Torque Twist

[SeanD]

I just finished extending my wheelbase to 12.5. I am not sure if its just my setup but there is a lot of torque twist when crawling. When crawling steep inclines the chassis twists and the left wheel tends to loose contact. I can't seem to find a thread that deals with this matter so I am wondering what others might have done (using the stock chassis) to combat torque twist.

I hope you can see my suspension layout in this picture:



Sean

[kurt]

you can try to get some weight on the axle on that side. Run a block pack perhaps.

[Badmuthatrucker]

With the stock chassis (and long links) my TLT was a real turd for it.

With the K2 frame, it hardly does it at all... Here are my thoughts on what has stopped it:

With the gear box change, the motor now, only sits lower, but faces the other way, on the other side of the chassis, so, I'm thinking, that it has to do with direction of rotation. If the motor happens to spin to same way the chassis tilts (toward the left) that mass will help the reaction of pulling the chassis over, if it spins into the lean, caused by the diffs try to spin in opposites to the drive shaft, it sort of acts like a balance shaft, or gyro, even.

Placing the battery over the front axle, keeps it pegged down a little more.

Mounting the shocks far out on the axle tubes, and close together on the chassis give a more progressive compression stroke, and limiting the lean. Shocks straight up and down, get really weak, and fall into being softer the more the suspension articulates, and you don't want this for anything.

[SeanD]

I was thinking about trying to weight the front axle but I think it would take quite a bit to keep it down.

I wonder would a heavier weight oil in the rear shocks help out? Anbody know of any oils that can be had in your local auto store that might work in the shocks?

Sean

[kurt]

how are you geared? if its all stock then i would try a higher spur and lower pinion. it will help take that initial punch away.

[BENDER]

Stiffer springs and thicker oil in the rear shocks will make a difference. Adding a little weight to the front axle will help too.

[SeanD]

Any type of heavier oil that can be readily bought - like a synthetic motor/gear oil? This hobby is not really popular here (yet) so the LHS only carries the "regular" weight shock oil.

Sean

[MikeSSS]

Mine has almost one inch of preload spacers on the right rear shock.

The front right shock has over a half inch of spacers.

Both right shocks are mounted outboard of the axle saddle by using longer bolts. This is at the bottom of the shock, the tops are mounted on the stock shock mount.

This WK always has body lean to the left but it keeps all four wheels on the ground when climbing. It has a 13" wheelbase, reversed chassis and the battery is mounted on top of the front top links.

[highhpcummins]

I did full droop on mine, 100% eliminated torque twist. I drilled new holes for the upper shock mounts to keep the ride height & ground clearance

[SeanD]

Some good suggestions. I wonder if I can't find a set of heavier springs for just the right side - basically the same as using pre-loading with spacers, I guess. I did put on the small spacers from the parts bag but they really don't so anything. My shocks are outboard as well but I have moved the front ones aft of the stock mounts to give more room for the steering servo.

Reducing this twist, I know, will make some dramatic improvements in climbing!!! I will have to do some playing around this evening.

Thanks,

Sean

[highhpcummins]

if you try full droop, try heavy shock oil, it works great. Doesn't unload when going vertical. I think I'm going to lighten mine up. I tried 2,000 wt. seems a little too thick.

[Tanis]

Here's a thread with lots of info.
torque twist

[SeanD]

highhpcummins: A picture paints a thousand words - don't suppose you have one do you?

Sean

[blakeski]

i read a thread on how a guy put a really stiff shock on the back opposite corner to help him keep his wheels down... but im not sure tho

[four wheel peel]

if you have any other rc'c look it their parts bag you should have a few spacers that might work if not pm me and i will send you a few just cause i have so many laying around and i haved used all i need so far i have three the same size as what came on my wk and it has helped alot but if you need some i have a few so just pm me and i;ll send em your way free of charge

[SeanD]

I broke a set of shocks on my first night of ownership (freak accident)!! I then ordered a new set so I had a spare pair lying about. I've used the spacers off these spare shocks and things have evened out quite a bit with the torque twist. Still some twiddling to do but I'm on the right track.

Much thanks four wheel peel for the offer but I'm good right now.

Sean

[scuzzy51]

i think its your link geometry! if you raise your upper link up on the axle so it makes your links more parallel i think that will help!! and put some thick oil in the shock that compresses!

[SACCO]

try standing those rear shocks up a little.

[SeanD]

scuzzy51: When you look at this picture, you can see that my links are pretty parallel with each other. When you say "raise your upper link up on the axle" where do you mean locate it/them?





Sacco: I thought about the shock angle but I do see alot of other rigs with similar or even more extreme low angles on their shocks. I still haven't tried moving them yet for optimum flex/compression.

[SACCO]

Originally Posted by SeanD

Sacco: I thought about the shock angle but I do see alot of other rigs with similar or even more extreme low angles on their shocks. I still haven't tried moving them yet for optimum flex/compression.

make the rear like the front and it will help a little I promise. the wk shocks are so soft, it doesnt take much angle and the torque twist will overcome them.

I love how you cut your tires. I might find some use for the stockers after all.