Photog's Lifted Suspension 2009 Roadtrek 190V

[booster]

Originally Posted by AZ ADVenturist

Hello Brian &/or Booster; I've been following both of your threads on lifting the RoadTrek vans.
First read Brian's on 'Expedition Portal'. You then directed me to this excellent "B" forum - thanks!
We have an '02 Chev. R/T 190V. It is currently in an independent shop in Prescott. The rear has been lifted 2" with blocks (I saw it today - looks good). We are using the Heavy duty truck coils you both suggested in front (should be done by tomorrow). The mechanic has said that he can't/won't do air bags in back because of the 'box frame'. And has shown me that the frame would have to be drilled, weakened & then reinforced somehow to handle airbags. He is also concerned with all the plumbing & wiring running along the frame member. So maybe airbags aren't feasible or cost effective. But, I like the heavy-duty leaf springs that Brian writes about, but wonder if You got any price quotes on them? I'm also considering the rear sway bar that Booster installed, but want to see how it's going to handle with the blocks & coils. I appreciate any addt'l input...
Both of you have provided very valuable info. I look forward to learning more from You.
Thanks very much. Ric. in Ariz.

Airlift and Firestone both make airbag kits for the box frame 3500 vans, so there should be no issue with the couple of small holes you drill in the frame to put them on. I am sure that Airlift and Firestone have done full stress analysis on them, and would be liable for any damage. If you look at the frames, they are pretty much Swiss cheese, with lots of access and tooling holes in them. If you use the air only fill setup (no compressor), you have one airline from each bag to someplace like the rear bumper, and have tire fill valves. Very little stuff to run, and even with a compressor it is just a power line and some extra air lines. I have no idea why your guy would be so scared of them, unless he is worried you are going to go beyond your gross weight limit because you can lift it back up. The shop that did the front springs for us (we did the airbags ourselves) said that they do hundreds of airbags into vans and pickups.

[AZ ADVenturist]

I'm still not real clear on lift provided by 22-1175s. We've already installed 2" blocks. I don't really want or need to go much higher. An inch or 1 1/2" additional would be ok. But I'm mostly concerned with weight bearing & handling. And, we are not going 4wd! thnx.

[AZ ADVenturist]

Booster; Thanks for your reply to my inquiry. I'm thinking this suspension subject is an ongoing exercise until we/I get it right for our individual needs & wants. I've passed all of this on to my mechanic, but not sure that I am qualified to educate him. But he is a Pro. & willing to experiment with my vehicle & my Money too. I think he is cautious though. And I do expect most of these mods. to be functional &/or (mostly) cost effective...
I'll post the results as we achieve them. Regards, Ric.

[Photog]

Originally Posted by AZ ADVenturist

I'm still not real clear on lift provided by 22-1175s. We've already installed 2" blocks. I don't really want or need to go much higher. An inch or 1 1/2" additional would be ok. But I'm mostly concerned with weight bearing & handling. And, we are not going 4wd! thnx.

With the new springs, you may not need the lift blocks.

I don't like lift-blocks. Currently our 4" lift-blocks place the rear 2 inches higher than the front. The front has the Tuftruck springs.

If you were to use the air bags, instead of the 22-1175 springs, you would also not need the blocks. When the bags bring the springs up off the rebound/overload leaf, the rear should be very close to level with the front and the Tuftruck springs.

Just food for thought.

[AZ ADVenturist]

Re: food for thought on springs vs. blocks vs. airbags. I'm sure you are right! Still trying to convince my mech. Blocks are already installed in rear. Coils are going in front today.
I should be able to drive it by end of week & then know more of what the next step is - $$$!
But it's good clean Fun. R.

[booster]

Originally Posted by Photog

I don't like lift-blocks. Currently our 4" lift-blocks place the rear 2 inches higher than the front. The front has the Tuftruck springs.

If you were to use the air bags, instead of the 22-1175 springs, you would also not need the blocks. When the bags bring the springs up off the rebound/overload leaf, the rear should be very close to level with the front and the Tuftruck springs.

