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 Suspension Debate

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81X11
gingergarnet1111
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gingergarnet1111

gingergarnet1111

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PostSubject: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 11:03 am

My suspension is shot, handles like a pontoon boat on rough water.

Debating the pro's and con's of the next system.

I would either like to do a fully bagged setup, or remove air all together and install a slight drop (spindles?springs?) with performance parts and improved sway.

I daily this car in the summer, my house has a crappy 1/4 mile long gravel driveway that limits my drop. I occasionally pull a boat/car trailer.

Options? Suggestions? Recommendations? Thank you
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81X11

81X11

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 11:46 am

I get asked this question all the time on forums and Facebook pages, and at the local car meets, especially by new wagon owners and folks that take a ride in my car or see me towing boats or motorcycles on my trailer.

The FIRST thing I do on my whale wagons is replace the rear springs with variable-rate Moogs and all four shocks with KYB Gas-A-Justs. The rear springs and four shocks can be sourced from Rock Auto for cheap. Then just tuck the air lines up out of the way in the back, pull the compressor fuse, and BE DONE.

My 96 Roady Wagon has had this setup since 2008, and I also did this on my '92 Custom Cruiser wagon. One of my favorite cheap, easy (other than the upper bolts on the rear shocks), and BEST mods.

Rides great with the MOOGs and the KYBs, still tows a boat fine, handles a full load of people an cargo, and I never again have to worry about shock or hose leaks, ride level sensors or compressor failures. All these components are just too old now...either worn out on the high-mile cars or dried-out on the low-mile cars. It's NOT worth the effort!

Rock Auto Parts and Pricing -
MOOG Variable-Rate rear coil springs, Part # CC623 - $48.79 pair
KYB Gas-A-Just Rear Shocks, Part # KG5504 - $29.89 x 2
KYB Gas-A-Just Front Shocks, Part # KG4515 - $33.79 x 2

DONE....forever.

-Texas Mike

****OH and Bilstein shocks are GREAT if you can afford them and want a bit firmer ride. Likewise many folks swear by the Monroe Severe Service Shocks (Taxi/Police), which are not expensive, but I ran those a year on my 96 Roady Wagon and found them just too harsh over bumps, potholes and highway expansion joints.

OH I also tried coil-over rear shocks from Autozone for a time, with the stock rear springs, but the actual shock inside the coil is really tiny, so the rear end was "bouncy". Replacing the actual factory springs with the Moogs and installing the KYB shocks was a MUCH better way to go.

The KYB Gas-A-Just, to me, are a great balance, they really firm the car up but it still rides smooth over all road conditions, and as you see above the pricing is very fair on them.

Hope this helps!

-Texas Mike

Suspension Debate 28575510
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gingergarnet1111

gingergarnet1111

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 12:57 pm

81X11 wrote:

Rides great with the MOOGs and the KYBs, still tows a boat fine, handles a full load of people an cargo, and I never again have to worry about shock or hose leaks, ride level sensors or compressor failures. All these components are just too old now...either worn out on the high-mile cars or dried-out on the low-mile cars. It's NOT worth the effort!

Rock Auto Parts and Pricing -
MOOG Variable-Rate rear coil springs, Part # CC623 - $48.79 pair
KYB Gas-A-Just Rear Shocks, Part # KG5504 - $29.89 x 2
KYB Gas-A-Just Front Shocks, Part # KG4515 - $33.79 x 2

DONE....forever.

-Texas Mike


Excellent info and prices! I have a small leak in one, as the compressor kicks on more than it used too haha. Can't wait to remove that from the equation. Thank you for the info!
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81X11

81X11

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 6:07 pm

gingergarnet1111 wrote:
81X11 wrote:

Rides great with the MOOGs and the KYBs, still tows a boat fine, handles a full load of people an cargo, and I never again have to worry about shock or hose leaks, ride level sensors or compressor failures. All these components are just too old now...either worn out on the high-mile cars or dried-out on the low-mile cars. It's NOT worth the effort!

Rock Auto Parts and Pricing -
MOOG Variable-Rate rear coil springs, Part # CC623 - $48.79 pair
KYB Gas-A-Just Rear Shocks, Part # KG5504 - $29.89 x 2
KYB Gas-A-Just Front Shocks, Part # KG4515 - $33.79 x 2

DONE....forever.

