Photog's Lifted Suspension 2009 Roadtrek 190V

[themexicandoctor]

Originally Posted by booster

Supersprings are an intersting company and have some nice stuff.

Personally, I don't like the idea of progressive bumpstop to increase front spring rate or height, as it puts the extra load on the wrong place in the suspension, eg the pivot bushing of the control arm and the arm itself. The will work, but I think aren't the best for durability if you can do it with springs.

I don't recall what we found out when we researched the Supercoils a while ago. Supersprings just gives the free length and "load" without what height that load would be at. Maybe someone remembers or can find the discussion that had the complete specs. I seem to remember them being a bit softer than the Moog 81006 and the same length. I do know they weren't considered a first choice.

The Sumocoils are just plain old coil spring rubber spacers that may have been updated a bit. Again, with the right springs, they should not be necessary, and the big thing about them is that because they somewhat immobilize part of the spring, the rest of the spring gets stressed more and will likely fatigue earlier.

Our vans run at nearly constant weight, with no big swings in how much weight is on any given wheel. For that reason, getting springs that are not progressive is a better idea than getting progressive. Progressive springs are made having smooth ride with light loads but still having the ability to carry heavy loads. If you use a progressive spring on a heavy, consistently loaded van, all that happens is the soft riding part gets compressed completely and the stiff section has to do all the work and is also less comfortable a ride. Putting all the stress in a smaller amount of the spring will cause faster fatigue. This is also one of the problems Erb had on his springs, as they were heavily progressive, and you saw what happened to yours, as I did in our testing.

As you can see, I am not a big fan of rubber helper springs or spacers. They will wear out way before most coil springs and they almost always are very progressive.

IMO, you will be way better off getting the correct springs for the height you want, and some good shocks. Use a stock height bump stop. I think you will be happy and also have a very reliable and consistent setup.

If you talk to Supersprings again, see if they will give you complete specs on their coil springs, so we can see where they would fit in your plan.

Quiting below from Gerry Lambretti;

I agree with a lot of what “Booster” has to say below. However a couple of qualifiers.


1. The Solo Sumosprings essentially replace the factory bump-stop so are located at a node point on the sub frame that is specifically designed to accommodate the loadings. Because the spring curve of the Solo Sumosprings (jounce type Sumosprings) is progressive (parabolic spring curve) the Sumosprings comes in soft then gives rapid support. This offers a better transition for the wheel travel rather than freeboard then hard-stop. It provides a much nicer ride quality. Furthermore because of the high damping qualities of the Sumospring material it dissipates a lot of suspension energy.

2. The Coil Sumospring is different to the old coil spring rubber spacers as they have inherent spring properties that are progressive in nature coupled with the very helpful damping properties. The old spring rubber spacers were really an upgrade from a piece of two by four.

Hoping this is helpful. End Quote

[booster]

I actually don't have any big issues with the comments from Gerry Lambretti. But as he said some clarification that is very much tied to personal opinion.

Concerning the Solo Sumosprings, the big difference in opinion comes as to whether you want to have "springs" that are highly progressive. Highly progressive is more capable of limiting very large displacements, but at the cost of ride quality. In general, the lower the progressivity, the better the ride quality, as long as you don't overtravel the suspension and hit a hard stop.

He is correct that the Solo would hit a welded on bracket on the subframe, that is not the area I was actually concerned about. The location of the solo on the edge of the control arm puts the additional load almost completely on one of the pivot bolts rather than on both, so could accelerate wear.

The extra damping that you get from the Solo may or not be desired in any given case, I think. The damping is normally handled by the shocks, so if they are properly sized, you could get to be overdamped by adding more damping, for instance. In the case where someone is just adding the Solo to stock springs and shocks, I certainly would agree that the added damping would likely be beneficial.

I think most of the above comments about progression and damping would also apply to the Coil spacers also. Their design is certainly better than the old crank in rubber, short, spacers, as they spread out the load better on the spring, but what they really do is make the spring more progressive, which I wouldn't want.

