Suspension : Stock spring replacement for softer ride

Grumpy Bear · December 9, 2020

1 hour ago, Yondu said:

I understand what you're writing here, but that's just a whole lot of math. I will add my 1" front leveling spacer is closer to 5/8 thick, so if it is 1" it's not a 2:1 ratio.

Another random factoid is CST makes double adjustable coilovers for our trucks that use 650lb springs for the crew cab 4wd, 600 for the 2wd. I believe you have a regular cab 2wd v6? I assume my truck would be quite a bit heavier. Most coilovers for our truck are 700lb. I'm hoping my springs are 650-675 now but I'm not smart enough to figure it out. Free standing height and coil length appeared to be identical to the stock spring I pulled off.

The leverage ratio is D2 / D1.

D2 is not to the center of the wheel but to the center of the lower ball joint.

How thick your spacer needs to be to move the ball joint 1" also depends on the shock angle at ride height.

Angle from vertical obviously increases the spacer thickness to achieve the required displacement

That kit builder has no idea what wheel width/ offset / tire height / knuckle combination/ UCA length your using and wouldn't care anyway. He isn't building a custom setup. His point of reference is the lower ball joint.

His number is 'nominal' not absolute.

And yea stock LCA ratio; it's 2:1

Grumpy Bear · December 9, 2020

Just now, Grumpy Bear said:

Another random factoid is CST makes double adjustable coilovers for our trucks that use 650lb springs for the crew cab 4wd, 600 for the 2wd. I believe you have a regular cab 2wd v6? I assume my truck would be quite a bit heavier. Most coilovers for our truck are 700lb. I'm hoping my springs are 650-675 now but I'm not smart enough to figure it out. Free standing height and coil length appeared to be identical to the stock spring I pulled off.

No idea about what spring CST uses. If you say 700# then 700 it is. My setup is King OEM. They have ONE OEM coil-over for ALL the K2's and all are fitted with the same 750# spring, linear piston, same 12-flutter-12 valving, 250 psi N2, zero preload and medium mineral oil shock fluid. I also have no idea what the rate was of the stock spring. It was a progressive spring thus without a linear rate.

But yes it would require a lighter spring to get the same installed and on the ground coil length.

lucas287 · December 9, 2020

11 hours ago, Yondu said:

I hesitate to mention ride quality changes because I just haven't driven much. I have a work vehicle and with Covid....well my 26 month old truck has 9950 miles, so that shows you how much I drive it! It is softer in the front of course and I still have the Bilsteins in the back. Partially because I want to evaluate this setup first, partially because I ran out of time. I do have the Koni rear shocks and will most likely install them.

I will update some more hopefully next week when I have some more miles on it.

My biggest complaint about the Koni's is they're a bit stiff on the compression side. The rebound side is much better than OEM, but OEM had softer compression for sure.

Also, I don't think those CST coilovers are "double adjustable" unless I missed something. That's what so appealing about the Vi-King setup! You can spec whatever coil spring you want to run AND independently adjust compression and rebound to YOUR liking.

Yondu · December 20, 2020

When I was looking at CST I talked to a rep there and he was telling me about the adjustable reservoir version that wasn't on their site, but it was a while ago so perhaps they're not double adjustable, I thought I remembered that though.

As a final update-

When I first put sulastic springs on the back I felt it made the rear a little bit softer than the front, so the front was the more harsh part of the truck. After the softer front springs and Koni front struts l, I determined it does ride nicer and again, I feel the rear is a bit harsher again. As a reminder, at this point I still have Bilsteins out back.

After a week or so of this, I decided to put the rear Koni shocks in. The truck rides even better yet. It finally rides like it should, how I remember previous Chevy trucks when they were new. Comfortable, good balance of soft and complacent. Firmer than something like a minivan or crossover for sure, but not harsh. I no longer notice even the tiniest of pavement marks, cracks are felt but not really noticeable or distracting.

Summary of modifications-

Front -

-4wd Tahoe front springs. Ended up lowering the front 5/8". My truck never say really really low up front like I see some trucks though (seems like more often double cabs)

-1" lower strut spacer, so the front sits about 3/8" higher than stock.

-Koni front struts.

