Cal Club Autocross Forums

anyone ever expereince a car feeling like it was skipping around a slow turn?

like the tire was roling, sliding, rolling, sliding......

if you did....any idea of the cause?

I saw it before with too much negaitve camber...or maybe it was some other alignment error as a result of camber change..

Appreciate you widom on this fine subject!

Steve G

Stuck/sticky diff could cause this.

I really miss the old '73 Spitty...that car was way too much fun.

Perhaps damping too low for the spring rates? Any chance you have a leaking shock?

A couple of simple questions:

1. Were there bumps around the turn (was it only one turn)? This then leads to shock settings or tired/leaking shocks possibly ...
2. Tire pressures? A bit too low? Was the tire(s) rolling over onto its shoulder too much?
3. On the other hand I've felt tires "skipping" on a kart before when it sticks, bounces, lets go, sticks, etc. Maybe somebody with karts can explain that one? I've seen it many times when the tires get warm and start to stick on a kart - myself and others .... is visible.

Reijo

Steve Glusman wrote:anyone ever expereince a car feeling like it was skipping around a slow turn?

like the tire was roling, sliding, rolling, sliding......

if you did....any idea of the cause?

I saw it before with too much negaitve camber...or maybe it was some other alignment error as a result of camber change..

Appreciate you widom on this fine subject!

Steve G

Oh yeah, I've experienced this before. I used to own a spitfire.

I agree with Larry. Check the diff.

a car with too high a spring rate can do the same thing.... right???

Tire pressures set too high can cause a car to skitter in a bumpy turn.

Karts have a solid rear axle, so unless the inside rear tire unloads it has to skip a little to turn.

Just to throw out another random possibility. Slow turns imply higher steering angle. I think Spits had poor ackerman to begin with and messing with it may have made it worse. If your two front tires are pointing different directions in a slow corner, perhaps they fight each other until someone "wins".

To eliminate this as a possibility, experiment with a lot less toe and a lot more toe. At some point you should neutralize the ackerman and the skipping would go away.

-- Bill

That also makes a lot of sense, Bill, and made me realize that Steve didn't indicate where the skipping was coming from.

So?

I knew you guys would have lots of ideas....

skipping was in the front and does NOT occur with all 4 of the same road tirs on the car -- no problem at this camber setting.....so I think my diff is ok.

This was an experiment with much wider tires....

sounds like maybe alignment and/or presures and maybe suspension/tire mix....

stay tuned


:gpower:

Steve Glusman wrote:I knew you guys would have lots of ideas....

skipping was in the front and does NOT occur with all 4 of the same road tirs on the car -- no problem at this camber setting.....so I think my diff is ok.

This was an experiment with much wider tires....

sounds like maybe alignment and/or presures and maybe suspension/tire mix....

stay tuned


:gpower:

Binding at higher suspension loads caused by more grip...

Does the outside front suspension bottom out?

Being its the front, I'd look closely at Bill's post.

Also, make sure the wide tires are not contacting anything under full compression.

This happened to me with the old Elan. Under full compression the fronts would rub causing skipping and sometimes impressive understeer.

note -- this was a SLOW left sweeping turn....

I think Bill is on it.....too slow for suspension to be a major factor and no signs on tire of any mechanical interference...

going to play with alignment...

stay tuned

Steve,

What size are the rims( and off set) and tires?

David Barrish

my normal street tires -- 13 x 6 wheels with 15mm offset -- tires are 175/70-13
my normal AutoX set up -- 13 x 5.5 wheels with 18mm offset with 185/60-13 tires
my experimental set up -- 14 x 6 with 26 mm offset and 195/55-14 tires

sig

Steve-

Mark the steering wheel with a piece of tape and take note of how far you are turned in the test sweeper.

Then turn the wheel that amount and visually inspect the ackerman (that is the difference in turning angle between the sides) at that steering input.

UPDATE ----

found out that by making some minor adjustments in camber myself, I induced a large amount of toe in...7/8" vs 1/16" spec. as well as having different camber on both front wheels....

will be re-trying the V710 tires in the near future and hope that caused the issue...

stay tuned