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Old 01-19-2013, 03:00 PM
  #16  
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corrected
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Old 01-19-2013, 04:15 PM
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Originally Posted by Robert_K
By the way, you've posted the Speed 8 (non HD) body pic,
The HD version looks like this:


It has to flaps in the rear, different cockpit and turbulent air bobbles at the front wheel arches.

They do have a different feel in driving. But not much.

Regards Robert
The odd "air bobbles" at the front on the HD version can be cut out as a vent to vent some of the air out from under the front which will give it a bit more front down force. But in ROAR races the only holes that are allowed to be cut out are for the body posts and antenna (in electric racing). So that negates a little bit of the effectiveness of the body. The rear wing on the HD version is a bit different from the regular besides just the vanes that adds a bit more rear down force.
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Old 01-20-2013, 08:46 AM
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Originally Posted by InspGadgt
The odd "air bobbles" at the front on the HD version can be cut out as a vent to vent some of the air out from under the front which will give it a bit more front down force. But in ROAR races the only holes that are allowed to be cut out are for the body posts and antenna (in electric racing). So that negates a little bit of the effectiveness of the body. The rear wing on the HD version is a bit different from the regular besides just the vanes that adds a bit more rear down force.
I never tried to cut them, that must be hard

These bobbles on the front wheels do more. But my technical English isn't that well developed to explain correctly. In short terms it creates a turbulent air above the front wheels. Turbulent air gives a higher pressure then just flowing air.

Regards Robert
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Old 01-20-2013, 10:59 AM
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Originally Posted by Robert_K
I never tried to cut them, that must be hard

These bobbles on the front wheels do more. But my technical English isn't that well developed to explain correctly. In short terms it creates a turbulent air above the front wheels. Turbulent air gives a higher pressure then just flowing air.

Regards Robert
so this is supposed to improve the steering then? good to know I never understood why they used these vents on real le mans series cars

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Old 01-20-2013, 11:05 AM
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Originally Posted by Robert_K
I never tried to cut them, that must be hard

These bobbles on the front wheels do more. But my technical English isn't that well developed to explain correctly. In short terms it creates a turbulent air above the front wheels. Turbulent air gives a higher pressure then just flowing air.

Regards Robert
Ah...your talking about the molded vents above the front tires. I guess those could provide a little bit more down force but it would be minimal. Personally I'd rather they leave that area smooth and give us stickers like HPI used to do. The area I am talking about is the deep indentations right next to the cockpit that are not on the normal Speed 8. Those if cut out can be ducts to exit air out from under the front of the body.
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Old 01-21-2013, 02:20 AM
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Originally Posted by Pulse_
so this is supposed to improve the steering then? good to know I never understood why they used these vents on real le mans series cars
Well No. For the LeMans Cars the do work as venting holes, but also give downforce.
But when you look at the BA003 from Black Art, it also has these 'ribbles' at the backwheels. The real LeMans car didn't had that. Also the front ribbles are really long, longer then the original. That made me wonder and I started asking at the University here with some Airo-student. They told me all this.

Originally Posted by InspGadgt
Ah...your talking about the molded vents above the front tires. I guess those could provide a little bit more down force but it would be minimal. Personally I'd rather they leave that area smooth and give us stickers like HPI used to do. The area I am talking about is the deep indentations right next to the cockpit that are not on the normal Speed 8. Those if cut out can be ducts to exit air out from under the front of the body.
Aahh, you're right. These cut's are also different from the Speed 8 to the Speed 8HD. I forgot about them.

Regards robert
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Old 01-26-2013, 10:12 AM
  #22  
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ok thanks for the explanation

here are some pics of our t-bar (sp12x)





I let extra room around the ESC to add weights. This is a first try of layout but let me know if you have any suggestion for an other configuration
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Old 01-26-2013, 11:49 AM
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that looks really good.

i might leave more wire for the motor though. i usually run a loop of wire under the shock and around and back to the motor so there is no change the wire will bind up the backside.

and man, thats a huge spur for a 10.5! you guys run blinky or boost?
I managed to use the same 78t spur in 17.5 and 10.5

my friend has an old 12L4 he wants to get together for his brother to try out. i might forward your pictures to him for ideas on how to put it together.
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Old 01-26-2013, 11:56 AM
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Originally Posted by valk
that looks really good.

i might leave more wire for the motor though. i usually run a loop of wire under the shock and around and back to the motor so there is no change the wire will bind up the backside.
I was thinking the same thing. When I drove a T-bar L4 I let me wires run over the T-bar, so that they won't bind the motor pod in any way. The wires enter the motor tabs via the other way.
The way they are now, there is a possibility they bind due to the body or the short 'stiff' wires.