-Texas Mike


Excellent info and prices! I have a small leak in one, as the compressor kicks on more than it used too haha. Can't wait to remove that from the equation. Thank you for the info!

That's what this forum if for! Take Care!

-Michael
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RedandBlack

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 6:11 pm

The CC623 are taller than stock. If you want to lower it - run these:

Moog 5662 front
Moog CC501 rear

Very similar to stock ride. About a 2-2.5" drop that these cars desperately need.
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gingergarnet1111

gingergarnet1111

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 6:27 pm

RedandBlack wrote:
The CC623 are taller than stock. If you want to lower it - run these:

Moog 5662 front
Moog CC501 rear

Very similar to stock ride. About a 2-2.5" drop that these cars desperately need.


awesome info Smile hopefully ordering next week.
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RedandBlack

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 6:36 pm

Old pic. 17x8 wheels and 235/55R17 tires on those springs.

Suspension Debate 10550951_10204624701044094_607480178421376220_n

Currently car has those springs PLUS 2" spindles up front. 22x9.5 wheel on a 255/30R22 tire. Same diameter as the 17" tire.

Suspension Debate 39959769_10217649946107080_3732645283977232384_n
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94Woody

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 9:19 pm

Same springs as RedandBlack on 15s.

Suspension Debate W6S9CMy

and on 18s....

Suspension Debate 5IX0uQX
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Aug 29, 2018 10:54 pm

RedandBlack wrote:
Old pic. 17x8 wheels and 235/55R17 tires on those springs.

Suspension Debate 10550951_10204624701044094_607480178421376220_n

Currently car has those springs PLUS 2" spindles up front. 22x9.5 wheel on a 255/30R22 tire. Same diameter as the 17" tire.

Suspension Debate 39959769_10217649946107080_3732645283977232384_n
You do not have wheelhouses in the front. Mine with drop spindles, and about 1 inch springs has trouble with 215/60/17s on the front. I will probably go back to stock spindles, and 2 inch springs for the Wilwood brakes I am going to install. I will probably go to 255/50/17s on the front after the change.
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gingergarnet1111

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeMon Sep 10, 2018 4:23 pm

Great info! Thanks all!
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeMon Sep 10, 2018 10:41 pm

If you put drop spindles on the car, you must run at least 17 inch wheels. If do not, and you have a flat, the shocks will hit the ground before your wheel, and it will tear your suspension off.
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gingergarnet1111

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeTue Sep 11, 2018 9:59 am

Good to know, what are good wheel sizes to run anyway? I have the impala SS rear axle which is a bit narrower. Trying to find a good set, really liking the look of the riddler wheels.
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeTue Sep 11, 2018 2:27 pm

Small wheels and big tires give you a soft ride. Small tires and big wheels give you a harsh ride. Just make sure the offset is correct. If you put drop spindles on the car, they will move your wheels about 3/8 of an inch out on the front.

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gingergarnet1111

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeFri Oct 12, 2018 10:15 am

Anyone have a photo of the fuse I am supposed to pull for the air pump? Also how much of this stuff can be removed without damaging anything? weight reduction time....
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeFri Oct 12, 2018 12:26 pm

The entire system can be removed without causing any issues. The compressor is behind the passenger's side bumper cover. You will loose about 15#.
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gingergarnet1111

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeFri Oct 12, 2018 1:03 pm

aWesome! TY!
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gingergarnet1111

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeFri Oct 12, 2018 1:22 pm

Anyone have the fuse number or picture of the block diagram? I don't have one.

Thank you.
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeFri Oct 12, 2018 2:10 pm

If you remove the entire system, you do not have to remove the fuse. Start by unplugging the pump.
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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeTue Apr 21, 2020 4:00 pm

I would certainly be an outlier in the ride height issues. While I agree that lower will handle better, I rarely have seen a vehicle with drop spindles handle as precisely as a near stock height one with the proper components and settings. Drop spindles mess up lots of the geometry away from optimum, including scuff, akerman, bump steer, etc. Stock geometry, while often needing tweaking, usually will be much better. Setup for hard cornering with drops and you may get poor tracking, bump steer, etc the rest of the time, or other issues. If you lower all the front suspension and steering, then you have a much better system, but it is a near impossible feat without huge amounts of work.

