Rear shock setting from slick to track with teeth?
 

Having a discussion on opinions of rear shock settings when leaving starting line. Shocks mounted behind rear end.Stock suspension either leaf or coil spring car. If track is slick would you loosen extension to plant tire and tighten compression to hold it there?

On a track that really has teeth you don't need to have shock extension that loose and can tighten extension?

I'm being told that tighter extension and looser compression on slick starting line.

This is just the initial leave on the starting and NOT down track with bumps or little prep.

Re: Rear shock setting from slick to track with teeth?
 

Just the opposite. ( as the top paragraph )This video is pretty informative . All Tim's videos are good


https://www.youtube.com/watch?v=loD8cpXxp_U&t=2s

Re: Rear shock setting from slick to track with teeth?
 

This is for a Koni double adjustable rear shock:

Move pin left or right to
increase rebound forces (counter-clockwise) Rebound - Insert a pin into the slotted adjuster located at the top eye (figure 1). Moving the pin from left to right (counterclockwise) will cause the forces to increase. From the minimum or factory positions, there are 12 possible sweeps of adjustment ( 1 sweep equals 1/4 turn).



Turn screw from left to right to increase compression forces (clockwise)Compression - Insert a screwdriver into the lower adjustment device (figure 2). Turning the screw driver from left to right (clockwise) will cause the forces to increase. From the minimum or factory positions, there are 12 possible "clicks" of adjustment.

Base line start with 7 swipes from loose on top and 4 clicks from loose on bottom… top setting is extension or (rebound) bottom setting is compression. When track is slick you want to loosen the bottom 2 clicks and tighten the top 2 swipes - on a good track just the opposite.

Re: Rear shock setting from slick to track with teeth?
 

Hey Herbie !

This is interesting .. One of these is wrong .... As the above video says just the opposite of what you posted. You would think with the mammoth amount of money these pro mods,top sportsman, pro stock style cars put into their cars and shock packages , they would know the fundamentals pretty good for the geometry of 4 link and shock adjustments ..

Re: Rear shock setting from slick to track with teeth?
 

These videos are very helpful and informative as both Tim and Chris are very knowledgeable and helpful guys in the business. On our end we get these questions a lot from our customers as well on how to help their cars on various track conditions - and this is the first place I start with them as well.

Please note that the cars that they discuss in their video series are all intended to build wheel speed at the hit, where we are all intending to dead hook (unless you're talking stick shift, where every driver has their own theory of how it should be done). It's a similar strategy - but we rely on front strut/shock adjustments also to help us hook where many of the fast cars use strut tightness to regulate drop out rates to ensure they don't disrupt the rear tire when the front is in the air about 50' out.

The adjustment methods they described are correct for a Penske shock. Note that all shock adjustment methods vary, and it can be extremely confusing for customers. Turning the knobs or sweeps can be opposite between Penske, Koni, AFCO and JRi - and it's all in how the shock is designed internally. I always recommend customers write on their shocks which direction is loose "--> L" after you look at the manual for that particular shock.

Mike Mans

Re: Rear shock setting from slick to track with teeth?
 

you are correct Jeff , I typed it backwards lol its been edited thank you for catching that.

Re: Rear shock setting from slick to track with teeth?
 

I was reluctant to reply, but the rule of thumb is: good track bite = stiff on the rear shocks : slippery track = soften.

Re: Rear shock setting from slick to track with teeth?
 

It would depend on if your set up to separate or squat also.

Re: Rear shock setting from slick to track with teeth?
 

In the video the tire rises into the wheel house / the chassis lowers on to the tire changing the angle of the lower four link bar to point down further in the front adding bite which will slow wheel speed.

Stock type suspensions tend to separate the tire drops out of the wheel house / the chassis rises causing the what would be the lower bar the leaf spring or trailing arm in a coil spring to change angle to point up in the front and take bite away. Am sure there are schools of thought on this and would love to hear everyone's ideas. My method is to let the tire drop as fast as is reasonable to plant the tire then keep it planted and use air pressure to control the tire from running over itself.

To let the tire drop out of the wheel house quickly the shock should separate easily, to keep the tire planted the shock should resist compressing.

Most double adjustable shocks control separation/extension on top, compression on the bottom. Check specification included with shocks when purchased identify minimum and maximum then start halfway between the middle and full loose on top and middle and full tight on the bottom.

Working with someone like Mike Mans or Santhuff will get you in the ballpark quicker.

Re: Rear shock setting from slick to track with teeth?
 

Guess I'm doing it all wrong. I never touch mine.