Also, it looks like spaghetti around the receiver, if you don't like to cut the wires or shorten them, maybe it works to 'double' fold the wires, and put some shrink-wrap around the folded wire.

Like so:


Also, The body tents to cut the receiver wire when you wrap it around a pole like that. I always shrink-wrap my antenna, so the body doesn't cut the receiver wire like so:


Regards Robert

Last edited by Robert_K; 01-26-2013 at 12:11 PM.
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Old 01-26-2013, 12:11 PM
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not sure whats going on with my iphone, doesnt take pictures the way it used to =(

this is how my 5.1 is wired right now. wires wont bind up on the pod.
for the 12l4 iw as more thinking of the single saddle pack he is using. they run offroad so im sure they could get their hands on a saddle pack. but i dont know anything about that car.

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Old 01-26-2013, 12:34 PM
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I see what you mean for the wires but there shouldn't be any resistance. I looked for free movement before I did the solderings, that's the reason why I soldered the cables verticaly on the speedo rather than horizontaly. This way the wires produce less resistance than if they where in the same plan as the ones connected to the motor. But still if it's too short I can re-do the wiring, that's no problem. This really is a first test.

Still I have a problem with standard sized tires on the SP12X considering it rubs against the spur (I will go for a smaller one but a driver told me that it's better to have a bigger spur and pinion than a smaller spur and pinion for the same rollout).. The old tires weren't as large so if anyone has an idea how I could solve this let me know

thanks or your help! and very good tip for the antenna!

I will mount the electronics on my 12R5.2 tomorrow so don't hesitate if you have some suggestions.

This is what I'll mount:
- HW 1S ESC
- Futaba S9650 servo + kimbrough servo saver
- GM 10.5 motor
- Orion 1S 6400MAH lipo (no saddle)
- RX451 receiver
- 16AWG wires for the motor, 14AWG for the lipo

What size of spur would you use with a 10.5 in blinky mode? I was looking for a 55 to 60mm roll-out for the local indoor carpet track (small and technical) that's why I bought a 40 and 41t with the standard 96t associated spur.

I will do many pics and vids of the progression of the car, its handling etc.. That's what I miss in most threads. Everything will always stay under construction and it's my pleasure to follow your tips and suggestions. Anything could be modified.

Last edited by Pulse_; 01-26-2013 at 12:49 PM.
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Old 01-26-2013, 12:58 PM
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i ran 56mm for 10.5 boost, so for blinky id shoot for closer to 70 probably. for my 12r5, 56mm was 33ish pinion 78 spur on cut down tires. bigger the tires, bigger the spur obviously. but that spur size gave a lot of options for gearing without rebuilding the dif.

when i tried world gt with 10.5 blinky i was running mid 60's rollout and it was stone cold. just make good use of your practice time to get in the ballpark.
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Old 01-26-2013, 01:04 PM
  #28  
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Originally Posted by valk
i ran 56mm for 10.5 boost, so for blinky id shoot for closer to 70 probably. for my 12r5, 56mm was 33ish pinion 78 spur on cut down tires. bigger the tires, bigger the spur obviously. but that spur size gave a lot of options for gearing without rebuilding the dif.

when i tried world gt with 10.5 blinky i was running mid 60's rollout and it was stone cold. just make good use of your practice time to get in the ballpark.
Good point, that's what I'm looking for too. Just play on the pinion even considering the differences of track and the tire wear.
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Old 01-26-2013, 01:37 PM
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So have you run the car and how does it go?
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Old 01-26-2013, 02:19 PM
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i dont really mess around with my 12ths cale too much. our track is always the same size.. full basketball court. it may change up in the layout but there is always a sweeper in the same place and i generally leave the car alone aside from toe/camber settings.
also dont really bother changing gears until my tires lose a mm at minimum of diameter.
i wish though that pancars were easier to adjust ride height on. you have to stay on top of it if you tune your car closer to the limit. i tend to leave 3.5mm ride height so i dont have to mess with it for a long while.
this is one thing i like about slower 12th scale. its kind of set and forget. just drive the car and maybe gear it up once in a while between heats.
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