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Sun Nov 14, 2010 1:01 pm

waltervee wrote: Hi Sugarbear,

Here's the link to Ratwell's Suspension and Handling section:

http://www.ratwell.com/technical/SwayBars.html

You'll find a lot of useful information from one of the real VW geniuses.

So it shall be written, so it shall be done.

Sun Nov 14, 2010 1:36 pm

SGKent wrote: Quote: You'll find a lot of useful information from one of the real VW geniuses.

Richard is a great guy and his website an extremely valuable resource. However there are many VW and car geniuses here and each have their own specialties. There are some here who understand suspensions far better than Richard so I would not discount their suggestions. Nor would I discount Richards's experiences.

Tightening up a suspension on a bus can make it easier to put on its side as there is less warning the limit is being reached but it will improve bump steer which is awful in a bus. Stiffening a suspension by use of heavier shocks is absolutely the wrong thing to do 100% of the time. Shocks serve one purpose and their mounts are made accordingly - they are designed to absorb the energy released by the springs / torsion bars. The springs are designed to absorb energy from the weight of the vehicle moving about so that the tires keep maximum contact with the road at all times. By using a heavier shock one changes the tire contact pressures which will make a vehicle handle worse than if the tire contact was stable.

When you see say an off road truck with three shocks on each wheel what they have done is put on three shocks which add up to the amount they really need from one shock - however the heat generated on a long race gets disipated over three shocks instead of one - and there is redundancy in case one fails. A formula car will walk over bumps just the same as a baja racer will walk over bumps like they weren't there. You can't do that with stiff shocks. You do it with ride height and spring rate.

Very well put. Many people do not understand the exact role of shocks. You need to bear this in mind: The KYB gas-a-jsut shocks are designed to be an upgrade in damping.....they are not a stock replacement. Typically they are 10-15% stiffer in both directions...compression and rebound. The factort literature used to note as much and those who sell them to you should as well....except that its harder to find knowledgable parts sales people than it is to find good parts these days.

On cars that are notoriously underdamped...say like the VW 411 and 412...these shocks are fabulous. If your vehicle has springs and you have uprated springs...gas-a-justs work great.

The GR-2 is slight upgrade and are generally close to stock valving...though they are about 5% uprated because they are an oil shock augmented with a low pressure gas charge. If your suspension is not fully in good shape...the GR-2 will exploit any weakness you have.

Far too many people simply look for anything that will physically fit their vehicle...without regard to internal valving. Ray

Sat Nov 27, 2010 4:03 am

ray Thanks for the knowlege 8)

I am leaning toward the Bilstiens, koni are a little out of my budget range.. im not going to lie im still a little confused on what is right for my bus.

No one is using the stock shocks boge/saches? i am still curious on how they are? buddepot has some for 57 & high end ones for 70 i think.

does anyone have a link to bilstiens?

Sat Nov 27, 2010 5:20 am

I'm using red Koni shocks at the front and Monroe Ride-Leveler at ther rear.
(the Monroe are adjustable in height by air pressure)

Sat Nov 27, 2010 5:28 am

Rs Man your undercarriage is glorious. how did you come to choose two different shock brands? wouldn't the same brand on all four wheels work better together?

After reading Ratwell I think I am going to go with saches/boge :) ill take pics and let you know how they are when i get them!

Sat Nov 27, 2010 6:09 am

On Topic:
I'm very pleased with the Koni's I used to travel the world. They were a big improvement on the gas-a-justs that the previous owner installed.

SGKent wrote: Tightening up a suspension on a bus can make it easier to put on its side as there is less warning the limit is being reached but it will improve bump steer which is awful in a bus. Stiffening a suspension by use of heavier shocks is absolutely the wrong thing to do 100% of the time. Shocks serve one purpose and their mounts are made accordingly - they are designed to absorb the energy released by the springs / torsion bars. The springs are designed to absorb energy from the weight of the vehicle moving about so that the tires keep maximum contact with the road at all times. By using a heavier shock one changes the tire contact pressures which will make a vehicle handle worse than if the tire contact was stable. I believe that you are wrong on the shocks and on the mounts. Shocks don't serve just one purpose. Besides absorbing spring energy they also damp the motion of the unsprung weight, crucial to tire-road contact.

