7 replies to this topic

[Pablo]

How does leaving the body sides in back of the rear wheels untrimmed help a race car aerodynamically?

 

I normally cut mine short to avoid body suck - am I missing out on a speed secret?

 

How can a small piece of flimsy Lexan fluttering in the wind help?

 

Thanks,

 

Pablo

[Martin]

Short answer it doesn't help. In fact the opposite IMO.

 

My M8 bodied Can Am car got hit in the rear in a race and the body did get pulled into the tires.

 

I cut the body behind the wheels, and never had that problem again, stopping to pull your body out, is no way to win a race.

 

So I would suggest the speed secret is remove it before it gets sucked in.

 

Remember air does not scale and and even if it did there are plenty of fast real cars with no rear fender, 917 comes to mind.

 

I say cut it short before it becomes a problem 

 

e.g. My old race bodies.

 

 

[Bill Breck]

I always cut the "flap" off on my LMP and Retro cars. Doesn't seem to be any reason to have it.

[Dave Crevie]

Check with the class rules. Some classes/organizations don't allow trimming the area behind the rear wheels. Try leaving a little of the rear panel as a gusset to give that area a little support.

[Bill from NH]

I haven't raced for a few years but I used to leave a 1/8 " horizontal strip across the back & down each side at the rear for some body support. I didn't race Eurosports. but they were doing the same thing as in Dave's post #4, about 15-20 years ago. The insides of the rear area were often reinforced with strips of lexan body armor to prevent body collapse.

[Pablo]

Thanks guys 

 

My wing-car-at-heart mentality makes me want to always cut it all off.

But somewhere out there are people who feel those tabs give some benefit.

 

IRRA BOD posted a clarification recently limiting the amount of said material to be trimmed on Stock Cars.

 

James Cleave in his UTube flexi videos leaves his almost full length. With reinforcement of course.

[John Luongo]

racing on ovals or short hill climb tracks i always reinforced the rear wheel wells and backend of the body. otherwise, a body wouldnt last but a couple of races. esp true on tracks with narrower lane spacing, hitting the boards would easily collapse the body work. 

[Dave Crevie]

It really just comes down to class rules. Trim it if you can.