Finally Setup!

[gbone]

Just thought I'd show you guys a pic of my setup as my motor and speed control came in today! Haven't been this excited since my first go kart!

I've only had it running around on the thick carpet in the house and it still takes off like a 1/18 scale car. 1/2 throttle punches just spin and ballon the tires. It is truly unreal and overkill power. After setting up the controller properly it didn't even get warm.

Thanks for looking!

Lehner 1920/8
12 Sanyo NiMh 3300 cells
Shulze 18.97FW
26/83 gears

Futaba Magnum Jr. AM (soon to be replaced by JR XS3)
Foam tires coming soon

[OptimaMan]

Where's the pic! Yeah, post a response ASAP... and I hope you don't bust something with that awesome power!

[gbone]

Sorry about that, picture was too big at first.

[OptimaMan]

Woah baby.... You're gonna FLY!!! I can't help but laugh and grin cuz I know you're going to flip out and your eyes are going to pop out tomorrow when you run it! Hahahaha I hope you have it geared so it won't go TOO fast! Even with a FDR of like 10:1, you'll probably go 60 mph easy!!!! Too bad I can't be there to see that thing fly. Make sure your aerodynamics are good. Make sure you use some traction compound on those rubber tires too. AND, don't blow out the tires by doing donuts! If you do donuts, the inner tires spin over 100 mph and they blow out reallll easy.

[OptimaMan]

Oh, just read your pinion/spur ratio.... that's too fast... too hot... What's the kV? What's the FDR, final rollout? Tire diameter? I'll give you an estimate on speed based on RPM and gear ratio and diameter if you want.

[OptimaMan]

Just checked the Kv. A FDR of 6:1 with 3.5 inch diameter tires will give you over 93 mph no load speed. I'm willing to bet you'll get it over 80!!! I'd gear it shorter!!! Besides, you don't wanna blow the controller or overheat it. I noticed you don't have the 18.97 with heatsink so you need to be a bit more careful. Get it started with a smaller pinion... since you don't seem to want to go with less cells...

[gbone]

Actually, I blew OFF the tires several times just messing around in the house because I hadn't glued them yet. I get more of kick out this than my friggin Savage 25. It's so satifying to watch tires that are seemingly so well secured to the wheel just balloon up in seconds and just fly off past your head AT 1/2 throttle. WOW.

I'll let you guys know more once its warm enough to run outside in this god forsaken land (cold southern ontario) or if I can find an indoor track around here (not likely).

Cheers,
G

[gbone]

Thanks for the advice. Right now it's hard to get 4mm pinions around here. It's more cost effective to get a bigger spur...maybe a 100 and sumthin or thereabouts. What do you think?

I did a few full throttle runs with the wheels off the ground (without the tires, before I glued them) and it was scary (well not really ofcourse, just awesome).

[OptimaMan]

A larger spur will slow it down a bit... but you know what? The heck with it. Just be gentle with the throttle. :) That's what I try to do.

[gbone]

Drove it quite a bit today. Tires are toest. Power is horrificly ridiculous. Actually got tired of driving it after 20 mins of high speed attempts and the batteries were still providing endless power. The speed control never got more than mildly warm which I was very happy about (lowest current setting). I've also decided that it is pointless to have this many cells with these crappy tires (which are also shot to ***** now). So I'll go down to 8 cells and try again tomorrow. Also, at no time did the motor even get more than slightly slightly warm.

One thing's for sure, this is a ridiculous amount of power. On two or three passes up a VERY long and wide straight I am positive I was doing well over 50mph around 70% throttle ...and then I would try to give it a little more and it would just simply loose traction (as if it had hit ice) and spin out violently. No matter how hard I tried easing on the throttle I could never get it passed 70-75%.

After thoroughly cleaning the car with an unused paint brush it looks almost like it was never run outside. The front drive belt also twisted itself over twice. I just can't stand all the frickin dust outside making a mess of my car. I just wish there was a big enough indoor track for this...I'll go searching for one this weekend.

G

[OptimaMan]

Aha! I thought you'd have too much power. :) My XXX-S only get's to 65 or so before it becomes absolutely ridiculous to control. It darts all over the place and traction is the issue now - not power! I've had better luck with rubber tires than foams for some odd reason though.

Those RS4 tires are no good though. I had those on my Optima Mid and they had no traction whatsoever.

