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Author Topic: Would dropped spindles help handling?  (Read 13168 times)

Offline brads70

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Would dropped spindles help handling?
« on: October 22, 2010 - 11:09:22 PM »
Wondering if the Magnumforce dropped spindles would help handling? I have the Hotchkis upper a-arms to install soon, and was wondering how dropped spindles would affect handling? I have 1" t-bars now and my adjusters stick out quite a bit.
I'm thinking it would lower the roll centers? Any thoughts?
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

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Would dropped spindles help handling?
« on: October 22, 2010 - 11:09:22 PM »



Offline Chryco Psycho

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Re: Would dropped spindles help handling?
« Reply #1 on: October 23, 2010 - 01:42:47 AM »
definatly help to lower the center of gravity
 are the spindles welded or cast in one piece , if they are welded I would avoid them

Offline 72bluNblu

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Re: Would dropped spindles help handling?
« Reply #2 on: October 23, 2010 - 02:11:58 AM »
Cast in one piece CP, they're great looking pieces. According to Magnumforce, they're over twice as strong as the originals.



Good question! ;D

Not sure I can answer it. :D HP2 needs to get in here.  :grinyes:

Off the top of my head, I'll say this. As you lower the car, you're changing the angles on the control arms. Which is why you need adjustable UCA's to get you're slammed on the ground car back into alignment. So, the drop spindles would help that. By moving the drop to the spindle, the control arms can return closer to the geometry they were designed to have.

On the other hand, you're moving the spindle closer to the upper ball joint and away from the lower. Which also moves it in relation to all of your steering. I frankly haven't looked into it before to know whether this would make things better or worse.

And finally- Hotchkis already changed the suspension geometry to improve handling and reduce bump steer. How will the drop spindle effect their calculations?

Sorry, I was an Aerospace engineer. My grasp of suspension engineering is a little vague, I've mostly just followed the tried and true advice of those that have done it before. This here is an actual engineering question.  :screwy: One of these days I'll have to spend some time reading all the chassis/suspension books I have.

I will also say this- I have the Magnumforce 2" drop spindles on my car. They are well designed pieces, and no doubt much stronger than the originals. When I installed them I also lowered my car, since I couldn't lower it with the stock spindles and 1.12" torsion bars I have. I thought it handled much better afterward, but my guess is that has everything to do with lowering the CG, and less to do with the spindles.

« Last Edit: October 23, 2010 - 02:52:52 AM by 72bluNblu »

Offline 72bluNblu

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Re: Would dropped spindles help handling?
« Reply #3 on: October 23, 2010 - 02:44:30 AM »
For reference...

Stock spindle




Magnumforce 2" drop Spindle




This picture gives you a good idea about how it changes some of the geometry. Look how much further the spindle is away from the lower ball joint and steering linkage...

Offline brads70

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Re: Would dropped spindles help handling?
« Reply #4 on: October 23, 2010 - 09:35:10 AM »
72bluNblu Looks like a strong part! With me having 15" rims I wonder if it would cause issues with the outer tie rod end hitting the rim? I can't figure out what it does to the upper control arm? :clueless: Raise it ( at the ball joint)? or lower it? or it stays the same?
I'm just thinking that I'm gonna have my front end all apart installing the Hotchkis stuff, so that would be the time to do it, if it's a good "upgrade" for me? I don't mind the height my car is at ,it clears speed bumps, headers are not dragging, etc... I don't want to create issues ? I'm up for lowering it "some" I just don't want issues with clearance. I can't see lowering it 2" though?  :grinno: As I said the t-bar adjusters are hanging out pretty good with the 1" t-bars. I'm sure when/if Boydsdodge reads this he will "give me the gears" about the height on my car though! :grinyes:

Neil, Here is Magnumforces description.......

Mopar 2 inch dropped spindles A, B, E-body
$440.00
MFR 192000 Mopar 2" Dropped Spindles. Magnum Force Inc is pleased to announce the introduction of the first one piece extreme duty dropped spindle for the Mopar muscle car from 1962 to 1976. Designed by Magnum Force and based on the big bearing, big ball joint 1973 and up spindles so commonly sought after by Mopar enthusiasts, these new beauties are made in the USA and allow the utilization of stock brake calipers and rotors as well as Magnum Forces incredible Magnum Force/Wilwood offerings of four or six piston calipers with rotors ranging from 11 to 14. They are even pre-drilled for Wilwoods Pro Series brakes so NO hole enlarging and tapping required. Use Magnum Force upper control arms and they can be bolted on to your early A-body as well as late model ones too! For all A, B, and E-body owners, just add a set of brakes and lower ball joints and you have a complete assembly that bolts right to your existing lower control arms! They fit F, J, and M-body cars too. Manufactured in the USA using grade 1 ADI, resulting in a tensile strength of 130,000 psi, and far exceeding the 60,000 psi rating of most factory castings. Advantages realized using this process include: Yield strength, toughness and impact resistance superior to many cast/forged steels Vibration dampening and heat transfer superior to other ferrous/non-ferrous alloys Significant weight savings over steel castings/forgings Increased fracture and fatigue strength

Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

Offline HP2

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Re: Would dropped spindles help handling?
« Reply #5 on: October 23, 2010 - 12:52:11 PM »
This is when it would be nice to have a software program to play with. Unfortunatly, all my work has been on a huge layout with protracters and straight edges, so I have a certain degree of miscalculation that can be introduced. Anyway...

The dynamics;
If the Center Of Gravity height drops, it exerts less lateral load on the car. Drop spindles lower the overall COG height. This is a good thing.

The closer the roll axis line is to the center of gravity location, the shorter the moment lever arm. The roll axis is the imaginary line from the front roll center pivot to the rear roll center pivot.

If the front roll centers drops, the moment lever arm lengthens, the car produces more body roll. If this arm shortens, then it produces less body roll.

With that, a 2" drop in ride height will produce a 1" drop on roll center height assuming all the control arm angles remain constant. The angle question is what I do not know about. My thought is that by dropping the ride height two inches, you can crank some preload back in to the t-bars and maybe raise the inner control arm pivots points up a bit. If these points rise, then the roll center height rises. So, the front roll center will either drop 1" or rise 1" depending on where the control arms end up. With that slight of change in range, the moment lever arm is only going to be changing .25-.38 of an inch, so we're talking subtle changes here.

IMO, the dropping of COG height has a bigger impact on improving things than the alterations to geometry will make in either better or worse geometry. For a street car, these changes are so minor, overall things will feel better, even if the geometry is worse.

Some background info.; all my calculations come from measurements on my car, which is lowered to a point that the lower control arms are level. These dimension can change from car to car depending on such simpple things as tire height, sidewall height, and wheel backspace.

Maybe since 72b&b has the drop spindles installed, he could provide some measurement insight to where his control arms are located with the drop spindles.

Offline 71cudajoe

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Re: Would dropped spindles help handling?
« Reply #6 on: October 23, 2010 - 02:15:18 PM »
I have the Magnum Force dropped spindles on my Cuda. I haven't really driven the car yet as it is on its final stage of restoration, but installation of the spindles was easy. Everything looks and works great so far.
David - '71 HEMI Cuda Retro-mod
FOR PICS VISIT www.71cuda.net

Offline 72bluNblu

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Re: Would dropped spindles help handling?
« Reply #7 on: October 23, 2010 - 08:56:14 PM »
72bluNblu Looks like a strong part! With me having 15" rims I wonder if it would cause issues with the outer tie rod end hitting the rim? I can't figure out what it does to the upper control arm? :clueless: Raise it ( at the ball joint)? or lower it? or it stays the same?
I'm just thinking that I'm gonna have my front end all apart installing the Hotchkis stuff, so that would be the time to do it, if it's a good "upgrade" for me? I don't mind the height my car is at ,it clears speed bumps, headers are not dragging, etc... I don't want to create issues ? I'm up for lowering it "some" I just don't want issues with clearance. I can't see lowering it 2" though?  :grinno: As I said the t-bar adjusters are hanging out pretty good with the 1" t-bars. I'm sure when/if Boydsdodge reads this he will "give me the gears" about the height on my car though! :grinyes:


I still have 15" rims on my car, no issues with hitting the rims. But the rims that are on my car don't have much backspace either, so your results may vary. If you have a big offset, it could create an interference problem.

The spindles are an awesome part, well designed and made. If that's what you're after, then Magnumforce also makes a standard height spindle out of the same improved material and casting. 

The big question for you is, will there be enough torsion bar adjustment to keep your car at the same height with the 2" drop spindles? My guess, based on what I see with my 1.12" bars, is yes, you will have plenty of adjustment. Even with the drop spindles, my adjusters are nearly all the way out still.  :eek7: I'm not entirely sure why my car is like that, or if the 1.12" FFI bars I have are really that stiff. I recently raised my car up half a turn, I got tired of banging my headers on speed bumps.

