Agile RIP kit "gave" me death wobble???

[nemesisnight]

So my Fab guy is gone for a couple weeks putting a Helephant 1000hp engine in a Gladiator. So I am going to attempt to weld on a shock tab myself tonight before I leave on a big 2 week trip tomorrow. Here is what I'm thinking of trying. The track bar mount seems like it would be a good place to put it, is there any reason I should avoid it? I might be able to go to the R of it but I'm not sure if there will be enough length before contact with the pumpkin. I want to keep it high and axle level to avoid hitting it on the trail like the original setup. There is a tiny space left of the mount that I could maybe squeeze it but the shock end might contact the track bar. The only issue I worry about with going on the track bar is hitting the drag link during full flex but it seems to have enough clearance.

Take a look and let me know what you think:

[arctictraveller]

Originally Posted by wahoo

I still was not satisfied with the handling so I decided to remove the steering dampener altogether just to try it. Wow, problem solved. I am a happy camper now with stabilizer still off.

Based on your experience, I decided to remove my damper as an experiment. Prior to removal, I suffered from what some have called "swim" That's to say, when a steering correction is needed, and the wheel is turned, there was a slight hesitation and possibly a small additional correction which then caused the van to move slightly more than intended, so a counter correction was needed to bring it back to straight. The result of this was a kind of see / saw motion of the wheel, with the van drifting left and right, and a bit of a struggle to keep going straight. If I didn't concentrate, I could easily have been mistaken for a drunken driver. When I first bought the van, it had a worn out Rancho damper. Replacing it with another Rancho improved the steering but it still sucked. A couple years later I installed a Fox damper, which was a bit stiffer. Through the years, I made lots of other improvements, but never totally got rid of the "swim" Yesterday, I removed the damper, and for the first time, the steering got more responsive. A very small adjustment of the wheel now results in an accurate movement of the van without all the corrections back and forth. I'm guessing the damper had masked other problems that I slowly corrected, to the point that I no longer needed the damper. I have no idea what will happen off road, but I threw it in the back so I can quickly reinstall it if needed, but so far it drives better than it ever has.

[carringb]

Originally Posted by nemesisnight

The only issue I worry about with going on the track bar is hitting the drag link during full flex but it seems to have enough clearance.

Take a look and let me know what you think:

Yeah, I think that' a good spot, but it does look tight on clearance in the pics. Only one way to find out for sure! Trickiest part will probably be with the dpax side under full compression with the wheels at full lock.

[nemesisnight]

So apparently I am still on the chase. After driving over 2000 miles on a trip the swim is better than before but still very apparent. Super frustrated, I still haven't installed my super beefy front sway bar but after that if I am still getting this swim I am out of ideas, maybe throw some airbags on the rear for road driving that have cradles and don't mess up articulation (anyone know what would work with a 6" lifted van? I wouldn't think I would need them though since I got the new springs made for the weight of my van from Agile. It still is somewhat intermittent where sometimes I can drive for hours and have no issues at all but usually it will occasionally kick in if I am going about 60-70 at least. Under that and it all seems pretty good. Maybe wind has a factor and when its windy out or I am at higher speeds its catching the soft top side of the progressive springs and working the suspension till i can calm it back down? Getting very frustrated at all of this. I did get the stabilizer mounted before the trip and had that on the whole time but haven't tried taking it off again, guessing it wont be a huge difference. Still can't believe all these problems just from lifting an extra 2" and having all new shocks and springs, I am stumped......

[carringb]

Originally Posted by nemesisnight

Super frustrated, I still haven't installed my super beefy front sway bar but after that if I am still getting this swim I am out of ideas, maybe throw some airbags on the rear

I still think you need to increase rear roll stiffness, to compensate for the high COG and rear weight bias of your van. Airbags won't help that. That larger front sway bar will help, but not as much IMO, since the tire sidewalls might just flex instead, having less weight up there but all the roll stiffness.

[TomsBeast]

I'm not sure I am following; Does 'swim' mean your are chasing the rear end (as it wanders from side to side) by steering the front wheels, constantly 'chasing it', a little like driving a forklift ?