I will certainly say the Gerry's reply was one of the best and thoughtful replies I have seen from a vendor. The normally go on the attack pretty hard on anyone who doesn't totally support their products for every application.

[themexicandoctor]

Supersprings & the Owners, Gerry & Mike are a Class Act.

They have a lot of good products & moreover, they are always eager to see if one of a combination of their different products, can solve our unique needs, sometimes at their cost.

Let's face it - the RV Manufacturers try to answer so many requirements of owners, the ride is always the last consideration. 1000 miles later the absurdly low plumbing fixtures, tanks & expensive fiberglass skirts arrive in the checkbook.

Supersprings instantly gave me 3 inches at the rear & has not shown any sign of fatique - Bill Erb for free replaced a bushing that was bad but I know that design has been upgraded 5 years ago.

I invite everyone to check out their line up - Booster by the way, if this Friday I replace the Erb Coils, do you recommend their Coil Sumo Springs if not for me but as 5 year value for the next owner?

[themexicandoctor]

Met with Jeremy Johnson today - not being an Suspension adept/Engineer I was unable to share with him by phone my exact needs & the measurements at play presently.

After driving down with the Van & meeting him in person, less than a foot away, I was even less able to communicate exactly what I needed nor understand him.

So I gave him the keys & we went for a drive - instantly he knew & even though I didn't, I knew I was in the right place.

Friday we are going to begin with the 2inch spacers, 4 new Bilsteins, new control arms, keep the Erb* Coils or when they are out, throw in some new but stock Gas coils he upgraded from a 3500 Chevy or try new but stock Diesel springs.

He said the Erb Coils are big & thick but not necessarily fatiqued but he would know better once they are out & caliper tested.

The shocks are dead.

WHAT IS THE OPINION OF MY LEARNED MEMBERS?

Try the stock Gas with the spacers or the Diesel units with spacers?

(If you had the options of replacing the Erb Coils, he did say it looks like they are giving me the height I wanted originally.

The Bilsteins are the Heavy Duty B6 yellow blue units - he said longer shocks just won't fit in there (or maybe I heard him wrong)

[Mat Mobile]

If the Erb aren't good anymore, I think I would go with the gas with spacer.

But Jeremy is way more of an expert than me. He's done many van builds from simple to extravagant.

Try the van out with him and see if you like the feel and lift and decide then.

[booster]

Originally Posted by themexicandoctor

Met with Jeremy Johnson today - not being an Suspension adept/Engineer I was unable to share with him by phone my exact needs & the measurements at play presently.

After driving down with the Van & meeting him in person, less than a foot away, I was even less able to communicate exactly what I needed nor understand him.

So I gave him the keys & we went for a drive - instantly he knew & even though I didn't, I knew I was in the right place.

Friday we are going to begin with the 2inch spacers, 4 new Bilsteins, new control arms, keep the Erb* Coils or when they are out, throw in some new but stock Gas coils he upgraded from a 3500 Chevy or try new but stock Diesel springs.

He said the Erb Coils are big & thick but not necessarily fatiqued but he would know better once they are out & caliper tested.

The shocks are dead.

WHAT IS THE OPINION OF MY LEARNED MEMBERS?

Try the stock Gas with the spacers or the Diesel units with spacers?

(If you had the options of replacing the Erb Coils, he did say it looks like they are giving me the height I wanted originally.

The Bilsteins are the Heavy Duty B6 yellow blue units - he said longer shocks just won't fit in there (or maybe I heard him wrong)

Easy stuff first.

The Bilsteins are great shocks. The only downside is if you get too high in the lift, they can get to be too short, and we haven't found a longer Bilstein that has the right lower mount. They will only work well and survive if they use GM style upper shock mounts though, so it the Biilsteins don't come with that style they need to get them.

I assume they would be putting in stock control arms, or control arms that have the same geometry as stock? If so, it is a good way to get all new balljoints and pivot bushing without all the work and potential for damage of manually replacing them all. Doing full arm replacements is getting to be the norm these days.

