double adjustable shock settings for the rear

I picked up some Viking DA coil overs for my ladder bar setup. Need to know where to start. They have 19 positions on the adjuster. Rear springs are 150#, car is 50/50 weight distribution and 3000#. Leaving off the trans brake at 4400 with 5000 stall and C6 with 2.40 first. Power is around 900, front is MII suspension that has QA1 singles at the 5 setting to keep it down.
I've seen recomendations opposite. Viking says low compression number and higher rebound for any suspension but I read that 4 link settings are opposite. Now I dont know what to believe.
If you have some experience here with a ladder please respond.
Thanks

IMO one generic rear shock valving starting point for both ladder bars & aftermarket 4-links with a big tire/no power adder/bracket-ish combo can be somewhere in the 50-60% tight on the extension/rebound valving, & 40-50% tight on the compression/bump valving (and TNT/work from there). And big tire/power adder combos can be somewhere in the 70-100% tight on the extension/rebound valving, & 60-90% tight on the compression/bump valving (and TNT/work from there). How aggressive the shock's installed valving is will also play a part too.

Other methods some people use are (A) the "start eveything at 100% full loose and work tighter" method (never liked it) & the flip side (B) "start eveything at 100% full tight and work looser" method (meh, sometimes it works ok).

That setup will most likely want a tighter setting. 4400 launch with a c6 will be hell on a shock.

Looks to me like no one can tell him what it wants until you know if it is separating or squatting on the launch.

So 50/50 setting until you figure out what it wants.

My car works the best with neutral or no movement of the suspension.

So from what Dave and Cool says the shocks need to be high up in adjustment and the rebound should be almost twice the compression. Tires are 32x14 trying to go in the 1.20s on the 60ft.
Compression at 8
rebound on 14

IDT-572 wrote:Looks to me like no one can tell him what it wants until you know if it is separating or squatting on the launch.

So 50/50 setting until you figure out what it wants.

My car works the best with neutral or no movement of the suspension.  

Our cars are very similar except for the glide which is a big difference. So you think that I should go 10 and 10?
Then tune it to the best reaction. Most ladder cars should be flat witnout seperation or squat?
I dont want to spend an entire day tuning shocks.

You can adjust the shocks a bunch and probably not see much difference with that heavy of a spring. I would put a lighter spring on to start.

whatbumper wrote:You can adjust the shocks a bunch and probably not see much difference with that heavy of a spring.  I would put a lighter spring on to start.  

that's the spring that they recommended.

i will be running a 150# spring on my 4000lb deal .... just saying ...i think you need a different spring as per whatbumper said

What length spring did they recommend with that 150# rate??

All the spring does is hold the car up basically but I wouldn't go too soft and be jackn it all up with the adjusters. Leaving @ 4400 with a c6 and ladder bars you will definitely get separation in the rear suspension. Get some good video of the back tire if you can.

Most in our camp run a 12" 110 spring we have 2 guys using a 125 rate but them guys are bolt action (stick shift) and we are around the 2800-3100 rang in weight

gmsmkr wrote:What length spring did they recommend with that 150# rate??

12 inch springs the adjuster is about 1.5 inches up to get the right ride height and shock spacing.

Well I think that's heavy too... But you got them by the company rec so give them a shot new springs ain't very expensive if you feel they won't work.

Their recommendation was based on first gear ratio and not necessarily car weight.   The problem with recommending on gear ratio is it's different to what most others have with this type of setup (glide) and most don't know how to compare.   Not anything negative intended,  just a fact we run in to.

I'd put them somewhere in the middle and adjust from there. If it deadhooks then tighten the extension.

A 150lb rear spring might sound kinda stiff for 3000lbs, but this car is sitting at 50/50 on aprox an 108" wheelbase. It's not a shorter wheelbase heavier nose/lighter ass combo like a Fox body setup. Another thing to think about is these 150lb springs might not be too heavy/be in the ballpark since he mentioned having to spin-up the spring perches X amount to reach Viking's C/C installed height spec. Or it might need 130, or 110, or ???, only testing will tell for sure.

Dave De wrote:...............the rebound should be almost twice the compression........
Compression at 8 rebound on 14

Counting from full-loose my bracket/no power adder 50-60% tight extension starting point suggestion equals 9.5 to 11.4 clicks on a 19 click adjustment range. And 40-50% tight compression starting point suggestion equals 7.6 to 9.5 clicks on a 19 click adjustment range.

