Speed run car: OFNA Ultra GTP - Neu 2215
 

I have been working on a speed run car for almost one year now. I called it the "X2". My original design was based on a RC10L3 with a Neu 2215/3Y, Castle Creations HV-110 and Thunder Power batteries. I have done about a year of testing and the 2wd drive platform with this amount of power has proven tricky. I kept blowing tires.

http://lh4.google.com/nick.maslowski...G1778.JPG.jpg"
The "X2"

I decided to get another car to put this power system into. I decided to use the OFNA Ultra GTP. I am calling it the "X3"

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"X3"

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"X3"

I have a blog where I keep all of my progress updated

I am currently working on laying out the electronics (thats why the car looks so messy) and making the motor mount for the Neu 2215/3Y motor. I do practice runs on 8s, but the final high speed design will run on 12s. I post all my detailed info on my blog but I will also keep this thread up to date on my progress.

SWEET!

I love the direct to tire power on the X2, that is killer. Pity the tires would not hold up!

BTW, welcome to the forum!

I was wondering when you would join the real deal power hungry field :lol:. I follow your thread in radiocontrolzone. You will be glad you joined here as some of the members are crazy about power :lol:. I hope to see your new car go at least 120mph. I might have a solution to all of our tires problem, but it'll have to wait until I go to Brasil and talk to my uncle. Good thing you are not using a Schulze controller. Mr. Schulze would have a heart attack if he saw all those wires :lol:. Welcome to RCM.

I hope I can break 120mph! I'll need a lot of luck.

Here are my calculations:

8s-108 mph

http://nick.maslowski.googlepages.com/x3_8s.jpeg

12s-160 mph

http://nick.maslowski.googlepages.com/x3_12s.jpeg

160 is not very realistic. You can see how many watts I am pulling. Too much for the Neu 2215. 120-140 mph is more reasonable.

That's realistic and with the Neu 2215 you could do it. Change controllers though. I think the Spin 200 or Spin 300 will be able to do the job. Go with 14S lipos.

Hey B4Maz, where do u run your speedruns at?
I got dizzy looking at those spreadsheets, but I did notice that you are running a qaurtermile, correct?

Yes, we test at the Houston Motorsport 1/8 mile strip. But we don't test on the drag racing surface. We test on the shutdown area. The drag racing surface is like ice if it isnt prepped with VHT. The shutdown area is fairly smooth and we get higher, more consistent traction.

Cool man. If you ever want to see RC dragracing, come to our TNT's and see what us goofballs do. Coming Sunday we will be at Track 21.

No joke, I hope I can make it out there this weekend too.

Dam dude! 8HP in that thing? You're crazier than I am! :lol:

Good luck with your project. Can't wait to see how you do!

Some updates
 

I got all the electronics installed and now I am ready to test this Saturday. Here is how the X3 looks now
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I saw on another post you modified your radio to extend the range. What mods did you do and where did you get them. I need to extend my DX 2.0 range for these speed runs.

BTW awesome setup. I am running smaller Neu motors then that and they are plenty for pushing my BIG MT to 80mph and this truck is no where near aerodynamic like your setup and its alot heavier. So you should easily hit some BIG speeds.

Looking good. Will the aliminum pinion handle the power?

Thanks for the comments
I added a 500mW amplifier and it seems to be working very well. I go into all the gory details in this post:

http://fastrc.blogspot.com/2007/11/m...ansmitter.html

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The gears are stainless steel. I am worried about wear too. I have run the car in front of my house for a few minutes and I can already see the wear patterns. I have some delrin gears coming with a stainless steel center. That should help with wear.

Body pics
 

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see snelleman, my yosa isn't overpowered, although i didn't see any graphs showing 8hp.

i'm excited that somebody here in h town is doing all this. i want to get my 1/8th out to that track for some speed action. i'm geared at 109 and was metered at around 6hp peak bursts.

Hey Tash, you and Blunted(Mr. 49V dragracer) are the highvoltage junkies at Hamdrl.

Bmaz, I'll see if I can make it Saturday and make a run with the pancar. Won't be as fast as yours ofcourse, but Tash's might be right behind yours(if his gears hold up).

8 hp from this motor, no way, lol. Its rated at 5000 watts according to Neu, so thats about 6.7 hp.