Just food for thought.

I am not a big fan of lift blocks either, except in the case where doing it with springs or bags would put too much arch in the springs. This can lead to the axle moving back and forth more than is desired when cornering. A track arm will take care of thT issue, if you have room for one.

The added height with airbags that Photog mentioned are pretty much what we found. Our 07 C190P sat 1" higher in the back than front from the factory, and was on the overload leafs in the rear. The Tufftruk springs took the front up two inches. The airbags (both Firestone and Airlift) gave a bit more than 2" available lift from stock in the rear. Going up an inch with airbags does put use quite level with the front, and off the overload leafs.

[AZ ADVenturist]

Brian, Booster - et al; We got the R/T C190V out of the shop last week. 2" blocks installed at rear & the Tuff Truck coil springs in front. Lift is about even - 2" - front to rear...
HOWEVER, the front bounces with every road imperfection!
Mechanic says the springs are To tall & the front weight is To light for the taller springs.
I say we need longer/stiffer shocks. He says No, that won't help. Upper steering control arms have also been changed, but I don't understand what effect if any that has on the bouncing.
I've reviewed Both of your build threads, but haven't found any reference to my situation with the Bouncing. Any ideas, suggestions, help from your experiences is welcome (needed).
Thanks, Ric. in Arizona

[booster]

Originally Posted by AZ ADVenturist

Brian, Booster - et al; We got the R/T C190V out of the shop last week. 2" blocks installed at rear & the Tuff Truck coil springs in front. Lift is about even - 2" - front to rear...
HOWEVER, the front bounces with every road imperfection!
Mechanic says the springs are To tall & the front weight is To light for the taller springs.
I say we need longer/stiffer shocks. He says No, that won't help. Upper steering control arms have also been changed, but I don't understand what effect if any that has on the bouncing.
I've reviewed Both of your build threads, but haven't found any reference to my situation with the Bouncing. Any ideas, suggestions, help from your experiences is welcome (needed).
Thanks, Ric. in Arizona

We used the 5000# springs and didn't get any bouncing, either with the low mile OEM shocks or the now installed Bilsteins. Both handled moderate bumps about the same, but the Bilsteins were softer on the small bumps and stiffer on the big ones. The springs did make it stiffer in the front on bumps, as it was mushy before, but it only does one bounce in a dip and settles right out. It sounds like your shocks may be worn out, and stiffer springs require higher damping than softer springs, so the springs could be overpowering the shocks.

The other thing you have, that we don't have is that your rear is probably still sitting on the overloads, making it very progressive in spring rate. If the shocks are week, it could be rotating around the rear, bouncing the front. That wouldn't have happened as much before because the front would hit the bump stops and also get very progressive.

[AZ ADVenturist]

Thanks, Booster. Will check the rear. And I'm sure Bilsteins all around are the next step. R.

[Photog]

No bouncing on ours either. On ours, the fronts feel as stiff as before, when we were riding on the yellow jounce bumpers. A properly damped suspension will have one cycle of hysteresis, as it settles from the "bump". It should not cycle up & down more than one cycle. If we drive through a dip, it feels like it went through 1/2 a cycle, as the 2nd 1/2 was so minor as to not be noticed.

If the suspension oscillates more than once, you need new shocks. They can be stiffer on compression or on rebound, or balanced between the two. With the new Tuff Truck springs, our suspension sits in the middle of the travel, and should probably have about equal damping on compression and rebound.

This subject can get deep quickly, and the valving and damping would be be set up different for pavement than dirt. If you want a spring/shock that can be dialed in perfectly for your needs, contact the folks at Boulder Offroad Vans http://boulderoffroadvans.com/gm__chevy_van_lift_kits. They can order a coil-over shock from King Racing Shocks, that will be perfect http://www.kingshocks.com/products/oem/gm-oem/. Based on the price of King's production coil-overs, I would guess the price would be $2000+ for a pair.

