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View Full Version : Front Axle: For those that want to update your front suspension.....



Mike Van Veghten
02-24-2015, 07:45 AM
Here's a handy little gaget to help design your new front suspension.
Most helpfull for setting the numbers to control the camber with chassis roll, and putting the roll centers in a good position.
Not much in the instruction front, but if you play with it enough, you'll figure it out.

You'll also see why parallel control arms are not the best for handling. As in the Stude design, also in the "basic" chassis setup you'll get from most of the chassis builder..."kit"...chassis or clips. You'll see why you need a custom (if you will) suspension setup with real numbers to the chassis company, so they can provide you with a more proper suspension design.

http://vsusp.com/

Mike

Alan
02-24-2015, 01:07 PM
Yes, Mike. On a stock Stude the pink dot is outside and on the opposite side as that diagram. On my installation the pink dot is another 80" farther out.

48skyliner
02-24-2015, 01:20 PM
I agree this program is a useful tool for someone designing a car from scratch, particularly a race car. But for the average guy trying to improve the driveability of his Studebaker, I would consider building a model. Since I did the design for the Stiletto ten years ago, my son has become quite adept at doing computer design work , and if I were doing it today, I would put him to work on the suspension design. At my age there is such an amazing amount of knowledge crammed into my brain that there is no room left to learn a new skill. I know many of you must feel the same way.

When I was designing the Stiletto, I built a model as suggested by Carroll Smith in his book "Tune to Win". My model used a sheet of paper with 1/4 inch grid, so it was 1/4 scale. I started with the observation that most cars with dual upper and lower arms had the lower arms approximately horizontal and upper arms sloping upward from the pivot points. By varying the widths of the pivot points and the lengths and angles of the arms, I found fairly quickly the optimum geometry for my requirements. I have been driving the vehicle regularly since 2009 and I am very happy with the ride and handling.

The suspension in my 48 Champion had downward sloping upper control arms. I cannot possibly imagine what the engineers were thinking that designed that suspension, but I absolutely do not accept the excuses I have heard from some Studebaker purists that "they were not trying to make a sports car, it just needed to drive straight down the road, etc, etc". The camber control is atrocious and because of the way it is built, there is essentially nothing you can do to correct it except throw the whole thing away and start over. There is nothing fundamentally wrong with dual A-arms and a transverse leaf spring, but when you start with a clean sheet of paper and design a new suspension, it does not cost any more to build it with the correct geometry.

41482

Stude Star
02-24-2015, 05:44 PM
We have a modded '51 and we also had a stock '51 business coupe. I went through the suspension on the business coupe and it's very convoluted, the camber/caster/ride height adjustment is a work of art, but is a compromise and not suitable for using with modern tyres. I can see why the previous owner of our '51 put in a Mustang 2/coil overs/rack front clip, it's the only way IMHO, I can now drive at 130 one handed:!:

Stude Star
02-24-2015, 05:56 PM
Stock - http://i877.photobucket.com/albums/ab338/aaroncorvette/Ford%208%20point%208%20mod/10175036_762926277072532_1766546879621859669_n_zpsjq3o1pgj.jpg (http://s877.photobucket.com/user/aaroncorvette/media/Ford%208%20point%208%20mod/10175036_762926277072532_1766546879621859669_n_zpsjq3o1pgj.jpg.html)

Modded -http://i877.photobucket.com/albums/ab338/aaroncorvette/Ford%208%20point%208%20mod/10350543_763861036979056_9072438369869682631_n_zpsbm1bx8h6.jpg (http://s877.photobucket.com/user/aaroncorvette/media/Ford%208%20point%208%20mod/10350543_763861036979056_9072438369869682631_n_zpsbm1bx8h6.jpg.html)
http://i877.photobucket.com/albums/ab338/aaroncorvette/Ford%208%20point%208%20mod/1187109_763861103645716_8504861661273065224_n_zpsddz0cfkz.jpg (http://s877.photobucket.com/user/aaroncorvette/media/Ford%208%20point%208%20mod/1187109_763861103645716_8504861661273065224_n_zpsddz0cfkz.jpg.html)
http://i877.photobucket.com/albums/ab338/aaroncorvette/Ford%208%20point%208%20mod/10339728_763861156979044_7900725853938248520_n_zpsxsmfwusq.jpg (http://s877.photobucket.com/user/aaroncorvette/media/Ford%208%20point%208%20mod/10339728_763861156979044_7900725853938248520_n_zpsxsmfwusq.jpg.html)

