[95wagon]

Here is a randum post on the measured effect
weight has on front ride height.

Two subjects
Stock Pontiac G8
Not so stock Caprice wagon.
Caprice has delalum control arm pivots and no front sway bar at the time of the test.

150 pounds of lead

Stir in a Pontiac with lead on centerline of engine

Roll back and forth and bounce.

Car goes down 5/8 of an inch .

Next subject , the Caprice .

Little less than 1/2 "

What good is this info ?
For me it is answering a question I didnt have

 

[toonwarrior]

.

 

[Z09B4U]

This leads to the rabbit hole of installing equivalent to driver's weight on the seat before setting spring height, and doing alignments with driver's weight installed.

This is where the self levelling air springs(bags) start a new debate. The height stays the same but the spring rate changes.

 

[95wagon]

Its nice down here with the bunnies .
If you are working with ride heights , corner weights you certainly account for the driver.
Alignment , usually
Some " our " ( I explained our elsewhere ) race cars that have big splitters , tunnels , defusers I don't bother with the driver weight after setup if doing alignment. Why ? The cars don't move from just driver weight.

Bone stock street cars , when I did that on a regular basis , just a quick sitdown in the seat would tell you how susceptible that car was.
Sometimes it would be best to deviate a bit for the driver on a bone stocker.
Funny aside. We had a lot of small English cars in Canada.
The Austin Marina was one .
No provision for caster camber.
Because they were designed as rhd cars they had backwards spreads in caster and camber.
Brand new you had to loosen strut mounts , crossmember , caster mounts and use every bit of slop to get them so they wouldnt head for the ditch on a crowned road

 

[95wagon]

Air bags yes totally agree.
Even the helper bags in springs if you are using them to fix ride height.
My bags typically only have a couple pounds in them , just enough to stop them folding.
The only time they have any pressure is when my wagon is loaded and that time ultimate handling and spring science is not at play.
The dual fill deal I also do not subscribe to.
I run tiny separate 1/8 od lines with the tee at the front.
The bags are effectivly about 20ft apart.
The bleed down takes for ever. Cross jacking at the low pressures I run would be measured in minutes

 

[SSandman]

Great info! That's about the height difference I would have guessed for that weight. It's definitely not as much as most would expect, and I would think spring rates wouldn't have to change that dramatically to accommodate.

As far as the air bags go, been trying to figure out a way to run some airlift 1000's with my rear coil over setup to help stiffen up the rear a bit on the launch, and also help maintain ride height when carrying a full load of passengers. Might get interesting though, I think I ran my 3" OTA's partially where the old oil springs would sit and the only way I could think of to secure the bags is to run some kind of a really weak spring in the original spring pockets

 

[Z09B4U]

the only way I could think of to secure the bags is to run some kind of a really weak spring in the original spring pockets

Have you looked at the "firestone" style bags that are used without a spring. There are a lot of kits for "overload springs" for trucks that use them.
The bags used in crown vics and towncars might fit where the old coils were but they have about the same diameter. They use the same perches as the coils on the panthers.

 

[SSandman]

Have you looked at the "firestone" style bags that are used without a spring. There are a lot of kits for "overload springs" for trucks that use them.
The bags used in crown vics and towncars might fit where the old coils were but they have about the same diameter. They use the same perches as the coils on the panthers.

I was thinking about that, just not sure I will have the room unless I can find something narrower than the typical. Going to have to get the car back up in the air when I get a chance though and see what kind of space I'm working with. When I was building the exhaust, leaving room for anything to go back in the original spring pocket wasn't really a priority and it was hard enough building 3" OTA's to fit as is LOL

I have considered building another exhaust with 2.5 axle back/OTA pipes, but I think I may be at the point where there may actually be a performance benefit to maintaining the 3" pipe all the way back. Would be interesting to try/dyno though.

 

[95wagon]

Never seen or used these , they always intrigued me though.

The Big Boy Jacker from Shadow Racing Products

Big Boy Weight Jacker from Shadow Racing Products - Fully adjustable, 6000 PSI positive lock adjustment

www.shadowracing.com

Hydraulic Adjuster for 2.5in Springs ALL64220

Hydraulic Adjuster for 2.5in Springs ALL64220 on sale now plus all the racing parts you need at Allstar Performance

allstarperformance.com

More to the application , as mentioned above one of the free standing supplemental bags would best address SSandmans issue.
They come as small as 3" dia and will still support 450 pounds each