Suspension Systems

[pangelechio]

Marty, come down and drive mine before you decide. I have the same rig you do in a 2013. (even the proper color)
I spend months researching, reading and talking to people. Then I went and started actually driving others trucks with setups like i was looking at. Dr Speed and I narrowed it down to BDS and Fabtech. I went with the Fabtech based on the ride I experienced in someone else's truck. The big thing for me was the shocks, I ponied up and got the Fox 2.0 (I was running Bilstine previous).

I wanted ride and looks in that order and am very happy with it still after 17,000 miles now.

Everyone has an opinion and good advice, I suggest actually driving a few rigs that have what you are looking for. This is not a cheap thing to do so you dont want to guess.

Seriously, feel free to PM me and drive my truck. Love it or hate it you will have a good understanding of what you want then.

 

[AEdelheit]

Marty, come down and drive mine before you decide. I have the same rig you do in a 2013. (even the proper color)
I spend months researching, reading and talking to people. Then I went and started actually driving others trucks with setups like i was looking at. Dr Speed and I narrowed it down to BDS and Fabtech. I went with the Fabtech based on the ride I experienced in someone else's truck. The big thing for me was the shocks, I ponied up and got the Fox 2.0 (I was running Bilstine previous).

I wanted ride and looks in that order and am very happy with it still after 17,000 miles now.

Everyone has an opinion and good advice, I suggest actually driving a few rigs that have what you are looking for. This is not a cheap thing to do so you dont want to guess.

Seriously, feel free to PM me and drive my truck. Love it or hate it you will have a good understanding of what you want then.

I would be very curious to know what other kits you drove that made you choose Fabtech? Fancy shocks are only good if valved properly, dont buy into fancy shocks just for looks and name.

 

[pangelechio]

I would be very curious to know what other kits you drove that made you choose Fabtech? Fancy shocks are only good if valved properly, dont buy into fancy shocks just for looks and name.

First, totally agree on the shocks comment. When buying more expensive shocks you have to get pretty specific about your setup. Fortunately for me, I have a suspension designer engineer friend. I let him do all the math etc.. Based on my wants and needs the Fox were valved best for my application in a non-resivoir style. Of course I could have spent even more and got custom valving but I didn't need it.

Everything I drove was 3-5 inches, 2005-2015. (6 trucks)
BDS long arm was great but there was too much understeer for me in the corners on the 2014
BDS Short was on a 2005, handled great and a nice ride but the suspension cycled differently than a 4th Gen so not a great fit (thats my seat of the pants feel not an engineers review)
AEV, I loved it. Had it on my Wrangler JK. At the time they did not make a full kit from my truck. I drove a dealers AEV truck (2015)
Procomp long arm, didnt like the ride but it had out of the box procomp shocks. Not sure it was the springs so much as the entry level shocks?
Fabtech long arm, still didnt like the steer of the LA kit but it rode very nice with the Dirt logic remote resivoir shocks
Fabtech short arm on a 2012. Really liked the handling, it had the Fox shocks, running 35's as I intended to do.

Also I found the Fabtech front springs to be a bit better ride than the stock springs but not "soft and sloppy"

BDS and Fabtech were similar in price. I think they are both good. But of course we all have different preferences.

I looked at Carli and a few others but the price was simply way out there and I wondered if the ride of performance was worth so much more. I realize a number of folks mix and match on these kits and get better pricing but I wanted one brand on the lift so if something didn't work right there was only one manufacturer to deal with. Then I simply upgraded shocks on the parts order.

Hope that helps. I did it last April so hopefully I recounted everything properly for your question. Again, personal opinion here not my engineer buddies thoughts. He just help me with the process and math on compression rate vs. shocks and so on.

 

[Busa Dave]

I run the BDS Kit. Not cheap but it works very well and the ride is even better along with handling both on and off road. This is the 3rd BDS I have had..

 

[MRoberts]

Thanks for all of the info! Also, I appreciate the offer to ride in/drive your truck, thats awesome. I don't get to Portland often, if I do plan on heading that way, I'll give you a shout.

Update as to where I'm at:

AEV - Just can't get over that spacer thing.

Thuren - Great site, great reputation and great info. I'm concerned about their statement that the rear end will behave more like a 1/2 ton.

Carli - Very interested in the Back Country system, $$$

BDS - Local dealer and installer is a plus, not crazy expensive. I have heard some good and bad. Biggest concern is that BDS is more a lift kit than a suspension improvement.

Still researching and would like some more feedback, preferably real experience.