Quote: In a vehicle, shock absorbers reduce the effect of traveling over rough ground, leading to improved ride quality and increase in comfort. Without shock absorbers, the vehicle would bounce considerably as energy stored in the spring is released to the vehicle, possibly exceeding the allowed range of suspension movement. Control of excessive suspension movement without shock absorption requires stiffer (higher rate) springs, which would in turn give a harsh ride. Shock absorbers allow the use of soft (lower rate) springs while controlling the rate of suspension movement in response to bumps. Along with hysteresis in the tire itself, they also damp the motion of the unsprung weight up and down on the springiness of the tire. Since the tire is not as soft as the springs, effective wheel bounce damping may require stiffer shocks than would be ideal for the vehicle motion alone.

And on the shock mounts. When VW needed to increase the payload of their commercial vehicles they installed coil over shocks. Exact same mounting also taking the weight of the vehicle.

Sat Nov 27, 2010 10:17 am

Quote: I believe that you are wrong on the shocks and on the mounts. Shocks don't serve just one purpose. Besides absorbing spring energy they also damp the motion of the unsprung weight, crucial to tire-road contact.

I will be polite by simply saying you are mistaken although that is what your perception is. Shocks are not and never were intended to be used this way. What you are doing is using a screwdriver as a pry bar. It can be done but that was not its intended purpose. The spring absorbs all the motion and the shocks keep it from rebounding again and again which a spring will do. The unsprung weight is by definition, unsprung. By making the shocks carry the load through gas pressure you are effectively making the whole bus unsprung weight. Instead of fixing it properly with spring ride height adjustments you have ghetto rigged it.

Sat Nov 27, 2010 11:03 am

SGKent wrote: Quote: I believe that you are wrong on the shocks and on the mounts. Shocks don't serve just one purpose. Besides absorbing spring energy they also damp the motion of the unsprung weight, crucial to tire-road contact.

I will be polite by simply saying you are mistaken although that is what your perception is. Shocks are not and never were intended to be used this way. What you are doing is using a screwdriver as a pry bar. It can be done but that was not its intended purpose. The spring absorbs all the motion and the shocks keep it from rebounding again and again which a spring will do. The unsprung weight is by definition, unsprung. By making the shocks carry the load through gas pressure you are effectively making the whole bus unsprung weight. Instead of fixing it properly with spring ride height adjustments you have ghetto rigged it.

X2. That is absolutely correct. The shocks have absolutely nothing to do with load control and load carrying. They are damping only and their valving must be synched to the rate of the spring. Ray

Sat Nov 27, 2010 1:19 pm

SGKent wrote: Quote: I believe that you are wrong on the shocks and on the mounts. Shocks don't serve just one purpose. Besides absorbing spring energy they also damp the motion of the unsprung weight, crucial to tire-road contact.

By making the shocks carry the load through gas pressure you are effectively making the whole bus unsprung weight. Instead of fixing it properly with spring ride height adjustments you have ghetto rigged it.
Although you may not be using the shock mounts properly, you are not making the whole bus unsprung weight. You are simply changing the point at which it is sprung partially to the shock mount. I redneck- rigged my rear end with coilovers and have had no problems, and adjusting the rear ride height is quite simple compared to redoing the spring plates! When and if I break a shock mount, I will post here that it happened. You all can flame me or whatever then. So far it works fine! I'll bet RSbadura has had good results with his Monroes as well. The best mod I did for wind wag ( and I endure some of the windiest conditions in the country) is Load range D tires.

Sat Nov 27, 2010 2:20 pm

TomWesty wrote: SGKent wrote: Quote: I believe that you are wrong on the shocks and on the mounts. Shocks don't serve just one purpose. Besides absorbing spring energy they also damp the motion of the unsprung weight, crucial to tire-road contact.

By making the shocks carry the load through gas pressure you are effectively making the whole bus unsprung weight. Instead of fixing it properly with spring ride height adjustments you have ghetto rigged it.
Although you may not be using the shock mounts properly, you are not making the whole bus unsprung weight. You are simply changing the point at which it is sprung partially to the shock mount. I redneck- rigged my rear end with coilovers and have had no problems, and adjusting the rear ride height is quite simple compared to redoing the spring plates! When and if I break a shock mount, I will post here that it happened. You all can flame me or whatever then. So far it works fine! I'll bet RSbadura has had good results with his Monroes as well. The best mod I did for wind wag ( and I endure some of the windiest conditions in the country) is Load range D tires.