I will jump to the end of your comments first, here. How high you currently are is pretty easy to measure, as we have those dimensions. GM gives a "trim height" that actually measures the suspension height, so they could check that while on a drive on or alignment rack. Nearly as accurate is checking from the ground vertically up to the wheelwell lip, at the center of the wheel. A stock Roadtrek 190 will usually be about 33.5" to maybe 34" depending on the weight in the van. If he is correct that the Erb springs are still at the height you want, the measurement will be at about 36". All of this is with stock tire size. I think you had mentioned that your was up 2.7" originally, so you would likely have been at 36.7" coming out of Erb's shop. If you truly are at the height you wanted originally, there would be no need for new springs or spacers, just the control arms and shocks, plus any other worn front end parts.

Now a word of warning that they probably already know, but here goes. If the Erb springs have not settled about .4", they will be longer than the stock springs, which just barely can be installed with compressing them. What this means is if they mistakenly think that they are stock length and just try to take them out without compressing them first, someone could get hurt by a flying spring.

If you use the 2" spacers in the springs, I think you would want to stay with the stock spring design, although it may put some extras stress on the part of the spring where the spacer isn't. The stock springs are overloaded by a Roadtrek, and that is why they sit so low, so if you just stiffen part of the spring, the other part does more of the work when it is already overloaded.

The one complaint I would have is that Supersprings does not publish what wire size their spring are, or how many coils they are, which would give us a better insight into how they will feel and how high they will lift. Marko had found some info that said the diesel spring they sell SSC-14 uses 8 turns of 1.06" wire, which would make it the same as the original Tufftruck springs that you did not like when you did them a few years ago. The stock springs are normally at about 7 coils of .94" diameter wire, and will be as mentioned earlier. The Erb springs are about 7 coils of 1" wire, but are longer than stock or diesel springs so get more lift.

Supersprings should be able to tell you how their springs fit into the above categories. Most of us are using springs that have 8 coils of 1.03" wire, which seems to give the best combination of good control without being too harsh, and also matches the damping rate of the Bilstein shocks well. In the stock 17.7" free length, they will give you about 1.75" lift which will be about 35.5" to 36" at the wheelwell as measured per the above method. This wheelwell height will put the van nearly right at what GM says the van should be for trim height, measured at the suspension, and will make for getting a good alignment. With a 1.03" wire spring as mentioned, you would not need the spacers in the springs. Several companies make these springs so they are off the shelf available if you decide to go that way. The springs are also linear, not progressive, which to me is better with the nearly constant front weight we see in the Roadtreks. The spacers will make the setup quite progressive.

What I know you will find, with the new control arms and shocks with good upper mounts, is that the van is going to get a lot quieter, which from what we have seen will also make it appear to be riding smoother. The extra noise has the affect of making the ride seem rougher for most people.

Obviously, you will need a good alignment when done. The Chevies seem to like 1/16" toe in (more will give tire wear), zero to +1/4 degree camber with it the same on both sides, and then the max caster you can get while keeping .4 degrees more on the right side. They drive very well when set there, but the specs allow a lot variation that can make them worse, so the closer to those numbers they can get, the better it will drive, I think.

[themexicandoctor]

In Summary I am more than satisfied with the results I received but first the photos

Front Drivers wheel now sits 39 & 3/4 inches
Front Passenger wheel is at 39 & 5/8

Rear Drivers wheel is at 40 & 3/8
Rear Passenger wheel is 40 & 3/8

[themexicandoctor]

/Users/sabrinabraun/Downloads/20180429_173859.jpg

/Users/sabrinabraun/Downloads/20180429_173942.jpg

[themexicandoctor]

The rest of the photos will have to wait until the next day or two, keep on getting logged out.

https://weldtecdesigns.com

Beau is the second in charge after Jeremy the Owner & he is th one who did all my work along with his apprentice Miles - they took their time, doing a great job, one time. There was some difficulty getting off the old parts but I was there for every minute & Beau paid attention, checked & marked every part before & after & then went to work with a detail & deliberation.