One experiment to try is this:


Reduce front tire pressure significantly, 15-20 psi less than the rear, and see if anything changes. Then do the inverse (make the rear 15-20 psi less than the front tires)



Sometime to achieve front to rear balance, you run out of the ability to improve the 'sloopy' end (front or rear), which could be the rear in your case.



One chassis tuner trick is to intentionally make the better end, behave worse, achieving balance. This my seem counter-intuitive, but in the case of racecars, will net you quicker lap times.



In the case of my street mid-engine Toyota MR2 (where Toyota's door sticker calls for a 10psi difference between front and rear tire pressures) it keeps that little go kart of a car from wandering down the highway. I think 1960's Corvair owners found the same thing.


It's worth trying in my view

[nemesisnight]

Originally Posted by carringb

I still think you need to increase rear roll stiffness, to compensate for the high COG and rear weight bias of your van. Airbags won't help that. That larger front sway bar will help, but not as much IMO, since the tire sidewalls might just flex instead, having less weight up there but all the roll stiffness.

So rear sway bar is the only way?? Was really hoping I could avoid that, what would even work for my van with the lift. Wonder how hard it would be to fab up a way to have quick disconnects on a rear sway bar. I think you might be right though, I keep feeling like it might be coming from the rear but tons of people have lifts as big and bigger than mine without this issue so what gives? With my 23 year old de-arched stock springs and lift block it never had any sway issues so why would these built for weight with no lift block springs be worse?

[carringb]

Originally Posted by nemesisnight

tons of people have lifts as big and bigger than mine without this issue so what gives? With my 23 year old de-arched stock springs and lift block it never had any sway issues so why would these built for weight with no lift block springs be worse?

Most trucks with giant lifts don't a CoG that's 4' off the ground. Or have most of their weight on the rear end. Besides the truck camper folks. They deal with this issue too.

The old springs likely had a stiffer spring rate. Definitely so if the bottom overload was engaged (that spring is rated at something like 800 lbs/inch). Stiffer spring rates also increase roll stiffness, but at the expense of ride quality.

[nemesisnight]

So when I got my rear leaf pack it had the overload springs angled downward just a little bit, so I had John at Agile send me a straight one to try and stiffen the rear a bit and change my rear valving to their stiffest V5 tune. I still have the slightly arched spring, maybe if I install that with the arch facing upward it would help a little to stiffen it just a tad more. The angle is pretty minimal but maybe it would help, I dunno at this point. Or I could have a shop angle it more if needed but I am not sure how else to get my rear stiffer without getting harsh and am not a huge fan on the rear stabilizer idea but do want a safe driving van.

[nemesisnight]

Originally Posted by TomsBeast

I'm not sure I am following; Does 'swim' mean your are chasing the rear end (as it wanders from side to side) by steering the front wheels, constantly 'chasing it', a little like driving a forklift ?


One experiment to try is this:


Reduce front tire pressure significantly, 15-20 psi less than the rear, and see if anything changes. Then do the inverse (make the rear 15-20 psi less than the front tires)



Sometime to achieve front to rear balance, you run out of the ability to improve the 'sloopy' end (front or rear), which could be the rear in your case.



One chassis tuner trick is to intentionally make the better end, behave worse, achieving balance. This my seem counter-intuitive, but in the case of racecars, will net you quicker lap times.



In the case of my street mid-engine Toyota MR2 (where Toyota's door sticker calls for a 10psi difference between front and rear tire pressures) it keeps that little go kart of a car from wandering down the highway. I think 1960's Corvair owners found the same thing.


It's worth trying in my view

You always have interesting ideas and background to go with it. I will definitely try that and see what happens. On this last trip I maxed out my front and rear BFG KO2's to 80 PSI to try and minimize any sidewall flex. And yes I feel like I hit a gust of wind or sometimes just randomly have it wander and am chasing it to try and settle it back down. If I am gentle on the over-correcting it seems to do best but with the feeling of going into another lane and a 23 year old loose steering box its a both hands on the wheel affair trying to steady it out. Going slower or windy roads are not as bad as straight high speed wide open roads. So I think its the softer spring rate towards the top and with the high top and lots of upper cabinets etc it just starts to sway and work the rear suspension. I wasn't sure exactly where it was coming from at the beginning of this thread but after all I have done it is better from all my front end work but appears some of the issue is the rear.