Help Setup Buggy For Track
 

Anyone here got experience with setting up buggies for racing?
Im looking at racing my BL 8ight at the club and have never setup a car for racing as I usually just muck around with them or race against mates (nothing serious).
Only things I have changed since the Race Roller setup is 5000wt front diff - 10000wt centre diff - 55 piston and 35wt oil (i put 35 in as I didn't have 40) front shocks.
The buggy seems alright to drive but has a few issues. The rear diff fluid is 2000wt and when I accelerate hard the back tires seem to balloon fair bit. It also likes to spin around when driving hard out of a turn. I was flying down the main straight today and hit a little bump which made the front end go down which made the rear go up and over/flip. I also noticed today that the inside of the front tires (mainly the right) has been chewed out abit.
The setup below is the roller setup. The changes I have done have been added as red.

http://i37.tinypic.com/289fymc.jpg

going up in rear diff will stop the rear from coming out under acceleration,will also stop any "fishtailing" you may have coming out of turns on power.


moving the rear camber link in the tower down to 4 hole with help with the rear bite also.

I run 5-10-3 in the diff's in my 8 with the stock shock pistons and 40wt oil all around,my track is rutty and it handles great,had to go up to the 40wt oil for the bumps.
everything else it the standard setup and does great for me,hope I helped you some

thinner in the rear will stop the fish tailing it gives it less direct drive the thicker fluid coauses it to want to spin out more

drop you center fluid down to 7 that will help with the rear overpowering the rest of the car

Thicker rear diff has less steering in the middle of the turn and more foward traction. The standard kit was running the rear camber link at 4-B and most of the setups on Losi site uses 4-B, so might give that a try

Alot of people have now said they run 40wt in the rear. Do you have the roller or the kit? The roller only has 25wt in the shock but runs a 56 piston whereas the kit runs 35wt and 55 piston

i have the race roller,I also have been running buggy's for many years,and thin rear diff fluid CAUSES fishtailing,not the other way around.the thin rear fluid unloads the diff from one side to the other.
thinnner rear diff fluid always has more steering than thicker rear diff fluid also
just my experience though

lets think about this thinner fluid alows the rear end to diff hence more power to the opposite side

thick diff fluid means the diff stays locked if your over powering the car and the rear tires are spinning and breaking the back end out you will want a thinner fluid

kevin 23 is also correct it just depends on how the setup is working out

Right-o, thanks for your help. Ill make a few changes. I'll put 40wt in the front (keep the 55 piston in for now) and put 35wt in the rear. Will move the camber link to #4 in the rear and will check what the camber is on both front and rear. Hopefully my ride height gauge isn't to far away. Will also change to 3000wt diff fluid as most Losi 8ight Brushless owners run 3000 in the rear.

My ride height finally arrived today. What is the best way to measure the ride height? It would be best to measure it with the battery in but when I compress the buggy up and down a few times and then measure it? My front end doesn't compress/rebound all the way up and if I put the gauge under it and push it up to the 26mm mark it will stay there.

The most important piece of your track setup is the tires. Even a perfect chassis setup can feel like junk if you do not have the proper tires under it. I would check with others at the track to find out what works best before fighting with smaller adjustments. You mentioned that your fronts are a bit worn, how about the rears? There are several tread patters that work pretty well on many conditions.

The ride height adjustment should be made from where the vehicle settles on its own after dropping the vehicle from several inches of the ground. You also need to take the measurement with the vehicle ready to go run. A measurement with out the battery would not be very useful!

Also, the heavy center diff fluid is good for our brushless setups for better efficiency, but it is not necessarily the best for chassis setup. The heavier center diff will prevent dumping power to the front diff and keep a closer balance front to rear. However, this has made the rear of my car a bit nervous at the same time. With a normal center diff setup, there is less power going to the rear, and less chance of breaking the rear tires loose. If you can keep control of the car, you will probably accelerate harder, but it will take some more effort to keep the rear from coming out under acceleration.

Bryan

http://www.teamxray.com/teamxray/sho...p?file_id=4461

Here is an awesome setup guide for buggy and truggy. Very useful when trying to solve a handling problem.

Its published by Xray but the principles apply to any buggy of truggy.

And I 100% agree with backfire. Without the right tires, you are just chasing your tail. Tires are the first and most importenat piece of any track setup.

To answer the dif oils questions:



EFFECTS OF DIFFERENTIAL OIL REPLACEMENTFront

Thinner

• Increases steering into corners (off-power)

• If oil is too thin the steering may become inconsistent, especially it can lose forward traction (and steering) during acceleration out of corners

Thicker

• Increases stability into corners during braking

• Increases steering on-power at corner exit

Center

Thinner

• Front wheels unload more during acceleration

• Decreases on-power steering (reduces oversteer)

• Easier to drive on rough tracks

• If a high-power engine is used you could waste too much power and sometime “cook” the oil in the center differential because it “overloads”

• More off-power steering

Thicker

• More all-wheel drive effect

• Better acceleration

• Increases on-power steering (reduces understeer)

• Better suited on high-bite, smooth tracks

• Car can be more nervous to drive especially if a high power engine is used - you might need to be smooth on the throttle

Rear

Thinner

• Increases cornering traction

• Increases steering into corner

Thicker

• Decreases rear traction while cornering

• Reduces wheelspin