The power adder suggestions (70-100% tight E & 60-90% tight C) workouts to 13.3 to 19 tight E & 11.4 to 17.1 tight C.

Dave De wrote:..........I dont want to spend an entire day tuning shocks.

But that's sometimes part of the deal. Besides you paid for it, you may as well make use of the extra adjustability & see what it does since it's there.  

DILLIGASDAVE wrote:A 150lb rear spring might sound kinda stiff for 3000lbs, but this car is sitting at 50/50 on aprox an 108" wheelbase. It's not a shorter wheelbase heavier nose/lighter ass combo like a Fox body setup. Another thing to think about is these 150lb springs might not be too heavy/be in the ballpark since he mentioned having to spin-up the spring perches X amount to reach Viking's C/C installed height spec. Or it might need 130, or 110, or ???, only testing will tell for sure.

This car was four corner weighed and I'm too lazy to pull the paperwork. It is heavier in the rear something like 53 % to 47% front. So the rear is around 1600 and some change. It is getting a good compression distance with the 150s. If Viking had 130s I would have gone there.
Dave-  I think I'm going to use your setting to start and go from there but leave off the brake at 4000 until its sorted out. It is a 108" wheel basd.

Thanks for your help and yes keep the shiny side up. I will report back on Monday after test. I hope the prep is halfway decent.

Dave De wrote:.....heavier in the rear something like 53 % to 47% front.....

Wow, that's a lot of rear bias. Got any pics showing how much engine setback the car has in relation to the front spindle C/L? Or possibly a measurement from the rear axle C/L forward to the engine mid plate?

Still using solid mounts on the engine with a semi flexible trans mount. The front of the balancer is roughly an inch behind the centerline of the spindles. That weight bias was with a D9 block. Now with the a460 its probably not as good. Another factor is the full 4" exhaust with Flowmaster 44s with tailpipes adding another 100 pounds to the rear.

Returned from the backup track because the primary track had new concrete poured 2 weeks ago and it got tore up on Saturday.
Best shock setting was 6 compression and 17 rebound. Ive had a hard time getting the car to leave staight it picks up and goes right. Slicks were swapped as well and it continues to go right. Best 60 today was 1.33, best 1/8 was 5.89 with major correction to go straight. The only full 1/4 was 9.21 at 147
I was entered in the trophy run to get a better test series and went out in the final round with an .014 RT

Dave De wrote:.............Ive had a hard time getting the car to leave staight it picks up and goes right. Slicks were swapped as well and it continues to go right.........

If there isn't anything mechanically wrong with the car/suspension (like staggered slick air pressures side-to-side, slick OD rollout measurement different side-to-side, dead/worn out front or rear springs side-to-side, staggered shock spring perches spun-adjusted to different heights side-to-side, something bent/broken/binding somewhere in the suspension, rear housing not sitting square in the car, incorrect wheelie bar height stagger, etc, etc, etc), then it sounds like a simple ladder bar side-to-side preload adjustment might be needed.

[edit] And of course it's always possible the track was just junk that day.

DILLIGASDAVE wrote:

Dave De wrote:.............Ive had a hard time getting the car to leave staight it picks up and goes right. Slicks were swapped as well and it continues to go right.........

If there isn't anything mechanically wrong with the car/suspension (like staggered slick air pressures side-to-side, slick OD rollout measurement different side-to-side, dead/worn out front or rear springs side-to-side, staggered shock spring perches spun-adjusted to different heights side-to-side, something bent/broken/binding somewhere in the suspension, rear housing not sitting square in the car, incorrect wheelie bar height stagger, etc, etc, etc), then it sounds like a simple ladder bar side-to-side preload adjustment might be needed.

[edit] And of course it's always possible the track was just junk that day.

This is the second time out where its picking up and going right that happened at different tracks. The shock height settings are equal for both sides and the car sets parallel to the ground. There is preload on the ladder bar. The car was on a rack this year to have the rear end squared up.
I am going to switch the QA1s up front and see what happens.
No wheelie bars on this car.

String it to check the tracking and pull a tape on the wheelbase. Depending on how narrow your ladder bars are you may take the left bar down and turn the front joint in half a round and fix it. A little adjustment goes a long way sometime.

Before you go to crazy with the shock swapping. Id take the preload out with the driver in the seat and full race trim. Start from there