Rear

-Sulastic shackles. - these essentially give the rear leafs a 3rd stage. They make the rear springs softer until they reach the limiter then they have no real effect on ride quality. I have firmer than normal ones but since they replace a solid shackle, they do make the rear springs softer and better isolated.

-Rear Koni shocks.

These mods may not be for everyone and It's about $875 (I spent a lot more doing my trial and error) but I paid too much for this truck to not like the ride. Since I live in the north we have a temp swing of over 150 degrees summer to winter and the roads get rough. If I lived in the south, where I noticed roads are usually smoother maybe I'd like the Bilsteins. I don't care for the 5100s myself, but if you like a firm ride they're probably a better way to go.

On 12/9/2020 at 9:54 AM, lucas287 said:

My biggest complaint about the Koni's is they're a bit stiff on the compression side. The rebound side is much better than OEM, but OEM had softer compression for sure.

Also, I don't think those CST coilovers are "double adjustable" unless I missed something. That's what so appealing about the Vi-King setup! You can spec whatever coil spring you want to run AND independently adjust compression and rebound to YOUR liking.

Edited December 20, 2020 by Yondu

Grumpy Bear · December 20, 2020

12 hours ago, Yondu said:

When I was looking at CST I talked to a rep there and he was telling me about the adjustable reservoir version that wasn't on their site, but it was a while ago so perhaps they're not double adjustable, I thought I remembered that though.

As a final update-

When I first put sulastic springs on the back I felt it made the rear a little bit softer than the front, so the front was the more harsh part of the truck. After the softer front springs and Koni front struts l, I determined it does ride nicer and again, I feel the rear is a bit harsher again. As a reminder, at this point I still have Bilsteins out back.

After a week or so of this, I decided to put the rear Koni shocks in. The truck rides even better yet. It finally rides like it should, how I remember previous Chevy trucks when they were new. Comfortable, good balance of soft and complacent. Firmer than something like a minivan or crossover for sure, but not harsh. I no longer notice even the tiniest of pavement marks, cracks are felt but not really noticeable or distracting.

Summary of modifications-

Front -

-4wd Tahoe front springs. Ended up lowering the front 5/8". My truck never say really really low up front like I see some trucks though (seems like more often double cabs)

-1" lower strut spacer, so the front sits about 3/8" higher than stock.

-Koni front struts.

Rear

-Sulastic shackles. - these essentially give the rear leafs a 3rd stage. They make the rear springs softer until they reach the limiter then they have no real effect on ride quality. I have firmer than normal ones but since they replace a solid shackle, they do make the rear springs softer and better isolated.

-Rear Koni shocks.

These mods may not be for everyone and It's about $875 (I spent a lot more doing my trial and error) but I paid too much for this truck to not like the ride. Since I live in the north we have a temp swing of over 150 degrees summer to winter and the roads get rough. If I lived in the south, where I noticed roads are usually smoother maybe I'd like the Bilsteins. I don't care for the 5100s myself, but if you like a firm ride they're probably a better way to go.

Good work here. :thumbs: True Hot Rod spirit. Best solution isn't always in the computer under make/model/year.

Yondu · December 23, 2020

On 12/20/2020 at 11:01 AM, Grumpy Bear said:

Good work here. True Hot Rod spirit. Best solution isn't always in the computer under make/model/year.

Thanks Grumpy. Once a tinkerer always a tinkerer. I can't help myself, always messing with something. I've been driving it a lot this week due to having some extra time off and I'm really happy how it turned out. As a package, it all works together nicely.

Grumpy Bear · December 23, 2020

4 minutes ago, Yondu said:

Thanks Grumpy. Once a tinkerer always a tinkerer. I can't help myself, always messing with something. I've been driving it a lot this week due to having some extra time off and I'm really happy how it turned out. As a package, it all works together nicely.

They make it much harder these days but the best and cheapest route is often OEM interchange/exchange parts. Ford use to, in the 60's/70's have books on this listing all the alternate parts that would fit/work. I built some thunderous 352's from FE exchange books. You can build an FE Ford between 332 and 445 CID in almost one inch increments with stock parts and a good machine shop. Books like these use to list all critical dimensions. Finding valve swaps was easy. Tinker on sir!!

lucas287 · March 10, 2021

@Yondu have any longer term thoughts on the front Tahoe springs? I'm considering doing this too! This ox cart ride has gotten old real quick.

