Quote:
Originally Posted by cruising7388
I need to check my pheromones. I've become a magnet for bad information.  These vans are not equipped with rear sway bars.
But considering that the 210 has an 18 inch frame extension plus a lot more weight on the back end than a stock van, I think you would play hell trying to make it over steer.
etrailer's fit for the 3500 express is the 1 1/2 inch version. They indicate that some drilling is required. I will check with them tomorrow but my guess is that this involves the upper end of the side link. Since this is a box frame perhaps it also has to be tapped.
It's interesting that you're going to try the beefier bar. What I wonder is if there is a tradeoff for this. No doubt it will provide more resistance, but could it consequentially accelerate the correction return rate somewhat?
BTW, I found etrailer's C/S impressive. Right away during our conversation, they were on the phone with Roadmaster to get up to date information. |
As I mentioned, the vans will not oversteer in the Roadtrek configuration, and that includes the extra length and extra weight in the rear. It would only oversteer in empty/lightly loaded stock vans, and that is why GM does not put a rear bar in them, as they need to prevent oversteer which is very dangerous compared to understeer.
This brings up an interesting point, and also ties in to some information that was given recently by a newer member who worked in vehicle dynamics (I wish he was still posting, but hasn't lately). His comments were in relation to dually setups, but the idea behind it would apply to all vans. To paraphrase, he said that dual rear wheels were "safer" (my quotes) because they increase in understeer (which also reduces oversteer). I don't want to be speaking for him, but the way I think this was meant is that the dual wheels will make a vehicle that tends to oversteer, eg an empty van, safer because they can get rid of the very dangerous oversteering tendencies. This makes perfect sense. What he didn't comment on, and would be interesting to hear, is if he thought dual wheels inducing understeer would be safer in a vehicle that doesn't have oversteer issues, like a fully loaded up class b with single rear wheels. Essentially all class b's have so much rear axle weight, it would be very hard to make them oversteer and they already have a bunch (usually too much) understeer in them. You then get to the question of if adding more understeer to them is "safer" or not. More understeer would likely not make it much less safe, just harder to drive, but IMO, probably wouldn't make it safer, either.
I haven't had a chance to thoroughly go over all the Roadmaster information, but it has been mentioned somewhere that Roadmaster said the 1.5" bar was mainly for class C rvs, not necessarily the smaller, lower class b vans. This is second, maybe third, hand information so not confirmed.
Going stiffer in the rear bar will change a number of things, some better, some worse, most personal opinions of what kind of handling you like.
A bigger rear bar will increase pitching from single wheel bumps or dips in the rear, as it effectively increases springrate on single wheel bumps. It won't be as bad adding rate to the springs, but could be noticeable.
The bigger bar should also reduce understeer more than a smaller one, which can be good or bad, and one of the things that can get to be very much personal taste. If you get understeer too low for your taste, most folks would call the handling "twitchy", meaning the van reacts too quickly to small steering inputs or corrections, causing overshooting. Most sports cars are twitchy to most people, especially if you normally drive a typical US vehicle that has a lot of understeer in it. Our van has very low amounts of understeer, and some would find it twitchy and not like the handling, but I really like it this way. I think some of it has to do with driving style and position, also. Those that drive with both hands firmly on the steering wheel all the time tend to make larger corrections, probably from the ergonomics of it, compared to us lazy folks that often drive with one hand on the bottom or top loosely on the wheel. The two handers will find a vehicle with more understeer OK because of the larger corrections, and a low understeer vehicle twitchy. One handers would find a vehicle with more understeer hard to control because they don't have the ability to do the larger corrections easily.
We are going to test a 1.5" rear bar in our 190 Roadtrek, but it is mainly to make sure we are as good as we traditionally have been. I removed the big overload leafs in the rear springs and now carry that weight on the airbags, which are a lower springrate than the leafs. Lower rear springrate normally will increase understeer, so going to the bigger bar would hopefully reduce that increase. Either way, for us, the changes are small tweaks, with the actual effects being quite small. Unfortunately, because of the springrate change, our test won't totally apply to other Chevies 100%.
I do think that the downsides of a 1.5" bar on a 210 would be less than on the 190s because of the extra rear weight and overhang.
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