Push!!!

[m00nst0ne69]

My Revo has always turned like a dump truck. I run mostly stock with P2 rockers and the stiff springs that came with the truck. I run Proline 40 series bow ties that hook up great!!! So great in fact that I push even more then when I ran the 2.5 chassis with the same setup. Any ideas on how to get things turning again?

 

[revo_rob_1984]

well you could lower it and when u go into a turn let off the throttle and let the front tires dig

 

[ThunderTiger]

You have the option of upgrading to more powerful steering servo's which will hold the wheels in the desired steering position more easily (unless you already have the single steering servo mod), Changing the suspension set up to "limit" chassis roll and thus "push" (although chassis roll is only a part of the issue !!!) and, depending on where you run a tyre type, preferably low profile to stop side wall flex, that suits the environment.

 

[liftedcj7on44s]

I used about 8oz worth of stick on wheel weights on the front of my revo and it helped tremendously. remember the revo is back heavy. So get the back suspension stiffer than the front. Swaybars and the wheel weights and it should turn alot better. I know mine did.

 

[ThunderTiger]

actually, the revo is nose diving happy. stiffening it up a bit in the rear only makes the front dive even more.

 

[weezracen]

Someone correct me if I'm wrong. U could move the rear suspension arm pins to the lower hole witch would give u more bit in the front. Also u could cut the turn stops off the steering setup I dono what the pieces is called though. This would make it so your tires could turn at a sharper angle. I do belive that I found that somewhere on this site it showes what the piece looks like. I haven't done that yet but I plan 2!

 

[liftedcj7on44s]

Yes the Revo does nose dive very bad under braking. But under breaking or off throttle is when the Revo will actually turn. But when giving the truck throttle it will do nothing but push the front end. When braking or off throttle there is more weight up front and this is why the front end bites more. When under accel the weight is at the back and the front wheels unload and it will no longer turn. So adding some weight up front will help alot.

It doesn't matter how sharp your truck turns if it pushing the front end.

 

[ThunderTiger]

actually, the revo is nose diving happy. stiffening it up a bit in the rear only makes the front dive even more.

Having said what i did in the above quoted message, i have since tested a couple of theories using my revo, so here goes.


Placing the rear upper suspension pins in the lower of the two possible positions does indeed raise the rear end up. The counter effect, is that under braking the nose will dive harder. If braking in a corner, it will dive and want to roll over towards the outside of the corner under the "off balance" push.

Adding some negative camber to the steering block is a possible solution as it will allow the tyre to bite more under "push" conditions and lessen it a little bit. This is due to more of the tyre being in contact with the surface due to the pre set negative camber. Caster is also another option to consider. more caster gives a sharper lean to the tyre under cornering, effectively giving slightly more steering capability.

Another possible aid, would be the fitting of ARB's (Anti roll Bars) most conmmonly known as "sway Bars". These act to level the suspension out in cornering effectively lowering the C.O.G a little and allowing a little more tyre bite.

Stiffening the front end suspension will also help a little as, under cornering, wioth a soft setup, the suspension will allow chassis roll, which in-turn, lessens the wheels biting capability. With a stiffer suspension, less chassis roll is caused and the tyres will bite and grip in better manner.

Adding weights to the chassis, especially at the front end, will cause the front to dive even more so than normal, especially if the rear end is set high and is using 120 rockers. A way to restrict rear end lift, is to use a "Limiter" to allow the rear end to Lift only to a certain point, which in turn will help to stop front end dive.

Fitting weights to the front wheels only serves to increase rotating mass and makes it harder for the servos to turn them, especially at speed due to the gravitational forces involved. It may also cause early hub bearing failure and undue stresses on such parts as the steering hubs themselves at the pivot ball cups and adding stress to the suspension arms. Jumping a vehicle with weight at the front end, may also make it not only harder to control but also, it may make it more "nose heavy" in flight after a jump.

also, a revo will "Squat under accelleration if the suspension at the rear end is set high and the shocks are set with too soft springs and oil. Even with full preload some springs, especially the stock "blue" band ones, are way too soft and allow to much squat. Squat as has been pointed out, is counter productive to steering. Therefore, setting the rear end for adequit "rigidity" shall we say, under acceleration and by the act of "Limiting the travel in combination with stiffening the front end suspension up, fitting front sway bars and adding camber and caster up front will all help towards working for more steering and help in limiting on power push under cornering.

Hopefully, i have not mistyped any of that !!

If anyone cares to do so, please correct me if i am wrong in anything that i have said.

 

[liftedcj7on44s]

I agree with most that you have said. I personally think the Revo needs better weight distibution. I have never done it but the truck needs to be balanced as close to 50/50 as possible.
Adding negative camber to the front and adding some toe-in on the rear helped my truck tremendously when cornering.

 

[andy_xr81]

thats pretty much sums it up. one point to note is that if you are going to set the truck up to corner you may loose some staight line drivablity. it can be a pretty fine line.

 

[ThunderTiger]

hmmmmm, when did i become so knowledgeable on the traxxas revo i wonder ?????

Reading my last post is scary, i know too much about Revo's already !!!!

 

[m00nst0ne69]

Thanks for all the information. Sorry I haven't replied much, I don't get to a terminal much. Toeing in the rear and balancing helped a bunch. The nose dive actually helps a great deal as it allows the rear to slide just enough and keeps the rest under control.

After some more testing I found that I need to get a new throttle servo. The one I am running is way too slow. I am getting serious delay in throttle response it takes forever to throttle up then almost as long to break! I'll let you know how she runs with a new servo as soon as I get one.

 

[RC Addict]

Are you running "AA" batteries in your receiver or do you use a receiver pack? I ask this because using a receiver pack will allow your servos to see and use more current than the "AA"s allow...

 

[MrClean]

Look at #3 here: Revo Steering Mod. It can be done to single or dual servo configurations. I removed the steering stops and it made a lot of difference on mine.

 

[weezracen]

Mrclean when u did that mod how did the stock servo work for U? I have a 5308. Just wondering cause I read up on that link and it was saying about using a servo that has enough range of motion. But I think they were referring to 5309???

 

[liftedcj7on44s]

i did the steering mod to my 5308 revo. Just taking the stops out only gets you a few mm more of travel. You are then limited by the steering servos arm. After that you are limited by the bulkhead and then you will be limited by the stock wheels and tires hitting the toe-link bars. 1/2" offsets cure that easily.

 

[MrClean]

Mrclean when u did that mod how did the stock servo work for U? I have a 5308. Just wondering cause I read up on that link and it was saying about using a servo that has enough range of motion. But I think they were referring to 5309???

It doesn't help as much on a stock set up as it does the single servo/arm, but I did notice a tighter turning radius. I don't race so it was real critical for me, but it does help.

 

[bobbyc1127]

alot of steering depends on the epa on the radio. and i ran 40 seris for a while and went to mtr tires and lpr tires and the turning increased. also adjusting the braking also helps. you actually want more on the back then the front. sway bars also aid in helping the revo holding a turn and try 40 wt. shock oil at all four corners...