Yondu · March 10, 2021

Lucas, the Tahoe springs ended up dropping the front about 5/8", maybe 11/16. Given that you would definitely want a 1" lower strut spacer. I have had no issues.

Can't say how much the springs helped as I did it at the same time as the koni shocks. I'd also recommend the sulastic rear springs too, as they helped a bit.

Finally, what size and type of tire are you running?

lucas287 · March 10, 2021

1 hour ago, Yondu said:

Lucas, the Tahoe springs ended up dropping the front about 5/8", maybe 11/16. Given that you would definitely want a 1" lower strut spacer. I have had no issues.

Can't say how much the springs helped as I did it at the same time as the koni shocks. I'd also recommend the sulastic rear springs too, as they helped a bit.

Finally, what size and type of tire are you running?

Yeah for sure hard to differentiate and give credit when multiple variables changed. I also have the Roadmaster Active on the rear to help with axle wrap since my traction bars didn't work out (they bind the articulation of the rear and make it worse). The roadmaster feels pretty good overall but I've got them cranked to their max to prevent axle wrap which makes them quite stiff/bouncy. Still better than stock shocks/no roadmaster though.

Currently running 275/55R20 Michelin Defender LTX. I gave up fighting Discount on them. One tire took about 4 oz and the rest took 6+ to balance. Have had them road force several times and tried different locations etc.. I even have intentionally done some wicked burnouts to round them out but I think it's just a sidewall stiffness variation. So that definitely contributes to the ride quality on the highway. And the 55 sidewall isnt doing me any favors either. Plus Michelins are pretty stiff anyways in my experience.

Long term plan is King 2.5s all the way around tuned by Thuren. Probably stage 2/1 front to rear. Then I'll put a set of Black Rhino Chase 17x9 and P285/70R17 probably Toyo Open Country. Between the sidewall increase and the Kings it should be a transformed ride quality.

Just looking for a bandaid between now and then. Might just go back to no sway bar for now. I've had it off 3 or 4 times experimenting and there's no denying it smoother without it.

Yondu · March 10, 2021

I just swapped my cooper at3 4s 285/70r17 tires (standard load) for my stock wheels with 265/65r18s and it rides sooo nice, a improvement over the off-road tired. I'm planning on putting on 275/65r18 tires of the same design but with white letters.

Aggressive tires aren't for me. Expensive lesson.

Yondu · March 10, 2021

4 hours ago, lucas287 said:

Yeah for sure hard to differentiate and give credit when multiple variables changed. I also have the Roadmaster Active on the rear to help with axle wrap since my traction bars didn't work out (they bind the articulation of the rear and make it worse). The roadmaster feels pretty good overall but I've got them cranked to their max to prevent axle wrap which makes them quite stiff/bouncy. Still better than stock shocks/no roadmaster though.

Currently running 275/55R20 Michelin Defender LTX. I gave up fighting Discount on them. One tire took about 4 oz and the rest took 6+ to balance. Have had them road force several times and tried different locations etc.. I even have intentionally done some wicked burnouts to round them out but I think it's just a sidewall stiffness variation. So that definitely contributes to the ride quality on the highway. And the 55 sidewall isnt doing me any favors either. Plus Michelins are pretty stiff anyways in my experience.

Long term plan is King 2.5s all the way around tuned by Thuren. Probably stage 2/1 front to rear. Then I'll put a set of Black Rhino Chase 17x9 and P285/70R17 probably Toyo Open Country. Between the sidewall increase and the Kings it should be a transformed ride quality.

Just looking for a bandaid between now and then. Might just go back to no sway bar for now. I've had it off 3 or 4 times experimenting and there's no denying it smoother without it.

So I have an absolutely terrible memory and didn't realize you were the one I was talking to before about this and I didn't scroll up to see old posts.