Tom -there is an old men's story - a guy in a bar says to the bombshell looking brunette next to him, "if I pay you will you go home with me?" She says, "are you nuts?" He says "$150,000 one night, I have the money." She thinks it over, and says, "Ok but you wear a condom." He says "I changed my mind how about $50." She gets pissed off and says "What, you think I am a prostitute?" He says, "I thought we proved that already, now we are just bickering over price."

Well Tom, If you weld your shocks to solid steel bars the weight will be 100% unsprung weight. With heavy gas shocks and coil overs you are just bickering over what percentage of the weight is unsprung. I prefer my bus to be 100% unsprung and my shocks to be dampers only.

Sat Nov 27, 2010 2:42 pm

Quote: Tom -there is an old men's story - a guy in a bar says to the bombshell looking brunette next to him, "if I pay you will you go home with me?" She says, "are you nuts?" He says "$150,000 one night, I have the money." She thinks it over, and says, "Ok but you wear a condom." He says "I changed my mind how about $50." She gets pissed off and says "What, you think I am a prostitute?" He says, "I thought we proved that already, now we are just bickering over price."

:D haha that is funny. saved in my mind now for sure.

Sat Nov 27, 2010 6:03 pm

Whether it's sprung from the shock mount or the swing arm, the same percentage is sprung. Good joke by the way.

Sat Nov 27, 2010 10:51 pm

TomWesty wrote: Whether it's sprung from the shock mount or the swing arm, the same percentage is sprung. Good joke by the way.

Well, I can't convince you otherwise so I'll have to accept that you are stubborn. We still appreciate your wisdom and view in spite of the stubborn streak. :)

Sun Nov 28, 2010 7:41 am

SGKent wrote: Quote: I believe that you are wrong on the shocks and on the mounts. Shocks don't serve just one purpose. Besides absorbing spring energy they also damp the motion of the unsprung weight, crucial to tire-road contact.

I will be polite by simply saying you are mistaken although that is what your perception is. Shocks are not and never were intended to be used this way. What you are doing is using a screwdriver as a pry bar. It can be done but that was not its intended purpose. The spring absorbs all the motion and the shocks keep it from rebounding again and again which a spring will do. The unsprung weight is by definition, unsprung. By making the shocks carry the load through gas pressure you are effectively making the whole bus unsprung weight. Instead of fixing it properly with spring ride height adjustments you have ghetto rigged it. On the shocks:
Could you please edit the Wikipedia article on Shock absorbers? they also damp the motion of the unsprung weight up and down on the springiness of the tire I guess stuff like that shouldnt be in there then! Shocks dampen all motion, and while they might have been first introduced to stop the car from springing up and down all the time, they have come a long way since.

On the mounts:
Correcting butt-sag by using coil overs is wrong, never said that would be the way to go. My own suspension is set up 100% correct and works flawlessly. Just saying that if you desire to increase the payload of your vehicle, there is no problem with using coil overs. The shock mounts will handle the extra stress. Or are you accusing VW of ghetto-rigging their rides?
The load levelers (which also transfer weight to the shock mounts) should not present any problem. A friend of mine drove his T2 from Buenos Aires all the way up to Alaska on 4 monroe load levelers without a single issue

Sun Nov 28, 2010 8:14 am

You guys are somewhat talking past each other but the fact of the matter is a shock dampens motion in both directions as you can prove by just moving one by hand. Fancy shocks are adjustable for both compression and rebound damping and they have to be carefully coordinated because to much rebound damping and not enough compression will cause the suspension to pack down over a rapid series of bumps... it will compress each bump but not rebound fast enough so the next bump will compress it further etc.

Anyway so when you hit a big bump at speed with any normal suspension system some of the impact is taken by the spring and some is taken by the damping of the shock and passed to the shock mount. That's just the way it is. If you hit the bump slower more of the impact is taken by the spring and less by the shock because the damper has more time to move. Shocks resist motion over time.

Sun Nov 28, 2010 8:27 am

WhirledTraveller wrote: You guys are somewhat talking past each other but the fact of the matter is a shock dampens motion in both directions as you can prove by just moving one by hand. Fancy shocks are adjustable for both compression and rebound damping and they have to be carefully coordinated because to much rebound damping and not enough compression will cause the suspension to pack down over a rapid series of bumps... it will compress each bump but not rebound fast enough so the next bump will compress it further etc.