TIA - Marty

First, totally agree on the shocks comment. When buying more expensive shocks you have to get pretty specific about your setup. Fortunately for me, I have a suspension designer engineer friend. I let him do all the math etc.. Based on my wants and needs the Fox were valved best for my application in a non-resivoir style. Of course I could have spent even more and got custom valving but I didn't need it.

Everything I drove was 3-5 inches, 2005-2015. (6 trucks)
BDS long arm was great but there was too much understeer for me in the corners on the 2014
BDS Short was on a 2005, handled great and a nice ride but the suspension cycled differently than a 4th Gen so not a great fit (thats my seat of the pants feel not an engineers review)
AEV, I loved it. Had it on my Wrangler JK. At the time they did not make a full kit from my truck. I drove a dealers AEV truck (2015)
Procomp long arm, didnt like the ride but it had out of the box procomp shocks. Not sure it was the springs so much as the entry level shocks?
Fabtech long arm, still didnt like the steer of the LA kit but it rode very nice with the Dirt logic remote resivoir shocks
Fabtech short arm on a 2012. Really liked the handling, it had the Fox shocks, running 35's as I intended to do.

Also I found the Fabtech front springs to be a bit better ride than the stock springs but not "soft and sloppy"

BDS and Fabtech were similar in price. I think they are both good. But of course we all have different preferences.

I looked at Carli and a few others but the price was simply way out there and I wondered if the ride of performance was worth so much more. I realize a number of folks mix and match on these kits and get better pricing but I wanted one brand on the lift so if something didn't work right there was only one manufacturer to deal with. Then I simply upgraded shocks on the parts order.

Hope that helps. I did it last April so hopefully I recounted everything properly for your question. Again, personal opinion here not my engineer buddies thoughts. He just help me with the process and math on compression rate vs. shocks and so on.

 

[Conifer]

I'm not affiliated with AEV in any way, just needed to clarify some stuff here. I literally just joined as I was browsing the forum and saw this post. I have run a Carli pintop on my old 2010 Ram 2500, and an AEV system on my current 2016.

I see forum post after forum post on other websites about AEV's "cheap spacer lift". When you lift a vehicle with a linked front suspension, you are doing two things. First of all, you are increasing the angle of your track bar and drag link further beyond horizontal. You want those two to be as horizontal as possible, which is why AEV flips the drag link to the top of the steering arm on the knuckle, and also adds a new mount for the track bar on the axle that raises the mounting point for the track bar up higher. Ever seen a three link suspension on a rock buggy with a track bar? There is often an almost comically tall track bar mount on the axle end. This is to not only keep that track bar as horizontal as possible, but to also keep your roll center high. If you have a low roll center (the point around which your truck theoretically pivots when it leans side to side) it increases the leverage that the center of gravity has on the truck, thus giving you more body roll. If you can keep your roll center high up, close to your center of gravity, you can all but eliminate excessive body roll. Long story short, keep the track bar and drag link as horizontal as possible, and keep them up high. You'll notice other kits doing things like adding a drop pitman arm to keep the drag link horizontal, but all that does is keep your roll center low, thus giving you more body roll and usually bump steer, as your drag link and track bar are now at two different angles. Also, whenever your drag link angle is increased, you get bump steer. This is because when your suspension cycles, that angled drag link will literally push your pitman arm back and forth, giving you what is known as bump steer, where the steering wheel will go back and forth in your hands while your suspension cycles. In some cases, this can even occur when turning, or due to body roll. Other suspension systems will add a steering stabilizer (or two!) to help buffer this, but it's just a bandaid. AEV's old Nth degree jeep systems fixed all this as well, I was always impressed by them.

Lastly, yes, AEV uses a spacer, but it's not a spacer! To move that axle forward and get clearance at the rear of the fender for bigger tires, you have two choices, since the stock springs can't be moved forward as it will put them at an angle. Either go to a coilover, which will require a new mount at both the axle and the frame, or do what AEV has done, and create a spacer that effectively moves the spring pad back on the axle, so that the axle can be moved forward. This can ONLY be done with a spacer/spring perch relocator, not with just a longer spring. Let me repeat myself, as there seems to be a large portion of the internet that doesn't understand this. This can only be done with a coilover, or with a spring perch re-locator, or in this case, AEV is calling it a spacer. To clarify though, it is not just a spacer. It is allowing you to do three things: Lift your truck, move the front axle forward, and keep your stock spring frequency. I'm not going to go into spring frequency right now, but having played around a bunch with race buggy and dirt bike suspension, it is a real thing and more important than you may think. Of course, by moving your axle forward, the drag link and track bar mounting points to have be relocated too to accommodate this, along with steering, which is accomplished with AEV's kit.

