Post by Crash Enburn on Mar 3, 2017 11:15:12 GMT -5
As you may well know, I simply love the Street Rod/Door Slammer class of PWD cars. I made models as a kid, and invariably broke them while playing with them, imagining them driving at speed. Enter the SR/DS class. Suddenly these beauties are moving!! 
There's not a lot you can do with the aero on these; I mean, the kit is a car, and not to be redesigned. Maybe put some air deflectors on either side of the wheels, but that 's about it.
Now, the 1-3/4" wide PWD chassis is quite a bit narrower than the bodies of these cars.
Example 1, the HiJack Lamorghini:
Look at the inset of the rear wheels
Example 2, the Calliente Dodge Charger:
Check those gaps front and rear
What if I widen the chassis to fill in those wheel wells? That would result in better aero, no? So, I set out to do that, and provide a much better (lighter and more aero) chassis.
Original chassis:
Pretty awful, huh? The chassis pictured here are ~3/8" thick, and solid end to end.
So, I made a couple ladder chassis (using Spacewalker's method of drilling out sections and then using a rasp to smooth it) and added width for all the wheels but the DFW:
I added some popsicle sticks to the underside so the skin I was about to put on would sit flush to the bottom of the car. By itself, the ladder weighed 3-4g
Also, you can see that on this car, there is room behind the chassis. I molded some aluminum foil to the shape of that pocket, and then poured melted lead into the mold (after removing it from the model), and glued the lead into that back pocket of the car. I hope the mailman wasn't able to dislodge it.
Then I added a skin to the bottom of the chassis.
And this is how the wheels fill the wells now:
Typically, PWD racers will say "don't widen the car". I think it has to do with pushing more air. The SR/DSs are already pushing the air, and it looks to me like the wheel wells are acting as parachutes. I left the DFW where it would normally be in a PWD car so the car will stay centered. But the remaining wheels are more flush to the body for aero. The skin underneath, you may have noticed, actually goes in front of, behind, and inside the wheels.
Both of these cars have been submitted to the March 4 race at NPWDRL.
The HiJack (Lambo) gave me mega-issues on the passenger side rear wheel — first it wouldn't go all the way in, then it wouldn't come back out, then it was fouled by a surprising amount of lint from my wife's woven dental floss, and was finally hammered into place as I couldn't see through the red mist of panic to simply not enter the car into the race.
The Calliente had no such problems, thankfully.
So, gut feelings on the veracity of this theory?
There's not a lot you can do with the aero on these; I mean, the kit is a car, and not to be redesigned. Maybe put some air deflectors on either side of the wheels, but that 's about it.
Now, the 1-3/4" wide PWD chassis is quite a bit narrower than the bodies of these cars.
Example 1, the HiJack Lamorghini:
Look at the inset of the rear wheels
Example 2, the Calliente Dodge Charger:
Check those gaps front and rear
What if I widen the chassis to fill in those wheel wells? That would result in better aero, no? So, I set out to do that, and provide a much better (lighter and more aero) chassis.
Original chassis:
Pretty awful, huh? The chassis pictured here are ~3/8" thick, and solid end to end.
So, I made a couple ladder chassis (using Spacewalker's method of drilling out sections and then using a rasp to smooth it) and added width for all the wheels but the DFW:
I added some popsicle sticks to the underside so the skin I was about to put on would sit flush to the bottom of the car. By itself, the ladder weighed 3-4g
Also, you can see that on this car, there is room behind the chassis. I molded some aluminum foil to the shape of that pocket, and then poured melted lead into the mold (after removing it from the model), and glued the lead into that back pocket of the car. I hope the mailman wasn't able to dislodge it.
Then I added a skin to the bottom of the chassis.
And this is how the wheels fill the wells now:
Typically, PWD racers will say "don't widen the car". I think it has to do with pushing more air. The SR/DSs are already pushing the air, and it looks to me like the wheel wells are acting as parachutes. I left the DFW where it would normally be in a PWD car so the car will stay centered. But the remaining wheels are more flush to the body for aero. The skin underneath, you may have noticed, actually goes in front of, behind, and inside the wheels.
Both of these cars have been submitted to the March 4 race at NPWDRL.
The HiJack (Lambo) gave me mega-issues on the passenger side rear wheel — first it wouldn't go all the way in, then it wouldn't come back out, then it was fouled by a surprising amount of lint from my wife's woven dental floss, and was finally hammered into place as I couldn't see through the red mist of panic to simply not enter the car into the race.
The Calliente had no such problems, thankfully.
So, gut feelings on the veracity of this theory?
"