What are you running tashpop?

sweet. more the merrier. I'm going to worry about my gears too. The problem I am having is that the motor shaft is mild steel. It isn't hardened and the set screw has a problem staying tight.

I dont think I can break 90mph with the motor I have. And I need better batteries to break 70.

you can harden the shaft yourself by heating the shaft untill it glows red and quench it in 30wt motor oil it will now be hard but brittle, you can now reheat the metal to about 500 degs (tempering), there is now a battle between the metal being hard and brittle the more you have of one the more you will have of the other...I dont know how deep this penetrates the metal but at least the surface would be hardened

that would depend on the grade of steel that's used for the motorshaft. And the motorshaft would likely get off the magnet if you heat it that far.

you can start with mild steel, all you are doing is adding carbon to the steel, I didnt see the part of it being the motor shaft, in that case I probubly wouldnt risk it, since the process of hardening could cause warping if you cool it too qiuckly, the metal gets harder the quicker you cool it

my car is simular to yours, just a different maker. i'm still using 4wd, and a 2speed center setup. 12s a123, turnergy 100amp hv esc, mega 22/45/2 motor. snelleman metered it with his eagletree but there was a glitch and it didn't capture voltage. based on amps (120) and capacity used (i forget, but it was very little) we guessed around 4500 watts. i'm working through gear issures and my day ended because i need to drill and tap a new set screw on the motor pinion. i can't wait to get another chance to get hard numbers, and meet you guys up for a top speed run at the 1/8th mile track.

Sweet. I saw the video of your DM-1 at TNT, that thing is sick. Its fast for 132' it would be cool to see what it does in 800'! We are testing today at Houston Motorsport Park at 10am. Sunny, Greg, Josh, Ben and I are going to be there. I think the rain is going to hold out today so we can get some good testing done

I tried to do some high speed tests today but the spur gear kept coming loose and I wasn't sure why. I later found out the setscrew was stripped and I replaced it. By that time I didn't have time for high speed stuff, but I did some quick runs in front of my house and I could only get about 1/4 throttle in the limited space I had:

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Heres the data from that run (8s geared 64 pinion, 36 spur):

http://nick.maslowski.googlepages.com/5-3-08_x3.jpg

Very nice. Only 50A+ spikes and it was moving fast, that's awesome and seems like you can still gear up some.

brave doing speed runs on a public street. me likey

Yea, I was quite happy that I was able to hit about 50mph with only 50 amps.

I went out later after I did that video and I did a much harder pull at about 50 % throttle for the last pass. This is what I got:

http://nick.maslowski.googlepages.com/5-3-08_x3_2.jpg

Still good. Man you can gear that thing to the moon if you only pulling those amps.

I did some testing this weekend and got the OFNA up to 73 mph.

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But after I got 73mph, I started to push it further and the car had a blow over. On this run, I could definitely tell the car was faster than 73, thats when the nose of the car picked up and it took off:

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As far as I can tell the damage is superficial and none of the vital components were affected. The body and right front tire seemed to absorb most of the impact. I have much more info at my blog. I have data from my Eagle Tree for those 2 runs.

This is what the car looked like before the takeoff.

wow, blowover with that heavy of a vehicle!!!! Time to vent your body man.

Vent?

yea drill/cut some holes in that body to release air going underneath the body. Works on my camaro body. You need to follow what the dragracers are doing and kinda corporate some of the ideas into your speed demon.

I had blowovers at around 57mph before and the last time I ran the camaro with a few holes in it, I had no blowover at 67mph. This Saturday I will see what I can get out of the body with an extra cell.

Yea, I already cut the back of the body:

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I could put 1,000 holes in the body or not even run a body and it would still blow over. Its the positive angle of attack of the chassis that caused my blow over. The chassis plate was acting like a wing. The rear of the car was scraping the ground and the front of the chassis was much higher than the back. I wasn't expecting to get these speeds so I didn't change the suspension much from stock. I need to put stiffer springs in back and play with the ride height to keep the chassis level or at a negative angle of attack to the oncoming air.

I would ditch the inline eagletree, it will be faster without. It adds resistance, guaranteed. i wouldn't use an inline measurement.

I just want to use it to see if my calculations for my amp draw were correct and I'm not pushing the motor/batteries/ESC too far. I don't plan on using it when I want to do a total "balls out" run.

that was awesome !!!! 10 10 10 !!!

Testing today. Hit 79mph
 

Video, pics and details here

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