After all that though, I will say that I am not the biggest fan of their digressive valved shocks that are included in the kit. If possible, do their kit and upgrade to a nice set of custom length kings or foxes from Thuren or a similar shock tuner of your choice. You'll be a lot happier.

Hope that all makes sense. Here's a video that they did on the subject that explains it a little better. https://www.youtube.com/watch?v=6u-BLepaShs

 

[AEdelheit]

I'm not affiliated with AEV in any way, just needed to clarify some stuff here. I literally just joined as I was browsing the forum and saw this post. I have run a Carli pintop on my old 2010 Ram 2500, and an AEV system on my current 2016.

I see forum post after forum post on other websites about AEV's "cheap spacer lift". When you lift a vehicle with a linked front suspension, you are doing two things. First of all, you are increasing the angle of your track bar and drag link further beyond horizontal. You want those two to be as horizontal as possible, which is why AEV flips the drag link to the top of the steering arm on the knuckle, and also adds a new mount for the track bar on the axle that raises the mounting point for the track bar up higher. Ever seen a three link suspension on a rock buggy with a track bar? There is often an almost comically tall track bar mount on the axle end. This is to not only keep that track bar as horizontal as possible, but to also keep your roll center high. If you have a low roll center (the point around which your truck theoretically pivots when it leans side to side) it increases the leverage that the center of gravity has on the truck, thus giving you more body roll. If you can keep your roll center high up, close to your center of gravity, you can all but eliminate excessive body roll. Long story short, keep the track bar and drag link as horizontal as possible, and keep them up high. You'll notice other kits doing things like adding a drop pitman arm to keep the drag link horizontal, but all that does is keep your roll center low, thus giving you more body roll and usually bump steer, as your drag link and track bar are now at two different angles. Also, whenever your drag link angle is increased, you get bump steer. This is because when your suspension cycles, that angled drag link will literally push your pitman arm back and forth, giving you what is known as bump steer, where the steering wheel will go back and forth in your hands while your suspension cycles. In some cases, this can even occur when turning, or due to body roll. Other suspension systems will add a steering stabilizer (or two!) to help buffer this, but it's just a bandaid. AEV's old Nth degree jeep systems fixed all this as well, I was always impressed by them.

A few things to Clarify again. Thuren and some Carli kits have full bump stop travel so you can not drop the track bar or change the draglink, the only reason AEV gets away with it is because they limit up travel but to say it as a good thing is iffy, I would rather have more uptravel from ride height. Have you ever compared the track bar angle on a AEV truck to others? Not as different as you may think.

Roll center is determined by the radius arm or 4 link geometry more then the Track bar location.

 

[GrantP]

I'm not an AEV basher whatsoever. I personally spoke to Dave Harriton years ago when I was doing some freelance writing and I think they make some great products. I'm just not sure I agree with his approach on this one. After watching the video what stood out to me is that Dave kept referencing the number of different springs used on the truck (44 different front springs), but there's only one shock option in their system? So they valved a "one size fits all" shock. I think it makes more sense to produce your own springs and tune the shocks accordingly. My .02.

 

[KPear]

Conifer, a quick question: How would you compare the two suspension setup's (Carli pintop and AEV)? Which one do you prefer and why?

I agree with you that AEV's suspension setup is more than a mere "spacer lift;" from reading the descriptions and reviews, it seems a lot of engineering went into it. It's pretty amazing that these suspensions can allow for up to 40" tires with a mere 3 inches of lift. I understand the logic behind using the stock springs with aftermarket spacer brackets, though I would've preferred that they used a different shock (similar to what Carli and Thuren use).

That said, I also see the advantages inherent to something like a Carli or Thuren package; those suspensions seem a little bit better tuned to offroad use, even if you are sacrificing a little bit of payload capabilities with some of their kits. My takeaway is that if you're looking for a mild lift and 35" to 37" tires, the Carli or Thuren kits could make sense. If you're looking for 40"s or bigger, AEV does seem better suited to accommodating bigger tires while keeping the lift mild and closely-aligned with the stock setup.

 

[Conifer]

Conifer, a quick question: How would you compare the two suspension setup's (Carli pintop and AEV)? Which one do you prefer and why?

I agree with you that AEV's suspension setup is more than a mere "spacer lift;" from reading the descriptions and reviews, it seems a lot of engineering went into it. It's pretty amazing that these suspensions can allow for up to 40" tires with a mere 3 inches of lift. I understand the logic behind using the stock springs with aftermarket spacer brackets, though I would've preferred that they used a different shock (similar to what Carli and Thuren use).