Xcalibur
02-24-2015, 11:17 PM
In reality, some things actually work better than they should when considered on paper. A properly set up "late" Stude front suspension is one of these things. I'm not a purist by any means, so don't get me wrong, but with very minor mods, mainly quick-steering arms and modern tires and wheels, Road & Track (as my memory serves now) had very positive things to say about the handling of the Blake Avantis. From my experience, if one is dealing with a good late front-end, meaning new parts installed and set up correctly, I think more is to be gained by expending ones resources installing an independent REAR suspension. I've one from an XKE (doesn't require narrowing) in my '63 Avanti and it remakes the car in nothing but positive ways. Just something else to consider where handling is concerned...

jlmccuan
02-25-2015, 05:50 AM
Have you set up a stock late Studebaker suspension with a link we can begin with? It would save a lot of duplicated effort for those wishing to experiment.

Mike Van Veghten
02-25-2015, 11:54 AM
Jim -

No sir. I did use a simillar but different calculator (than this one) back when I built the C4, Corvette suspension on my Lark. Made a couple of changes from the dimensions that GM used, per the calculator (and racing suspension book) I used. I started with the OEM crossmember for the original Vette control arm dimensional locations. Then used a simillar calculator and change the width and wheelbase to suit the Lark, and did a couple of changes per that info.


Xcalibur -

In "reality"...using good math IS a very good place to start when designing and building a front suspension...on "any" brand of car, race car or otherwise..! If you want it to handle as well as it can, within the confines of the car you are working on..............
If you feel you can do better with the stock suspension, then by all means, go for it..! Who am I to stop anyone from doing anything they feel like doing.
Like a Rack & Pinion steering on a stock Stude chassis...!!!
As another here says, your car, your time and money..

This is just another method of determining...the most proper dimensions to try to build to. As my original note sorta said, just buying an aftermarket front clip, will most likely NOT provide a better handling car than the Stude engineers designed.
BUT...with information like this, one CAN help that aftermarket builder design you a front suspension that works better than the Stude designers designed, 60+ years ago..!

Mike

Stude Star
02-26-2015, 02:21 PM
I think the main problem with stock suspension is the amount of caster you (can't ) get out of it, I had the same problem with my '71 vette, ended up with 5 1/2 degrees of caster with aftermarket arms. If I was a welder I guess I could have moved the suspension to frame points but it's way easier to install offset arms. This is due to older cars having less caster so that they could be steered with manual boxes. Stock c6 vette has around 9 degrees of caster for comparison.
Also guys who mod their cars generally want them lower and the stance I have on the Stude now would never happen with stock suspension unless the frame was modded with a 5" kickup. (which it now has).
If you want to go as far as modding the frame/disc brakes etc it makes sense to so SLA from the pre existing parts bin.

Mike Van Veghten
02-26-2015, 08:42 PM
Stude Star -

WHY.....would one need more than 5-1/5 (or 9 !!) degrees of (straight line) caster on a street car...?!

It does appear that you have a "little" better upper control arm placement. Hopefully you set it up with an adjustability in the body roll caster & camber and turn caster & camber also. And yes, it appears you can adjust more straight line caster into the suspension (more than 5-1/2 degrees !?).
But....there's much more to a good handling car than just those couple of additions over the Stude assembly. It's difficult to see but, is the R&P pivots in the correct location ? Have you verified the bump steer action ?
There's also more I don't see, especially for all the work you did.

Again, the calculation program noted above is one of MANY ways to check your work for proper or close to proper pivot points. It wasn't meant to start a big deal whether it's worth all the work to....do your up-front homework.
That's all up to the individual.

Mike

Stude Star
02-27-2015, 03:05 PM
Stude Star -

WHY.....would one need more than 5-1/5 (or 9 !!) degrees of (straight line) caster on a street car...?!

It does appear that you have a "little" better upper control arm placement. Hopefully you set it up with an adjustability in the body roll caster & camber and turn caster & camber also. And yes, it appears you can adjust more straight line caster into the suspension (more than 5-1/2 degrees !?).
But....there's much more to a good handling car than just those couple of additions over the Stude assembly. It's difficult to see but, is the R&P pivots in the correct location ? Have you verified the bump steer action ?
There's also more I don't see, especially for all the work you did.

