MG Metal Works DIY kit knowledge share

[Lilnuts2]

MG do you know what the rate of the CC880s is? The SSC-31 is 5000# I know Moog lists an inch rate. I'm trying to compare the overall rate between the 2 springs.

[Houstonredrider]

Ins Diam Bar Diam Rate Load Install H Free H
CC860 4.03 0.81 512 1510 15.5 18.31
CC860S 4.03 0.83 549 1797 16 19.27
CC880 3.98 0.78 589 1850 13 16
CC880S 4 0.81 652 3006 12 16.6

[b. rock]

Have the SSC-31s settles in at all? We see a fair amount of washboard, including the road we live on, so a stiff ride isn't quite what we are looking for.

[mgmetalworks]

Originally Posted by b. rock

Have the SSC-31s settles in at all? We see a fair amount of washboard, including the road we live on, so a stiff ride isn't quite what we are looking for.

They're actually pretty good for ride quality. Better than I originally expected out of them. I put on a set of the SumoSpring bump stops and those helped a lot for bigger bumps/potholes. I do also have Agile Offroad tuned shocks up front. It all adds up to a pretty nice ride considering the weight up front with the Cummins/Allison and big steel bumper.

[b. rock]

Well I have 2 out of those things so far. Haven't yet decided on a front bumper but it's in the works for the next year or so. I really like the look of the F-series ARB but I can only copy your van so much, ha.

Good to know on the springs though. I've had vehicles with stiff front ends and it's been tough to deal with them on rough surface roads with much velocity, or to get much of any flex off road.

I have a set of Fox shocks, monotube with an off the shelf tune. We'll see how they do.

[Lilnuts2]

Originally Posted by Houstonredrider

Ins Diam Bar Diam Rate Load Install H Free H
CC860 4.03 0.81 512 1510 15.5 18.31
CC860S 4.03 0.83 549 1797 16 19.27
CC880 3.98 0.78 589 1850 13 16
CC880S 4 0.81 652 3006 12 16.6

I'm trying to compare the SSS 31's rate to the CC880s to determine how much stiffer the 31 spring is, is it 10% 20% etc


Is the CC880s rate (load) 3006# compared to the SSC 31s 5000#?

The difference in rate between the CC880 and the CC880s is confusing. The rate on the S spring only slightly higher then the non S spring, yet the Load 70% heavier on the S spring.
The S spring is .6" longer and heavier, yet when installed it's an 1" shorter then the non S spring?

Coming from a motorcycle racing background it amazes me how the auto industry is so vague about springs rates and doesn't use a common measuring method. The Jeep springs crowd is the worst for this.

This applies mostly to coil springs.

If they published the overall uninstalled height of the spring then listed how much pressure (rate in lbs) to compress it per inch, for every inch until coil bind. You could weigh the front of your van and know very precisely what the ride height would be and with the total compressed height you would know how much travel you would have left in the spring before total coil bind for every different spring on the market that fits your van. Because the springs on our vans have no adjustable preload there is no real variance. You can't preload the spring an 1" to change ride height like a race car or truck. So the spring is always going to act the same, we have no adjust ability. If it takes 1000# to compress spring A 2", no matter what van you put that spring on, it's going to take 1000# to compress it 2"

Some people like progressive rate springs, some like straight rate springs. With this measuring standard you would know exactly what you were buying and have a pretty good idea of how it was going to perform.

With this info the size of the wire, number of coils installed height wouldn't matter. The installed height is relative to each vehicle anyway.

Then 4x4 conversion and suspension companies could publish the exact ride height their system was designed for. So if you wanted to add a snow plow on the front of your van, you would know exactly what springs to buy for your custom needs. Or if you varied out of that designed height at least you would know it and could adjust accordingly.

We all want the best ride we can get in our vans, but the coil spring industry isn't helping much at all. If you pay for custom rear leaf springs they build a pak that fits your needs. You can't build a pak for a coil spring, so at least tell us what it is going to perform like so we choose which spring works for our van.

Rant over.

[Houstonredrider]

On the Moog info I posted, it is quite consistent. Keep in mind, that the install Height is the height of the spring once is under maximum load. When you install different springs on the same vehicle, the load is the same, that's why you get clearance gains with a stiffer spring (all things being equal).

On the Moog table, if you divide the Max load by the stroke (Free H- Install H) you will get the publish rate. Being variable rate, the calculate rate is most likely and average as the initial stroke will be softer.

The SSC31 only info I got is that the load is 5000lbs and the height is 16.25". Somewhere also read that they will not change the vehicle height (Which vehicle? I do not know)

[Lilnuts2]

Houston, I follow your Moog reasoning on comparing their to each other.
If I use similar math to try and figure out the rate of the SSC31

The two springs are very similar in height.
16.25" - (assuming around a 12" installed height) =4.25

5000# divided by 4.25= 1,176# !!

That rate is 524# heavier then the CC880S spring, how is that possible?

Even if the installed height was 10' that is still a 800# spring.

And you have 2 springs so the difference is doubled.
The combined rate of the heavier springs means you would have to add over a 1000# to get near the same rate as the CC880s springs.
It's my understanding 7.3 owners have used the 880s springs and were happy. So how could you add 1000# heavier springs and have it even move.

This is where I'm not understanding the relationship of these two spring rates.
Not trying to beat this to death, just trying to understand.

[Houstonredrider]

Your math is correct. And I was getting the same number. I think what we are doing wrong is the assumption that the install height is reached with 5000 lbs. It seems that the height with the van weight (W) is similar to that on the 880s.

If they initial height (Hi) and the final height (Hf) are similar and W is the same, then both springs have similar Rate. The difference is probably that the 880s is progressive and at 3000lbs is bottomed out and the SSC31 being constant rate can compress further until it bottoms out at 5000 lbs.

[winnievan]

Does anyone know what the carrier break is on the Sterling E-Locker? I found a killer price on a 3.55 gear rear axle, but I really want to go with 4.30 gears.

At this price -- makes sense to pull it apart and change the gears, but I'm not sure if the e-locker carrier can accommodate the lower gears.

Anyone know for sure?