Dropped A-Frames

[dq409]

Who's Charley????? Is that the mastermind behind all of lingenfelder vette's.... sounds like maybe...... I beleive you have to draw yourself a picture dq409, and think about it ,, I want to correctly help this person out the best I possibly can with the question he is asking,, and all you are doing is telling him false info... or heresy , if I will.
And by the way Chevy is and always will be better than Ford.....

Now it sounds like YOU are trying to start a fight !!! :takethat

I`m trying to help him also and I do know what I`m talking about and it is not hearsay !! I quote Charley because he is the expert on lowering cars and trucks and has many more years experence doing it then you or me or anyone else on this site combined.

I brought him into the mix because I was being told I didn`t know what I was talking about.

I believe you are misleading Russ IMO !!!

Go ahead and use your dropped spindles,,,,,,, NOT ME !!!

When Russ gets back we will meet at Charley`s shop and he can see all the diagrams and listen to a "master in this field" explain the difference between the two methods.

And we do agree on some thing,,,,,,, CHEVYS !!!! ,,,dq


PEACE

Charley`s Drop Shop



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[threeimpalas]

Here are roughly the effects of each method of lowering on the geometry of the suspension, post alignment for proper caster and camber.

IC = Instantaneous Center
RC = Roll Center

You can clearly tell that each method changes the geometry of the suspension. Some more than others.

 

[threeimpalas]

Some reading that may be worthwhile.

http://members.aol.com/sccacuda/cars/5SmthTa.html


How long a person has been "dropping" cars means squat. Whether they understand the engineering and dynamics of what happens as a result is what matters.

 

[Gus68]

thank you 3impalas... (as i'm about blue in the face!!!!!)

 

[dq409]

Well I`ll be dipped !!!

You outa be blue in the face !!! :?

He does know his dynamics,,, he has drawn the diagrams,,,
I am running his stuff and know how they handle,,,steer and feel.

Use what you want,,,,

 

[dq409]

This outa really make your face blue !!
This is taken off that site threeimps posted.
And using his drawing and this tex I would say that the stepped a-arm is better.
which is what I was refering to several post ago.

Read this and let me know what you think,,,, But be nice,,,, were friends here
----------------------
Before describing exactly how to determine the roll center of a car let's examine the main advantages and disadvantages of both a high and a low roll center and see why at best, any design is a compromise.


The amount of body roll attained from a certain roll center height is dependent on the leverage effect between the roll center and the center of gravity height. The higher the center of gravity and the lower the roll center, the greater amount of body roll there is (because of a high amount of leverage between the two points). The higher the roll center and the lower the center of gravity, the less body roll there is (because not much leverage is. placed on the roll center by the center of gravity).

If there is a high roll center and thus very little body roll and weight transfer, softer springs can be used to control what body roll there is. This is one reason why the rear end of a stock car always has softer springs than the front end. The major disadvantage to a high roll center is that the lateral force of the car during cornering, rather than exerting itself as body roll,. exerts itself, in terms of lateral. force at the tire contact patch creating instability during cornering. In other words, with a high roll center, weight is pushed sideways on the tire creating tire scrub.

With a low roll center, weight is transferred more in a circular motion, or in other words, it is picked up from the top of the inside wheel and forced down on top of the outside wheel. The advantages of a low roll center are less tire scrub, but the major disadvantage is that there is more weight transfer and body roll to control and this is the reason for the front anti roll or stabilizer bar (which will be discussed in two more chapters).

 

[threeimpalas]

You just kept insisting that the stepped arms don't change things, when in fact they do. Granted my illustrations aren't to proportion and more than likely exaggerate the effects of the changes, but you can see that the stepped arms actually change the geometery quite a bit more than using the dropped spindles and roughtly the same as the springs.

You're major pro of using the stepped arms, aside from thinking the geometry doesn't change, has been the supposed ability to use the soft stock springs. However, with the stepped arms, you'd need to use stiffer springs to counteract the roll effect caused by the lower RC location. What you've also forgotten to consider is the location of the CG in these cars. If they've got a higher CG, then coupled with the low RC and stock springs, you'll get undesireable results.

Without more information about the actual dimensions of the suspension and vehicle properties (such as CG, wheel offset, tire type/size, etc), intended use, etc., all you're doing is making a guess as to which method is the "best" - short of re-designing the suspension for a lower ride height.

My reason for suggesting the use of lowering springs instead of stepping the a-arms is primarily due to the fact it's MUCH less work and will still end up with a result that Russ will find more than adequate.

 

[dq409]

OK, threeimps,,, I do get your point !!!

I should also state that what I meant about changing the geometry should be interpreted as "changing it in such a way that it can`t be corrected to drive right".

