Saggy Bum

[Velma's Dad]

"If Cali owners want to drive a van with compromised steering feel so that the floor is level when parked up , I guess they can."

Genuine question, just curious: can someone can explain to me why the steering would be compromised by the rear body ride height being "wrong" (rather than if the rear of the van was overloaded, changing the centre of mass rearwards)?

 

[clarinetbcn]

Genuine question, just curious: can someone can explain to me why the steering would be compromised by the rear body ride height being "wrong" (rather than if the rear of the van was overloaded, changing the centre of mass rearwards)?

Just to be clear, that's a quote from CRS performance on the T6 forum, where they state that the "correct" setup is a rake 40-50cm from back down to front, and making the van level makes the steering go light. They do a brisk business selling spring spacers to raise the rear.

 

[andyinluton]

Genuine question, just curious: can someone can explain to me why the steering would be compromised by the rear body ride height being "wrong" (rather than if the rear of the van was overloaded, changing the centre of mass rearwards)?

Im guessing that the rear hight makes no difference at all to the steering.

A T6.1 panel van is designed to be up at the back when empty, about level when half loaded & down at the back when fully loaded. ( I'm referring to the floor of the van, not any optical illusions)

I refuse to believe that VW don't take account of this when designing the suspension / steering at the other end of the van.

An empty California is the same as a half loaded panel Van.

 

[andyinluton]

Just to be clear, that's a quote from CRS performance on the T6 forum, where they state that the "correct" setup is a rake 40-50cm from back down to front, and making the van level makes the steering go light. They do a brisk business selling spring spacers to raise the rear.

They also state in the same post:
"30 to 40 mm drops wont affect steering geometry at all , The suspension moves further than that when going over bumps"

 

[sidepod]

Genuine question, just curious: can someone can explain to me why the steering would be compromised by the rear body ride height being "wrong" (rather than if the rear of the van was overloaded, changing the centre of mass rearwards)?

Vehicle rake (angle to the road) affects castor angle at the front which alters suspension dynamics/feel, not that anyone here in a builders van could notice!

 

[sidepod]

Im guessing that the rear hight makes no difference at all to the steering.

It does and don’t guess

 

[Velma's Dad]

Vehicle rake (angle to the road) affects castor angle at the front which alters suspension dynamics/feel, not that anyone here in a builders van could notice!

I was guessing it might be something to do with castor angle but/and as you say is only going to make a difference if you're trying to set lap times on the Ring.

 

[sidepod]

Imagine a line through the front strut intersecting the road. Viewing from the side the angle this line makes relative to the road is Caster.
Caster is what (among other things) creates self correcting steering.
If the angle is too steep (high rear end) steering looses feel. Too slack and steering becomes heavy.

Awful lot of over thinking on this thread. Just use spacers/coil overs and preload to set the van up to what ever rake makes you happy. Done. FFS!

 

[B J G]

Ever heard of pre-load?

Are you saying that coilovers will sit at the same level with fuel and water tanks empty and no holiday gear or passengers in as they do fully loaded for a trip?

 

[clarinetbcn]

CRS posts don't say making the van level affects the castor angle, they say that unless the rear is raked 40-50mm higher than the front, the steering "goes light," and this should take precedence over having the floor, kitchen and beds level. Hmmm.

 

[B J G]

They also state in the same post:
"30 to 40 mm drops wont affect steering geometry at all , The suspension moves further than that when going over bumps"

As a check I had my air suspension alignment set up then dropped it to see what effect it had on alignments--result was minimal change. That was from a normal field clearance height to a motorway height. Not all up to all down as no point looking at that.

 

[clarinetbcn]

If the angle is too steep (high rear end) steering looses feel.

That is exactly the opposite of what CRS says. They claim raising the rear 40-50cm above level increases steering feel. It doesn't make any sense.

However, what it will do is raise the center of gravity at the back of a very heavy vehicle. Does anybody think that's a good idea? I've seen posts on here by people who have had their vans lowered to increase stability, and then have the rear raised above level again to eliminate "sag."

 

[B J G]

I've gone to the expense of having the adjustable poly bushes fitted to the front and rear suspension.

