bodies/downforce
 

Can any of you race guru's explain,
with our r/c bodies we use, is there enough downforce to "really" make a difference to our racing.

I am just watching the Australian touring cars racing at the Gold Coast in Austrailia on NZ tv here in New Zealand, and I got to thinking, does it 'really' make a difference to our rc cars?

This has never been explained to me, and I just assumed that it would make a difference to rc cars as it would for 1:1 cars, as would different body shapes/styles.

Also, whats your favorite body shape that suits your driving styles. I am running Mazda 6 bodies at present for 2010 season.
All help welcome.
Dave

Body shape seems to make quite a big difference in the "feel" of the car. The Mazdaspeed 6, for example is less aggressive feeling than the LTC-R, which is less aggressive than the R9-R.

For me it really seems to depend what the traction is like, and what the layout is when it comes to body choice. On small tracks with tons of traction I usually like the LTC-R, but on longer flowing tracks I like the Speed 6. Bumpy tracks regardless of layout I generally stick to the Speed 6, just for its stability.

Is there anybody running the new p37-r body? Just wondering how it compares to the ltcr and spped 6?

Simple experiment to prove this. Take the wing off your TC and then go run some laps and compare the times with the lap times with the wing on.

I'm pretty sure you'll find that with the wing off the car is extremely unstable in high speed corners. I've had wings ripped off in crashes and the car was pretty much undriveable in high speed corners. Straight line speed was noticeably faster without the wing.

A boosted 13.5 is going to be hitting around 60km/h or more depending on gearing which is quite a bit of air flowing over the body even though it's a relatively small body. The Protoform bodies I've tried seem to have various channels molded into the body to capture the air and route it differently. I'm no expert on aerodynamics but at high speed different body shells definitely seem to react differently.

Right now my favourite shell for my driving style is the LTC-R.

Yes, the "race" bodies that most use make a difference in the handling of your car. I'd say the body's aerodynamics starts affecting the car's handling after 7-10mph; as an experiment, try running a non "race" body, then run a "race" body and you should see and feel a difference.

My favorite body was an HPI stratus Aero 2 but it's no longer in production.

thanks for your input..........
I am currently running boosted 13.5 tekin/rs-pro.
Im possibly going to use the LTC-R body for 2011.

You really have to try at least the speed 6 in addition the the LTC-R. Try the others if you can as well. Protoform does a good job of making each body(speed6, LTCr, and R9R) handle differently enough to matter. I have not tried the p37 yet, but I will order one with my next order. I prefer the stability of the speed6, but I have an LTCr in my back pocket all the time.

I run the speed 6 in 09 nz champs and local track season in stock touring and 13.5, I found they break easier than the mazda 6, therefore went back to the mazda 6 for late 09 and 2010 season.

What characteristics does the the p37 body have?

I once triad running a couple of laps of our track without a bodyshell on. I couldn't even turn into the faster corners without a shell. It really make a big difference to handling. Before trying this I also wondered what they actually did.

I used to race go karts at Summit Point, a big sports car track with a LONG front straight. Once I hit terminal velocity, I could stick my hand out and watch the tach drop. :D

Yes, bodies make a BIG difference. And not just which body you use but how it is mounted.

Wingracer,

Can you elaborate on the mounting?

Thanks

Position makes a difference. Forward = more steering, back = more stable.

Also, things like rake, height, front ground clearance and other factors can have an effect.

OK, thats clear.
Was curious to what you meant.

Bodies make a huge difference for RC, even for smaller scales and slower speeds actually. I went to 1/28 scale Mini-Z's and now we're getting into all sorts of elaborate aero devices:

http://img819.imageshack.us/img819/6249/img0493na.jpg

http://img233.imageshack.us/img233/5051/img0508g.jpg

Front diffuser and rear wing alone cut 3 tenths (went from 8.3xx to 8.0 flat), and the hood vents (they duct air out from the front bumper intake) are in testing now, they seem to add steering in high-speed sweepers. These cars are only doing 20mph on the track tops, most of the racing is 5mph and below and the aero still matters. When you guys go 60mph on the back straight I'm damn sure the aero makes a big difference. :weird:

I've heard some people arguing in the past that aero doesn't matter in RC because the downforce generated is nowhere as high. But the counterpoint is that the weights of the cars are also nowhere as high, so the downforce you can generate becomes a significant percentage of the car's weight, and makes it matter. I was never hardcore enough in 1/10 to put one through the wind tunnel, but I have a friend who put a 1/28 through one and it generates about 2 grams of downforce at speed. Granted, the box-stock cars generate a little lift, but 2 grams is not a lot of downforce. Evidently enough, however, to make a difference when the cars are ~180g.

Now 1/10 cars are in the kilogram range (give or take, I know TC is heavier and WGT is lighter) so I would probably guess that 10's or low 100's of grams of downforce would be completely sufficient to make a large handling difference. That's also completely possible given the shape of the bodies (those scoop wings and pan car bodies...). Curious to see if anyone's stuck one of the more recent TC or WGT bodies into the wind tunnel and can post some results.