Rear Coil Input - Softer Spring Rates?
 

Howdy,

A lot of people have actually posted threads about having rear coil sprigs that are too soft and significantly limit payload. I'm actually in the opposite boat and that's by design. I'm running what I refer to as a hybrid rear suspension. It has a full dual air bag setup but also with coils. I won't bore you with all my reasoning for doing it this way.

I installed Western Chassis 6" drop coils. I assumed these would be overly soft springs but they seem very, very hard without ANY air bag support. I haven't been able to ID the spring rate but did notice these are NOT progressive coils. Anyone try running Western Chassis drop coils?

At this point, I'm only able to identify progressive coils as one potential solution, but I'd hate to send the $200 only to find they are also too hard.

Would anyone happen to know if there are other auto applications with softer spring rates that are compatible with for our lowered trucks?

My goal is to use my air bags to adjust the overall ride quality in the rear. So I'm seeking fairly softer springs. Also gives me the option to actually use my truck as a truck.

Re: Rear Coil Input - Softer Spring Rates?
 

This is an interesting question since, as you mention, most do not want a softer spring in the rear. I don't know the specs on all the different springs available (and there are quite a few!) but I have experience with several.

I've had heated stock springs that dropped the truck about 4". To be honest, these weren't that bad when cruising and I could load them down to max payload with no problem. Ultimately I decided this wasn't the "right" way to do things.

Then I went to a 5" ECE. This spring was very soft compared to my heated stock spring. It was also quite low, requiring a C-notch. I would bottom out routinely with this spring. One time I put a couple hundred pounds of dirt in the bed and the truck was completely bottomed out on the ride home. The only travel I had was in the tire sidewalls. That made for a very bumpy ride! I've heard that this is just a Chevelle spring that also fits the C10, but I've never confirmed that. This may be why it's so soft in a truck.

Lastly, I moved on to a 4" HD spring from CPP. This spring is definitely the best I've tried so far. It has a nice ride quality. A touch on the firm side, but it pairs well with the 3" CPP drop springs I have on front. I'm getting about +/- 3" of suspension travel with this spring. It also performs admirably with some weight in the bed. I've had it loaded close to 700 lbs and it still rode really well. I didn't even bottom out at all.

I had considered the airbag trick that you talked about, but after going with these 4" springs I don't think I need to do that. The ride height is where I wanted it and I can still haul some stuff around. Hope that helps!

Re: Rear Coil Input - Softer Spring Rates?
 

I considered getting the 4 inch CPP HD Springs that they say are for Suburbans, but I was afraid, I would not really get 4 inches of drop in a truck with a lighter rear.

Do you think you really got the 4 inches of drop?

I had the regular 4 inch CPP on another truck and always thought the rear looked slightly sagged and the springs seemed super soft.

Re: Rear Coil Input - Softer Spring Rates?
 

cpp uses the springs from a chevelle to lower the rear end of our trucks and most of the time, those are the springs that people say are too soft.. ( well yeah, theyre car springs) if youre looking for some give, those might be the way to go

Re: Rear Coil Input - Softer Spring Rates?
 

I wish I could have measured before/after, but with the way I did my suspension work it wasn't really possible. I will say, when I add up all the things I did to lower my truck it does sit about where I expected it to, so I probably did get close to 4" out of those springs.

Re: Rear Coil Input - Softer Spring Rates?
 

You might try talking to these guys. When I was at body shop we had a customer who used them to make custom springs for a Jeep FC 170 project.

https://springworks.com/pages/coil-spring-service

If the Chevelle springs fit then there are several options there for you. As GM had different springs for 2 door A-bodies, 4 doors, station wagons, and El Caminos.

Re: Rear Coil Input - Softer Spring Rates?
 

Great idea on the Chevelle springs or A body springs.

I do see Chevelle springs generally lower our trucks by 2"? So a 1" Chevelle drop coil results in a 3" drop on our C10 trucks.

I ran into BMR progressive springs, P/N SP015R, which is only $120 for a progressive. Reviews show these coils drop a Chevelle by 3" to 3.5" (they are marketed as 2" drop). Even found guys saying the CCP coils are terrible and replaced by the BMRs.

Variable 125-200 lb/in spring rate which is pretty darn soft. Hopefully not too soft for the BMRs

My experience with CCP is awful and never recommend their products. Horrible customer service too. Buyer Beware.

Let u guys know how they turn out.