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View Full Version : my losi double xt cr is having performance problems please help



map10684
07-17-2000, 08:57 PM
i built this truck myself and i haven't had one satisfying run since i got it
motor:speed gems 2 16 turn triple
speed control:novak 410-m1c
batteries:dyna sport 1500
charger: dynamite mega 1
thats about all the info i can think of. my main problem is lack of speed
please help

mshipley
07-17-2000, 09:25 PM
ok now I can help you here, you said lack of speed now what are you comparing this too? Mine usually goes oh I don't want to overestimate, 15-25 mph depending on the pack, so, is that near yours or is yours slower than that?

I also have a 13 turn reedy, but I run a 1400 scr pack piece of crap (i need to upgrade)

Another question, did you tighten the diff up to much? Also, if you hold the truck up by the chassis, truck pointing upwards, spin the front left tire, how long does it spin?? If it only spins for a short time you've cranked your wheel nuts down to tight and are impeding the bearing as it turns and could damage your wheel bearings, try this.. and see how it is,

also, are you running a hydra-drive or a slipper? you might not have the correct gear mesh, and you might not have the correct pinion gear for your truck/ motor combo. My truck came with a 88t green spur gear, I imagine yours has the same, now check your pinion gear, count the teeth, look on the gear whatever just find out how many teeth are on there, and post it so we can compare your gearing, ok that should get you started, let me know by posting back again tonight,ok later, mike

map10684
07-17-2000, 10:18 PM
my neighbor has an old rc10t with a midnight2 stock and it kills mine it probably goes 30-35 (no joke) he has the same type of batts and charger that i do and he does no maintenance what-so-ever and i just cant figure out how or why his is still running so much better than mine.i have every size pinion gear imaginable and i am (like you said) running the bright green spur gear you were talking about my front wheels spin fine i learned about that with my old truck i think part of my problem might be the camber i have lunsford titanium turnbuckles and rpm short ballcups and the front of the fron wheels are pointed away from eachother slightly and the front of the back wheels point inward slightly thats all i can think of for now if you need more info or if i left anything out let me know

mshipley
07-17-2000, 10:52 PM
Well let's see front tires pointing away from each other is not a good thing, if at all should be even or pointing in towards each other

now when you look down at the truck from the top are the front wheels pointing in or out?

Look at the back wheels too, they should be pointing inwards toward the steering servo basically

also are your batteries being charged all the way? I can't remember if that's a timer charger or not, but if you only leave it on for 15 minutes it's probably not getting a full charge

did you buy an hopups for the gear box? New topshaft maybe? there are two different ones, a 2.19 (truck) and 2.61 car model that would make you go slower

what kind of pinion are you running with your stock spur?

Looking back mine might make 35-40 after all I did up in that 13 turn triple, hmm, gotta go out in the street now... drag race time.. hehe, excuse me didn't mean to ramble

If you spin your rear wheels with the pinion not meshed with the spur do they spin freely?

again let me know and I'll see if I can think of anything else that might be happening, what do you estimate your top speeds to be at? and are you sure, abosolutely that your friend didn't take a 12 turn armature and put it in a midnight can and fake you out? just had to ask, later, let me know

map10684
07-17-2000, 11:20 PM
my wheels don't spin freely when i spin them without the gears being meshed and i have a timer charger but i run it at least twice through i mainly do it by temperature of the battery i'm not sure they're getting fully charged but they gotta be getting close.i know my neighbor didn't put a 12 turn armature in a midnight can cause he (as little as i know) doesn't know anything he didn't even put the stuff in his truck he had a guy that works for his dad put it all together for him. he's just a rich kid he basically just got one cause i had one if you think about it he basically got a rtr, since he didnt have to do anything but flip a couple switches to get it running. none imparticular right now i have about twenty different pinions so wich do you think would be a good one i've got everything from 12 to 37 i guess thats all 4 now bye