Bilstein makes two different shock lines for the Buicks, hopefull someone will remember the numbers. I went from KYB gas adjusts that were cheap and good for testing handling because that is what they are good at, to the softer version of the Bilsteins this year. The Bilsteins are much more comfortable and quieter on the small bumps with at least as good of response and control on the big bumps. They also have bigger isolator mounts on the front so a bit less hit. They are about 4 times the cost of KYB, so that makes the choice much harder to swallow.

Handling is very a very personal thing with most everyone preferring different feel, so really you have to try a few things to see if they move you in the direction you want to go. Throw in desire, or not, for a smooth and comfortable, quiet ride, and it gets even more personal.
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeTue Apr 21, 2020 7:24 pm

Properly designed drop spindles do not upset the parameters of stock suspension. The Ackerman is the same, because the ball joints and outside pivots for the tierods are in the same relationship to the original spindles. Bump steer is not changed, again, because the outside pivots for the tierods are in the same location in relation to the ball joints, as the originals. The height of the axle does not change the geometry. The advantage of the drop spindles is that you still have the original suspension travel. There are few disadvantages to using properly designed drop spindles. The only issues on the B Bodys are that you must run 17 inch wheels, because the ball joint will hit the ground before the rim in case of a flat, the added track will keep the tierods a little more taut, and the front wheels have about 3/8~1/2 inch of increased track per side, which limits the width of the front tires, unless you get a rim with a +12~+15 offset. The individual tires/wheels will tend to roll a little bit when turning the steering, because of the additional track, and the ball joints being in the original place. The added offset above would counter that slight roll when turning. It would be like running a 4 inch smaller diameter (2 inch smaller radius) tire with a -4 offset.
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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeTue Apr 21, 2020 8:14 pm

Fred Kiehl wrote:
Properly designed drop spindles do not upset the parameters of stock suspension. The Ackerman is the same, because the ball joints and outside pivots for the tierods are in the same relationship to the original spindles. Bump steer is not changed, again, because the outside pivots for the tierods are in the same location in relation to the ball joints, as the originals. The height of the axle does not change the geometry. The advantage of the drop spindles is that you still have the original suspension travel. There are few disadvantages to using properly designed drop spindles. The only issues on the B Bodys are that you must run 17 inch wheels, because the ball joint will hit the ground before the rim in case of a flat, the added track will keep the tierods a little more taut, and the front wheels have about 3/8~1/2 inch of increased track per side, which limits the width of the front tires, unless you get a rim with a +12~+15 offset. The individual tires/wheels will tend to roll a little bit when turning the steering, because of the additional track, and the ball joints being in the original place. The added offset above would counter that slight roll when turning. It would be like running a 4 inch smaller diameter (2 inch smaller radius) tire with a -4 offset.

If you leave the ball joint in the original position, your scrub changes a lot, so you to move out the wheel, which increase the arc that is turns. It all gets really complex, especially since you normally wouldn't be moving the steering gear and idler to get parallel to the proper place to prevent bump steer, which is big issue with drop spindles. Some spindle kits give you a new upper arm to address of it, some drop the lower ball joint, but all have compromises. Drops probably aren't as bad as lift spindles, which often make the trucks they use them on very twitchy, but you will really not see geometry as good as with the stock ride height on most vehicles, at least the ones I have seen. The drops have the advantage of limited travel before they hit things, and that will minimize the issues, but they are likely still there. I have seen track cars that only have maybe 1" of uptravel handle quite well, but that isn't what I would want on the street in a cruiser or daily.

IMO, whenever you change the relationship of the balljoints to the a arm pivot points, or the ball joint inclination angle that determines scrub, or the distance between the balljoints, or the tie rod to lower control arm angle or attachment point, things change. As I mentioned before, everyone has their own opinions on handling stuff, and is totally entitled to have them. Many will be very happy with drop spindles, but the wouldn't be my choice unless appearance was the most important part of it, or I was going to limit travel and setup the alignment for specific track use, but that is just me.