That said, I also see the advantages inherent to something like a Carli or Thuren package; those suspensions seem a little bit better tuned to offroad use, even if you are sacrificing a little bit of payload capabilities with some of their kits. My takeaway is that if you're looking for a mild lift and 35" to 37" tires, the Carli or Thuren kits could make sense. If you're looking for 40"s or bigger, AEV does seem better suited to accommodating bigger tires while keeping the lift mild and closely-aligned with the stock setup.

They both have their advantages and disadvantages.

The main advantage to the Carli kit was the shocks. King makes an incredible product, and when Carli adds their valving specific for these trucks, they are even better. I did find my rear Carli shocks to be a bit soft for my liking out of the box, but I had a lot more weight in the bed of my 2010 truck 100% of the time than most people do. The big disadvantage, at least for me, was the greatly increased bump steer and body roll. I have to disagree with AEdelheit on this a little bit, on a truck with a non-triangulated linked suspension, or with radius arms, the track bar mounting points are going to play a huge part in determining where your roll center will end up on the truck. Too low of a roll center, as in the case of a track bar mounted low on the axle, and your truck's center of gravity is going to "lever" against that lower roll center and create much more body roll around corners and such. On top of that, when your tie rod and track bar are at more of an angle, you end up getting more bump steer from the tie rod pushing the steering wheel around as the suspension flexes. Carli's suspension systems don't really compensate for this, although they do make an incredible kit. I have recently driven a newer radius arm truck with one of their systems on it and was blown away, although the bump steer and roll still remain. If you want supple, fast, long travel on one of these heavy trucks though, that is the price you pay.

On the AEV side, they have done what Dave explained in that video above, and essentially moved the mounting points on the axle for the track bar upwards to keep the track bar at stock levels of horizontal, while also moving the tie rod connecting point at the knuckle from the bottom of the knuckle arm to the top. This keeps your bump steer and roll center at stock-like levels, in comparison to the truck's center of gravity. The kit drives extremely well on the road and at speed, with negligible amounts of body roll, and no additional "felt" bump steer. My biggest complaint with the kit was the shocks, I have never been a fan of digressive valving, especially on larger/heavier vehicles, and would much prefer a well-tuned King or Fox with progressive valving set up for the truck's weight, similar to what Carli does. I do agree that the AEV kit does not gain you much in the way of additional travel, but does allow you to run a much larger tire for more clearance under the truck while maintaining a stock like level of handling and steering. Having said all that, check out the Project Howitzer that diesel power products did, they used an AEV system combined with some slightly taller springs and some Fox shocks and did some awesome stuff with it at Moab, proving in my opinion that massive amounts of travel aren't everything.

If I were to pick a perfect system, I'd run the AEV kit with a better set of Thuren-valved King shocks, or a set of Fox shocks from the tuner of your choice. You could likely sell the AEV shocks on the AEV forum to someone looking for a replacement set, those Bilstein's that they use don't last a very long time and aren't rebuildable. Also, if it was possible, I'd put in a Carli front sway bar. Sadly, as I found out, you cannot run the Carli front sway bar with the AEV kit, so you either have to go without a sway bar, or just use the stock type one.

Hope this helps.

 

[AEdelheit]

As I noted before AEV drops the bump stops down, you can not relocate the track bar or draglink angles like AEV does without dropping the bump stops and I would much rather have the added up travel. No point in getting fancy shock with super stiff stock springs, if you want a well performing suspension then you have to get away from the stock coils and though a super fancy one the AEV kit is end of the day a spacer lift with poor coil and shock choice.

It is odd they put so much time in designing all the other parts of the suspension then went with stock coils and generic shocks, the whole "44 different coils" excuse makes no sense at all. If the trucks were so sensitive to coils springs why are they going to a different coils then the exact one that came on the truck? When designing a coil the weight, travel and use are the key factors and that does not very much on these trucks.

 

[Conifer]

As I noted before AEV drops the bump stops down, you can not relocate the track bar or draglink angles like AEV does without dropping the bump stops and I would much rather have the added up travel. No point in getting fancy shock with super stiff stock springs, if you want a well performing suspension then you have to get away from the stock coils and though a super fancy one the AEV kit is end of the day a spacer lift with poor coil and shock choice.

