costst of lowering
2/14/08, 03:16 PM
#23
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The panhard rod issue is simple physics... If we assume that the axle is centered properly under the chassis with stock suspension, then ANY lowering (or raising, for that matter) will necessarily shift the axle location. Period. the panhard rod is a fixed link, running parallel to the long axis of the axle, with mount points at the frame at the passenger's side, and on the axle at the driver's side. As the suspension moves upward (same thing as hitting a bump, or lowering the car), the length of the rod will force the axle towards the driver's side. There's no getting around this one, kids.
I personally think the whole "some cars don't need it" paradigm stems from a combination of two different factors. Manufacturing tolerance could allow some of the cars produced to be incorrect from the factory, which are then "corrected" by the drop. The other is the human factor, where some can't tell if it's off, or simply don't care. Personally, I can spot the shifted axle position a mile away. It's not an issue that will cause drivability problems (in general), but the condition still exists.
Same situation up front with camber angles. Once the car drops, the camber will change. Perhaps it still falls within the factory spec-range, perhaps it doesn't. If, after 5000 miles, you notice accelerated wear on the inside edge of the tire tread, that would be your only sign that the angle is "off." Except in extreme cases, or with large side-to-side differentials, you won't notice camber being off when driving the car.
In the end, it's up to the individual what they are looking for out of the lowering kit. I would, at a minimum, suggest camber bolts and a panhard rod, and if you're going hard-core with it, LCA brackets, adjustable UCA, X-5 ball joints and a bump-steer kit, to get the roll centers back where they're supposed to be.
I personally think the whole "some cars don't need it" paradigm stems from a combination of two different factors. Manufacturing tolerance could allow some of the cars produced to be incorrect from the factory, which are then "corrected" by the drop. The other is the human factor, where some can't tell if it's off, or simply don't care. Personally, I can spot the shifted axle position a mile away. It's not an issue that will cause drivability problems (in general), but the condition still exists.
Same situation up front with camber angles. Once the car drops, the camber will change. Perhaps it still falls within the factory spec-range, perhaps it doesn't. If, after 5000 miles, you notice accelerated wear on the inside edge of the tire tread, that would be your only sign that the angle is "off." Except in extreme cases, or with large side-to-side differentials, you won't notice camber being off when driving the car.
In the end, it's up to the individual what they are looking for out of the lowering kit. I would, at a minimum, suggest camber bolts and a panhard rod, and if you're going hard-core with it, LCA brackets, adjustable UCA, X-5 ball joints and a bump-steer kit, to get the roll centers back where they're supposed to be.
2/14/08, 03:22 PM
#24
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My Family has been in the suspension biz for 45 years! Cutting springs used to be common place! If your happy thats what counts . If the cuts not to drastic there usually is not any real safety issues!
2/14/08, 06:56 PM
#26
Legacy TMS Member
good stuff. I started out cutting the rear springs. I wasn't so sure wheather I could cut the fronts or not. Did you cut the upper coil or the lower coil off of the front springs?
2/14/08, 07:31 PM
#27
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2/15/08, 06:19 AM
#28
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I am thinking about lowering too with an Eibach Sportline kit. If I have a non adjustable upper control arm, as well as non adjustable lower control arms.....will I run into any issues??
2/15/08, 10:50 AM
#29
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Unfortunately, there's no hard and fast answer... If you lower your car with fixed-length rear control arms, you will change the static pinion angle, and you will alter the rear instant center. Depending on the final ride height of the suspension, it may be fine, it may not. Worst case, you'll wind up replacing the UCA with an adjustable, and adding LCA relocation brackets. For whatever reason, some cars are more sensitive to pinion angle than others, and you'll want an adjustable UCA if you go with a 1-piece shaft. I would try it and see what you get out of it, and then change out parts as necessary.
3/1/08, 02:14 PM
#31
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Steeda Ultralites $200 (used)
BMR LCA w relo brackets $170 (Got the relo's used)
Steeda Panhard and Panhard support $200
Tokico D-specs $476
Alignment ($50 plus another $50 after I install my D-specs.)
GMS A-arm brace $30
GMS front swaybar delete $30
Install $0
Total $1206
Assuming I switch out my rear sway add another $300.
Key to modding look in the for sale section regularly. There's always people selling almost new stuff just because they want to try something else or change mind about current setup. Their loss your gain.
BMR LCA w relo brackets $170 (Got the relo's used)
Steeda Panhard and Panhard support $200
Tokico D-specs $476
Alignment ($50 plus another $50 after I install my D-specs.)
GMS A-arm brace $30
GMS front swaybar delete $30
Install $0
Total $1206
Assuming I switch out my rear sway add another $300.
Key to modding look in the for sale section regularly. There's always people selling almost new stuff just because they want to try something else or change mind about current setup. Their loss your gain.
