How much clearance do you have before hitting the bump stops on your lower arms?

How much clearance do you run between the factory rubber bump stop and frame in front

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I have 11/16" Energy bump stops and I am about 1/2" from them at ride height.
 
longarm said:
So I see a lot of I got this and I got that.
What is the correct answer?
Is there a correct way to set this adjustment
or a factory ride height chart or spec?


http://student.ccbcmd.edu/~smacadof/Books/A4_SuspSteer_Student Work Books/SWB_a4_m04b_Final.pdf

http://www.carcraft.com/techarticles/ccrp_0910_diy_alignment_guide/viewall.html
Click to expand...

There's a factory procedure and height laid out in the service manual, which would be the "correct" way to do it for stock cars.

Keep in mind that "stock" here doesn't just mean stock torsion bars, it also means stock tire size, at least height wise. It also means stock alignment figures, because the suspension geometry changes with ride height. Sure, you can adjust the suspension once the height is set, but some of the geometry is based on that height (control arm angles, roll center, etc).

Here's the procedure for adjusting the height. Obviously its part of doing an alignment in the manual, but the factory specs for alignment are for bias plys, and should NOT be used on anything that runs radial tires. Which is why I didn't post it. For that matter, all of the geometry called for by the factory is based on those crappy tires. So, I would take the specs called for by the factory with a grain of salt. They mean next to nothing if you're running different sized radial tires, and ABSOLUTELY nothing if you're running larger torsion bars and adjusting the geometry for road handling. The factory specs and parts set the car up for significant understeer, which is not what most performance minded folks will want. There's a lot more to setting the height than just "will it hit the bump stops".
 

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Actually the factory ride height ignores tire size. It is completely irrelevant to the measurement. I don't use the factory method because it's a PITA. I just measure from the LCA to the frame, get that inch (approximately) between the bumper and frame, and then make sure both sides are the same.
 
As a small note, I ran across some aftermarket bump stops that are meant to assist the factory springs. They are tall multi-donut looking things. I recall generic, not specific to any Mopar models. I don't know if they are intended to touch in normal driving, or just when you hit a bigger bump. I would be worried about them squeaking if they always touch. I was looking for front shocks w/ helper springs for my C-body since new torsion bars are ~$400 for it.
 
Jim Lusk said:
Actually the factory ride height ignores tire size. It is completely irrelevant to the measurement. I don't use the factory method because it's a PITA. I just measure from the LCA to the frame, get that inch (approximately) between the bumper and frame, and then make sure both sides are the same.
Click to expand...

For the sake of the factory measurement, yes, you're correct, the tire size doesn't matter. It's only finding the angle of the LCA, not the actual ride height.

But, if you're not running stock size tires, using the factory specs will result in a change in the factory ride height. Since the measurement ignores tire size, it also ignores the final ride height of the car. Its just finding the LCA angle, so if you put taller tires on the car and use the factory specs you're raising the cars ride height. Which of course would raise the center of gravity, and have a negative impact on the handling of the car.

So, the tire size is still important, even if it doesn't factor into the measurement/spec, because I'm sure that the factory spec'd the tire size also. If using the factory specs is that important to someone, you can't mix and match, you have to use all of them. Otherwise, you're changing the geometry anyway, and possibly even for the worse. Although I'd argue that the factory geometry is a bad idea to begin with, unless you're running the stock bias plys.
 
The spec did not change for the different size tires available from the factory, however you are correct that adding taller tires will also raise the COG and affect handling. We also agree that the factory specs are completely irrelevant now with modern tires and shocks as well as larger torsion bars.
 
Tires do make a difference in the way a car handles,
but if the suspension is not setup properly travel wise
you can forget any kind of performance handling.
If your on the bump stops whats the point in
shocks or swaybars not to mention any alignment gains.
All your doing is bashing the a-arms and stressing
the steering components.
You might run drop spindles to lower the car without
compromising handling.
QA1 has some decent tech on the subject as do a lot
of other shock and steering component manufacturers.
 
Does this help? From my 1972 moog manual.
 

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longarm said:
Tires do make a difference in the way a car handles,
but if the suspension is not setup properly travel wise
you can forget any kind of performance handling.
If your on the bump stops whats the point in
shocks or swaybars not to mention any alignment gains.
All your doing is bashing the a-arms and stressing
the steering components.
You might run drop spindles to lower the car without
compromising handling.
Click to expand...
Ding ding ding ding ding! Finally somebody gave correct information! Drop spindles is the ONLY correct way to drop your front end!
 
