Hey guys, I own a 2012 Chevy Express 2500 extended and I'm looking to improve its offroad performance. I dont really want to lift it and have heard that that does not really increase clearance anyway. It already has some BFG KO2s and a G80 locking diff, so I'm looking for advice on suspension upgrades or modifications that will actually increase its performance. I'm talking progressive springs, new shocks, track bars that sort of stuff. Does anyone have any advice? The things that it currently suffers from are (1) its departure angle sucks, (2) it tends to 'shutter' when the tires lose traction off road, and (3) it hops around on washboard, especially around corners. I'm not looking to go rock crawling I just want to improve the ride and decrease the abuse the van experiences off road. Thanks.
Improve Chevy Express Offroad Performance
- Thread starter emyers
- Start date
Thanks for the perspective on lifts. My goal is to make a trip to Alaska more comfortable and not shake the inside of my camper to pieces and if that means a lift then that's fine. Do springs like this give a lift or just make it more comfortable? I'm mainly against using blocks. Whats the advantage or disadvantage of adding a leaf to my spring pack?
1stDeuce
Explorer
Three things I read in your inquiry.
First, the "shudder" is wheel hop, and it is a VERY good indication that you are running too much pressure for the (soft) surface you are on. If you are running the pressure on the door, or the side of the tire, and you're driving the van mostly unloaded, then your are setting yourself up for failure. Learn to adjust tire pressure to where it needs to be for both the load, and the surface you are on.
Second, you're talking about ride on washboard, and the two things that greatly influence this are tire pressure and shock valving. We just covered tire pressure, and I'd still recommend running less pressure when you know you'll be on back roads for a decent amount. Shocks are a mess... The OE shock valving for that van is probably the best valving you'll fine in a normal shock for washboard. My experience is that ANY aftermarket shock is going to be stiffer, and that's going to work against you on washboard. If you peek under there and see yellow or white shocks, someone put Gabriel Ultra's or Monroe whatever's on it. Take them off. Buy the OE P/N AC Delco shocks off rockauto or amazon. OR if you want to save a little money, you an buy the AC mid-grade shocks, which are stiffer than stock, but not as bad as Gabriel or Monroe shocks. (My opinion from recent experience with a Chevy 2500...)
Third, I should think that your breakover is your weakness with such a long wheelbase. Approach and Departure are still not great with a stock height van though. A very mild lift, and perhaps going up a size in tire will only help your back road mobility. You'll scrape less, and a slightly larger tire will help with ride, as well as traction and performance in soft terrain, particularly if you adjust air pressure when it makes sense. Very mild could be 1-1.5", which shouldn't be that expensive, and would still use the OE shock length.
I guess I've said tire pressure enough that I should consider covering a 4th topic that you didn't mention. I would recommend that you get some sort of on board air functioning ASAP. I used a Viair 400C compressor on my truck, and it works great. When you aren't afraid to air down a bit because it's easy to air back up, you will find that your vehicle becomes more comfortable and capable in almost all off road terrain with reduced tire pressure. This is most evident in soft sand, where you can get stuck with highway pressure in the tires, air down a good amount, and literally drive right out assuming you didn't completely bury it. It really is amazing were a 2wd van will go with about 15psi in the tires.
Good luck!!
First, the "shudder" is wheel hop, and it is a VERY good indication that you are running too much pressure for the (soft) surface you are on. If you are running the pressure on the door, or the side of the tire, and you're driving the van mostly unloaded, then your are setting yourself up for failure. Learn to adjust tire pressure to where it needs to be for both the load, and the surface you are on.
Second, you're talking about ride on washboard, and the two things that greatly influence this are tire pressure and shock valving. We just covered tire pressure, and I'd still recommend running less pressure when you know you'll be on back roads for a decent amount. Shocks are a mess... The OE shock valving for that van is probably the best valving you'll fine in a normal shock for washboard. My experience is that ANY aftermarket shock is going to be stiffer, and that's going to work against you on washboard. If you peek under there and see yellow or white shocks, someone put Gabriel Ultra's or Monroe whatever's on it. Take them off. Buy the OE P/N AC Delco shocks off rockauto or amazon. OR if you want to save a little money, you an buy the AC mid-grade shocks, which are stiffer than stock, but not as bad as Gabriel or Monroe shocks. (My opinion from recent experience with a Chevy 2500...)
Third, I should think that your breakover is your weakness with such a long wheelbase. Approach and Departure are still not great with a stock height van though. A very mild lift, and perhaps going up a size in tire will only help your back road mobility. You'll scrape less, and a slightly larger tire will help with ride, as well as traction and performance in soft terrain, particularly if you adjust air pressure when it makes sense. Very mild could be 1-1.5", which shouldn't be that expensive, and would still use the OE shock length.
I guess I've said tire pressure enough that I should consider covering a 4th topic that you didn't mention. I would recommend that you get some sort of on board air functioning ASAP. I used a Viair 400C compressor on my truck, and it works great. When you aren't afraid to air down a bit because it's easy to air back up, you will find that your vehicle becomes more comfortable and capable in almost all off road terrain with reduced tire pressure. This is most evident in soft sand, where you can get stuck with highway pressure in the tires, air down a good amount, and literally drive right out assuming you didn't completely bury it. It really is amazing were a 2wd van will go with about 15psi in the tires.
Good luck!!
Thanks for the detailed reply. I'm familiar with airing down and do so regularly, I've got a Vivair300P. They are load rating E tires and take 80 psi in the rear, and I'll go down to 35 or so offroad and you're right, it makes a huge difference. Interesting thoughts on shocks. I'm pretty sure they are the original factory shocks from 2012 so they are due for a change anyway and was considering Fox shocks. How much could I lift the van before needing longer shocks? Do you have experience with Sumo Springs or these active suspension kits? Trying to figure out if they're a gimmick.