3/1/08, 11:02 PM
#32
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Heck, might as well post what I have bought so far (install pending)
Steeda Ultralites 170
Tokico D-Specs 476
Steeda Panhard Bar and Brace 200
total to date: $846
To fully finish:
Alignment est. 100
Lca and relo's est. 435
Key is to stick with Leo's posts on deals
Steeda Ultralites 170
Tokico D-Specs 476
Steeda Panhard Bar and Brace 200
total to date: $846
To fully finish:
Alignment est. 100
Lca and relo's est. 435
Key is to stick with Leo's posts on deals
3/3/08, 11:07 AM
#33
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Why? Have any of you done the geometry on this drop and how it will affect the panhard bar????
Here are a couple of assumptions:
1) The panhard bar is perfectly horizontal from the factory at the stock ride height (this is the WORSE case for the drop)
2) The drop is 1 1/2" (this is a run of the mill drop for sport springs from various manufacturers)
3) The panhard bar is 4 feet long (I haven't measured it, but it looks to be APPROXIMATELY this long. If it is shorter or longer, then the offset will be worse or better.
The system can be modeled as two right triangles sitting back to back. The short side of the large triangle is 1 1/2" tall and this is the middle side of the small triangle, so it is also 1 1/2" tall. The hypotenuse of the large triangle is 48" (aka: 4 feet). The middle side of the large triangle is some length "a" and the length of the short side of the small triangle is (48" - a).
So, we know b (1.5") and c (48") of the large triangle, so Pythagorean theorem dictates that a^2 + b^ = c^2 and we already know b and c. That means we can simply calculate c^2 and then c. So c = 47.9766".
Now we can calculate the offset, which is side b of the small triangle: b = 48 - a.
Or the offset is a HUGE 0.02344".
Again: 0.02344"
Note that is NOT 1/4". That is 1/10 of 1/4"!!! That is less than the clearance between the piston and the cylinder walls of our engines!
Not only will dropping your car NOT shift the axle that 1/2" some have posted, it won't even shift it enough that you could SEE it if you knew which way it moved!
Here is another way of putting it: If you installed an adjustable panhard bar that had 16 threads per inch on the adjuster (probably close given the size of the hardware), than "correcting" this offset would require 1/3 of a SINGLE turn from the factory stock length. If they had a turn buckle type of adjustment, that would be 1/6 of a single turn...
So, all this long post is saying is that dropping your car has just about NOTHING to do with the axle position. It CAN'T. If your axle is offset from the factory (not sure how that could occur, but...), then you might need an adjustable panhard bar to recenter it.
But if it was centered before you dropped it, then it is still centered within 24 thousands after you dropped the car. And I really doubt anyone's eyes are good enough to detect that small a shift.
Here are a couple of assumptions:
1) The panhard bar is perfectly horizontal from the factory at the stock ride height (this is the WORSE case for the drop)
2) The drop is 1 1/2" (this is a run of the mill drop for sport springs from various manufacturers)
3) The panhard bar is 4 feet long (I haven't measured it, but it looks to be APPROXIMATELY this long. If it is shorter or longer, then the offset will be worse or better.
The system can be modeled as two right triangles sitting back to back. The short side of the large triangle is 1 1/2" tall and this is the middle side of the small triangle, so it is also 1 1/2" tall. The hypotenuse of the large triangle is 48" (aka: 4 feet). The middle side of the large triangle is some length "a" and the length of the short side of the small triangle is (48" - a).
So, we know b (1.5") and c (48") of the large triangle, so Pythagorean theorem dictates that a^2 + b^ = c^2 and we already know b and c. That means we can simply calculate c^2 and then c. So c = 47.9766".
Now we can calculate the offset, which is side b of the small triangle: b = 48 - a.
Or the offset is a HUGE 0.02344".
Again: 0.02344"
Note that is NOT 1/4". That is 1/10 of 1/4"!!! That is less than the clearance between the piston and the cylinder walls of our engines!
Not only will dropping your car NOT shift the axle that 1/2" some have posted, it won't even shift it enough that you could SEE it if you knew which way it moved!
Here is another way of putting it: If you installed an adjustable panhard bar that had 16 threads per inch on the adjuster (probably close given the size of the hardware), than "correcting" this offset would require 1/3 of a SINGLE turn from the factory stock length. If they had a turn buckle type of adjustment, that would be 1/6 of a single turn...
So, all this long post is saying is that dropping your car has just about NOTHING to do with the axle position. It CAN'T. If your axle is offset from the factory (not sure how that could occur, but...), then you might need an adjustable panhard bar to recenter it.
But if it was centered before you dropped it, then it is still centered within 24 thousands after you dropped the car. And I really doubt anyone's eyes are good enough to detect that small a shift.
3/3/08, 06:41 PM
#35
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RRRoamer... Please double-check my math, but I think you may have missed the target a little bit.