It is odd they put so much time in designing all the other parts of the suspension then went with stock coils and generic shocks, the whole "44 different coils" excuse makes no sense at all. If the trucks were so sensitive to coils springs why are they going to a different coils then the exact one that came on the truck? When designing a coil the weight, travel and use are the key factors and that does not very much on these trucks.

Totally understood. I believe, although I may be wrong, that AEV is mainly sticking with the stock springs for two reasons.

One, because the Ram 2500 has a coil sprung rear end for the first time ever, and having frequency matched springs front and rear can greatly help with spring oscillations being consistent (this document goes over it in a bit more detail if you want to read: http://www.optimumg.com/docs/Springs&Dampers_Tech_Tip_1.pdf), although keep in mind that this argument doesn't stand up with the 3500's as much as they have rear leaf springs, which aren't as sensitive to frequency changes.

Two, because AEV's suspension does something which no other suspension system for the radius arm trucks does, and that's that it moves the front axle forward. As I'd mentioned in my first post, they can only do this by keeping a stock length (or similar) spring and by literally relocating the spring perch on the axle by creating their offset "spacer". To me, having that extra gap between the rear of the front tires, and the fender, makes a huge difference as that has always been a prime spot for tire rub, especially when flexing the suspension and turning the tires at the same time.

I totally understand on the travel and shock comments though, as I personally feel that their shock choice is extremely poor, although they did announce on their forum recently that they are working on a reservoir shock option for the truck. If all out travel is needed, then this is not the setup to go with.

 

[KPear]

How much does the axle get moved when going with a Carli or Thuren 2.5-3" lift? Don't they offer kits that maintain the radius arm and sway and track bar geometry?

 

[AEdelheit]

How much does the axle get moved when going with a Carli or Thuren 2.5-3" lift? Don't they offer kits that maintain the radius arm and sway and track bar geometry?

The axle barely moves back any due to the radius arms being so long. A kit with full bump stop travel wont have sway bar drops or much longer end links as it will cause bind on compression but it really is not an issue as the sway bar has a range that it works on and it is within that range. On the earlier 4 link truck you could move the axle forward about 1/2" with longer arm, on these radius arm trucks that is not the case as there is about 1/8" of clearance at full bump but again they are withing the operating range. Same with the track bar and drag link, they are designed to work within a certain range and they are within that range and as noted many times you can not drop them easily with factory bump stop travel.

 

[AEdelheit]

Totally understood. I believe, although I may be wrong, that AEV is mainly sticking with the stock springs for two reasons.

One, because the Ram 2500 has a coil sprung rear end for the first time ever, and having frequency matched springs front and rear can greatly help with spring oscillations being consistent (this document goes over it in a bit more detail if you want to read: http://www.optimumg.com/docs/Springs&Dampers_Tech_Tip_1.pdf), although keep in mind that this argument doesn't stand up with the 3500's as much as they have rear leaf springs, which aren't as sensitive to frequency changes.

Two, because AEV's suspension does something which no other suspension system for the radius arm trucks does, and that's that it moves the front axle forward. As I'd mentioned in my first post, they can only do this by keeping a stock length (or similar) spring and by literally relocating the spring perch on the axle by creating their offset "spacer". To me, having that extra gap between the rear of the front tires, and the fender, makes a huge difference as that has always been a prime spot for tire rub, especially when flexing the suspension and turning the tires at the same time.

I totally understand on the travel and shock comments though, as I personally feel that their shock choice is extremely poor, although they did announce on their forum recently that they are working on a reservoir shock option for the truck. If all out travel is needed, then this is not the setup to go with.

I have heard the argument for stock coils but do not buy into it, I deal with suspension every day and have not seen any the potential issues mentioned with aftermarket coils assuming the coils are still designed properly.

While moving the axle forward does have some advantages it also adds alot more components that can cause potential issues long term, not saying they will but adds potential too.

Even if they come out with a remote reservoir shock all they can do with stiff coils is use super light compression and real heavy rebound but small bump compliance will always be difficult with a high spring rate IMO.

 

[Task125]

I am leaning towards the 3" BDS radius arm kit. trying to solve the problem of factory rear air in the 3500

 

[Cummins12V98]

" trying to solve the problem of factory rear air in the 3500"

What problem is that?

 

[Task125]

can't lift the rear without computer trying to correct the height . need a spacer or bracket to adjust rear height sensor

 

[Cummins12V98]

Don't think it would be too difficult to fab something up.

 

[MRoberts]

I've been researching brands like crazy and have found that most think BDS is an OK kit, but that they lean more towards a lift kit, rather then a suspension kit. I'd recommend contacting Thuren or Carli to check on solutions for your 3500.