And I could have saved money by buying the shocks somewhere else & having them shipped to me & I probably could have had them installed by myself however I am so glad it dint. - That kind of labor is not worth it.


FRONT
My original appointment was to have some repairs made & a 2 inch Spacer
https://weldtecdesigns.com/product/c...ling-spacer-2/

Bthey realized the Spacer wouldn't fit the extra large Erb Coil & it wasn't such a great idea compared to the 3inch Spindle Kit plus the steering geometry, etc stays the same, it gives you a wider track, plus plus plus.
https://weldtecdesigns.com/product/c...-lift-spindle/
The 2inch Spacers are $299, the 3inch Spindles $1500.

THEY WERE RIGHT.

It was well worth the extra money invested now & will be the best long term solution for my needs.

I was happy with the ride the BILL ERB / Valley Spring Works Coil already gave me up front. They said it was in great condition & it too is over 5 years old but apparently didn't show any signs of serious fatigue.

Then I replaced the Upper Control arms & had B6 Bilstein Heavy Duty installed up front - when the KYB Gas Shock came of it was in pieces & you could see the huge difference in build quality between the two beginning where they mount.

Costs
3/Three Inch Spindle $1499
Installation 4 Hours $ 400
Bilstein B6 Shocks $ 230
Installation $ 150

REAR
I already have had for over 5 years the Supersprings Overleaf Helper at the Rear which gave me 3 inches the day it was installed.

To even everything out I added their Aluminum Blocks at 2 inches
No link to be found

And their U Bolt System - internally they code Chevy & Ford the same.
https://weldtecdesigns.com/product/f...s-van-u-bolts/

Plus added the 2 B6 Bilsteins in the rear also.

Cost
2" Lift Block $ 150
U-Bolts 11 1/2x3 $ 99
Installation $ 150
2 Bilstein B6 $ 230
Installation $ 150

FRONT & REAR
Grand Total; $3058
WORTH EVERY PENNY

[Mat Mobile]

That's great news! I just wish we could see your pictures!

(if it helps, send them to me by e-mail and I'll publish them)

[User1213]

I'd recommend that you start your own dedicated thread so that your mods (and not Photog's) can be documented properly.

[Mat Mobile]

Originally Posted by Hondo

I'd recommend that you start your own dedicated thread so that your mods (and not Photog's) can be documented properly.

I agree, this thread is a very important resource on the net for lifting Roadtreks and has seen it's fair share of hijacking (in a positive way). But let's give the final details of themexicandoctor's upgrades in his own post/build thread.

But just as a reference, here's a sneak peak:

[themexicandoctor]

Please give me a couple of days & I shall include all the details relevant. Along with photos.

[Rulebreaker]

Hi All,

I have a 2019 Roadtrek 210P built on a 2018 Chevy Express 3500 chassis and would appreciate suggestions for upgrading the suspension.

I'd like to increase ground clearance by 2" - 4" to make it easier traveling rough roads to boondocking sites. I'd also like more wheel travel before the suspension bottoms out.

I've taken the RT210P to a couple of spring shops. Both suggested upgrading front coil springs (one proposed (Husky?) CS-SC20470 Savana/Express front coils) and adding an extra leaf spring on both sides in the back (LF 250-401-60). Another shop suggested a similar approach but also said they would re-arch the original leaf springs. Neither recommended replacing or upgrading shocks or thought a sway bar would be helpful.

Based on scale readings, vehicle weight is 9,900lbs fully loaded: 5,800lbs rear; 4,100lbs front. Driver's side 5,120lbs; passenger's side 4,780lb, I believe more due to the weight of refrigerator and storage (rather the driver. )

Tires are Bridgestone LT245/75R16; 80psi rear and 50psi front.