First, your assumptions. I don't have my car handy to measure and photograph (in the body shop for paint), but I don't believe that the panhard rod sits parallel to the rear axle housing. If it did, the frame would need to be at the same ride height as the driver's side panhard rod location, and I know that isn't the case. IIRC, with a 1.75" drop in the rear, my panhard rod still has an uphill run from driver's to passenger's side, maybe around 3" or so. As lowering a car would cause the frame to be closer to the axle, this certainly suggests that the stock height is greater than this, perhaps 4.75".
The angle of the rod is absolutely crucial to the difference in lateral location. The more vertical offset (short side length: "B" of the triangle), the more difference (delta) in the location of the A-C vertex, given a fixed hypotenuse. A parallel panhard rod is not the "worst case," but the best. For example, given the triangle with a C of 48", and a B of zero (parallel arrangement), the A length is necessarily 48" A 1.5" change in B yields an A length of 48.02" a negligable change. However, if you adjust your baseline (B) length to 4.75", you have an A length of 48.23", which with a 1.75" drop (B of 3.00) changes to 48.09", for a difference of .14", or a touch over 1/8", which certainly IS visibly noticeable. As a matter of fact, it's just about what all the Shelby GTs have for side-to-side variance sitting on the dealer lots.
You really only need one triangle to see the situation, the second one merely clouds the issue. The A-C vertex is the point where the panhard rod mounts to the axle, the C-B vertex is where it mounts to the frame, and the A-B vertex is the point where the frame mount vertical axis intersects the horizontal axle axis.
I certainly may be off in my numbers, but I'm pretty sure about my assumptions...
First, your assumptions. I don't have my car handy to measure and photograph (in the body shop for paint), but I don't believe that the panhard rod sits parallel to the rear axle housing. If it did, the frame would need to be at the same ride height as the driver's side panhard rod location, and I know that isn't the case. IIRC, with a 1.75" drop in the rear, my panhard rod still has an uphill run from driver's to passenger's side, maybe around 3" or so. As lowering a car would cause the frame to be closer to the axle, this certainly suggests that the stock height is greater than this, perhaps 4.75".
The angle of the rod is absolutely crucial to the difference in lateral location. The more vertical offset (short side length: "B" of the triangle), the more difference (delta) in the location of the A-C vertex, given a fixed hypotenuse. A parallel panhard rod is not the "worst case," but the best. For example, given the triangle with a C of 48", and a B of zero (parallel arrangement), the A length is necessarily 48" A 1.5" change in B yields an A length of 48.02" a negligable change. However, if you adjust your baseline (B) length to 4.75", you have an A length of 48.23", which with a 1.75" drop (B of 3.00) changes to 48.09", for a difference of .14", or a touch over 1/8", which certainly IS visibly noticeable. As a matter of fact, it's just about what all the Shelby GTs have for side-to-side variance sitting on the dealer lots.
You really only need one triangle to see the situation, the second one merely clouds the issue. The A-C vertex is the point where the panhard rod mounts to the axle, the C-B vertex is where it mounts to the frame, and the A-B vertex is the point where the frame mount vertical axis intersects the horizontal axle axis.
I certainly may be off in my numbers, but I'm pretty sure about my assumptions...
3/5/08, 05:07 PM
#36
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Let's see if I can get off my butt and climb under my car with a ruler. It will be pretty easy to measure the heights of each end of the panhard bar and recalculate the actual offset for my car with my springs in it. Of course, I still have to assume that it dropped 1 1/2", which should be about right as I measured it at 1 3/8" right after I installed the springs and it has settled a bit since then.
You are right about the horizontal NOT being the worse case. The actual best case would be that the bar was 3/4" high at the axle end before it was dropped 1 1/2" which then put it 3/4" below the axle afterwards and exactly in the same place. My worse case was based on not allowing the axle to cross horizontal as it was dropped.
I'll get a few measurements and make a few more calculations this weekend and post the results. Who knows? I might have to eat some crow!
You are right about the horizontal NOT being the worse case. The actual best case would be that the bar was 3/4" high at the axle end before it was dropped 1 1/2" which then put it 3/4" below the axle afterwards and exactly in the same place. My worse case was based on not allowing the axle to cross horizontal as it was dropped.
I'll get a few measurements and make a few more calculations this weekend and post the results. Who knows? I might have to eat some crow!
3/5/08, 06:33 PM
#37
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Let's see if I can get off my butt and climb under my car with a ruler. It will be pretty easy to measure the heights of each end of the panhard bar and recalculate the actual offset for my car with my springs in it. Of course, I still have to assume that it dropped 1 1/2", which should be about right as I measured it at 1 3/8" right after I installed the springs and it has settled a bit since then.
You are right about the horizontal NOT being the worse case.
Hey, even a blind squirrel gets a nut once in a while!