The difference in handling and comfort is very much improved. Money well spent.

Front Caster, Camber and alignment now to spec.
Left & right had quite different Camber & Caster figures.

Rear camber and alignment now to spec. Left & right had different camber figures previously.

All set up to VW half load alignment figures with suspension at moderate lowered level as set on air system which will keep these constant with or without load.

 

[sidepod]

Are you saying that coilovers will sit at the same level with fuel and water tanks empty and no holiday gear or passengers in as they do fully loaded for a trip?

Not at all. I’m saying it’s entirely possible to create whatever static ride height you want. All you can do is set up for an average loading.

 

[sidepod]

I think we/I misunderstood your post.
You said it was impossible to achieve a level ride with coil overs. I think you were meaning a dynamic level as opposed to static.

 

[Bobby D]

Some will claim this is level...it's not. Please measure the jacking points along the cill on level ground. Or try the actual jack on the front and then try to get the same jack at the same height under the rear jacking point...it doesn't fit as the rear is about 15mm lower (when loaded) than it ideally should be.

 

[Bobby D]

VW's image of 'Level'

 

[andyinluton]

View attachment 86223

Some will claim this is level...it's not. Please measure the jacking points along the cill on level ground. Or try the actual jack on the front and then try to get the same jack at the same height under the rear jacking point...it doesn't fit as the rear is about 15mm lower (when loaded) than it ideally should be.

Its impossible to tell from that picture, the van is not at 90 degrees to the camera, the camera needs to be at the mid point lengthways of the van & the ground needs to be level. If you line up the plinth that the building is sitting on with the top or bottom edge of the screen you will see that either the camera angle is distorting things, the building is sloping, the ground is sloping or a mixture of all three.

15mm = approx 1/4 of a degree difference on the castor angle. as the factory tolerance on castor angle is between +0.25 and -1.05 degrees that 1/4 degrees of castor angle is going to be making no difference to the steering feel.

I presume you always drive round with your van fully loaded & bikes on the back?
Our van gets used empty for probably 46 weeks of the year & fully loaded 6 weeks. I would prefer mine to be set to look right for the 46 weeks.

 

[adamsteele2802]

I have used crs to level out my cali, the rear stayed pretty much the same just stiffer and the front lowered slightly, it drives much better to standard even with 20s. Also fitted HD arbs so it is no longer like being on a boat with no crashing over bumps, even seems to rattle less!
Obviously not everyone's cup of tea and I wouldn't want it any lower but I'm happy with it now and it wasn't all for looks as using my cali as a daily I would have moved it on by now rather than suffer the strange crashy but boat like drive VW managed to achieve!

Sent from my EML-L09 using Tapatalk

 

[clarinetbcn]

View attachment 86223

Some will claim this is level...it's not.

Who? I've never seen a post where someone claims that a van which is lower at the back is level. There are, however, endless posts by people who claim that when the van is level it's sagging, and take their vans to suspension shops who leave the vans with front and back wheel arches the same, the back raised 40-50cm higher than the front, and specify that level vans have compromised steering feel (see post #50).

I think it would be helpful for us all to take a look at the image at the top of this Forum page, which is the forum's official image for its worldwide audience (visible on laptops, not phones). That says it all.

 

[Bobby D]

I'm happy with my 32 springs and non saggy rear (measure take from floor to vehicle jack points front and rear).

It rides much much better too.

 

[B J G]

Not at all. I’m saying it’s entirely possible to create whatever static ride height you want. All you can do is set up for an average loading.

That's what I would expect, it was just that you claimed 100% level with coilovers.

Close as you can get to 100% level with steel springs is by using coilovers or adjustable height rear springs only.

 

[tedgina]

That's what I would expect, it was just that you claimed 100% level with coilovers.

Close as you can get to 100% level with steel springs is by using coilovers or adjustable height rear springs only.

Can anybody with the correct qualifications and experience settle this post?

 

[WelshGas]

Can anybody with the correct qualifications and experience settle this post?

VW?

 

[soulstyledevon]

VW?

I could just imagine the boys at Wolfsburg…
“Some bloke in Cannock told you what…???”