Any ideas for a car that loves to fish tail? Steering is fantastic but the rear end keeps breaking loose. TC6.1 Worlds built to the manual's stock setup (except for a gear diff up front). Running on ozite carpet, VTA tires, Saucing all 4 with sticky fingers about 15 minutes before the race.

If it is happening under power, you may want to put more droop in the rear. Are you running drag break? If it's fish tailing going into a turn that may be your problem.

Where the car is breaking loose would be helpful.

-softer spring rear
-angle shocks in rear
-more rear camber
-More rear toe

Again these may change depending on where the loss of traction is occurring.

D.

It's on-power steering, mid way and near the end through sweeper turns. On the tight ones when I brake it's not really an issue. Off power and steering while braking is pretty solid. It just won't stay planted during acceleration or trying to hold a turn under power .

I did try standing up the shocks to the most outer hole, but that resulted in traction rolling in the same turns rather than traction breaking away into a fish tail.

If it's corner exit that's the problem, rear droop shouldn't make a difference since the rear will be under compression. I would adjust your front droop to allow more down travel. I word it this way because more/less droop is often misinterpreted. This should help the rear retain traction exiting the corner.

What rear diff are you using? It's possible a looser rear may help. What front diff? It may be helpful if you could provide other info. such as camber, tow, etc.

I assume this is on both left and right handed corners?

I once experienced severe traction issues by simply changing tire sauce, I switched from Paragon white to black and it felt like I was driving on ice, after switching back to white sauce, my car was hooked up again on an outdoor asphalt track. The black sauce seems to work better for slick tires and foams, not sure why, but that's my experience.

lowering rear ride height is another tuning option to consider in addition to the previous list of ideas, perhaps going with a thinner diff fluid in the rear might help too.

You are correct, both left and right hand turns where everyone is staying on power through them. Both gear diffs are built to the spec in the manual with 40wt shock oil included in the kit. Running the kit silver springs all-around as well.

It's funny you mention the diffs. All the fast guys at the track swear by running no oil in the diffs and just a couple of shots of WD-40. I stayed with the kit build though to start.

No additional toe or camber outside of what the manual called for.

+1

Wait a sec... You're not running 40WT oil in the front diff, are you? If so, that could be a problem.

But I still think allowing more front downtravel is your best bet. Lifting from ride height, how much can you lift the front of the car before the tires come off the ground?

Hmmm, don't have it in front of me to measure, but I'll give that a shot as my first tweak tonight. Everyone seem to be agreeing on this point

And yeah... 40wt. I just stuck to what the manual had as a starting point. I was leaning towards something along the lines of 3000k to try next. Or would you go more? Would that affect keeping the rear planted? I'm an oval guy so 4wd is a bit new to me.

Definitely go WAY up in front diff oil weight, IMO. I was running either a gear diff with 2.5 million(!) in it or a slipper spool with success. I've run as light as 50k in the front on asphalt and it was fine on a low powered VTA car, but for carpet I ran much higher. Hope this helps!

Oh, another question... Has the car always performed like this on carpet since you built it or has this been a gradual change over time?

I usually run a spool in the front but in those few occasions that I run a front diff I runn between 100,000 to 1,000,000wt depending on the track.

The 40wt in the front diff is likely your problem. You can install the kit spool to see how it changes the handling.

The typical front diff fluid is at least 500k but most will use 1 or 2.5 million. Silicone ear plugs are often used as well which will firm it up even more.

I too have the same issues with my worlds. This is on outdoors medium to high grip asphalt. After the straight on to the sweepers if I get on throttle I end up doing a donut.

Spool in front
Total rear toe is 3*
I have rear silver springs
32.5 shock oil with #2 piston
0 rebound
Ride height is at 5.6 I think front and rear
Droop is 5 rear & 6 front.
Rear diff is 45 shock oil
Rear shocks are 3-b

That was on sorex 32, but now I went team powers 36 which is way better, but its still there.

Haha yes. Not sure what I was thinking there. Meant front. Anyway, the 40 weight in the front diff is probably the issue.