ZX-5 weight balance and balancing the wheels

[dagfather]

I drive the ZX-5 and are starting to get som decent laptimes on it now.

One problem however is that the car is a bit "wild/wiggly" in the air and on the long straights.

I have a graphite chassis with stickpack. I do believe that the balance is a bit off...
The side with the ESC and the motor is a bit heavier than the batteryside.
The front and rear balance seems to be ok.

What's a good advice for balancing this car properly?
Get four weightscales and put each wheel on a different scale?


Could the "wild" attitude be because of the wheels needs balancing?
What's a good tool to do that? How? And will I see much improvement?

[Col]

Wheel balancing in off road?
We leave that to the anal retentives (touring car drivers)

I've never had this problem with my sp. It is heavier on the motor side running lipo, but never seems to bother it much.

[Migs]

if u dont have 4 sets of scales, just take everything on the left out of the car and weigh it, eg esc, motor, reciever all on the scles together, and then do the same for the right side and work out the difference, then you'll know how much and which side of the car to add weight to, whether u want to put that weight forward, middle or back depends on what the car is doing, i'd suggest spreding it evenly along the chassis, basically, if you're running a lipo, you're going to try and make up for the weight of the nimhs

[dagfather]

Thanks for the answers.

I checked my tires today and it seems they are not glued properly. I guess reglueing them will make som difference.

I also drive two different Lipo packs. Two practice packs that are softpack and two racepacks that are hardcase. I think your suggestion about removing everything and wheying the different sides would be good. Then I can add different weight to the different batterypacks.

Do you think that will go just as well? putting the balancingweight spread out on top of the batteries?

[SimonW]

If you have a look down the middle of the chassis you will notice a channel running from the motor mount to just behind the steering, I have drilled and countersunk a few holes from underneath and bolted lead strips cut to fit in the channel.

HTH SimonW

[RogerM]

When I corner weighted the SP I found it was 217g heavier on the battery side with a 47/53% front/rear weight distribution.

That was with

HiTech 925MG servo
LRP Sphere TC speedo
Novak 6.5L motor

E-power 4500 cells

With that in mind I'd imagine a car with one of the current generation of LiPo packs in the cell side would be near perfect side to side.

[mattb]

your right there roger but what i found is that when you weigh the whole car with a lipo in track power 3600 the car is below the legal weight mine was about 1450g so i did add some weight.

[dagfather]

But how do you weigh your car perfectly. As I read somewhere there could be trouble with shockhardness and such when putting each wheel on a scale.
A touring guy said something about at weight tool for touring cars, but he hadn't heard of one that does 1/10 offroad.

I do believe that getting the info about the ESC, motor and steering servo and then the battery will give you a good starting point. But front and rear is a bit trickier isn't it?

[mattb]

all i did was get the weight of my esc,motor and servo which was 275g then my lipo was 200g so i put 100g of lead under the lipo so it ran under the battery and then folded up the back of it the keep the weight the the rear and then put some weights behind the motor and it jumps perfect and seams to handle that bit better with the weight in.see some of rogers set ups on line to set the car up.

[mattb]

http://progressiverc.com/Servo.html have a look at this link for your servo weight as for back to front weight i just took my car to local track and it was just trail and error and a few shock towers lol!!!!!!!

[dagfather]

Originally Posted by mattb

http://progressiverc.com/Servo.html have a look at this link for your servo weight as for back to front weight i just took my car to local track and it was just trail and error and a few shock towers lol!!!!!!!

Cheers.. That helps..

Will it make much of a difference if I just use the info from the manufacturers webpage?
It's a pain to take it all out again, when it's finally installed correctly and nice.

- Servo - 46 g
- LRP SPX Brushless - 45 g (+wiring I guess 10 g)
- Vortex race 5.5 - 164 g

All together: 265 g

Battery weight:
- Hardcase 305 g
- Softpack 247 g.

I use the softpacks for training mostly.. so These will need some extra grams. When using the hardcase I need to put som extra grams on the ESC side.. Hmm..

Or perhaps the best idea is to make both sides 305 grams, whichever battery I run...