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Old 05-30-2007, 09:33 AM   #16
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Originally Posted by ziggy12345
Hi Nick

How did the motor testing go? I hope everything is OK. I am still stuck in Lagos and wont be home for another week. All the stuff has been delivered to the house so i can start putting the thing together when I get back.

I have the 3 engines and all the belts and pulleys for the high ratio rear drive. I'll send you some pics an how its looking when I get it half together.

I am still looking for some hard 1/8th tyres but no luck yet.

Cheers
I got the motor last night. I have to make a couple modifications to the clamps. There are some tie wraps that are in the way of the clamps doing their job. (pics are here at http://www.fastrc.blogspot.com ) Also, the wires that come out of the motor are very stiff and they need to bend around the edge of the motor. Hopefully tonight I will be able to actually to a bench test at 8s. I wont use the full 12s.
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Old 05-30-2007, 10:14 AM   #17
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WOW thats a beast! Whats the HP of that thing?

You realise we are on the verge of answering the age old question......

Whats faster IC or Electric!

Do you have the details of the track you will be running at? Whats the length of the run up and whats the measured distance your timed across or is it spot speed with a radar gun?

I intend to run a normal 1/4 mile drag strip and will check the speed at the end of the run.

Let me know how the test goes

Cheers
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Old 05-30-2007, 10:25 AM   #18
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Quote:
Originally Posted by b4maz
I got the motor last night. I have to make a couple modifications to the clamps. There are some tie wraps that are in the way of the clamps doing their job. (pics are here at http://www.fastrc.blogspot.com ) Also, the wires that come out of the motor are very stiff and they need to bend around the edge of the motor. Hopefully tonight I will be able to actually to a bench test at 8s. I wont use the full 12s.
With that motor should have plenty of torque. I think you can easily break into the 200mph mark...
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Old 05-30-2007, 10:47 AM   #19
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With that big motor you should be able to gear it 1to1 final drive. The motor should have plenty of torque. I think you can easily break into the 200mph mark...
OPPS!!! I looked over at your set up and I see it's direct with no gears I over looked that the first time, Man that car is going to be something to talk about for years to come once you do a speedrun... That car is INSANE!!! Best of Luck to you.
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Old 05-31-2007, 08:09 AM   #20
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Quote:
Originally Posted by ziggy12345
WOW thats a beast! Whats the HP of that thing?

You realise we are on the verge of answering the age old question......

Whats faster IC or Electric!

Do you have the details of the track you will be running at? Whats the length of the run up and whats the measured distance your timed across or is it spot speed with a radar gun?

I intend to run a normal 1/4 mile drag strip and will check the speed at the end of the run.

Let me know how the test goes

Cheers
The official contest will be on a 1/4 mile drag track (1320 ft). I heard that for this years contest they will use a 1/10 scale drag timing system. That system uses light sensors spread 10' apart and it times how long it takes to cross those beams. I assume they will also have a radar gun.

I am still getting the electronics worked out. last night I machined some material off one of the clamps so it can clear the tie-wraps on the motor can. Hopefully I can get the ESC installed and batteries wired up so I can do some bench testing.
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Old 05-31-2007, 08:48 AM   #21
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I see Modman has had his car up to over 100 already! He had some wheel spin issues trying to lay down all the power.
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Old 05-31-2007, 08:54 AM   #22
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looking at your areo deformation on the car nose

just from experience, I would suggest a flat nose with less slope. check out some of the bodies used for velodrome racing. I use a Mcallister dodge charger high speed. it has a flat nose, and very low roof line.

I would also suggest a rear wing. the flat back cut of will create lift.

also you may want to do sum underbody areo to create a vacume. although there probably is not enough room to make this practical.

there is a thread somewhere here in the rctech forum on rc areo. and there is a lab that can even run windtunnel test. however for a small fee. actually a big fee. lol.

good luck, I wanted to be at the hi speed run but I will be running at the Encino Velodrome that weekend. Maybe this time I won't break my car!!

Wn
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Old 05-31-2007, 08:53 PM   #23
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Well, first bench test was just done. I hooked up my 2 Thunder Power 4s packs in series to get 8s (around 30v) which gives me about 15K rpm. I free wheeled to check tire growth and how the tires would hold up. As you can see... not too good. I have a video of the failure here: http://fastrc.blogspot.com/2007/05/first-test.html
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Old 05-31-2007, 10:13 PM   #24
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about 108 mph at 15,000 RPM. Here is another type of tire that may go higher. Also they may go higher with the road pushing it in every revolution and some downforce. I have some of their foams on the way to test on my pan.
http://rc4less.safeshopper.com/11/cat11.htm?3218

I agree with wayne that your body looks like it will create lift. Even more after the distortion at speed. You do have lots more windtunnel time than we do, though.
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Old 05-31-2007, 10:54 PM   #25
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wayne,

I wondered what happened to you at the last Velo race...you disappeared...

What did you break?
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Old 05-31-2007, 11:18 PM   #26
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nice video. i've never seen a foam tire expand like that

that direct drive is probably a good idea since it should give you a somewhat "soft" launch off the line.
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Old 05-31-2007, 11:58 PM   #27
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After seeing the vid of those Foam tires you may want to go with Rubber, they will flex alot more. This is just an idea but in almost situation the batts on a 1/12th scale are as far back as they can go to help with rear taction, I don't know if you have tried or can with your design, but you migh want to look at sliding that stickpack on top to the far end of the lipo's. Or since from the pics it looks like there is a shock in the way, make a saddle pack to go up there, I am sure you could hold it down with some good servo tape.
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Old 06-01-2007, 12:03 AM   #28
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Nevermind I see A. its a lipo as well, and B. its not being used in the speed run.
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Old 06-01-2007, 12:13 AM   #29
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Quote:
Originally Posted by b4maz


Well, first bench test was just done. I hooked up my 2 Thunder Power 4s packs in series to get 8s (around 30v) which gives me about 15K rpm. I free wheeled to check tire growth and how the tires would hold up. As you can see... not too good. I have a video of the failure here: http://fastrc.blogspot.com/2007/05/first-test.html
These are the soft drag wheels and tyres you told me about right? I thought they might be a bit soft.

Parradoxically the tyres will go faster when they are on the ground. On the bench they are subjected to the same force all the way around and and they stretch untill failure. On the road the weight of the car depresses the tyre at the bottom and this keeps it together for higher revs.

I have some 1/8th tyres coming that are 45 shore. They are good for about 140mph. I am looking at covering them with a steel belted rubber skin that will keep them together for over 200mph.

How are you measureing the RPM? Are you sure it was only 15k?

Cheers
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Old 06-01-2007, 12:19 AM   #30
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With 3 1/4" tyres and 15k RPM = 145mph!!

Cheers
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