The actual best case would be that the bar was 3/4" high at the axle end before it was dropped 1 1/2" which then put it 3/4" below the axle afterwards and exactly in the same place. My worse case was based on not allowing the axle to cross horizontal as it was dropped.
I'll get a few measurements and make a few more calculations this weekend and post the results. Who knows? I might have to eat some crow!
I've got an idea!
Bartender!! Canfield's for everyone!!
3/5/08, 10:32 PM
#38
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The angle of the rod is absolutely crucial to the difference in lateral location. The more vertical offset (short side length: "B" of the triangle), the more difference (delta) in the location of the A-C vertex, given a fixed hypotenuse. A parallel panhard rod is not the "worst case," but the best. For example, given the triangle with a C of 48", and a B of zero (parallel arrangement), the A length is necessarily 48" A 1.5" change in B yields an A length of 48.02" a negligable change. However, if you adjust your baseline (B) length to 4.75", you have an A length of 48.23", which with a 1.75" drop (B of 3.00) changes to 48.09", for a difference of .14", or a touch over 1/8", which certainly IS visibly noticeable. As a matter of fact, it's just about what all the Shelby GTs have for side-to-side variance sitting on the dealer lots.
You really only need one triangle to see the situation, the second one merely clouds the issue. The A-C vertex is the point where the panhard rod mounts to the axle, the C-B vertex is where it mounts to the frame, and the A-B vertex is the point where the frame mount vertical axis intersects the horizontal axle axis.
I certainly may be off in my numbers, but I'm pretty sure about my assumptions...
You really only need one triangle to see the situation, the second one merely clouds the issue. The A-C vertex is the point where the panhard rod mounts to the axle, the C-B vertex is where it mounts to the frame, and the A-B vertex is the point where the frame mount vertical axis intersects the horizontal axle axis.
I certainly may be off in my numbers, but I'm pretty sure about my assumptions...
SoundGuyDave,
I think your logic correct but your numbers are off. If the stock panhard rod is 48" length A can never be longer than 48", right? A goes to 48 as B goes to 0. I however, ended up with the same .14 inch shift that you did when I used a drop from 4.75 to 3.00 for length B.
just an fyi, my steeda panhard rod was 41" out of the box, I dont know how much adjustment it has, but I doubt it is 7 inches.
3/5/08, 11:31 PM
#39
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SoundGuyDave,
I think your logic correct but your numbers are off. If the stock panhard rod is 48" length A can never be longer than 48", right? A goes to 48 as B goes to 0. I however, ended up with the same .14 inch shift that you did when I used a drop from 4.75 to 3.00 for length B.
I think your logic correct but your numbers are off. If the stock panhard rod is 48" length A can never be longer than 48", right? A goes to 48 as B goes to 0. I however, ended up with the same .14 inch shift that you did when I used a drop from 4.75 to 3.00 for length B.
just an fyi, my steeda panhard rod was 41" out of the box, I dont know how much adjustment it has, but I doubt it is 7 inches.
Panhard rod length (stock) measured bolt-hole-center to center
Rim-to-plumb on each side, stock and lowered, before adjustment and after.
Frame-mount ride height stock and lowered
Panhard rod angle stock and lowered.
Anybody think of anything else to measure?
3/6/08, 06:42 AM
#40
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I was only able to measure it because I still haven't installed my new suspension parts yet. Wasn't this post originally about total cost. Here is what I have so far.
All Steeda Parts.
From Tillman Speed ~ 750 Shipped to my door
555-1050 Adj. Front Sway Bar
555-1054 Comp Rear sway bar with endlinks
555-4109 Adjustable Upper Comp/Street Kit - Bushing End & HD Mount
From CJ Pony Parts ~ 775 shipped to my door
555-4405 Billet Rear Control Arms
555-2551 Street Panhard Bar
555-2555 Heavy duty Panhard Bar Brace
555-8119 Lower control arm relocation brackets
555-8106 Bumpsteer kit
So that puts me at $1525 and I still need to by shocks/struts, springs, and upper strut mounts.
My wife got a wedding and everything on the registry … so I got car parts. I’m still way behind in the total money count.
All Steeda Parts.
From Tillman Speed ~ 750 Shipped to my door
555-1050 Adj. Front Sway Bar
555-1054 Comp Rear sway bar with endlinks
555-4109 Adjustable Upper Comp/Street Kit - Bushing End & HD Mount
From CJ Pony Parts ~ 775 shipped to my door
555-4405 Billet Rear Control Arms
555-2551 Street Panhard Bar
555-2555 Heavy duty Panhard Bar Brace
555-8119 Lower control arm relocation brackets
555-8106 Bumpsteer kit
So that puts me at $1525 and I still need to by shocks/struts, springs, and upper strut mounts.
My wife got a wedding and everything on the registry … so I got car parts. I’m still way behind in the total money count.