Not trying to pick an argument, but that is how I have seen the issues over the years.
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeTue Apr 21, 2020 9:47 pm

The drop spindles on my car have the same geometry as the OEM spindles, except for the height of the axle, and a slight increase in track. The balljoints have the same relationship to the A arm pivots. I have no bump steer, because the steering parts are located at the same place relative to the OEM balljoints. The spindles have the increased track to clear the lower balljoint with a 15 inch wheel. A +12~+15 offset wheel would put the tire on the same arc as the stock spindles.

I have been driving this car with drop spindles for about 10 years. I also have an identical car that has OEM spindles, and they drive the same. It has no bad habits as far as the steering, and suspension are concerned. If I had poorly designed drop spindles, you would be correct, but these are extremely well engineered. I understand the geometry needed to get a good handling car, and know what causes bump steer, and Ackerman, or antiAckerman.

Not arguing, but just stating my personal experience with drop spindles on a B body. There are a lot of people who do not understand front suspension, and steering, and a lot of them race cars that handle poorly. The winners figure it out, and the losers don't.
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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Apr 22, 2020 10:43 am

I would agree that if you have available drops that leave all the original parts that you have the same basic geometry with those parts and will keep that geometry.  The other issues may be something that would be noticed, or not, depending on the use of the vehicle and other things.  

The movement of the wheel up compared to the rest of the parts makes the road contact point move in relation to them.  As you say, the offset can be used to bring in the wider track and straight ahead scrub, but in turns and bumps other stuff can happen. The roll center will also move down so will get increased roll on the front.  There are basically 3 angles you deal with, the ball joint inclination which is fixed within the knuckle but changes with suspension movement, the caster angle, and the mounting angle of the upper control arm relative to the horizontal plane which makes for a dynamic caster change with suspension movement.  The only real way to know what goes on is if you can build a 3D model to show things in motion.  From what I have seen with only brief searches in the past, that is what some of the manufacturers are doing with some very good results.  Don't know if they have them to fit the Buicks, but IIRC a lot of the parts are the same as earlier model rear drivers from past decades so they may fit.  They would give the more common now negative camber progression we see would see on the newer double a frame designs and much higher caster positive.

The norm for a long time is if you want to get to Autocross type handling without a lot of changes in the rear drive stuff is to put in a tall upper balljoint in one way or another so you get negative caster progression on compression instead of the positive progression in most of older rear drives.

Personally, for a driver like I am doing, I don't mind the positive camber progression as positive camber will give a bit better directional stability and steering return most of the time.  Both of these are not really a benefit at an Autocross.  To limit the progression in harder cornering, increased anti sway keeps it reasonable for a spirited daily.

One thing that I think most every vehicle should be checked for, especially if changes in anything are done, be it spring height, spindles, upper joint, arms, whatever is the camber progression so you know how to set the straight ahead camber.  I have found that with a lot of rear drivers with positive camber progression, particularly if they have high scrub radius like is common with oversize tire fitting, they can give a odd driving feel if they are aligned with a negative camber.  I think it is probably because even on small bumps the camber goes from negative to positive and back again all the time.  This would move the major contact and force lines from the inside to the outside and cause a small pull away from the side of the vehicle that got compressed.  It might show up in the steering wheel as minor shimmy that only shows up on one wheel bumps as when both are compressed together the forces change the same on both sides.  Our Chevy 3500 van had this issue big time when we got it and if you went through a dip (9600# pound vehicle) it would  take off to one side.  Turned out one side was side positive camber and the other minus.  Evened them out and it mostly went away.  This van also had -6 offset wheels on a van that was designed to +28, so the scrub was very large.  Going to the correct offset wheels also helped a whole lot.  It is also good check to see what the camber does in turns and how the caster changes might affect it as you can get some funny mid turning changes in effort sometimes.  My Buick did that until I was able to move the caster up to over double what I could get with stock setup upper arms.  It would almost self turn at about 1/2 way to the stops.

The newer vehicles seem to have gone to self centering steering gears, probably with the hydraulics doing it.  The wife's CRV is downright springy to to center even if sitting still, so most of the "road feel" is really simulated.  Our 07 van has a different valve on what appears to be the same gear as previous years.  It is bigger and only serviced as an assembly as far as I could find out.  It also has a springy feel to it that the older ones didn't, but not nearly as exaggerated as the CRV.  The center feel is much different in those two vehicles compared to the Lee built gear in the Buick which is relatively soft in the center so takes little effort to move the small center corrections which is how the older vans used to feel like also.  The ones that seem to be locked to center internally tend to be a bit tiring if you are in a constant side wind and have to hold against it all day if the springy force is fairly high, where the older ones need less effort to hold them.  The self centering ones give the alignment shops some interesting options though, as it appears you can manipulate them a bit to get the vehicle to go straight if you have a pull for some other reason by offsetting the center a bit with side to side toe settings.

