15LikesLittle aero secrets
01-16-2017, 11:03 AM
#76
Agreed. If only a Mercedes CLR body was created!
My first attempt will be a chassis protecting under tray which leads back to a fan blown diffuser. I'll see how things go from there.
My first attempt will be a chassis protecting under tray which leads back to a fan blown diffuser. I'll see how things go from there.
01-16-2017, 11:17 AM
#77
Kyosho/Tamiya had/has the CLR GT body.
Then there's -> http://jethobby.com/_shop/product/pr...ail.php?id=470
Remember, you want the air from bellow the tray to travel faster than the air going over the body.
Then there's -> http://jethobby.com/_shop/product/pr...ail.php?id=470
Remember, you want the air from bellow the tray to travel faster than the air going over the body.
01-17-2017, 08:16 AM
#78
Cool, thanks for the link, I was not aware one existed! That was meant to be a joke, as the CLR had some pretty frightening flips from poor design / aero based on the restrictions which existed at the time.
01-17-2017, 09:49 AM
#79
Today I learned that Polycarbonat does not like to get bent with a heat gun 
First I started with drawing:
The diffuser was the first part I wanted to shape. Therefore I put the sheet between two large tubes and cared that it couldn't move in the process. This first step went pretty well, even though it wasn't easy to adjust the angle. Then I wanted to bend the first air channel and disaster striked. I have to add that for this step I pressed the sheet between two flat wooden boards to prevent unwanted areas to bend. With the heat gun I worked on the air dam until it had the right angle. The I took the sheet out and it wasn't flat anymore The whole sheet was tweaked... So the heat gun was no good idea.
Ok, so I will go back to the way I built the first undertray (no my oven is to small to bake the sheet in it and it is for food only
), but first I have to visit the hardware store, again 
First I started with drawing:
The diffuser was the first part I wanted to shape. Therefore I put the sheet between two large tubes and cared that it couldn't move in the process. This first step went pretty well, even though it wasn't easy to adjust the angle. Then I wanted to bend the first air channel and disaster striked. I have to add that for this step I pressed the sheet between two flat wooden boards to prevent unwanted areas to bend. With the heat gun I worked on the air dam until it had the right angle. The I took the sheet out and it wasn't flat anymore
The whole sheet was tweaked... So the heat gun was no good idea.Ok, so I will go back to the way I built the first undertray (no my oven is to small to bake the sheet in it and it is for food only
), but first I have to visit the hardware store, again
01-17-2017, 10:14 AM
#80
Just skimmed this thread, but saw some discussion about body skirts...
We used to race r/c cars at the Indianapolis Major Taylor Velodrome bicycle track. Here is a video from a 2009 event. Not sure if Nic Case was at this event, but I know here at least attended a few races there.
https://www.youtube.com/watch?v=h6EJTMKEAIE
----------
At lot of racers thought you had to slam the chassis and/or bodies to the ground to help with the aero on the car. Too often people would make their car too low and would have problems with their chassis/body bottoming out and would lose control. Often crashes resulted from this as the driver wasn't understanding that they were preventing the suspension from working.
A good solution was to mount the chassis and body high enough that the movement of the suspension wouldn't bottom the car out OR cause the body to rub anywhere (ground or tires). The problem with this was that there would be a large gap between the body and the ground.
The solution was to use some kind of tape to seal off the body to the ground. The tape would allow some flex if the suspension would have a dramatic movement without upsetting the chassis too much.
We used to race r/c cars at the Indianapolis Major Taylor Velodrome bicycle track. Here is a video from a 2009 event. Not sure if Nic Case was at this event, but I know here at least attended a few races there.
https://www.youtube.com/watch?v=h6EJTMKEAIE
----------
At lot of racers thought you had to slam the chassis and/or bodies to the ground to help with the aero on the car. Too often people would make their car too low and would have problems with their chassis/body bottoming out and would lose control. Often crashes resulted from this as the driver wasn't understanding that they were preventing the suspension from working.
A good solution was to mount the chassis and body high enough that the movement of the suspension wouldn't bottom the car out OR cause the body to rub anywhere (ground or tires). The problem with this was that there would be a large gap between the body and the ground.
The solution was to use some kind of tape to seal off the body to the ground. The tape would allow some flex if the suspension would have a dramatic movement without upsetting the chassis too much.
01-17-2017, 11:27 AM
#81
Just skimmed this thread, but saw some discussion about body skirts...
We used to race r/c cars at the Indianapolis Major Taylor Velodrome bicycle track. Here is a video from a 2009 event. Not sure if Nic Case was at this event, but I know here at least attended a few races there.
https://www.youtube.com/watch?v=h6EJTMKEAIE
----------
At lot of racers thought you had to slam the chassis and/or bodies to the ground to help with the aero on the car. Too often people would make their car too low and would have problems with their chassis/body bottoming out and would lose control. Often crashes resulted from this as the driver wasn't understanding that they were preventing the suspension from working.
A good solution was to mount the chassis and body high enough that the movement of the suspension wouldn't bottom the car out OR cause the body to rub anywhere (ground or tires). The problem with this was that there would be a large gap between the body and the ground.