Our rigs are heavy, but they don't have to ride so stiff. One advantage we have, over a cargo truck or van, is our weight is fairly stable. Our suspension does not have to transition between an unloaded to an overloaded condition. It is always overloaded. Therefore, we should be able to purchase suspension components that allow our suspension to work perfectly, and smoothly. That is not what comes on a R/T, nor is that what is on my R/T right now. But, I am working on it.

In a previous post, I mentioned a set of leaf springs, part numbers 22-1175. I don't think those will work either. They don't have enough arch, and they will be very stiff. They have 3.5" of arch and a 3700#/spring load rating. That is approximately 1000#/inch of spring rate. OUCH, that is stiff.

[Photog]

Concerning the rear springs:
I have run this calculation a few times. Here are the parameters:
Rear suspension travel of 8 inches. I want the static load to place the suspension in the middle of the travel, leaving 4 inches of upward, and 4 inches of down travel.

When the leaf spring is flattened out, that will be the maximum up-travel point. Assuming the axle down-travel will be limited by the shocks and not by the springs, we will also assume that the bottom of the travel will be at the point where the springs are in their free state.

With these limits, the leaf spring will need to have an 8 inch "free arch" and a 4 inch static-load arch. With the load on the rear axle of 5400#, or 2700# per spring, the calculation looks like this:
(Static Load) / spring compression = spring rate.
or
2700# / 4" = 675#/inch.

So, to compress the rear suspension another inch, we would have to add another 1350# on the rear axle.

This might still be a bit stiff, but it is much better than the 22-1175 springs that are at least 1000#/inch.

It is time to talk with a spring manufacturer.

[Photog]

The latest adjustment to our suspension: Remove front sway-bar.

If you have followed this thread, you know that we replaced the factory front coil springs with a stiffer spring from Tuff-Truck, and added a rear sway-bar. This stiffer spring raised the heavily loaded front suspension up off of the jounce bumpers. Now the suspension has more travel, when we drive through dips, bumps etc. But, these stiffer springs are almost as harsh a ride as when is was riding on the jounce bumpers. It shouldn't be this way.

Background:
The stiffer springs also added roll stiffness. This is a very common side effect of changing spring stiffness. The most common way of changing roll stiffness is to increase/decrease the stiffness of the sway-bar. If you want to maintain the driving characteristics of a vehicle, the sway-bar and springs need to be changed at the same time (i.e. stiffer spring and softer sway-bar, or softer spring and stiffer sway-bar).

We added roll stiffness to our van by adding the stiffer springs, but we did not reduce the existing sway-bar stiffness. Now the roll stiffness is very high. This may or may not be good. Also, the sway-bar can add harshness to the ride. As one tire hits a pothole, the shock is transferred to the frame, through the sway-bar. With a softer sway-bar, less of this pounding is transferred to the frame.

Test:
I wanted to run a test, to see if the new springs offer enough roll stiffness, to reduce or eliminate the sway-bar. I removed the front sway-bar on our 4Runner, when I added stiffer front springs, and it works great.
For this test, I disconnect the sway-bar at one end, allowing each side to travel without involving the sway-bar. On our Chevy van, I also had to re-route the brake line, so it would not contact the end of the sway-bar, when the suspension traveled up/down.

Results:
The Tuff-Truck springs offer plenty of roll stiffness for the front suspension. Now there is a tiny bit of extra roll in the corners, similar to a stock van. If it was set up this way at the factory, nobody would notice any driving issues (with front sway-bar removed & rear sway-bar added). The HUGE benefit is the smoother ride. Small bumps the front tires hit, do not get transferred to the frame, and this really reduces the harshness of the ride. The second benefit is less swaying, when crossing the threshold into parking lots. It seems that the sway-bar didn't allow the font suspension to act independently, and it was forcing the whole van to lean with the front suspension. Now, one tire can rise on its own (to a point). This has decreased the wallowing, when driving over these uneven bits of road work. This week, I will remove the front sway-bar completely.