All in all, none of any of the theoretical things don't matter in the real world if the driver is happy with the way the vehicle drives.  I know from letting people drive the various vehicles I have had over the years that some people will call a responsive handling vehicle "twitchy" and others will love it.  Some will really like the driving of a big understeering vehicle and others with think is horrible, and it will always be that way, I think.

I found it interesting the stock steel wheels for the wire wheel covers were +8 when I expected them to be them to be zero.
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Apr 22, 2020 11:38 am

The B bodys OEM wheels are supposed to have a +6 offset. 

I have noticed that as the suspension is compressed, that the camber becomes more negative. To drop the suspension with shorter springs, you must remove 0.030 shim for every half inch of drop. That negates the induced negative camber. I do my own alignments, and have done a number of cars with a 2 inch drop. I have also noticed that there is not much return feel in the steering wheel, no matter how much caster you have.

Most people need a car that understeers, because they have no idea of how to handle oversteer. Fortunately for most drivers today, they have front wheel drive cars that are notorious for understeer.
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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Apr 22, 2020 12:06 pm

Fred Kiehl wrote:
The B bodys OEM wheels are supposed to have a +6 offset. 

I have noticed that as the suspension is compressed, that the camber becomes more negative. To drop the suspension with shorter springs, you must remove 0.030 shim for every half inch of drop. That negates the induced negative camber. I do my own alignments, and have done a number of cars with a 2 inch drop. I have also noticed that there is not much return feel in the steering wheel, no matter how much caster you have.

Most people need a car that understeers, because they have no idea of how to handle oversteer. Fortunately for most drivers today, they have front wheel drive cars that are notorious for understeer.

How low is the suspension when you see the negative camber? I measured mine when I had the springs out and putting in the new front end parts. I used the FSM which showed the doofy GM "trim height" measurement to very hard to measure places. I also do my own alignments so had the decent bubble gauge. Since there was no spring in, on checked it at both the Buick and Chevy trim height spec which were about 1" different with the Chevy higher (that is where the Moog springs put it, also). I could just jack up the lower a arm with nothing else changing so was really easy to do then. I had to go up a long ways before the caster started to move toward the negative side when starting at about +1/4 degree. It started to move toward negative when the upper arm went past horizontal, which is what would be expected. I have seen similar to what you are seeing, but it was on vehicles with short springs in them. Never ran across it in the older vehicles at factory height.

What orientation is your upper arm sitting at compared to the ground?
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Apr 22, 2020 1:29 pm

It is above horizontal. I have not measured it. With 2 inch drop springs, it required the removal so 0.120 inches of shims to get the camber sorted out.
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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Apr 22, 2020 3:33 pm

That would certainly explain the difference, ours is below horizontal, as is our van and probable most stock height and spring length vans. Do you have stock length springs in it?
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeWed Apr 22, 2020 8:09 pm

I have 2 inch drop springs.
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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeThu Apr 23, 2020 8:43 am

Thanks Fred, that fills in the puzzle for me as it explains the negative camber progression thing. It would also explain the camber shim change if the springs went in at the same time as the drop spindles, as the spindles, if as advertised as identical geometry, shouldn't have changed the shimming unless the extra 3/8" negative offset lowered it enough to cause it by leverage.

All of this suspension stuff is a big dance of parameters, IMO, and what is good in one combination of changes can be bad in another and vice-versa. I think that is why it so important to carefully define what you are trying to accomplish in making the changes, and those goals can be hugely different. Some may want make cornering ability to autocross or just because they prefer that, others (like me) want to have a daily that will haul, be very easy to drive in everyday or long drives and handling that is very good but not the maximum. Getting the right combination of things to do is very often very hard to do, as we often see single changes pushed as being the "best" all the time. I have always been kind of wondering about all the articles about how the older, positive progressive camber, vehicles were of poor design. Personally, I think they were designed to do exactly what they did well, straight tracking and stability without much effort and a comfortable drive when coupled with, many times the preferences of the day, super light power or manual steering. Today's preferences have changed, with handling performance moving up the scale of importance, so we have seen more tilt toward handling (which honestly a minority of people really ever need or use) in everyday drivers. The then had to make the driveability better so the influx of self centering steering gears and racks came, both hydraulically and electronically to get that back and have the better of both.

