My almost perfect Cougar

[moth898]

I almost got my Cougars handling perfect, I run on a very variable rough suface. I'll post my setup a little later, but I'm having one problem I need help with.

At even the smallest pull of the trigger the rear end wants to swing out left and only left. No binding in the drive shaft's, any ideas?

[slow bob]

problem with your diff ?

only other things to look at are bearings but doubtfull as they should be nice and new

[lochness42]

is it balanced/symmetric left to right?
oh and check wheels - mabe unglued tyres or very unbalanced wheel?

[PsycoChris]

Originally Posted by moth898

I almost got my Cougars handling perfect, I run on a very variable rough suface. I'll post my setup a little later, but I'm having one problem I need help with.

At even the smallest pull of the trigger the rear end wants to swing out left and only left. No binding in the drive shaft's, any ideas?

Had the same issue, my tranny gears were locking up. Check your thrust bearing too. Maybe a locked bearing somewhere.

[moth898]

Originally Posted by lochness42

is it balanced/symmetric left to right?
oh and check wheels - mabe unglued tyres or very unbalanced wheel?

Its not the wheels because I changed five sets during testing and it did the same thing all five times. The weight idea is good but I don't have a four wheel balance to test that, I'll try to figure something out. Psycochris had the same thought as I did about the thrust bearing.

Thanks guys, I let you know what happens.

[moth898]

I just finished taking apart the gearbox and got surprised at what had happened.

Dirt had gotten into the gearbox and idler gears and worn out to almost failing.

[moth898]

I'm going hi-tech, of hi-overkill, on finding out why my rear swings out on throttle. I just finished building a wieght balance, I want to se the weight distribution per wheel on the Cougar and how it affects handling. I also bought the HUDY 1/10 setup kit...if you thought your settings are perfect think again, I had spent hours tunning the car to what I thought was square, but I was off by a couple of degrees in all four corners. Its well worth the money.

I'll update this evening.

[Raul Garcia]

Originally Posted by moth898

I'm going hi-tech, of hi-overkill, on finding out why my rear swings out on throttle. I just finished building a wieght balance, I want to se the weight distribution per wheel on the Cougar and how it affects handling. I also bought the HUDY 1/10 setup kit...if you thought your settings are perfect think again, I had spent hours tunning the car to what I thought was square, but I was off by a couple of degrees in all four corners. Its well worth the money.

I'll update this evening.

I have the new Hudy 1/10 off road setup station as well. VERY Nice..

[fastinfastout]

have you checked your droop settings?

I know once when I had a problem like that, one of my shock lengths was longer than the other.

pick up your car from the middle of chassis with a pick or something small both front and rear. See if both wheels leave the ground at the same time. If not, your shock lengths need attention.

I would think setup stations are an overkill for offroad. I use them for onroad, but have no inclination to use in offroad.

[Raul Garcia]

Originally Posted by fastinfastout

have you checked your droop settings?

I know once when I had a problem like that, one of my shock lengths was longer than the other.

pick up your car from the middle of chassis with a pick or something small both front and rear. See if both wheels leave the ground at the same time. If not, your shock lengths need attention.

I would think setup stations are an overkill for offroad. I use them for onroad, but have no inclination to use in offroad.

Chassis setup is as equally important in offroad as it is in onroad. All chassis settings play a role in the way the cars handle the surface they are being used on. Ride height, tweak, balance, and alignment are the key factors in a proper handling car, your eye is not that good even if you are a jewler. Still think it's overkill?

[moth898]

I don't think it too much either, the shock lengths are equal front and rear. My ride hight is 1mm more in the front to reduce steering a little and my rear droop is level. I think I'm good at building cars, everything else was checked twice. The only thing I haven't checked is the wieght distribution, with the board finished I'll be checking it after work today. I have the feeling the motor is to much to the right of the chassis and is the reason for my problem. I'll also try and post some picture of the results.

[fastinfastout]

even if the motor is too far to the right, no one else is having the problem, so its your car.

how is the diff?

just for arguments sake, change the shocks around, left to right, right to left, and see if its spinning out in the same direction.

[fastinfastout]

Originally Posted by Raul Garcia

Chassis setup is as equally important in offroad as it is in onroad. All chassis settings play a role in the way the cars handle the surface they are being used on. Ride height, tweak, balance, and alignment are the key factors in a proper handling car, your eye is not that good even if you are a jewler. Still think it's overkill?

I do everything possible to balance the car, check for tweaks, ride height, camber, droop, so on, so on, and manage without an off road setup station, and so does 99.9% of club racers. So I will say, yes a setup station for offroad is an overkill.

but each to their own

[moth898]

I did everything you said last week. Reversed the diff, shocks and everything else was checked. Don't get me wrong, the car handles great, I made 4th on only my second race. But I like to be more aggresive with acceleration so I'm having that problem with my car.

Now getting to the result of my balance test. The car rear was unbalance by 18 grams to the right( to the spedo side) It took 35 grams of lead right in front of the pinion and spur gear to balance the car. The car is almost perfect 40/60 weight distibution from front to rear, 305g per front wheel and 485g per rear wheel.

I know how you feel about this weight thing fastinandout, but give it a try, you have nothing to loose and everything to gain.

I'll post pictures of the weight station later if people want to try it themselves.

[moth898]

So here are the pictures of the balance I made and the wieghts instaled. The car tracks very straight now. Its made of 1 1/4 thick pressed wood, 15 inches by 20 inches with adjustable supports in the corners. I also glued two levels on opposing sides. The scales are from a speciatly food aplliance store. THe board has to be leveled before using the scales.

[Chillout47]

This is a great idea!!! I am definitely going to give this a go. Weight distribution is an absolutely essential part of setting up a full size race car, but generally I rekon this gets seriously overlooked at small scale. I know people move weight around to counter under/oversteer etc. but as an initial set up I think we are missing out here.

[moth898]

Thanks, it seems as if Grant Williams had the same idea at the EPR nationals with his Cougar, but he only used 10g where as I found that 35g balanced the car.

[Malek]

Nice setup there moth.Looks like i won't have my cougar on time for the next race.I am going to have to go with the other car for now.

[moth898]

my setup is your setup my friend anytime

[JustARcFan]

Just built the same weight board as you did + the hudy set up board.

As said before, don't trust your eyes to adjust camber toe etc..

My car is perfectly balanced now with 30 gr under the receiver at the motor side.

It's logic that adding the weight has a lot to do with the heavy speedy I'm using ( SP GT 2.1)

Front per wheel: 303gr
Rear per wheel: 480gr

Cheers