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Old 02-15-2017, 11:32 AM   #106
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Hahaha, yeah I hope this work wasn't for nothing.

Today I finally married the chassis with the completed floor.
Therefore the chassiplate had to come off the car. Then the brace got attached and the edges sealed with Tesa to prevent the air from above getting sucked through the gaps. The next step was to build little brackets that hold the wing sections. The target was to make very light and strong brackets out of the 0.5mm Lexan. This step went very well. The good thing is that I could easily customize every bracket as the available space in each corner is different.
When this was done I could focus on the lower skirts which seal the sides of the floor. I decided to go for the once mentioned idea to use tape. So the height of the tape skirts is much more than needed. I then bend the tape inwards. This way the chassis is influenced less when it leans while cornering. The rear diffuser also got tape skirts. It is hold up with strong tape to prevent it bending downwards and to lead the created downforce into the chassis.
In conclusion the mk.3 floor could take on a lot more force before its starts bending in a way that it loses its function. Several hundred grams of downforce can be transfered into the chassis. Not sure if this will happen, but at least it is possible.
This time I left the floor without color. So it is by far not as beautiful as the mk.2 floor... I hope you still enjoy what you see:











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Old 02-15-2017, 02:14 PM   #107
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Very nice. Its the performance which counts, dont worry about the looks too much. You can always improve that. Why do the side skirts start high and flare down low immediately behind the front wheels? I havent seen that before, but from a reverse airfoil perspective it makes sense.
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Old 02-15-2017, 05:28 PM   #108
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Sorry this a bit off topic,but

Very interesting find with the software. Used it to model some off road bodies we use for our applications and used it to confirm what many had thought. So big thanks for sharing that information! Greatly appreciate it!
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Old 02-16-2017, 01:32 AM   #109
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WTCC - Your work is absolutely fantastic!
I really enjoy to follow Your work, and I hope it will pay off on the track. Very professionel.

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Old 02-17-2017, 12:03 PM   #110
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As the car is finally ready I will give it a first shakedown tomorrow.
I put the car on a scale and it shows an impressive 1301grams RTR
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Old 02-17-2017, 03:01 PM   #111
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Very nice weight for such a complex car......
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Old 02-19-2017, 07:34 AM   #112
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Very good article on motorsport.com regarding aero in F1 through the years.

https://motorsport.com/f1/news/retro...ct-era-873918/
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Old 02-20-2017, 02:54 AM   #113
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I am back from a rough rc weekend.
I participated at the Tamiya Euro Cup and after 4 (of 5) TQ runs I had to disqualify them, because I forgot to remove the tire inserts which is mandatory for the Stock class (stupido, stupido stupido!). In a rush I could get legal tires to at least drive two laps in the last qualifier. Otherwise I wouldn't have been allowed to race in the finals...

Back to topic:
I drove two packs after the Tamiya race on a strange feeling carpet. The first pack was driven with skirts. These only slightly seems to reduce the top speed, but were severely burned away after 7 minutes.
Did they work? Again hard to say... I drove against one guy with Xray T4'16, 8.5t motor and Sorex 28 (my setup: Xray T4'15, 13.5t motor, LRP G32 outdoor tires which are around 3 tenth slower than Sorex 28). He set a fastest lap of 10,5s and I could manage a 10.6s lap. That is not bad, but I would have wished for a more noticeable grip gain.
After discovering the damaged skirts, I cut them away. The second run wasn't slower, so the benefit of having them on high grip carpet is in doubt.
On the positive side: This floor is strong, light and doesn't bend. It was easy and pretend able to drive.

I will remove it again and store away for the outdoor test. The higher speeds and faster corners in combination with lower grip should give a more clear feedback.