The solution was to use some kind of tape to seal off the body to the ground. The tape would allow some flex if the suspension would have a dramatic movement without upsetting the chassis too much.
We used to race r/c cars at the Indianapolis Major Taylor Velodrome bicycle track. Here is a video from a 2009 event. Not sure if Nic Case was at this event, but I know here at least attended a few races there.
https://www.youtube.com/watch?v=h6EJTMKEAIE
----------
At lot of racers thought you had to slam the chassis and/or bodies to the ground to help with the aero on the car. Too often people would make their car too low and would have problems with their chassis/body bottoming out and would lose control. Often crashes resulted from this as the driver wasn't understanding that they were preventing the suspension from working.
A good solution was to mount the chassis and body high enough that the movement of the suspension wouldn't bottom the car out OR cause the body to rub anywhere (ground or tires). The problem with this was that there would be a large gap between the body and the ground.
The solution was to use some kind of tape to seal off the body to the ground. The tape would allow some flex if the suspension would have a dramatic movement without upsetting the chassis too much.
01-20-2017, 02:46 PM
#82
No I'm not gonna lead the air away behind the front tires. The space is really tight there and I don't think this area is compareable to a 1:1 TC regarding the bodywork. So this part is for bending up for the air channel.
That is how things are now. The rear diffuser is finished. The two air channels on both sides still need the outside skirts and the front is yet to begin with. Also still missing are the attachments to the hubs. For the front I plan to cut the bumper sides to make space for another two air channels. At least another full day of work (fun
) ahead.
That is how things are now. The rear diffuser is finished. The two air channels on both sides still need the outside skirts and the front is yet to begin with. Also still missing are the attachments to the hubs. For the front I plan to cut the bumper sides to make space for another two air channels. At least another full day of work (fun
) ahead.
01-23-2017, 09:59 AM
#83
Sorry to keep you guys waiting.
Still so much to do... I had to do so much small work and fitting for the right sitting to do. Also waiting for the glue to dry.
Right now the upside of the skirts are glued and need to dry. Tomorrow I could add a line of glue to the downside. I gave up on the front air channels, as I am afraid that it would trouble the airflow to much for the middle and rear part of the tray.
Then one of my Dodge Darts will be sacrificed to be part of the whole aero system... So still two days until everything will be finished. And then I wish I had build it better
Still so much to do... I had to do so much small work and fitting for the right sitting to do. Also waiting for the glue to dry.
Right now the upside of the skirts are glued and need to dry. Tomorrow I could add a line of glue to the downside. I gave up on the front air channels, as I am afraid that it would trouble the airflow to much for the middle and rear part of the tray.
Then one of my Dodge Darts will be sacrificed to be part of the whole aero system... So still two days until everything will be finished. And then I wish I had build it better
01-24-2017, 07:15 AM
#84
Did I say two days... I meant one day 
Suddenly I finished everything. Let the pictures talk:
That is how it looks. Right now I am not fully satisfied. I am happy that the double floor principle adapts into the Xray T4'15 chassis and happy about the look.
For the full vacuum effect the lexanfloor just isn't stiff enough. At some speed the air will pull the wings and diffuser to the ground which limits the overall pull down. Additionally the whole assembly is heavy. The car is 38gr. above minimum weight. To make it perfect a carbon frame should support a 0.3 or 0.5 thin lexansheet. The attachment hubs should be aluminium parts, small and strong. The rear diffuser needs support to prevent it from bending down rearwards from the vacuum.
Suddenly I finished everything. Let the pictures talk:
That is how it looks. Right now I am not fully satisfied. I am happy that the double floor principle adapts into the Xray T4'15 chassis and happy about the look.
For the full vacuum effect the lexanfloor just isn't stiff enough. At some speed the air will pull the wings and diffuser to the ground which limits the overall pull down. Additionally the whole assembly is heavy. The car is 38gr. above minimum weight. To make it perfect a carbon frame should support a 0.3 or 0.5 thin lexansheet. The attachment hubs should be aluminium parts, small and strong. The rear diffuser needs support to prevent it from bending down rearwards from the vacuum.
01-24-2017, 08:13 AM
#87
Very impressive, great job! I think your suggested further improvements are right on the money.
01-24-2017, 09:36 AM
#89
WTCC, you have always been one of my heros, your work is just outstanding! Just a comment on your outside tunnels. Looks like the rear tires kind of block the outlet and then when you enclose the rear wheel openings, you are restricting the flow even more. I'm betting you can get more flow through your tunnels if your remove the wheel pants.
01-24-2017, 09:57 AM
#90
Thanks a lot!
I am glad you mention it. I am still unsure if it would be better to open the wheel arches or to open the rear above the diffuser more... With the last argument I could maybe profit from the low pressure area at the trunk.
More opinions on this?
I am glad you mention it. I am still unsure if it would be better to open the wheel arches or to open the rear above the diffuser more... With the last argument I could maybe profit from the low pressure area at the trunk.
More opinions on this?