As far as what the spindle does to the upper control arm- If you look at the pictures of the stock spindle vs the magnumforce spindle, you can see that the actual spindle, the part that is the wheel axis, moves 2" closer to the UCA. Now, as you lower the car, the control arms (both of them) change angle. The pivot location (at the frame) moves closer to the ground. The ball joint doesn't move (because the tire doesn't), so the angle the control arms sit at changes. On most of these cars, the control arms slope down from the frame toward the ground. In an extreme example, if you lowered the crap out of it, your control arms could become parallel with the ground (like HP2 said his LCA's are :o). Now, if you put drop spindles on the same car, and kept it at the same ride height, 2" of the drop would move from the control arms to the spindle, allowing the control arms to regain a more normal angle. Which, in theory, should work better, since it would allow them to be closer to the "designed" angle.

Like so.... (NOT to scale!). First picture is stock, second picture would be lowered 2", third is lowered 2" with drop spindles.






This is when it would be nice to have a software program to play with.


Yes it would!!! I used to have one, but it resides on a floppy disk and only runs in DOS.  :D Not sure I could make that happen anymore...

IMO, the dropping of COG height has a bigger impact on improving things than the alterations to geometry will make in either better or worse geometry. For a street car, these changes are so minor, overall things will feel better, even if the geometry is worse.


This is exactly my experience. Lowering the car was a huge improvement. Whether or not the geometry is actually "better", I don't know. But my guess is you're right on, the small geometry change is outweighed by the COG change.

Some background info.; all my calculations come from measurements on my car, which is lowered to a point that the lower control arms are level. These dimension can change from car to car depending on such simple things as tire height, sidewall height, and wheel backspace.

Maybe since 72b&b has the drop spindles installed, he could provide some measurement insight to where his control arms are located with the drop spindles.


Would love to, but its actually raining here in CA, and my car is outside. Maybe in a day or two? ;D. I can tell you that my LCA's are not parallel with the ground though. And even lowered to where my headers would bang on every speed bump in the area unless I took them at 45 degrees and at 5 mph, that was still the case. I couldn't even get a standard floor jack under my K-member. My signature picture shows the old ride height, I had about 1/2" an inch of tire above my wheel arch. Currently, the top of the tires are level with the wheel arch and the arch is 24.5" off the ground inline with the hub. Tires are 225/60/15's, should be about 25.5" tall, guess there's about an inch of sag and tire wear.
« Last Edit: October 23, 2010 - 09:09:46 PM by 72bluNblu »

Offline boydsdodge

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Re: Would dropped spindles help handling?
« Reply #8 on: October 23, 2010 - 09:47:38 PM »
I have a set on my Challenger and think they look great, really help with the adjustment on the 1.16 bars.
Hey Brad when are you going to make that cars ride height look like it's going to be driven? lol. JK
Jackson from Toronto.

Offline brads70

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Re: Would dropped spindles help handling?
« Reply #9 on: October 23, 2010 - 10:01:23 PM »
I have a set on my Challenger and think they look great, really help with the adjustment on the 1.16 bars.
Hey Brad when are you going to make that cars ride height look like it's going to be driven? lol. JK

 :smilielol: :2thumbs:  .....I was waiting for that! :bigsmile:
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

Offline brads70

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Re: Would dropped spindles help handling?
« Reply #10 on: October 23, 2010 - 11:09:43 PM »
  Currently, the top of the tires are level with the wheel arch and the arch is 24.5" off the ground inline with the hub. Tires are 225/60/15's, should be about 25.5" tall,

Just for kicks I just measured mine and it's exactly the same as yours?( 24.5") Same tire size too! How can that be? :clueless:
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

Offline 72bluNblu

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Re: Would dropped spindles help handling?
« Reply #11 on: October 24, 2010 - 03:22:09 AM »
Just for kicks I just measured mine and it's exactly the same as yours?( 24.5") Same tire size too! How can that be? :clueless:


You have 1" torsion bars. I couldn't get mine that low without the spindles, even with the torsion bar adjusters backed all the way out. With the 1.12" bars my car sat at or slightly above stock ride height without the spindles.

Now, if boydsdodge comes on and says his is lower, I may have to go and swap my torsion bars side to side. I swear I put them in right, and I know I checked it 3 times. But it did sit awfully high. And FFI only stamped one end of one bar. Which is, by the way, the end I put in the LCA. 'Cause I'm just smart like that.  :icon16:  :banghead:

This is the before and after on the spindle installation, both are with the adjusters about 1 thread engaged just so there was still tension with the suspension completely unloaded (you know, in case I went airborne  :rebel:).

I guess I raised it up a little more than I thought when I made those adjustments the other day. As I mentioned before, it now sits so the top of the tire is about level with the bottom of the arch. The "after" picture shows I had more than 1/2" above the arch before  :o. And yes, I drove it for about a year and about 10k miles that low.