/6 Matt said:
Ding ding ding ding ding! Finally somebody gave correct information! Drop spindles is the ONLY correct way to drop your front end!
Click to expand...

Ding ding ding ding....

You're wrong.

Lots of other parts, intentions, and use of the vehicle change what's right and wrong. Lots of different ways to get to the same place. And we are modifiing cars. Is there only ONE right camshaft, carb, header, etc for everyone?

And the drop 2" spindle changes the front roll center.
 
/6 Matt said:
Ding ding ding ding ding! Finally somebody gave correct information! Drop spindles is the ONLY correct way to drop your front end!
Click to expand...

Umm, NO, they're not.

autoxcuda said:
Ding ding ding ding....

You're wrong.

Lots of other parts, intentions, and use of the vehicle change what's right and wrong. Lots of different ways to get to the same place. And we are modifiing cars. Is there only ONE right camshaft, carb, header, etc for everyone?

And the drop 2" spindle changes the front roll center.
Click to expand...

Exactly. Adding larger torsion bars reduces the amount of travel the suspension has, so lowering the car is possible without hitting anything, even though the clearance has been reduced.

My Duster for example. Stock V8 torsion bars are .87", with a 120 lb/in spring rate. My current bars are 1.12", with a 300 lb/in rate. That's a 250% increase in rate. Do you really think they need the same amount of space for travel?

There's a lot of variables when it comes to suspension, intended use, weight of the vehicle, spring rates, shock absorbers and valving, tire size and compounds, sway bars, etc. Saying there's only one way to correctly do ANYTHING is just silly.
 
I think there is a big misconception concerning the
intended purpose of the bump stop.
It is not only used to stop the a-frame and shocks
from crashing to pieces, they are used primarily to
increase spring rates as the car enters a turning situation
and end of travel.

Possibly a tutorial on their purpose might help the understanding
of how they are used in suspension control but its to deep for
me to explain when theres so many variable at work and opinions on
the subject.
I'm sure someone has a more in depth explanation than this but
heres a start.

http://performance-suspension.eibach.com/motorsport/products/accessories/bumpstops
 
autoxcuda said:
How were the condition of the front shocks when you got it? Original front torsion bars?
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The shocks were shot and it still has the original torsion bars. Originally a 318 car. I put some KYB shocks on and took the time to adjust the torsion bars until car sat even. Then drove right to the alignment shop and got that done
 
I just lowered my car this weekend. I went from a 318 to a 360, not sure of the weight difference but the car sat to high in the front. I ended up dropping the car over 1.5" and probably have between 3/4 and 1" between the bump stop and frame. I more or less set my height to were I thought the car looked good and so the TTI headers would clear speed bumps or other things. I could probably drop it more but Im still running stock torsion bars so I'll play it safe there
 
My car is at factory ride height on this pic. How much lower would you want to go.
Measured like I stated pin and ball joint to the ground and subtracted. With the rear of the car sitting on a jack in the middle of the rear. Add 1.5 turns to left bar for street use with stalilizer bar and SS springs.

Take the bar off and remove the 1.5 turns and it leans to the left hard. Drag race set up.
 
I think my car is just right, but one thing I accidently also "set" is at my ride height, my upper control arm is perfectly flat and during any compression I get camber gain like say into a corner. That is bitchen in my book, gotta love A-body geometry.
 

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I think I'm at a similar height, although the rear drops about an inch when I fill up both the propane tanks in the trunk.
The Dart has 6 leafs per side and Monroe-SensaTrack loadadjuster shocks, but I plan to install an extra long leaf pretty soon, along with maybe 1" lowering blocks.


IMG_2869_zpsc63d13a8.jpg
 
I don't recall, and it's too cold to go out and measure it, and theres 4 inches of snow on the hood.
But I can offer this; my K sits about 5.75 to 6 inches off the pavement with 245/50-15s@29psi. It hammers over speedbumps real nice, with TTIs. If/when I get air-born, the oilpan takes a hit making life easy for the shaved,poly,bumpstops! Well it did that just once, and then I fabbed a skidplate; a big fat skidplate. Welding up cracked oilpans is not my forte.
1.03 bars are not too big, and 1.25 swaybar is not too big, and HD shocks are, but they gotta be there.
I don't jump it any more.....
 
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