Since the rear of our van is heavier than the front, I plan to leave the rear sway-bar in place. Also, we plan to replace the rear springs with a softer spring, with more travel. this softer spring will offer less roll stiffness, and we might need to increase the stiffness of the rear sway-bar, to properly balance the system.

[booster]

Originally Posted by Photog

The latest adjustment to our suspension:

If you have followed this thread, you know that we replaced the factory front coil springs with a stiffer spring from Tuff-Truck, and added a rear sway-bar. This stiffer spring raised the heavily loaded front suspension up off of the jounce bumpers. Now the suspension has more travel, when we drive through dips, bumps etc. But, these stiffer springs are almost as harsh a ride as when is was riding on the jounce bumpers. It shouldn't be this way.

Background:
The stiffer springs also added roll stiffness. This is a very common side effect of changing spring stiffness. The most common way of changing roll stiffness is to increase/decrease the stiffness of the sway-bar. If you want to maintain the driving characteristics of a vehicle, the sway-bar and springs need to be changed at the same time (i.e. stiffer spring and softer sway-bar, or softer spring and stiffer sway-bar).

We added roll stiffness to our van by adding the stiffer springs, but we did not reduce the existing sway-bar stiffness. Now the roll stiffness is very high. This may or may not be good. Also, the sway-bar can add harshness to the ride. As one tire hits a pothole, the shock is transferred to the frame, through the sway-bar. With a softer sway-bar, less of this pounding is transferred to the frame.

Test:
I wanted to run a test, to see if the new springs offer enough roll stiffness, to reduce or eliminate the sway-bar. I removed the front sway-bar on our 4Runner, when I added stiffer front springs, and it works great.
For this test, I disconnect the sway-bar at one end, allowing each side to travel without involving the sway-bar. On our Chevy van, I also had to re-route the brake line, so it would not contact the end of the sway-bar, when the suspension traveled up/down.

Results:
The Tuff-Truck springs offer plenty of roll stiffness for the front suspension. Now there is a tiny bit of extra roll in the corners, similar to a stock van. If it was set up this way at the factory, nobody would notice any driving issues (with front sway-bar removed & rear sway-bar added). The HUGE benefit is the smoother ride. Small bumps the front tires hit, do not get transferred to the frame, and this really reduces the harshness of the ride. The second benefit is less swaying, when crossing the threshold into parking lots. It seems that the sway-bar didn't allow the font suspension to act independently, and it was forcing the whole van to lean with the front suspension. Now, one tire can rise on its own (to a point). This has decreased the wallowing, when driving over these uneven bits of road work. This week, I will remove the front sway-bar completely.

Since the rear of our van is heavier than the front, I plan to leave the rear sway-bar in place. Also, we plan to replace the rear springs with a softer spring, with more travel. this softer spring will offer less roll stiffness, and we might need to increase the stiffness of the rear sway-bar, to properly balance the system.

That is very interesting, and does make sense. Reducing the front sway bar size, or eliminating it, should also tighten the front end up and give better steering response. I have toyed with going to softer endlink bushings on ours, but haven't done anything to this point.

It will be interesting to see how the van performs under varying conditions. I would think that one wheel dips at highway speed might be the most critical, as the steering geometry will change more on one side than the other. Of course wind and sway may change. I am sure you will find out quickly what is better and what isn't.

The less pitch going into parking lots, etc, seems to be the opposite of what we found when we added the rear bar to ours. On right turns or in and out of drives, we found it pitched a lot less toward the low point, and thus less back the other way, as both rear wheels moved up or down together.

Be sure to let us know how it all turns out.

[Photog]

Originally Posted by booster

......The less pitch going into parking lots, etc, seems to be the opposite of what we found when we added the rear bar to ours. On right turns or in and out of drives, we found it pitched a lot less toward the low point, and thus less back the other way, as both rear wheels moved up or down together.

I found this interesting also, since our results were the same as yours. The rear sway-bar improved this wallowing on uneven sections.