Before


After

« Last Edit: October 24, 2010 - 03:27:00 AM by 72bluNblu »

Offline brads70

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Re: Would dropped spindles help handling?
« Reply #12 on: October 24, 2010 - 08:22:48 AM »
So if our cars both being at the same height ( which works good for me,I don't hit anything) is there any benefit to me getting the magnumforce spindles? Trying to think here?.... if you compared both our cars both at the same chassis height the pick up points on the chassis be at the same spot. The center of the ball joint would be different. So with that being so it will change the roll center, yours being higher.( ball joint is closer to the spindle pin)  Is that a benefit worth me buying the spindles? In theory your car should have less body roll correct? Am I "seeing " this correct? Will this help me or hurt me? How does this factor in with the Hotchkis a-arms? ( They mount different from stock, they move one pivot point taking out some anti-dive)
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

Offline HP2

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Re: Would dropped spindles help handling?
« Reply #13 on: October 24, 2010 - 01:11:35 PM »
Here's the picture of my previous set up, 235/60x15 on a 7" rim. My lower ball joint and torsion bar were both 9.75" above the ground.



My current set up has changed so once I get the engine back in and reset my ride heights, I'll have to see if I need to recalc everything and see what I need to change. My new front tires are 26" tall. My fender lip sits at 24", lower ball joint is at 10.25 and my t-bar is at 11.25. I'm thinking with the engine/trans back in, my t-bar point will drop the next inch to even things back up.

As I said the t-bar adjusters are hanging out pretty good with the 1" t-bars.

Even with the drop spindles, my adjusters are nearly all the way out still.   


You know, there is a trick to correcting this problem. It actually is a cheap way to lower the car. The half round saddle in the control arm where the t-bar adjusting block sit under tension needs to be lengthened. Every .125 you take out of this area will lower the car .5 with the t-bar adjusters at the same position. Alternatively, if using drop spindles, this would allow you to twist the adjuster in further to obtain the same preload you had previosly.

if you compared both our cars both at the same chassis height the pick up points on the chassis be at the same spot. The center of the ball joint would be different. So with that being so it will change the roll center, yours being higher.( ball joint is closer to the spindle pin)  Is that a benefit worth me buying the spindles? In theory your car should have less body roll correct? Am I "seeing " this correct? Will this help me or hurt me? How does this factor in with the Hotchkis a-arms? ( They mount different from stock, they move one pivot point taking out some anti-dive)


I'm not sure how exactly this will change until we get some measurements of the pivot locations with the drop spindles. The hotchkis arms wouldn't impact this since only one point is relocated. Their big advantage is that they cycle in a different range to improve tie rod angles. This won't be an impact on ball joint location and movement.

Offline brads70

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Re: Would dropped spindles help handling?
« Reply #14 on: October 24, 2010 - 02:59:52 PM »
You know, there is a trick to correcting this problem. It actually is a cheap way to lower the car. The half round saddle in the control arm where the t-bar adjusting block sit under tension needs to be lengthened. Every .125 you take out of this area will lower the car .5 with the t-bar adjusters at the same position. Alternatively, if using drop spindles, this would allow you to twist the adjuster in further to obtain the same preload you had previosly.
Do you have a picture of this modification? Also preload is somewhat important to the ride also I'm thinking? Wouldn't the "ride" change/be different if the same bar is "wound" tight and the other is not? ( meaning not using the adjuster much?) I'm thinking t-bars work by increasing the resistance as it twists? So if it's already twisted almost to the max won't the ride be "firmer/harsher"? Lot's here to keep my mind busy! LOL  :grinyes:
I'm not sure how exactly this will change until we get some measurements of the pivot locations with the drop spindles. The hotchkis arms wouldn't impact this since only one point is relocated. Their big advantage is that they cycle in a different range to improve tie rod angles. This won't be an impact on ball joint location and movement.
Seeing how are cars are at the same height, that would mean the pivot heights/location are the same regardless of what spindle is used. So I could measure mine to get the numbers? Yes? If so mine are....center of t-bar at the lower control arm is 10.875" ( t-bar gets lower as it goes back towards the t-bar crossmember) and the center of the lower ball joint is 9.375"-9.5" ( hard to know exactly as the center of the ball is covered in the casting)OOPS-EDIT... I just realized the ball joints on a dropped spindle are at different heights!  :screwy: Now I'm wondering if they are 2" different just like the pin on the spindle? ???  :popcorn: Also  the dropped spindle ALSO lowers the tierod , which changes the bumpsteer..... and factor in the firmfeel fast ratio pitman, and idler arms that I have to install.. :pullinghair:  my head hurts!  :lol:
« Last Edit: October 24, 2010 - 03:18:20 PM by brads70 »
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

Cuda-Challenger.com

Re: Would dropped spindles help handling?
« Reply #14 on: October 24, 2010 - 02:59:52 PM »