mshipley
07-18-2000, 12:12 AM
you might have a problem in your tranny if when yo ugrip both wheels and try and turn in the same direction it won't go easily, that's about all I could tell you, but the truck is a marvelous one when working right, the tranny seems to be the problem to me, but before you tear into and rebuild it, wait till the administrator car action guys get on here and let them read the post see what they have to say about it, as for the gearing, I'm running a tooth or two high with a 13 turn reedy motor 88t/21t so I can't remember which way you want to go, probably lower, when I had a stock they told me 17 or 18 teeth, so try 19 tooth, give it a run, feel if the trannies hot, and then let the board know, I'll check back tomorrow during work, let us know what's going on dude, I wish there was more I could do for you, by the way, I know the whole rich kid thing and how you feel, happened to me, I still beat the kid and he doesn't know how to drive/or maintain his car, doesn't like me unless he needs something worked on, well gotta head to bed, have a good night later

FLYBOY7
07-18-2000, 12:23 AM
it's probably something real simple....

1. without the motor even on the car, push it to see how easy it moves... if it pushes like something is binding, loosen up your diff till it pushes easier

2. like mentioned above, check to make sure your pinion isnt too close to the spur gear... a little loose is better than too close...

3. make sure your wheels arent tightened up too much.. spin each of them to make sure they spin freely

4. check to make sure the slipper is set correctly... make sure it isnt WAY too loose

5. make sure the esc and radio are set correctly.... i would put money that this one is your problem <--

6. you might have a REALLY bad wire connection either from the battery to the esc.. or from the esc to the motor.... after driving the car feel all the wires and connections.. if it is really hot somewhere then you need to redo that connection...

7. if none of these work then its time to start changing parts..
install a different motor first... then a different esc next to see if either of them were the problem....

good luck man.... http://www.rccaraction.com/ubb/smile.gif

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~~FLYBOY7~~
RC10-B2
Losi Junior T

"you can never have enough fun, friends, or Horsepower!"

DerekB
07-18-2000, 09:44 AM
Guys,

Please don't tell people to loosen the diff to go faster. That just won't work! Everybody had some good points in checking to see if anything is binding. Here is another checklist:

1. Is anything getting hot quickly? If so there is excess resistance and try to find what is causing it.

2. How old is the motor and have you played with the timing? Maybe it's time for a cut and brushes.

3. Check to see if the ESC is adjusted properly. It sounds like you are not getting full speed. I'll agree with flyboy that this is what you are missing.

4. Try another battery, maybe this one is spent.

I hope you get back up to speed!

Derek

map10684
07-18-2000, 09:45 PM
hey to all of you that said check my speed controller........THANX ALOT!!!!!!!!that was the problem it is running awesome now i don't know why i never thought of that i checked everything else imaginable i can't believe it it's like a whole new truck now thanks alot

FLYBOY7
07-19-2000, 12:13 AM
glad you got your vehicle going full speed bro... !!! http://www.rccaraction.com/ubb/smile.gif

btw the reason why i mentioned loosen the diff, is because one time i had adjusted mine WAY too tight... the thing would barely move... and once i properly adjusted it my car was 20 times faster...... you hate to tell anyone to loosen their diff... but it was a possible problem...... (and hey, if i overtightened it once... im sure its been done a million times... LOL)

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~~FLYBOY7~~
RC10-B2
Losi Junior T

"you can never have enough fun, friends, or Horsepower!"

pa_racer
07-19-2000, 12:23 AM
the diff shouldn't effect top speed though. only in preformance should the diff effect any speed(handling turns). if u tighten it up all the way, it would just be about the same as having a straight axle. the only reason it should effect, i guess, is that u have some ball diff that when tightened, tightens up on the bearings, causing resistance.

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pa_racer
07-19-2000, 12:28 AM
oh yea and i u tighten up the diff, and turn the tire, making the other one spin backwards, it should be harder to turn. but only that should be harder to turn. if u spin both wheels at the same time they should both go at the same time and speed freely. if not u might have resistance in just one wheel or one of the bearings.

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:!**sH!8**!:
[__]---[&#0124; &#0124;&#0124; &#0124;]---&lt;{[[[]-