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Fred Kiehl

Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeThu Apr 23, 2020 9:14 am

Camber change is also a function of body roll. The less body roll, the less camber change. Sometimes the camber needs to compensate for tire tread/sidewall rollover. The whole purpose of suspension is to keep the tread flat on the road surface. Negative camber progression allows the body to roll, and still keep the tire flat on the ground when the suspension compresses in a corner. More rollover requires even more negative progression. This is why most high performance cars have short sidewalls. There is less distortion of the tire, allowing the suspension tuner to be more accurate in all positions of the suspension by removing the variable of the tire sidewall. A wider rim also makes the tire more stable, and the suspension movement can then be more accurate. The other side of that is that the ride becomes more harsh with the wider rim, because the sidewall can not flex as much.
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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeThu Apr 23, 2020 9:37 am

Fred Kiehl wrote:
Camber change is also a function of body roll. The less body roll, the less camber change. Sometimes the camber needs to compensate for tire tread/sidewall rollover. The whole purpose of suspension is to keep the tread flat on the road surface. Negative camber progression allows the body to roll, and still keep the tire flat on the ground when the suspension compresses in a corner. More rollover requires even more negative progression. This is why most high performance cars have short sidewalls. There is less distortion of the tire, allowing the suspension tuner to be more accurate in all positions of the suspension by removing the variable of the tire sidewall. A wider rim also makes the tire more stable, and the suspension movement can then be more accurate. The other side of that is that the ride becomes more harsh with the wider rim, because the sidewall can not flex as much.

Yep, for sure. It is interesting, though that from what I have read is that it it not really possible to get enough negative in roll situations from the suspension to cover the roll change in cornering, and that is why you see the big static negative camber settings on road race, autocross, cars and one side of the roundy round cars. It is also why, as in my case where I want to keep the positive camber progression, that it is critical to reduce roll and understeer to preserve the already reduced contact area, and this would cover nearly all stock height unmodified older vehicles. The reduced aspect ratio is, as you said, another compensation to the issue as they can't really put enough negative initial camber on to cover the roll and not wear out the tires. Daily driver street performance really complicates it all as it has to cover way too many things to optimize them all. If they put in too much sway bar to stop roll, the ride can get harsh again. ( of course the low aspect ratio gives the same rough ride issues)

Of interest to me was an article I saw, from a writer that seemed to truly understand the physics of it all very well, that said he would never do a drop spindle unless the spindle had the raised upper ball joint mount or used a tall upper joint. His claim was that the drop spindle lowered the roll center compared the the CG and that in turn increased roll in turns. The raised upper joint would counteract that issue by raising the roll center closer to the CG and reducing the roll, which really made sense. Your drop springs, combined with the drop spindles, probably are working as complimentary and offsetting changes.
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Fred Kiehl

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeThu Apr 23, 2020 3:13 pm

The drop spindles do not change the original suspension geometry other than lowering the car. The drop springs allow the arms to both angle upwards from their original positions. My wagon corners almost flat even without a rear anti-roll bar.
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94Woody

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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitimeThu Apr 23, 2020 7:03 pm

Wow.

All a drop spindle does is "DROP THE SPINDLE". Everything stays in the same place except for the SPINDLE. The spindle is the end that the wheel hub/bearings rides on. They are used to lower the car without changing springs or messing with any other parts but the spindle.

https://www.roughcountry.com/gm-lowering-kit-727.html?gclid=CjwKCAjw-YT1BRAFEiwAd2WRtqqDhp0jpyOlQOf_Iuh4v1aK_tIQTheGEuk8Df8eRtZLMWozgUSNBBoCNeUQAvD_BwE

Quote :
Maintains factory geometry and optimum component angles.
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PostSubject: Re: Suspension Debate   Suspension Debate Icon_minitime

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