Desert Dynamics Spring Rates

[acefuture]

So I'm going down the road of getting my car correct. It's never quite been right. It's a DD sand car chassis, car weighs about 2600lbs without people in it. Don't know exact corner weights unfortunately. Here's my dilema; my car has 2 interesting features. The original springs on it are completely unknown. They aren't king, eibach, hypercoils, etc. and have no markings on them. They've also been powdercoated about 15 times. I also have coilovers that do not run any nitrogen, they are essentially a coil carrier. I may change that later with a new cap and turn it into an emulsion shock. 

So I'm starting from scratch. I had a shock guy rebuild them for me since I kind of botched it the last time I did it. And we ordered some new eibach springs. The fronts are a good starting point, but the rear is wear I'm stumbling. We started with a 275 over 350 to see how the car sat, then would make adjustments. It was so soft the car sat on the ground. So we jumped it up to a 400 over 500. The car is obviously higher, but I need another 4" to reach correct ride height. So we're bumping up to a 500 over 650. When I input numbers into a spring rate calculator it says 400 over 550 or in that range. What are other DD owners running? I know there's some drastic differences in cars, but want to get a pulse. We'll get to valving, secondaries, tuning etc once I get the correct ride height.

Photos of the car for reference with original springs on the rear





Photos of the 400 over 500

 

[Bobalos]

I dont have a DD, but my A-Arm PSD which sits just a hair over 2600 Lbs w/fuel & w/o passengers has these.

 

[Rockwood]

So I'm going down the road of getting my car correct. It's never quite been right. It's a DD sand car chassis, car weighs about 2600lbs without people in it. Don't know exact corner weights unfortunately. Here's my dilema; my car has 2 interesting features. The original springs on it are completely unknown. They aren't king, eibach, hypercoils, etc. and have no markings on them. They've also been powdercoated about 15 times. I also have coilovers that do not run any nitrogen, they are essentially a coil carrier. I may change that later with a new cap and turn it into an emulsion shock. 

So I'm starting from scratch. I had a shock guy rebuild them for me since I kind of botched it the last time I did it. And we ordered some new eibach springs. The fronts are a good starting point, but the rear is wear I'm stumbling. We started with a 275 over 350 to see how the car sat, then would make adjustments. It was so soft the car sat on the ground. So we jumped it up to a 400 over 500. The car is obviously higher, but I need another 4" to reach correct ride height. So we're bumping up to a 500 over 650. When I input numbers into a spring rate calculator it says 400 over 550 or in that range. What are other DD owners running? I know there's some drastic differences in cars, but want to get a pulse. We'll get to valving, secondaries, tuning etc once I get the correct ride height.

Photos of the car for reference with original springs on the rear

View attachment 49328

View attachment 49329

Photos of the 400 over 500

View attachment 49330

View attachment 49331

You can calculate spring rate based on number of coils, length and wire diameter.

Is the picture above with 4" of preload?

 

[acefuture]

I dont have a DD, but my A-Arm PSD which sits just a hair over 2600 Lbs w/fuel & w/o passengers has these.

View attachment 49340

Awesome, thanks for the info

You can calculate spring rate based on number of coils, length and wire diameter.

Is the picture above with 4" of preload?

Unfortunately the springs on the car did not correlate with any other spring manufacturer when cross check number of coils, length and wire diameter. They are really odd springs.

The top pictures are with the old springs on, at 3.5" of preload. Car does not ride as it should

Bottom pictures are with new springs (400 over 500) at 1" of preload

 

[Rockwood]

Awesome, thanks for the info

Unfortunately the springs on the car did not correlate with any other spring manufacturer when cross check number of coils, length and wire diameter. They are really odd springs.

The top pictures are with the old springs on, at 3.5" of preload. Car does not ride as it should

Bottom pictures are with new springs (400 over 500) at 1" of preload

Have you measured ride height with the paddles on it?  The loaders will bias weight towards the rear from rake.

 

[J Alper]

On the Same car, with a Iron LS, i ran, 650 over 700 in the rear, the front I have 200 over 250, 

 

[acefuture]

On the Same car, with a Iron LS, i ran, 650 over 700 in the rear, the front I have 200 over 250, 

Awesome thanks Jason

 

[acefuture]

Have you measured ride height with the paddles on it?  The loaders will bias weight towards the rear from rake.

I set the ride height with original springs and paddles on it, then put it on loaders. So I know where the ride height should be with the loaders and I'm 6 1/2" off from ground clearance, And 4" off from exposed bypass shaft

 

[Rockwood]

I set the ride height with original springs and paddles on it, then put it on loaders. So I know where the ride height should be with the loaders and I'm 6 1/2" off from ground clearance, And 4" off from exposed bypass shaft

I’m saying the backwards tilt from the loaders will put a little more weight on the rear axle.  If the chassis is level (blocks under the loaders), no big deal, but the perma-wheelie might skew a bit.

Either way, your spring weights are pretty close to what Shock Talk set up for my buddy’s DD with LS1/2D. Had to up them for his iron 6.0/S4, but not sure what the weights are. 

 

[L.R.S.]

So I'm going down the road of getting my car correct. It's never quite been right. It's a DD sand car chassis, car weighs about 2600lbs without people in it. Don't know exact corner weights unfortunately. Here's my dilema; my car has 2 interesting features...

I'll have my scales at Roadrunner this weekend of you want to weigh your car.

 

[J Alper]

Awesome thanks Jason

Dominic has the same car with a aluminum block and we did 550 over 650 in the rear, with the tubular rear arms,  best upgrade was the class 10 shock towers for the front, i can cut some out, by play with the spacers (moving each shock farther out) i did 12'' shocks and the bypass is now a 2.5'' 

Also on my blue sandcar, i did shock buckets like the buggy works 10'' travel car, so dong buckets on the sand car chassis you can run 12'' shocks also, will look like a extreme echo 1 arm,