I was happy with the ride with the suspension and the Cooper tires, I just got tired of the average gas mileage, "tough" look and the Coopers on the Method wheels were never completely smooth. I have pretty bad OCD for smoothness and ride, if it's not obvious. I had them road force balanced 2x and the last time all the numbers were good but one only got down to 24lbs IIRC. I should have pushed for them to try harder or replace it as I bought the wheels and tires there, but I figured I'd give it a shot. 99% of people would drive my truck on the Coopers and not notice any issues. I decided to go back to stock wheels and tires and the ride from doing that alone is significantly better and smoother. It's like riding on a stick of butter it's so smooth and comfortable. When I replace these Goodyear Fortitude HT's it will be with the 275/65r18 version of the same tire. All terrain tires excel off road and you pay for it on road. I expect my mileage will shoot back up to 25-26 again (highway, 5.3 4wd crew).

My opinion isn't what's popular here and I started out wanting Duratracs and a 1" lift. It certainly looked cool and I won't knock anyone here for doing it but it's all a compromise and anyone who says otherwise is blowing smoke or unaware.

lucas287 · March 10, 2021

1 hour ago, Yondu said:

So I have an absolutely terrible memory and didn't realize you were the one I was talking to before about this and I didn't scroll up to see old posts.

I was happy with the ride with the suspension and the Cooper tires, I just got tired of the average gas mileage, "tough" look and the Coopers on the Method wheels were never completely smooth. I have pretty bad OCD for smoothness and ride, if it's not obvious. I had them road force balanced 2x and the last time all the numbers were good but one only got down to 24lbs IIRC. I should have pushed for them to try harder or replace it as I bought the wheels and tires there, but I figured I'd give it a shot. 99% of people would drive my truck on the Coopers and not notice any issues. I decided to go back to stock wheels and tires and the ride from doing that alone is significantly better and smoother. It's like riding on a stick of butter it's so smooth and comfortable. When I replace these Goodyear Fortitude HT's it will be with the 275/65r18 version of the same tire. All terrain tires excel off road and you pay for it on road. I expect my mileage will shoot back up to 25-26 again (highway, 5.3 4wd crew).

My opinion isn't what's popular here and I started out wanting Duratracs and a 1" lift. It certainly looked cool and I won't knock anyone here for doing it but it's all a compromise and anyone who says otherwise is blowing smoke or unaware.

Haha all good Yeah I will ALWAYS get balanced and road force sorted out to my liking within the first few weeks going forward. Discount is real easy to work with if you're polite about it. On my wife's CX-9 I told them up front that I want ALL FOUR tires under 10 lbs RFV and we went through 9 Michelin Premier before switching to Falken CT60 and finally got all four under 10. Smooth as glass ever since. It helps if you rotate at home because I tell them, "look, if you get these perfectly smooth - you probably won't see me until it's time to replace them - because I do my own rotations at home". In short, yes, I hear you! I am very particular when it comes to tires and balancing.

Anyways, I digress. I might try to find some of the same springs on the cheap and swap 'em out just for fun.

If you feel up for it - try taking off your swaybar. Takes about 5 minutes. It makes a difference in NVH for sure. I've had engineers turn blue in the face with frustration telling me "there's no way it changes the ride" or "that's not how it works"... I agree - "in theory" but the reality is that it changes the ride.

Grumpy Bear · March 11, 2021

5 hours ago, lucas287 said:

If you feel up for it - try taking off your swaybar. Takes about 5 minutes. It makes a difference in NVH for sure. I've had engineers turn blue in the face with frustration telling me "there's no way it changes the ride" or "that's not how it works"... I agree - "in theory" but the reality is that it changes the ride.

Yea, about that. Two schools. Heavy springs and no bar or light springs and a heavy bar. I go to school #2. Of course it matters. A sway bar forces both springs to react to one wheels deflection. :wtf:

The whole point of a sway bar it to allow the softest spring possible to be used to allow each wheel the maximum of compliance with the road. Stiff springs and light or no bar only work well on glass smooth tracks.

Grumpy Bear · March 11, 2021

7 hours ago, Yondu said:

My opinion isn't what's popular here and I started out wanting Duratracs and a 1" lift. It certainly looked cool and I won't knock anyone here for doing it but it's all a compromise and anyone who says otherwise is blowing smoke or unaware.

My opinion either, but it doesn't mean you're wrong. Love my Pirelli Scorpion Verde All Season Plus II street tires. Don't need no stink' n road force balancing. Not a tire on her required more than 2 Oz of weights. Smooth as glass.

IMHO RFB is for badly flawed tires.