Anyway so when you hit a big bump at speed with any normal suspension system some of the impact is taken by the spring and some is taken by the damping of the shock and passed to the shock mount. That's just the way it is. If you hit the bump slower more of the impact is taken by the spring and less by the shock because the damper has more time to move. Shocks resist motion over time. Thats what I meant 8) Thanks

Sun Nov 28, 2010 12:31 pm

Well I will explain that to all the formula one guys, off road racers and authors of the books written on the subject. Check Wikipedia again I think you misread it.

If you are the reading kind, here are some places to start. Let me recommend them. I have some others that can be recommended when you are done with these.

Competition Car Suspension: Design, Construction, Tuning by Allan Staniforth

Competition Car Suspension: A Practical Handbook by Allan Staniforth

How to Make Your Car Handle by Fred Puhn

Sun Nov 28, 2010 4:22 pm

raygreenwood wrote: SGKent wrote: Quote: I believe that you are wrong on the shocks and on the mounts. Shocks don't serve just one purpose. Besides absorbing spring energy they also damp the motion of the unsprung weight, crucial to tire-road contact.

I will be polite by simply saying you are mistaken although that is what your perception is. Shocks are not and never were intended to be used this way. What you are doing is using a screwdriver as a pry bar. It can be done but that was not its intended purpose. The spring absorbs all the motion and the shocks keep it from rebounding again and again which a spring will do. The unsprung weight is by definition, unsprung. By making the shocks carry the load through gas pressure you are effectively making the whole bus unsprung weight. Instead of fixing it properly with spring ride height adjustments you have ghetto rigged it.

X2. That is absolutely correct. The shocks have absolutely nothing to do with load control and load carrying. They are damping only and their valving must be synched to the rate of the spring. Ray

well i am pretty sure absorbing spring energy and damping unsprung motion would be the same thing, just phrased differently, so this arguement can't go too far.

on the original topic of shocks, the GR2s massivly underwhelemd me in stiffening up the ride, and even with a cut and turn front end (more preload on the front bars) and a set of gas-a-justs on all 4 corners, the ride in my bay is still real nice and smooth. thie absolute best thing you can do for a bay is proper tires, i when from no shocks to gr2s and gasajusts, had passenger car tires, still ran like poop, a tiny bit stiffer ride over bumps. put some c rated tires on it, and oh. my. god. soooo much better. tires make a huge difference.

Since this is a thread on shocks aside from the common ones, does anyone know of a stiffer front shock than the gas-a-justs? and when you adjust a koni, does it adjust rebound, compression, both?

Mon Nov 29, 2010 12:17 am

Quote: Since this is a thread on shocks aside from the common ones, does anyone know of a stiffer front shock than the gas-a-justs? and when you adjust a koni, does it adjust rebound, compression, both?

That is probably a question for Koni but I would guess in both directions if the shock is originally constucted to work in both directions. Not all shocks work in both directions and it would depend upon the application. I had an Opel GT for example that only worked in one direction. Dual action would beat you to death in that Opel. I know because I tried it for 48 hours - that is all I could take.

As to the confusion on dampening unsprung weight. That is kinda the whole argument. You don't want the sprung weight moving. You want just the suspension to rise and fall. You don't want the sprung weight accelerating up and down. The shocks are just to take energy out of the springs, not cause the springs to avoid absorbing the energy. If the spring rate is too soft, lighten the vehicle or use heavier springs/torsion bars. A pickup truck can be made to ride like a Cadillac if you put enough weight in it to offset the heavy springs. VW buses have a lot of bump steer so that is why stiffer shocks are probably an illusion of better handling. A stiffer sway bar would eliminate some of the bump steer caused by roll. But then there will be less roll warning before a rollover. I can see ways to make it handle better - go to lighter material than glass for the windows, get all the weight possible down closer to the ground - lower the seat pedestals etc. The top might be made lighter with a fabric or plastic sunroof of some kind - maybe tinted or light fabric lined to keep the sun out - noiser but lighter. Get the rack off the roof, chop the windows to lose some of the metal. Then redo the steering with a rack and pinion setup - lnks etc. It would handle really nice. Probably have to lighten the rear axle, wheels and tires too. Get the unsprung weight down. Use real mags and don't bump any curbs. Put in a 6 cyl Porsche drive train and it would be a very fast well behaved bus - although it couldn't carry anything anymore like a stock bus. 1 or 2 people max.

Mon Nov 29, 2010 3:34 am

fusername wrote: and when you adjust a koni, does it adjust rebound, compression, both? On the Koni's for our Busses you can only adjust the rebound.