Shock/Strut Suggestion

[invisiblefrisbe]

This weekend will be my second autocross. The first time out I wasn't worried to much about the setup of my suspension...just learning about the event itself and having a good time.

This time around I want to mess with the suspension and dial the car in a little.
You can see the mods below in my signature, except I haven't gotten around to installing the torque arm yet. I'm running Kuhmo Ecsta XS tires on all four corners. 255/40/17 in the front and 295/35/17 in the rear (yeah I know it's not square) on RPF1 wheels.

For the wheels I plan on starting at 35 PSI with some chalk on the sidewalls and adjusting from there.

My question is about the Koni Yellow shocks/struts that I have. Where should I start on the front and back with these?

 

[ConeCrusher281]

What is the Max/min that they can be adjusted to? I have the tokico d-specs and the adjuatability is from 0-7.5 turns

 

[invisiblefrisbe]

I get about 2.5 turns out of them. I ended up using about 1.5 turns from soft on all four corners. Seemed to work well. I didn't try making any adjustments between runs, so I don't know if something else would work better or not. I did get better times by moving my tire pressure up some. I ended with a cold pressure of 37 in the front and 35 in the rear.

 

[ConeCrusher281]

With the tokicos, I go 2 turns in front and full hard in the back. But to really get it fine tuned, use tire pressure like you mentioned

 

[98cobraRx]

You need to provide us with some info buddy. I am not as concerned about your suspension set up as what the car was doing. Was it pushing? Were you having a hard time putting down power? I run koni yellow front is 1 and 1/2 to 2 turns from soft (depending on the surface) and 3/4 turn from soft in the rear. I am running 875 lb springs in the front and 300 lb in the back. I would also say try 36lbs pressure in the front and 32 or 33lbs in the rear.

 

[David Hester]

^ Agree.
If you raised tire pressures, similar to going tad stiffer on shocks/struts.
I've found shock/strut tuning affects intial turn in more than anything.
Nothing wrong with going full firm at the lot, then fine tune with tire pressure.
That will vary from event to event, depending on surface (smooth or bumpy?), ambient temp (how warm tire get), and weather (wet/dry). Full firm will help with intial turn-in by slowing weight transfer, handy for slaloms and tight corners. Things will happen a tad quicker full stiff. If you have trouble keeping up, soften a notch.
Autocrossing and road racing, I go full stiff unless it is wet or bumpy, then go softer. I have the D-Specs, also.

 

[blacksheep-1]

One cautionary tale that involves tire pressure. More psi will (also)allow the tires to warm up faster than less pressure. Something that is needed at most autocrosses, there is also a significant difference between "autocross" and "road race" tires. The compound make up of the a/c tires will adhere much faster when cold and need less warmup than race tires sued as autocross tires. (and visa versa which can mean that a/c tires will "chunk or blister at a road race course)