Bump Steer on a Viper

[DFW GTS]

Looking at the service manual for a '96 GTS I see that the factory specs call for .36 degrees of bump steer throughout the front suspension travel. Everything I have ever learned says that, for best handling, you should try to achieve zero degrees of bump steer.

I have to wonder if this built-in bump steer might contribute to the Viper's tendency to wander on uneven road surfaces.

Does anybody know why the Viper was designed with bump steer built into the suspension?

 

[GTS Dean]

.36 degrees isn't much. What's bad is if it reverses direction thru the travel curve. The tendency to wander is due more to road rutting and camber thrust from the wide tires because the suspension usually isn't moving at all.

 

[mjorgensen Woodhouse]

Remember that is through all the travel and you only use about 1/4 of that on the road so that makes it really insignificant. It should be checked and corrected though when you do suspension work or adjust the ride height consideably since you change the used range of motion.

 

[Catwood]

Mark,

I'd say you'd see more suspension travel on the track, would you agree?

I'd also say getting a low BS # is more important for track days.

 

[Jeff Monheim]

I know nothing about bump steer, all I know is that it can help when properly adjusted for the track. Is bump steer adjustable on the stock set up? I guess it would have to be for proper allignment. I see aftermarket "adjustable" BS parts for sale. They seems to imply that the stock set up does not come this way (adjustable). Can I get some more info on this? or am I hijacking this thread?

 

[mjorgensen Woodhouse]

Mark,

I'd say you'd see more suspension travel on the track, would you agree?

I'd also say getting a low BS # is more important for track days.

Bump steer is more important for stability at the track with higher speeds and more violent chassis movements especially under braking.

I know nothing about bump steer, all I know is that it can help when properly adjusted for the track. Is bump steer adjustable on the stock set up? I guess it would have to be for proper alignment. I see aftermarket "adjustable" BS parts for sale. They seems to imply that the stock set up does not come this way (adjustable). Can I get some more info on this? or am I hijacking this thread?

Jeff, the bump steer is adjustable by shimming the steering rack up or down depending on needs. Most cars don't have this option and the compensate with longer tie rod ball joints and washers under them.

 

[GTS Dean]

The rear is also adjustable.