48 2.2 Looking for advice on Setup

[Kozzy]

Hello all,
I'm looking for some advice to resolve this issue that I'm currently having at the track (after the track and weather changed)
The track is dirt, medium/high grip, bumpy with tight corners.

The issue:
OverSteer when entering a corner. (many times the car would spin in place) and overall unstable car.

After many changes that I tried, I eventually reverted to the stock setup except for the following:
Diffs: F10K,C7K,R7K
Shock oils: F400cst R500cst (emulsion)
Sway-Bar: R2.6 F2.5
Tires: TZO 402/601/500 Super-Soft/Soft

Everything else (Camber,Toe,Droop,RideHight... and all links positions) is according to the stock setup.

Without explaining here what I've already tried, what would you recommend to try in order to have the most impact?
(considering it's not the transmitter settings and that there are no parts/assembly issues in the car as far as I can see)
Thank you

 

[Matthew_Armeni]

You said to not consider the transmitter settings but honestly that's always a great (and easy to overlook) place to look first.

You might simply have too much steering. Try turning your steering D/R down to 80% and drive a few laps. Then go to 85%, then 90%. Another thing is your servo might be overly fast. People often think they need a servo with a lot of speed, like .08 or something around that fast. That can often be much too fast. Try turning your servo speed down or adding a little bit of expo.
You mentioned your setup is box stock, are you positive you're measuring your droop correctly? Too little rear droop will cause an unstable rear under braking. Another thing I noticed is that your swaybars are also slightly heavy, especially the front. That heavy of a front bar would typically cause the car to push, not oversteer. Did you install that bar to try and tame the oversteer?
If you can get some pics of your car that might help, you may have overlooked something simple.

 

[Kozzy]

Hello @Matthew_Armeni
Yes I tried changing some of the transmitter setting (dual rate and exponential for the steering)
I admit that it could be that I gave up on that too quickly I'll try it again

I'm using the same servo (Futaba CB701) from my previous buggy so the speed is less likely to be the issue, but again I'm going to try everything again.

I wrote this post after re-setting everything and measuring everything again. yes the droop is on spot.

I tried heavier sway-bars, just to see if they will help out preventing the oversteer.

1. I'll try to see if changing the steering settings will help.
2. I'll send a short video of the car as soon as I can.

Thank you for the quick reply!

 

[davidg]

I think it would be helpful if you posted what you have tried and how it affected the buggy. Also, is the rear loose on or off power? I haven't driven a 2.2 yet but my 2.1 has most of the 2.2 changes. I have a ET48 2.2 that I driven yet and I"m curious how it will feel with the new shock setup. I would probably try going heavier on the front shock oil and softer on the rear shock oil. You could also play around with different shock springs. Have you tried adjusting the pills?

 

[Kozzy]

I think it would be helpful if you posted what you have tried and how it affected the buggy. Also, is the rear loose on or off power? I haven't driven a 2.2 yet but my 2.1 has most of the 2.2 changes. I have a ET48 2.2 that I driven yet and I"m curious how it will feel with the new shock setup. I would probably try going heavier on the front shock oil and softer on the rear shock oil. You could also play around with different shock springs. Have you tried adjusting the pills?

I didn't try changing any pills yet.
Some of the things I remember trying which didn't have good effect so far:

1. Moved the rear hubs forward (replacing the 1 & 2mm shims)
2. Moved the rear camber links to the inner bottom on the tower.
3. Green Springs at the Rear. (softer)
4. Thinner and thicker oils (front 350 -> 450 rear 400 - 550)
5. Lighter and heavier sway-bars

 

[davidg]

Adjusting the pills is something you can try that doesn’t take much time to do. You could try adding some rear toe and maybe some anti squat.

 

[Matthew_Armeni]

Hello @Matthew_Armeni
Yes I tried changing some of the transmitter setting (dual rate and exponential for the steering)
I admit that it could be that I gave up on that too quickly I'll try it again

I'm using the same servo (Futaba CB701) from my previous buggy so the speed is less likely to be the issue, but again I'm going to try everything again.

I wrote this post after re-setting everything and measuring everything again. yes the droop is on spot.

I tried heavier sway-bars, just to see if they will help out preventing the oversteer.

1. I'll try to see if changing the steering settings will help.
2. I'll send a short video of the car as soon as I can.

Thank you for the quick reply!

That's an incredibly fast servo. At 7.4v it has a transit speed of .075. Your fully charged rx pack is 8.4v, so it's moving even faster. For sure you should turn down servo speed on the radio.

 

[Kozzy]

Here is what I tried (one change at a time) so far and the results:

1. I added ~10ms of delay to the servo (that enabled me to drive the car like I should)
2. I shortened all Camber links by moving them to the outside links and making them shorter in total length.
3. I changes the diff oils to 20K,12.5K,10K after many other combinations
4. changed pills in A+B blocks to add 1 degree kickup
(I will soon try 12.5K,12.5K,10K)
5. I moved the shocks to the inner holes on the shock towers (F+R)
6. Tried different tires (so far the TZO 202/402 seem to work the best at our current track condition)
7. Changed the pistons to VRP 20h (F+R) - They really work well for me.
The track changed a lot and it's much more bumpy now, with lots of traction and bag sands here and there.

With these changes I'm finally able to drive the car again.
It is much more stable and allows me to drive it faster. just to make it clear how bad it was, I removed ~3.5 seconds from my laps.

I still have the oversteer issue from time to time mainly when entering a corner, but so does other drivers with other cars... I'll try some more changes, but I'm very happy with the results so far.

If I'll manage to kill the oversteering completely this will make the car even faster so I'm still on that.
Thank you everyone for your help.