I'd like to tap into all the expertise and experience of the people on this thread regarding which configurations worked well to get your recommendations. Feel free to offer "Good", "Better", "Best" options (if that makes sense).

Thanks in advance and let me know if you need more info.

Cheers, Brian

[booster]

Originally Posted by Rulebreaker

Hi All,

I have a 2019 Roadtrek 210P built on a 2018 Chevy Express 3500 chassis and would appreciate suggestions for upgrading the suspension.

I'd like to increase ground clearance by 2" - 4" to make it easier traveling rough roads to boondocking sites. I'd also like more wheel travel before the suspension bottoms out.

I've taken the RT210P to a couple of spring shops. Both suggested upgrading front coil springs (one proposed (Husky?) CS-SC20470 Savana/Express front coils) and adding an extra leaf spring on both sides in the back (LF 250-401-60). Another shop suggested a similar approach but also said they would re-arch the original leaf springs. Neither recommended replacing or upgrading shocks or thought a sway bar would be helpful.

Based on scale readings, vehicle weight is 9,900lbs fully loaded: 5,800lbs rear; 4,100lbs front. Driver's side 5,120lbs; passenger's side 4,780lb, I believe more due to the weight of refrigerator and storage (rather the driver. )

Tires are Bridgestone LT245/75R16; 80psi rear and 50psi front.

I'd like to tap into all the expertise and experience of the people on this thread regarding which configurations worked well to get your recommendations. Feel free to offer "Good", "Better", "Best" options (if that makes sense).

Thanks in advance and let me know if you need more info.

Cheers, Brian

Your are pretty typical of what many 210s we have heard about run.



First off, you are overweight at 9900# unless GM has changed the GVWR very recently. In has normally been 9600#. Rear would be rated at 6080# for the the axle, but without corner weighing you could be overloaded on the left rear tire which is rated at 3040# because it is typical for the Chevies to run 2-300+# heavier on the driver side.



210s tend to have very low load capacity, especially if they have generators and lots of batteries, so you may need to get at least 300# out of it to get to max allowable (if it hasn't changed).


As to the lift, there have been quite few done by members here and several threads on them. Spring lifts in the front are by far the most common, and in the rear air bags for most and spring replacements second. I prefer air bags myself.


A spring lift in the front with Moog 8004 springs normally would give about 1.75" lift, but lately users have seen more than that that. More than 2.5" and you can get into some issues with handling and bump steer which will bother some drivers and not others. Rear airbags will give 2+" of lift, more or less, depending on rear weight. Both of these increases actually put the van back at factory recommended ride height so can improve steering geometry and handling.


A rear sway bar is great for handling, but will not do much for clearance or bottoming. If you have a generator, only a Roadmaster bar will fit and they are expensive. No generator and you can use a Hellwig bar which is much less money.


Any spring lift will give you more travel before you bottom out the suspension as it just raises the body. Stock length shocks work fine as you are at original height. GM shocks aren't really great and many of us have gone to Bilsteins which are very good on the Chevies.


There is another issue with the Roadtreks that might be of interest, especially with your overloading issues. If you have aluminum wheels, it is likely they have the incorrect offset (the wheels are outboard too far) which can affect handling and bearing wear. The factory steel wheels are correct offset and an option, as are a pickup truck aluminum wheel for original tire size. If you want to upsize tires to add some safety factor for the high weight, there is only on wheel available to do that, and it is a wider pickup truck wheel of correct offset. It will handle a 265-75-16 tire and give 300# per tire or so more capacity. They will just fit the front and normally lots of room in the rear. There is also a discussion of this in this thread IIRC.


At 4100# front weight on the Bridgestones, I think you will find it will drive better at 65psi pressure in the front.


Good luck with your adventure. We have been lifted longer than almost anyone else and have not had any issues except not bottoming out anymore

[Rulebreaker]

Booster, thanks for this wealth of information! Very much appreciated!

Front:
I'd be interested in your opinion on the merits of the Moog 18004 vs the Husky SC20470. It seems the 18004 is constant rate while the SC20470 is progressive? Might this translate into smoother ride on the SC20470 at the expense of reduced vehicle height versus the 18004?