You're going to seriously have to put a huge wing in the back, cut out the whole rear end (for ground effects) and not cut out the wheel wells (for even more suction). Then, you have to make sure you have enough suspension travel to handle the bumps of a street but yet firm enough so it's controllable. Too many problems with going that fast.

After it's all said and done, I think you'll get to the point I'm at... "now what?" You've seen more than enough power. You'll eventually get it going so fast you'll be out of radio range in seconds and then you'll ask, what next? Then you just go back out racing if they'll let you race against those brushed motors or against the nitros. Nothing else to do!

[glassdoctor]

I get a kick out of this stuff. I need to bookmark this thread to have when the "I did 100mph" posts appear. It's hilarious to hear people say they swear they did 80 or 90 down their neighborhood street.

I recall Cliff Lett's 100 mph car required a special body with bracing to keep from collapsing at these speeds. It's about handling and aerodynamics to do 100. I have an old Associated video of an insane speed run where he did 96mph. Several others took their shot too and most had trouble getting up to speed without spinning out or blowing over... and a couple cars had mechanical failures when they got up to speed on the high bank oval.

Anyway, it's cool to see how fast you can go... and it seems that 60-70 range is about it without special circumstances... the right aerodynamics and the right surface to run on.

Keep us updated... :D

BTW, what GPS are you guys using? Is there one that' particularly small, lightweight, or rugged? Or are they all aobut the same? I have never shopped for one, but I think I want one... :cool:

[gbone]

Did some more running today at the local indoor arena (astro turf type ground) and it grips ALOT better. The acceleration is ridiculous :D :D ...literally like a sling shot once I apply the throttle properly...and this is at the softest/lowest current setting. If I increase it the car just rakes the belts making a very ugly sound. I have awesome run time too, didn't charge it much since my 20 min run earlier today and another good 20 min of hard running :eek: . You would never think it weighed 5 pounds. I am totally not for modifying my TC bodies for the sake of aero dynamics. I'll just go with the Lambo murcelahgo body as that wedge shape looks like it's built for good down force :cool: I also need to lower the car another 2 mm or so ...but then I run the risk of shredding the batt straps. I also desperately need some more tires as mine are wearing down FAST.

I think with 14 cells, highest current setting and proper suspension and aerodynamics, 90 mph is possible in less than 5 secs :cool:

[gbone]

Is there anyway to retard the ballooning of the stock tires? (as this is why i can't drive past 60 or so) Gotta post a video of this it's too cool.

Is it just my poor instruction manual skills or does the schulze future controller not have proportional reverse? Mine just waits 2 second then full powers in reverse. :confused:

[glassdoctor]

You might need to go with foam tires. 1/8 scale onroad cars commonly do 70mph on a big track on foamies....

[gbone]

THANKS! :o

other than the tires, is the shape of the body the only other thing that keeps them planted to the ground? They don't seem that heavy...

[havy]

Yep, you might want to consider if a GTP type body is availale for your car, if not, take a big piece of leaxant and bend it into a wing, put two other pieces of lexant on the sides from the side of the body onto the wing. This will help keep the ody tracking straight.

Good luck, the car sounds AWSOME!!!!
havy

[gbone]

Guys, do foam tires generally wear out faster considering the speeds and torque we're dealing with here? I don't want to spend more on tires if a better quality rubber tire will suffice and last much longer if you know what I mean.

Thanks for your input Havy! I found this body available. I don't really dig the styling of non sedan type bodies but more and more I'm realizing that aerodynamics are critically important for my setup. Now, if only someone had one in stock ... :(

[gbone]

I got bored and decided to try a Nuclear Power stick pack (6 Sanyo 3300s as well. I charged it till it was pretty warm and let her rip. I was astounded at how much punch it had for so little power. The car also looks alot cleaner and balanced with a stick pack. The top speed was FAST just past uncontrollable, definitely faster than my Krypton 8t/Super Rooster in my old TA04 chassis with the same battery pack. The controller got a little bit warmer this time too. I should also mention that I ran the controller this time with another layer of black heatshrink so it would match everything and look neat (heat's not really a big problem with this setup so far). I will try the same 26 tooth with a 75 spur instead of the stock 83 and see how she runs. I have the controller on the 2nd softest current setting.