I would agee that it might be easier and cheaper to use the lowering springs and get great results but what I stood firm on was the stepped a-arms are a very good way to lower cars and trucks and is the prefered way by me, others and Charley.

With a shorter spring you lose some travel in the suspension where as in either the stepped a-arms and spindles you don`t.

Now where this loss of travel is noticable ,, I can`t say.

So ,,,, I think it is a preferred preference. Like I said before ,,, It`s an arguement like which is better F**d or Chevy,,,,,,,, dq

 

[dq409]

Lets look at this from another angle.

Just say you want to drop your car two inches.

You can order the:
- dropped spindles
-dropped A-arms
-two inch lowering springs

If you order the springs ,,,, it will lower your car two inches from what/where?
Do they measure the drop with the weight of a six cylinder? 283/327?
Or a 409?

And there are other issues that you have to take into account, bushing wear? Tire size? Roll cages? etc

When you use either the the dropped spindles or a-arms you will get a two in drop from where the car sits now !!

Yes the springs are half the price of the other two options but do you get 1 1/2 or 2 1/2 lowered hieght?Somewhere in the middle? More ? Less?

Threeimps, have you used any of the above ?

If so how did they work.
If the springs, where did you end up? did you measure before and after?

Again,,really not trying to start anything , just trying to share and get more info.

lets look at this as a forum of different opinion and views,,, dq

 

[threeimpalas]

With a shorter spring you lose some travel in the suspension where as in either the stepped a-arms and spindles you don`t.

Now where this loss of travel is noticable ,, I can`t say.

The loss of travel isn't a problem on these cars, as you'd be scraping exhaust on the pavement when the bumpstops hit the frame. You'd have to be low to begin with for that to happen unless you're going over a pretty darn big dip in the road.

The '61 wagon has the McGaughy disc brake drop spindles and new springs to compensate for the increased weight of a BBC (I don't remember if they were stock length or shorter). It originally had cut stock 6 cylinder coils. Too many things have changed on that car at once to give a good estimate of what did what; not to mention it was a while ago.

The '59 SDL uses an air suspension, which is another option, but not cheap or fitting of the "theme" that Russ and many others here have for their cars.

A place like Eaton (http://www.eatonsprings.com/) can build you a set of springs to suit what you want and what you've got.

 

[Va348]

Ok here is my take on this,As I stepped my a-arms.

Been a Old oval racer, and if you are going to do well you better know front ends.
And I'am one those guys that loves to make things.

One every important thing that you'all are forgeting about is camber gain that you
really need with radial tires.Stepping the a-arm is like lenghting the spindle.

Before I stepped arms it had Pos camber gain like 1/2 deg per in.
what it has now is 1//4 deg per in neg. gain.

all so I narrow mine 3/8 in it has disk brake on it. I all so level the top ball joint up
Top a arm was easy you need to study it a little. If you saw it beside joint toward motor its easy. Now you need to be a good welder to do all this. You can not tell I cut mine now. I made a little gig. to hold my spindle were I want it. and then welded it. By the way bump steer is .030 per in up to 2 in.

You need to make your own judement on this!


Dale

 

[threeimpalas]

Stepping the a-arm is like lenghting the spindle.

How is stepping the a-arm like lengthing the spindle? The distance between the ball joints is still the same as stock.

Narrowing or lengthing either control arm (the lower one 3/8" in your case) will change the camber curve, however.

 

[dq409]

Ok here is my take on this,As I stepped my a-arms.


Before I stepped arms it had Pos camber gain like 1/2 deg per in.
what it has now is 1//4 deg per in neg. gain.


Dale

Thanks VA348 !! Thats what I was told and what I printed back a few posts.,,, dq

 

[Va348]

You are right threeimpala, The distance is the same between ball joints.

Get some true measurements off a car at ride height, and get the centers on all hook up points .

But remember the angle of the ball joint end of top a-arm is moving up 2 in also.
That's what change the camber gain, Not narrowing up 3/8, Narrowing Help the bump Steer.

Like I said it works for me. And I kike to build,Plus it did not cost anything.

We were stepping a-arm in 1970 on oval cars to fix Camber gain. Plus lowing them
Remember this is before you could ( Buy Everthing )or have spindles made like they do today.

I know not everone a can do this or want too. In my opinion only, it the Best way.
I just fix's everthing.

Dale

 

[threeimpalas]

Narrowing the lower control arm will also cause the camber curve to go less negative, which is the wrong way to go on these cars. You'd also need to narrow the upper arm to compensate for the change.

In regards to the change in ball joint locations, using the lowering springs will have the same effect.

 

[Va348]

The upper A-arm was shorthen too.I was thinking I had that in there.

I used lowing springs in my 55 It work OK. Just a little choppe for me.

My cars I like to ride like todays and hear nothing but G Jones on radio.


Have a good Day

Dale