Flex v.s. Rigid body styles

[Halo Blu]

While researching Balsa, I hit conflicting info about what body style works best.
I've seen cars cut out,(Not Balsa) and made to flex, to reduce vibration.(Usually by back and forth cuts through the wood) But, most info on here about Balsa, is using CA Glue to stiffen it. Why dampen the flex? Does Balsa just get so twisted, it needs the glue?
The X Car types, and other "Experimental" bodies that remove as much wood as possible, use a film or cover to stiffen. Why kill the flex?
I can't imagine the film adds any aerodynamic value, when the body is already void of most of the wood. Why use Balsa, when you have to add weight to stiffen it?

 

[Obsessedderbydad]

I don't know why you'd use balsa either, other than to fill. Sugar Pine has always worked best for me.

 

[Quicktimederby]

I don't reduce the flex at all. My light weight body's are covered with vinyl, for aerodynamics. The only place where I would be worried about flex is between the rear wheels but I never open up that area, I keep it solid back there.

 

[GravityX]

Are you talking about this sort of car body? I believe the idea behind this sort of car was to reduce track infliction on the car when on a wooden track. Think of a car with 4 wheel independent suspension, it rides smoother than a car with "solid" axles.

 

[B_Regal Racing]

The term "light-weight" is interesting in itself. What is considered light-weight? I would hazard to guess that each builder defines the term light-weight differently. For me, I tried, solid sugar pine at 1/8" thick between the front and back axles, ladder style chassis, chassis that are hollow with no additional support, balsa filled chassis, etc. The list goes on and on. I finally found a style that seems to work for me, which comes in somewhere around 9 to 11 grams. I’m not sure I would consider that light-weight, but more on the average side. How decide to cover the chassis may also affect the chassis style used, as well as what tools / skills you have. I have none, so my chassis are a bit simpler.

I don’t know if I subscribe to the micro-vibration or flex theories yet. I do believe chassis can be warped, depending on your covering. Dirty air, “wiggling”, transitioning, (e.g. other things that cause a car to become unstable) are more important than chasing down flex. My answer would be build the different style chassis and race them. Wood is cheap.

 

[Fumbles]

I always thought that stiffer was better so that the steering geometry would not change in the transition... however, I'm starting to re-think that stance. Next cars I'm going to build with some flex in them, just not at the rear axle though.

 

[BulldogRacing]

Are all the top cars under 10 gram body weight?

 

[Fumbles]

No idea but I'm trying for sub 6 grams on my next chassis but allow for some flex. I've gotten 6.5 g and pretty firm so far but I'm thinking the flex may help in some instances... isn't this the joy of discovery? Wish I had a track... :-(

 

[OPARENNEN]

To me, the answer is simple. Reducing weight up front allows more weight on the rear. More rear weight allows more acceleration while car is on the slope.

 

[Rocket car]

Are all the top cars under 10 gram body weight?

Probably not. Most cars are between 10-20grams body weight.

 

[Chief]

Are you talking about this sort of car body? I believe the idea behind this sort of car was to reduce track infliction on the car when on a wooden track. Think of a car with 4 wheel independent suspension, it rides smoother than a car with "solid" axles.

I actually saw the car on the left built and raced against it...and you all know how fast Im not...well that was in my graphite days and we smoked that car by a couple car lengths... just sayin

 

[GravityX]

Was that on a wooden track Chief or aluminum?

I personally would not try to build a car like the one I pictured. It would just take too much time to build and weight placement would not be ideal.

 

[Chief]

It was an aluminum track. I have to say I was really impressed with the guys car. My thought at the time that it took too much energy or motion while traveling down the track slowing it down??

 

[Kinser Racing]

Rocket car is about right on I think, though 20 grams would be on the extreme high side. I've got a thin car that wins, a full solid car that wins and my new SS is hollowed out and didn't do to terribly bad. Anyway you want to go can work.

Concerning the micro vibrations, I believe they do exist. With the new outside lane setup for Street Rod, the cars don't have much in the way of dirty air but they are much slower during a race than when they run alone.

 

[HurriCrane Racing]

Are all the top cars under 10 gram body weight?

Nope!

 

[GravityX]

It was an aluminum track. I have to say I was really impressed with the guys car. My thought at the time that it took too much energy or motion while traveling down the track slowing it down??

I believe a car, like the one represented, could do better on a rough track. But being that I never built one, it's only speculation.

 

[Crash Enburn]

With the new outside lane setup for Street Rod, the cars don't have much in the way of dirty air but they are much slower during a race than when they run alone.

Are you saying that testing your car by itself ran faster than when in the dual-format race? Or speaking historically in regard to the four-up format?

 

[Kinser Racing]

With the new outside lane setup for Street Rod, the cars don't have much in the way of dirty air but they are much slower during a race than when they run alone.

Are you saying that testing your car by itself ran faster than when in the dual-format race? Or speaking historically in regard to the four-up format?

During tuning yes, my SR ran faster by itself.

 

[Mr Chips Racing]

For those of us who have been in the league racing we have seen some very cool, unique and even weird ideas. Simple answer is you don't see any of these cars listed in the top 50. I watched a car that balanced on 2 wheels claim to be so fast but the wipe out was epic. The formula for success has been posted and re-posted. Its the fine details which make the 1% in the leader boards.

 

[Fumbles]

Screw that 2 wheel stuff.... I'm working on a 1 wheel car ! I'm sure it'll be successful !