If I decide to seek additional height later using 3" spindles as some have done, would both of these springs likely still work for me?

Rear:
Is it just the adjust-ability of airbags that you prefer over using additional springs? For me, vehicle loading is pretty constant and we don't tow anything, so no trailer tongue weight to consider. (I'm just trying to rationalize the added cost and complexity vs. the benefits.) As for type of airbag; it seems some have used Firestone, while others chose Air Lift. Integral bump stops within seems to be a worthwhile feature. Is there a particular make and model of airbag that you recommend?

Shocks:
Bilstein B6-24-187435 front and B6-24-221948 for the rear seem to be the shocks of choice. Your thoughts? I gather if I decide to pursue 3" spindles for additional lift later, these B6 shocks might be too short? True?

Rear Sway Bar:
Vehicle has an under-hood generator (rather than under vehicle) so a Hellwig sway bar should work.

Overweight Vehicle, Wheels, Tires, etc.
Yep, vehicle is definitely overweight by about 3%, so I'll look at what I can do to lighten it. I do have aluminum wheels, so the offset issue you mentioned applies. Tires still have lots of tread, but when they're due for replacement I'll definitely look at upgrading wheels and tires to provide more load capacity.

As for front tire pressure; it seems 50psi is what's recommended on the vehicle nameplate as well as on Bridgestone load tables at the 2,050lb load per tire I have. I understand 210s tend to be lighter in the front than 190s due to the overhanging weight at the rear. Is the move to 65psi in the front, (presumably to improve handling and ride quality and to reduced heating and rolling resistance) likely to cause uneven/excessive tread wear in the center of tires over time due to crowning?

Recently I measured ground clearance on my rig to the fresh water tank drain valve and it was a measly 4-3/8", so I'm definitely looking forward to gaining some additional clearance from these mods.

Cheers,


Brian

[booster]

Originally Posted by Rulebreaker

Booster, thanks for this wealth of information! Very much appreciated!

Front:
I'd be interested in your opinion on the merits of the Moog 18004 vs the Husky SC20470. It seems the 18004 is constant rate while the SC20470 is progressive? Might this translate into smoother ride on the SC20470 at the expense of reduced vehicle height versus the 18004? The Husky seems to be listed as a constant rate where I looked and a cross for Moog 81006 which is shorter than the 81004 most have used in post 2002 models. You would have same rate but less length and lift. I don't like variable rate for constant heavy loads because the softer coils are over worked.

If I decide to seek additional height later using 3" spindles as some have done, would both of these springs likely still work for me? Some have done OK with them and some have not. Personally I don't like knuckle lifts because they mess up the suspension and steering geometry, and I can always feel it. I am pretty particular in regards to steering, others not so much.

Rear:
Is it just the adjust-ability of airbags that you prefer over using additional springs? For me, vehicle loading is pretty constant and we don't tow anything, so no trailer tongue weight to consider. (I'm just trying to rationalize the added cost and complexity vs. the benefits.) As for type of airbag; it seems some have used Firestone, while others chose Air Lift. Integral bump stops within seems to be a worthwhile feature. Is there a particular make and model of airbag that you recommend? Adjustability is nice, but most have found they ride a bit better also, but some claim worse. We are currently running ours the stock springs with the overload leafs removed. It really improved the ride, but there is only one other van doing the same and was just recently done, so not ready to say for sure good to go yet. With the overload out, we need to use bags with built in bump stops in case a bag pops as the bags sit where the original bumps were on the axle. Firestone bags would not need the internal because theyn are not mounted on the axle. I prefer the Airlift as they are larger diameter so less pressure plus they put the load directly on the axle tubes rather than on the lower spring bottom plate. Neither brand is bad IMO.