With our 4Runner, we found that the front was so stiff, that when one front tire was lifted on a rock or dropped in a hole, the whole body would lean with the front suspension. If I drove up on a pair of ramps, at opposite corners (L-rear & R-front), the rig did not sit level, it leaned with the front, in this case leaning to the left. When I removed the sway-bar, the and ran the same test, the rig sat much closer to level. The rear sway-bar on the 4Runner needs some stiffer bushings.

I think this is what is happening to the van, when crossing into a parking lot. The front is so stiff, it forces the van to conform to the front suspension angles. Adding the rear sway bar, allows the rear suspension to put more force on the front suspension, overcoming some of the front roll stiffness.

Yesterday, we drove it for about 6 hours, in town and on the highway, with the sway-bar disconnected. So far, it drives and handles as it did before, except for the reduction in harshness.

I will report back on this mod, as we get more road time. So far, so good.

[booster]

I just did some GM part lookup reading. There is a smaller bar available for the Express. They use the same bar for 8500# and above and another bar for under that. I didn't get a chance to look into control arms and such to assure fit, but most likely it would be OK as they make the 2500 Express in both load ranges, I think.

[Photog]

Based on my testing, I would say a softer front sway-bar would be an improvement for our rigs that have added the stiffer front springs. And definitely add the rear sway-bar to control the heavy rear end.

[Photog]

This is a post from another thread, that seems to properly describe the reasons for my suspension mods.
______________

Most over-landing does not require a 4X4, but the vehicle does need to stand up to rough roads.

I think the washboards found on most dirt roads, would completely dismember the interior of my R/T 190. I also believe there are some simple ways to improve the strength of the cabinets and their mounting points.

Also, the suspension needs to be somewhat compliant, with uneven terrain, like rutted roads, or the transitions between the main road and a side road (both roads being dirt).
__________________________________

With judicious loading (keep most weight low), purposeful suspension modifications, improved cabinet structure, and a good set of tools and self-extraction equipment, I think we can greatly expand our travel options and improve the locations of the sunrises we wake up to.

[Photog]

I just installed a new set of lift knuckles from Boulder Offroad. These knuckles are supposed to provide 3 inches of lift.

Now we have 11 inches of clearance below the tanks/skirts; a little less below the dump valve.

As posted earlier, the previous set of front knuckles I installed didn't work out very well. They were built well and provided good lift (4"), but the steering geometry was incorrect, causing severe bump-steer. This is because they were designed for the Chevy 3500 Silverado, not the van. The truck and van geometry are not the same.

The knuckles from Boulder Offroad are designed specifically for the Chevy 2500 & 3500 vans. All of this info is in previous posts in this thread.

Here are some pictures:

This is the knuckle, installed, without the bearing assembly. Notice the lower ball joint, showing through the bearing port. On the factory knuckle, the lower ball joint is well below the bearing port.


I replaced the bearing assembly at the same time, with a bearing for the 10k-12k GVW van. It has identical mounting dimensions, and bolted right in.

Here is the van, with the front complete:


In that photo, there are 4" lift blocks at the rear, heavy duty Tuff Truck springs up front, and now the 3" lift knuckles. I still need to confirm some measurements, but the van looks nearly level (front to rear).

[Photog]

Here is before & after the lift knuckles. Both have the Tuff Truck front springs. The 3" lift is difficult to see on a rig this size. Compare the lip of the front bumper to the center line of the front wheel.

Before Boulder Offroad Knuckles:


After 3" knuckle install:

[Photog]

There is a problem with the factory shocks and the Bilstein replacement shocks. The shocks are too short. We don't have that much wheel travel up front, and the shocks prevent almost 2 inches of that travel. I need to find a shock that is about 1 inch longer. This photo shows the shock length, with the suspension at full-droop (the hump in the middle is the steel shock bucket, not the rubber bushing). Not enough sticking out to even thread a nut on. I don't mind compressing the suspension a little to get the stud to peek through the bushing and washer, to tighten down the nut. In this case, I have to compress the suspension almost 2", just to get the nut on the threads.

Note: To compress the shock 1 inch, we must compress the suspension almost 2 inches, due to the position of the shock on the lower control arm.