[OptimaMan]

G bone, there is no current setting with the Schulze - what you're referring to is timing. The second softest timing is what is optimal for Lehner, Hacker, and other 2 pole motors. You don't want to change the timing to a harder timing - that's like advancing the timing of a brushed motor and if you advance it too much, you won't gain more power, just more heat! (I believe that's what it is) That motor is around 3919 rpm/volt. The 1920 5 turn is 6270! Now, with 6 cells, the 5 turn is approximately 60% faster with the same gearing! That's why I'm always telling people the 1920 5 turn is the most insane motor for 6 cells in a touring car.

Foam tires have more traction, and sometimes less traction. For some odd reason, in the front of my street, rubber tires have more traction at very high speeds. Foams, however, chunk easily and if you're flying and you get a little sideways, you'll have chunky tires real soon. Why don't you just put some traction compound on those rubber tires and spray some cheap soda or sugar water on the street! You'll stick real good then.

[DualBL]

next time you buy a set of rubbers, run a piece of tape along the inside of the tire.
this will help stop the tire from ballooning soo much.
-Nick

[jocktheglide]

is that a super rs4?

[DualBL]

yeah, it's a super.
note the 8 battery slots/cells
-Nick

[gbone]

Optimaman, thanks for the correction!

DualBl, my tires and other little goodies have been order from towerhobbies today. I will try that tape trick when I get the items. Thanks.

I took today (Good Friday) as an opportunity to use the freshly paved EMPTY local parking lot. I charged my 12 cells until they were quite warm and took my just cleaned body and super rs4 out to really see what it could do. I gradually got accustomed to the feel of the car and as the tires warmed up the traction got MUCH better. In my FIRST attempt I ran the car across the parking lot to near 85% throttle and the car started to sway a bit (this is when I had really bad feeling) and started the beginning of a very ugly spin out. Then it hit what must of been a little stone and went flying about 5 feet into the air onto its side and back and just skated across pavement for another 20-30 ft. (ahhh I love destroying lexan). 76.3 mph on the on board GPS. I think I could've have indeed passed 80 if everything was going right. Also, lost a battery in process (found it 5 min later). It was too easy to get that fast. Must have done it in little less than 6 secs (if traction wasn't an issue it would've been 3 I'm sure).

Now my car's all dusty as hell again and almost nobody has the friggin super sized bodies in stock. The tires are useless and really shot to hell now. Oh well I love taking it apart, cleaning everything and putting it back together again.

Lessons learned so far in using extremely high power brushless setup:

Keep lots of spare tires
Keep spare bodies
Shrink wrap your batts
Murphy's law seems like the only law once you past 60.
Using a rugged, larger than 1/10 size car pays off (belts and everything are in great shape).
Keep a video camera handy (videos coming soon)

Man, I gotta say it again, this thing is so damn fast. I love it.

G

[glassdoctor]

Awesome! Did you get any video of the wipeout? :) I mean :(

I have never seen much info or disussion of the 1920 motors. How do they compare with the Basics in power, etc?

[OptimaMan]

The 1920 is bigger and badder than the Basic series. It's not as big as a XL, but it's more efficient. Plus, you have the ability to change the motor from one configuration to another. IE: 1920 5 turn could be converted to 1920 9 turn by simply changing some solder joints. It's got 4 mm shaft so either you need to special order a 1/8 inch shaft or get 4 mm pinions.

The 1920 5 is much more powerful than a Basic 5300. I have a 1930 5 turn coming in soon - similar to an XL4200 but a bit more efficient for my emaxx!

[glassdoctor]

Wow, I wonder why the 1920 is not more common? It's a little pricier than the Hackers, (but not much...same as a "c" series) maybe that's why.

Sounds good to me. I'm getting more interested in an efficient/cool running setup rather than a battery-smoking, controller-frying one...

I could run a 1920 wired as a 9 turn in a 1/8 buggy, then put it in a 1/10, etc as a 5 turn. That is pretty cool.

I need to find the k/v ratings for these.... :)

[OptimaMan]

Yup, you got it! Two motors in one! But for some reason, I don't find myself changing those configurations!

[gbone]

A 1920/5 with 6-8 cells is what I was going to do originally but I wanted to have efficiency, reliability and LONG run times. Right now I have all 3. Very long run times (just over 20 mins on last non fatal run.) I also didn't want to have to worry about the torque in case I went to a 1/8th buggy (although I probably will need an XL sized motor the anway.)

Inspite of all this I'm going to try a 1930/5 with a 11.1 volt lipo pack when the new ones come out. My only concern is will my 18.97 be able to take that hot motor. What do you guys think?

I will have a video for you sometime next week or the next when I finish my new lambo body (whenever the hell I can get here).


G