No Directional Stability

[snmhanson]

Now that I seem to have the engine running right I am having issues with keeping my RC10GT running straight. Whenever I hit the throttle with more than just a VERY gentle pull or whenever I get it up to speed my car wants to drift off to one direction or the other (it is to the left the majority of time). If I give it full throttle it will basically get itself into a situation where it will just go around in a tight circle doing a sort of drawn out doughnut. I know the steering is aligned straight because when I am going slow and not giving it throttle it does not drift plus visually it looks dead on. It is impossible to drive it on a track like this as I am always having to make small steering adjustments which usually just end up sending it off course even more or causing it to spin out. I can't even get it to hit a ten foot wide jump with any speed at all. What could the problem be? Do I need to rebuild my tranny or is there something else that could be causing this? FWIW I am running a .18 cvr engine but I do not think this is simply a case of a big engine making it uncontrollable. Thanks for any advice.

Matt

 

[beason]

it could be one of the wheels binding.. make sure they all roll freely.. check your bearing in the wheel hubs.. also pull the diff and make sure it rolls freely.. could also be a messed up shock.. try those and get back to me..

 

[Lessen]

check to make sure the diff is tight enough. If that's good and nothing seems to be binding like beason mentioned try adding a bit of toe-in to the rear wheels. But if it's consistantly going to one side it's probably something binding, check bearings and things of that sort.

 

[.21Rc10GT]

Make sure your front wheels are toed out just a hair... That should stop it... If that isnt the problem, check your diff and hubs to make sure nothing is binding

 

[FastEddy]

Loosen the slipper on your spur gear.
Much of what your getting may be torque steer.

 

[Nitroftw]

If none of the above works you can try checking your radio/servo. Make sure the truck is tracking straight when you aren't steering one way or the other.

 

[snmhanson]

Thanks for all of the advice. I will check those things out ASAP. It might be a little bit before I get the time as I am preoccupied with several other projects right now as well. I'll get back to you all and let you know what the prognosis is.

Matt

 

[jkoch]

I had this same problem the other day at the track. Half way through the race I couldn't punch the throttle without the truck darting to the left. Upon closer inspection I found the rear toe-in block was cracked.

 

[Mortifyd_Penguin]

In my humble opinion i think it would most likely be the rear toe seeing how it mainly does it on the throttle. mine did the same thing but it was do to a locked diff and a heavy throttle finger.

 

[dannthenitroman]

yeh sounds like the toe to me, i like about 5 degrees of toe in in the rear.

Dann

 

[snmhanson]

Just an update: I rebuilt my diff and transmission and I think it helped quite a bit. When I got it all apart I turned the diff and it felt a little stiff in one direction so I did a good cleaning and put in new rings. It was a little off after that but noticeably better. Upon closer inspection I discovered that the wheels were not aligned perfectly (just slightly off) so that was probably a big factor to my problem also. I straightened them out and tried to run it today but now I am having engine problems. (Stalls after idling for several seconds or when I hit the throttle after it idles for a few seconds. Now I'm bumming since I just finished building my track today and I haven't even been able to put one lap on it yet.) Anyway, at least I think I am on the path to straight stearing. Thanks for the input.

Matt

 

[.21Rc10GT]

yeh sounds like the toe to me, i like about 5 degrees of toe in in the rear.

Dann

I have only seen 3 or 0 degree arm mounts... there really isnt any more to adjust it...

 

[dannthenitroman]

i have a rusty to begin with, and I've got custom made arm carriers, that sweep the arms 4 degrees further forward

Dann

 

[snmhanson]

One last update - It hooked up better after I rebuilt the diff and tranny but still not great. The day after I did the rebuild I blew the clutch bearing and had to order some new ones. Since I was placing an order I decided to get some new tires as well so I ordered a pair of Gladiator IIs. I swaped out my old Fuzzy Ts and put the new tires on and all I can say is wow! Maybe the Fuzzy Ts didn't have enough tread to handle my engine or something but it drives like a whole nother car now. I can just about punch the throttle and it takes off straight and keeps going in that general direction until I want it to turn. I've got a little tweaking with the steering to do but it is now clear that the tires were my main problem. Thanks for all of the input and help. I'm in RC heaven right now...

Matt

 

[beason]

it takes off straight and keeps going in that general direction until I want it to turn.

Matt

lmao.. dunno why but i find that hilarious.. sounds like me.. "well it was going in the general direction i wanted it to" lol

:ha:

 

[Tweak]

I had a simalar issue with my RC10GT. the pins going thru the axle shafts had stripped out the inner, plastc part of the hex wheel, causing everything to LOOK fine (I.e Clutch, diff- witch I rebuilt thinking it would help) but the same thing would happen. It was so bad that as soon as I realized what was wrong the damn thing wouldn't move at all. Congrats on geting it fixed.

 

[Pinblaster]

Isn't it amazing how much difference the right tires make to drivability. I see it all of the time at our indoor track. New guys will come in with their RTR trucks with Step Pins and do spin outs and either end up in the wall or on the tubes every 3 seconds. Hand them a set of Losi pink Taper Pins and they are hooked up and having fun.