Again, the calculation program noted above is one of MANY ways to check your work for proper or close to proper pivot points. It wasn't meant to start a big deal whether it's worth all the work to....do your up-front homework.
That's all up to the individual.

Mike

Dude, I can throw this car around like you would not believe. Front steer rack and pinion with decent caster, surely you can see from the pic the angle of the steering arms, get those babies flat at ride height and who needs to check bump steer? Caster is what provides straight line stability, the reason a new vette has 9 degrees is for that reason. Old cars had very little and it's their main problem. I've had my '71 vette at 150 and it was awesome (mainly due to the caster).
I modded the rear end diff crossmember to raise the diff and bring the half shafts as level as possible. Smart struts, yellow stuff pads, 285's, HD half shafts etc

http://i877.photobucket.com/albums/ab338/aaroncorvette/Corvette%20pics/rsz_crossmember.jpg (http://s877.photobucket.com/user/aaroncorvette/media/Corvette%20pics/rsz_crossmember.jpg.html)
http://i877.photobucket.com/albums/ab338/aaroncorvette/Corvette%20pics/524896_425796534118843_992820006_nvette.jpg (http://s877.photobucket.com/user/aaroncorvette/media/Corvette%20pics/524896_425796534118843_992820006_nvette.jpg.html)

The only car that has beat me on the street is an Audi R8 v10

I drive my cars hard and I won't tolerate them messing me around.
If you want a lowered ride height on an old car you need to do work, keep the wheels perpendicular with the road, keep the steering arms straight, increase castor (a lot) and add in some camber.

You can bench race all you like but I mod, then drive, then mod etc

http://i877.photobucket.com/albums/ab338/aaroncorvette/Corvette%20pics/SantaPod-1.jpg (http://s877.photobucket.com/user/aaroncorvette/media/Corvette%20pics/SantaPod-1.jpg.html)

karterfred88
02-27-2015, 05:13 PM
Yikes, I just want to be able to turn and not scrub the rubber off my tires, I think that's as far as Studebaker went. The above mentioned calculator makes some assumptions that do not work well with the Stude suspension. First and foremost, it assumes the pivot points at the front and rear of the control arms are equal and parallel to the frame rails and the arms are perpendicular . Neither is true for Studebaker's front end. The front pivot point is far outboard of the rear as the arms form a "sweptback" orientation and the trunnion pivots in a virtual plane, verses the axle and spindle swivel which present a different angle. I think the suspension was designed by the cut and try method, well before ball joints were considered strong enough to use. I'm just going to leave it alone--worked so far. I'd have to start with a complete new frame and suspension to get things "right". Lowering the inboard upper shafts will help the camber gain (lack of any on the Stude), but anything more requires more fabrication and math than I want to deal with. It will never handle like a sports car of today, may not even be as good as today's economy cars, but it works well enough.

Jerry Forrester
02-27-2015, 08:12 PM
Yikes, I just want to be able to turn and not scrub the rubber off my tires, I think that's as far as Studebaker went. The above mentioned calculator makes some assumptions that do not work well with the Stude suspension. First and foremost, it assumes the pivot points at the front and rear of the control arms are equal and parallel to the frame rails and the arms are perpendicular . Neither is true for Studebaker's front end. The front pivot point is far outboard of the rear as the arms form a "sweptback" orientation and the trunnion pivots in a virtual plane, verses the axle and spindle swivel which present a different angle. I think the suspension was designed by the cut and try method, well before ball joints were considered strong enough to use. I'm just going to leave it alone--worked so far. I'd have to start with a complete new frame and suspension to get things "right". Lowering the inboard upper shafts will help the camber gain (lack of any on the Stude), but anything more requires more fabrication and math than I want to deal with. It will never handle like a sports car of today, may not even be as good as today's economy cars, but it works well enough.

Hear! Hear!
Well said.

Xcalibur
02-27-2015, 08:44 PM
Mike, don't get me wrong, I did all this with the calculator and Puhn's book many years ago and when starting from scratch it is a great way to go. What I was perhaps ineffectually trying to say is that it takes very little to make a late Stude front-end handle far better than most will ever have a need to improve upon or be good enough to tell.