Shocks:
Bilstein B6-24-187435 front and B6-24-221948 for the rear seem to be the shocks of choice. Your thoughts? I gather if I decide to pursue 3" spindles for additional lift later, these B6 shocks might be too short? True? Knuckle lifts usually leave the lower control arm in the stock location and would use the same shocks, AFAIK. If you go more than about 3" up with springs, you will need longer shocks most likely.

Rear Sway Bar:
Vehicle has an under-hood generator (rather than under vehicle) so a Hellwig sway bar should work.

Overweight Vehicle, Wheels, Tires, etc.
Yep, vehicle is definitely overweight by about 3%, so I'll look at what I can do to lighten it. I do have aluminum wheels, so the offset issue you mentioned applies. Tires still have lots of tread, but when they're due for replacement I'll definitely look at upgrading wheels and tires to provide more load capacity.

As for front tire pressure; it seems 50psi is what's recommended on the vehicle nameplate as well as on Bridgestone load tables at the 2,050lb load per tire I have. I understand 210s tend to be lighter in the front than 190s due to the overhanging weight at the rear. Is the move to 65psi in the front, (presumably to improve handling and ride quality and to reduced heating and rolling resistance) likely to cause uneven/excessive tread wear in the center of tires over time due to crowning? It appears the plates are the stock ones or copies of the same pressures, and would be inteneded to cover an empty or full van without changing pressure. The 50psi squeeks in capacity at full load and would ride decently at low load, so a compromise on both ends. The 65psi is what most have found to be the best mix of steering response and tracking vs ride quality. Some like less, a few like a bit more. The tires will run cooler and wear the edges less at 65psi in most cases. Be aware you may have more weight on one side than the other by a couple of hundred pounds so splitting an axle weight can be a bit off.

Recently I measured ground clearance on my rig to the fresh water tank drain valve and it was a measly 4-3/8", so I'm definitely looking forward to gaining some additional clearance from these mods. Very believable at your weight. Probably low point right at the fragile tank valves and macerator, like we had.

Cheers,


Brian

See notes above

[hbn7hj]

Just a comment. I have Firestone air bags. They don't have the lifting range to match the Moog Springs up front. I run them at 80psi. Air Lift air bags I think would.

[markopolo]

Originally Posted by hbn7hj

Just a comment. I have Firestone air bags. They don't have the lifting range to match the Moog Springs up front. I run them at 80psi. Air Lift air bags I think would.

I don't know anything about the Firestone air bags for vans so I'm not disputing what you posted but am somewhat surprised by that info.

I thought I'd point out though that what most of us accomplished with the Moog front coils on GM vans is not actually a lift (meaning higher than factory specs). We just restored the Z trim spec back to what it would be in a new unloaded van. The vans end up not being any higher than factory specs even though the front now sit up to two inches higher. Air Lift bags in the rear level out the van.

[booster]

Originally Posted by markopolo

I don't know anything about the Firestone air bags for vans so I'm not disputing what you posted but am somewhat surprised by that info.

I thought I'd point out though that what most of us accomplished with the Moog front coils on GM vans is not actually a lift (meaning higher than factory specs). We just restored the Z trim spec back to what it would be in a new unloaded van. The vans end up not being any higher than factory specs even though the front now sit up to two inches higher. Air Lift bags in the rear level out the van.

This is a very good point and is probably why very few, if any, folks have had handling get worse, and most say it go better. The geometry of the steering is back to the position it was designed for so it works better. Knuckle lifts are the ones that mess up geometry and are the ones that give "lfits" the reputation of bad handling, which is very common with them.


We have had the Firestones and Airlift bags in ours, and the lift and bottoming out points seemed to be pretty similar, with both being a bit less than expected at maybe just under 3" IIRC. Now we have the Airlift with the internal bump stop and the "apparent" range is even less, but the difference is that the regular ones are a hard stop and bump stop is a springy stop. Where it sits on the bump stop with no air, for height, is determined by the weight on the bag when empty. The Firestones are smaller diameter bags so have less capacity, which is not a big deal, and also require about 50% or so higher pressure to support the same weight.