1stDeuce
Explorer
Ok, so you just unwittingly said what I feared... Your tires do not "take" 80psi unless that's what the door tag says, and even then, they only need that much pressure if you are running fully loaded to GVW. If you've gone to larger than stock tires, they will take slightly less pressure to safely carry the same load. If your van is built out as a camper, it is very likely only loaded to 50% or so of it's max rated payload. You would very likely be fine at 60-65psi in the rear, and 50 or so in the front, and your everyday ride will improve, as will your tread wear.
This is important because getting the tires all the way up to 70 or 80psi with a 12v pump takes a while, but hitting 50 or 60 takes significantly less time.
Shocks... If you have leaking shocks, then they certainly need to be replaced. If they are not leaking, they're very likely working fine. Contrary to popular belief, shocks don't really "wear out". They can loose seals, and dump oil, which means it's time to replace them, but aside from that, they are likely providing the same damping that they did when new. Unfortunately, the shock industry has convinced people otherwise, and they stiffen up the valving on aftermarket shocks so you notice a difference when you replace your perfectly good shocks. And the down side of that is a rough ride. My best riding truck has 175k on the stock shocks. They're not worn out, they're just not overly stiff like the aftermarket shocks I ended up with on all the rest of my trucks.
Fox generally has some of the best valving for washboard, at the expense of being able to banzai without bottoming out. Bilstein goes the other way, with a stiff ride over washboard, but with better control for pushing vehicles with limited suspension travel faster over rough terrain without bottoming out. I have not been able to try out fox shocks for two reasons: 1. $$$$ and 2. The extended length is a couple inches shorter than other shocks for the same application, and I need the droop travel for my slightly lifted TJ.
I generally say that 1-1.5" of lift is fine with factory length shocks. You're basically reducing available droop travel by the amount of lift, and your stock height van likely has plenty of droop anyway. I'm running my truck about 1.5" higher than factory, and I've not noticed any issue with ride quality due to the reduction in droop travel.
Sumo springs and the like keep the van more level if you're running fairly loaded or overloaded. If that is the case, we should back up because the best thing you can do for offroad ride and performance is to lighten the van!!
Honestly, the "active" things are a gimic, and aren't actually active at all. They're putting stress on the front half of the springs that does you just about no good for much of anything, other than breaking stuff sooner.
Unless you are really loaded, a 1-1/2" lift block in the rear would be the easiest thing to do, and will work fine. If you are fairly loaded at all times, then I would recommend an add-a-leaf would be better, but I'd have a spring shop make one, rather than buying one of the over-arched aftermarket ones. They'll likely do a nice job of getting it the right length for your pack, while an aftermarket one is likely too long or short, but can be mashed in the pack to provide some lift, so makes it to market...
Mighty Dodge Ram
Explorer
I don’t drive that van but I do drive a Silverado 2500HD longbed so same wheelbase. Of course, agreed on airing down. In regards to shocks, I’ve run both Fox and Bilstein and prefer the Bilsteins. 1stDeuce is right on with the comparison between the two, but my highway miles far exceed my offroad miles, thus my preference. I’m assuming you have the 6.0 gasser with torsion bars up front and the GM limited fender clearance, more so with the vans. 4.10 gears? You might consider a slightly larger tire than the stock 245/75-16. Pitifully small. You should be able to run a 265/75-16 and a very slight torsion bar crank without drama. While only a bit over 1” taller, you’d be surprised at how much a 1/2“ of additional clearance can make a difference. Larger tires than that will bring clearance, low end acceleration, and mpg issues. Personally, my experience with lifts, even mild lifts, had me chasing other issues. YMMV. I don’t currently drive one but still consider myself a “van fan”, if you count the VW Westfalias owned close to 50 years ago. ? Interested in following your progress. ?
As 1stDeuce mentioned, airing down (further) will make a huge difference. Try that before spending $$$ on custom suspension.
My 9500 lbs truck/camper combo on 265/75/16 on require 30 psi off road. That's 5400 lbs on rear axle. I bet your van is lighter, try 25 or even 20 psi depending on tires.
Disconnecting sway bars also helps, especially with skidding on corners. As you load up the outside tire in a turn, a sway bar makes the effective spring rate much higher during a bump. My IFS/IRS Explorer, with longer travel Rancho struts, both sway bars removed, tires at 18psi, feels like a mini-baja truck on washboard corners, absolutely glued to the road!
My buddy's 4runner leaves me on the technical sections, but on washboard FSRs, I can go at least 10 mph faster, at greater comfort.
My 9500 lbs truck/camper combo on 265/75/16 on require 30 psi off road. That's 5400 lbs on rear axle. I bet your van is lighter, try 25 or even 20 psi depending on tires.
Disconnecting sway bars also helps, especially with skidding on corners. As you load up the outside tire in a turn, a sway bar makes the effective spring rate much higher during a bump. My IFS/IRS Explorer, with longer travel Rancho struts, both sway bars removed, tires at 18psi, feels like a mini-baja truck on washboard corners, absolutely glued to the road!
My buddy's 4runner leaves me on the technical sections, but on washboard FSRs, I can go at least 10 mph faster, at greater comfort.
Mighty Dodge Ram
Explorer
RoyJ: that’s almost exactly what I run on same size Toyo AT2. ‘02 Silverado 2500HD longbed, 9200# GVW. I tend to follow the “half your normal street pressure” suggestion for average offroad/gravel/washboard conditions; lower in more “technical” terrain (which I try to avoid) or even lower in sand.