Pictures of Tracer Racing lakester at Elmo:

[Rex Schimmer]

I am posting two picture of the Tracer Racing no. 117 yellow lakester from the Nov. Elmo meet. I always like to see the pictures of the cars "in action" because I think that you can tell alot about the cars aero from the dust that it is trailing. I looked at the pics posted on the SCTA site and noticed on the Tracer lakester what appeared to be a "ring" of dust that is coming from where the body transitions at the rear of the car. I thought maybe it was just the picture then I looked at the pictures posted on the Elmo section and there was a different picture of the Tracer car but it still had the "dust ring" located in the same place. I find this very interesting and I attribute it to the lack of any radius when the body transitions from the main straight section to the tapered rear section. It appears to be making a low pressure area that is drawing air (and dust) up into the area of the transition. Look at the pictures and give me your thoughts. I just find it interesting and it shows the value of running in the dust.

Rex

[jl222]

 
   Looks like tracers to me.

                JL222

[Dr Goggles]

Full marks Schimmer, you can go home early!

very interesting observation Rex, it does seem like that is what is happening....surprising that it is quite as obvious in such a slight reduction as that but shows what happens when as you say there is a lack of radius or an even transition....wonder what the force/drag involved is?... 

[Rex Schimmer]

Dr. Goggles,
I would bet that the drag penatality is pretty close to if they didn't have a tail at all on the car. Obviously the "fix" would be a new tail section with proper radius of the transition but I am wondering if a quick fix would be some vortex generators located right at the transition, maybe a little behind it, but these might generate some attached vortex that could draw the passing air back to being attached with the rear section of the body. It would be an interesting thing to try.

Rex

[SPARKY]

Ratical has over lapping skin joints---there are little dirt lines  behind each---I think (guess) that on my skin joints it is tripping the air and when it changes direction the heavier dirt continues then HITS the skin as it falls out of suspension.  There would, could, or should be eddies or roll clouds behind the joints also

[Rex Schimmer]

Sparky,
I have looked at your car and there are certainly areas such as your panel joints that could be better but you make up for these possible aero deficiencies the old fashion way: HORSE POWER!!! But that being said I am SURE that you have looked at your number one, Mr. S. Hammond, competitor's new car and I am also sure that you noticed the quality of the finish on the body, not many body lap joints or other things that could trip the air. Seth has probably set the standard, as his cars normally do, for your class and to be faster you will probably need to at least meet these standards.

Changes in aero, frontal area X Cd, are equal, in affect to horsepower when it comes to maximum speed, so a 5% aero efficinecy improvement is the same as a 5% horsepower increase.

Rex

[Sumner]

.................. Seth has probably set the standard,...........Changes in aero, frontal area X Cd, .....................

Seth has definitely set a new standard, but I feel the car has more frontal area than he needed and leaves something on the table there.  Sparky's rat has less and is maybe going to get smaller,

Sum

[Dynoroom]

.................. Seth has probably set the standard,...........Changes in aero, frontal area X Cd, .....................

Seth has definitely set a new standard, but I feel the car has more frontal area than he needed and leaves something on the table there.  Sparky's rat has less and is maybe going to get smaller,

Sum

Seth's new car actually has a little less frontal than his old lakester if I remember correctly.

[1212FBGS]

does anybody have any good pix of Seth's canopy hinge and latch set up?
kent

[Rex Schimmer]

Kent,
This is a pic of Seth's car with the cockpit open. Don't know if you can tell anything.

Rex

[SPARKY]

Rex---I have the smallest AA eng and probabaly the least HP---the 5% aero would be worth a lot more than 5% hp---there are also other things that count.

[SPARKY]

Rex, I agree Seth has a beautiful car---I haven't the time, the inclination, nor the MONEY to even try to compete with his cars apperance and workmanship----now SPEED is another matter !!!!!!!!

[1212FBGS]

thanks rex... im kinda looking for some close ups of the hinge assembly....kinda thinking i might go his direction for the new liner...
kent

[saltsho1]

I'm sorry for hi-jacking the thread for one quick question and I hope I'm forgiven.  Does someone know what motor Tracer is running in the lakester this year?

Thanks
Ernie
Car #1147  F/Pro

[dwarner]

Ford SHO w/roots type supercharger.

DW