag. Lower the car as much as you can. Remove your wipers.

If you have unlimited time on your hands then go crazy and block off everything and make a full flat underbody ;)

We went 207mph in a Mazda RX-7 with turbo LS3 making about 650rwhp in 1 mile. Didn't even remove the mirrors. Stock ride height, 275's at all corners, basic tape on the hood/pop up headlights.

If you are only planning on going 150mph just remove your mirrors. The aero drag doesn't really get bad until much higher than that speed. Run small front tires to reduce drag. Lower the car as much as you can. Remove your wipers.

If you have unlimited time on your hands then go crazy and block off everything and make a full flat underbody ;)

We went 207mph in a Mazda RX-7 with turbo LS3 making about 650rwhp in 1 mile. Didn't even remove the mirrors. Stock ride height, 275's at all corners, basic tape on the hood/pop up headlights.
Completely wrong on that. Aero starts coming into play as little as 40mph. I'm noticing gains in the 1/4 with trapps up to 130mph with a bolt-on crate ls6.

My calculations show that even in 1km race 10% reduction in drag results in 2-3mph, even more than that in 1mile. And that is big difference :)

HIo
Nice looks on rear underbody

Thanks, I'm going to smooth up under the front soon also.

On my car I have a full undertray and placed 3 NACA ducts, one at the oil pan placed backwards, the next one in front of the catalytic converter to move heat down the exhaust tunnel even though the entire exhaust is wrapped, finally I have the last one in front of the diff with a piece of aluminium on the bottom and up to the back (to move the air efficiently across the diff cooling fins.

And with the Aero, 25% of drag on a CRX is caused by the wing mirrors (that was in one of my aerodynamics books)