Now I want to build a stronger mk.2 floor and try it again.
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Old 02-20-2017, 04:33 AM   #114
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Great work on the undertray!
I have a tip for improvement though that might make a big difference:

Your rear diffusor angle is WAY to steep (and the edge is too sharp on the mk.2 as well), there is no way the air will keep attached to that. Try a smoother transition with a maximum angle of 7-10 at the top!!
Side tunnels look good, but again I would try and go for less curve

With aerodynamics, less is often more. A de-/increase in 1 angle can make the difference between insane downforce + no drag or flow seperation (no downforce and lots of drag)

Some people think (often seen in hillclimb races) that if you crank the angle on aero parts, dowforce will keep increasing but that is not the case. It all comes down to reducing drag in order to keep the flow attached because attached flow means aero parts work more efficiently and you can create lots of downforce with little angle
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Old 06-01-2017, 04:17 PM   #115
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@wtcc: First, congratulations on your work! Nicely thought and executed. Now sorry to be the bearer of bad news I've been running your aero configuration on the program and there's some flaws, not your fault though.
Main issue is that the venturis aren't well fed nor the air extracted correctly. The front wheels cover the entrance and the rear wheels block the exit. I'm sorry to disappoint you but at least I can offer you a solution. Transform the current bottom into this, as is used in most GT cars, racers or not. Changes would be the deleting of the venturis, flattening the bottom but using dams to direct flow away from the tires into the centre of the bottom, then use rake and a diffuser to suck air from beneath.

Also I have perfected my ideas about an TC bodyshell that could theoretically have less drag, more downforce, lower CG and weight while still being legal, the overall difference would be around 10% in efficiency (very conservative) and 2.5% in lap times. By regulations the windshield is oddly shaped but I think I can play a bit with the way it's measured and lose almost 5mm each side (big gain), there's some loopholes regarding the rear end and I think I can make big gains there. If a manufacturer is interested PM me for further assistance.
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Old 06-02-2017, 02:06 AM   #116
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Quote:
Originally Posted by 30Tooth View Post
...

Also I have perfected my ideas about an TC bodyshell that could theoretically have less drag, more downforce, lower CG and weight while still being legal, the overall difference would be around 10%(very conservative) in lap times. By regulations the windshield is oddly shaped but I think I can play a bit with the way it's measured and lose almost 5mm each side (big gain), there's some loopholes regarding the rear end and I think I can make big gains there. If a manufacturer is interested PM me for further assistance.
Conservatively estimated 10% lower laptimes. Wow. Nice claim. Please make one and prove it. I heard too many claims that were never proven. I'd like you to succeed, though. Please make a mould, have it pulled in Lexan somewhere and take it on-track.

Good luck,

Hugo
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Old 06-02-2017, 02:46 AM   #117
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Quote:
Originally Posted by HugoW View Post
Conservatively estimated 10% lower laptimes. Wow. Nice claim. Please make one and prove it. I heard too many claims that were never proven. I'd like you to succeed, though. Please make a mould, have it pulled in Lexan somewhere and take it on-track.

Good luck,

Hugo
You're right! I mixed up two things I was calculating as I typed, efficiency and predicted improvement on lap times.

About the mould, I made a mould of a 235mm pro10 out of plaster and it is a PITA to handle, a core made of styrofoam (or any type of foam) is a necessity. Was making a vacuum forming machine but never got it working, will make the drawings and send them to a carpenter to make it. Already have the lexan sheets so it isn't far away.

Thanks, and if anyone want to test one send me a PM.
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Old 06-02-2017, 03:17 AM   #118
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Here's a clip of my vacuum machine, simple diy device made off table grill elements, some wood, aluminium tape and foil and a vacuumcleaner. The latter barely makes the pull, I need a stronger one.
R/C Tech Forums - View Single Post - Custom Lexan and Vacuum Forming

I make my moulds from balsa wood, contra-cast them in silicone and cast a pull-mould in plaster:
R/C Tech Forums - View Single Post - Custom Lexan and Vacuum Forming

Lots of work for a single body...

Hugo

Last edited by HugoW; 06-02-2017 at 12:52 PM.
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Old 06-02-2017, 04:46 AM   #119
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My machine was going to be like yours. Oversized so I can make 1/8th Lola bodies.

Too much work indeed, that's why I am trying to use styrofoam to speed up the process of making the definite mould. I used around 4kg of plaster in my pro10 body...
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Old 06-02-2017, 07:52 AM   #120
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This... is so getting banned.

And that's beautiful work. Don't stop :-)
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