raydengt2000

iTrader: (1)

Hello all,

I'm very new here, but just need your advice on how you guys usually balance your car. I drive a TC5 using Justock 21.5 brurshless and 7200mah lipo. The car is handling great except for the big push on a fast right turn, left turn is great. I tried everything from using soft and hard shocks, sub-trim, travel etc, I also added front and back anti-roll bar. Stiffening the shock and installing the anti-roll bar help a bit, but the car is still turning wide specially on half throttle. I weighed the car on both left and right, and noticed the left side is 100 grams heavier than the right. I already ordered those adhesive weight and hopefully it would help, but looking for other advice that might help. Thank you!

RaydenGT2000

glennhl

iTrader: (16)

Car could be corner weighted badly. That is two diagonal tires are taking more weight than the other diagonal. If it's pushing in a right hand, then the right front and left rear could be carrying more weight than the left front and right rear. Do you have a friend that has some corner weights? If not, then you can use a tweak station. Without that, you can still do a darn good job by watching this video:

Xrayray

How did you weigh each side of the car?
The lift test is good enough to make sure one wheel isn't too low and putting more pressure on that corner of the car.

raydengt2000

iTrader: (1)

Cool! I'm watching this now. Thank you!

raydengt2000

iTrader: (1)

I have two identical micro postal weight scale. So I tested both left and right and prop a thin screw in the back middle. Did the same thing in the back and gave me the same 100grams difference.

raydengt2000

iTrader: (1)

Glennhl, this is very good I will try this next week. But what about the imbalance on the car's left and right which is about 100grams? Won't the CG change as well, most specially at speed?

glennhl

iTrader: (16)

100 grams is too much and the only way to fix this is to move physical weight. Is the battery side heavy or light? If it's light, then just put some weight under the battery or buy a heavier battery. If it's heavy, then try and buy a lighter battery or add some weight under the ESC and Receiver. Try to get it to under 20 grams difference right to left. Then weigh your car in the front, keeping it level, weigh the right front and left front at the same time since you have a pair of scales. Repeat for the rear and again keep the car as level as you can. Then work hard on getting the difference between the front and rear about the same on each side. You can do this by adjusting the spring preload of the diagonal pairs at the same time. Normally I'll add 1/8 turn preload on one diagonal pair while subtracting 1/8 turn preload on the other diagonal pair. Since typically the rear is a little heavier, let's use an example where the rear is 40 grams heavier than the front, then on each side try to get the rear about 20 grams heavier than the front on the same side. Another way to do this is after you get the right to left weight as close as possible, now try to get the weight of the diagonal pairs as close as possible. Hope this makes sense. Good luck.

Xrayray

Oh speaking of scales, the micro guys use 4 identical scales to go under the tires. Not sure if that could work here.
What you did sounds good to me though.
Btw the MR33 tweak station is about $50.. I'd throw it on that to make sure about the setup.

sosidge

Although there is some really good advice here about weight distribution and tweaking, are you 100% sure that the car is mechanically the same on both sides?

A noticeable uneven "push" on part throttle sounds more like the steering isn't set up for even lock left and right (could even be a mistake in the radio settings), or that something is binding/catching and stopping the suspension or steering from moving smoothly.

A TC5 is pretty old so there's a good chance it has had a rough life already.

raydengt2000

iTrader: (1)

Hi guys,

Thank you for this. The manual pre-load balance made a night and day difference. I raced last Friday and the car was really holding up with the fast guys, It made 5th place on the A-main (could've been higher if it wasn't for the crash). I think I'll invest on the corner weights. Yup TC5 is old, and I plan to rebuild later, but she's really fast. :-)

raydengt2000

OVA

iTrader: (86)

There's noting wrong with old TC , just keep up with the good work. learning about your TC better and better.

old_dude

iTrader: (1)

I read all of this advise and it is all good. It reminds me that before I raced R/C I worked on a full size race car. On them the scales are king. Getting cross weight right is very important as is the total balance of the car. A car will push both directions with too much nose weight and be loose with too much rear. I know that sounds wrong but inertia (mass moment ) is the culprit. It is hard to get a TC into those situations but it isn't on a pan car. Just a lot of learning to getting the weight right and owning a set of matched scales is important. Don't just buy a set and think they are matched. Mark the scales to identify them. Move them around under each wheel. If scale "A" reads less than scale "B" under the same wheel add thin tape to the top of "A" until the read the same. If you have 4 scales they must all read the same under any one wheel. I actually only use two scales and a same height bar. That simplifies the calibration of the scales.

glennhl

iTrader: (16)

Thanks for the explanation on weight on the front or rear. It does seem counterintuitive but just like you said, more weight makes that end of the car want to keep going in the same direction (inertia), so more weight on the front makes the car push and more weight on the rear makes the car loose. It's the opposite of what a lot of people think that the extra weight makes the tires on that end stick better. Just the opposite. Thanks.