Corvette Forum : DigitalCorvettes.com Corvette Forums banner

1 - 20 of 35 Posts

·
Registered
Joined
·
2,366 Posts
Discussion Starter #1
This how I envision it

Basically your making a setup similar to 2 parallel bottom tie-rods but instead of the second tie-rod your using the half shaft. So I need a link that is as long as the have shaft from pivot point to pivot point. I like to see things in 3rd grader terms

It still seems like a rather simple build. Besides the PITA front bushing. I could have that tig welded just for an extra safety measure. The rear link mount on the TA could even be bolted on maybe.

I could use the global west bushing also. If I could find it. Or even the guldstrand one but redvetracr doesn't like this one.

I'll post more when I get back from the dentist
 

·
Premium Member
Joined
·
10,260 Posts
it's 9PM now.... you must be in bad shape.....
:rolling: or he realized there's more to a 5-link than a few welds and heim joints...
 

·
Registered
Joined
·
2,366 Posts
Discussion Starter #4
Nah I got back and went to finish up my truck

My new springs came in today. I'll have to try and get some pics of it. Its a beater but I love it lol

Everything went well at the dentist :thumbsup: :laughing:
 

·
Registered
Joined
·
2,366 Posts
Discussion Starter #8
If you look at his design it's the same exact thing as I want to do minus the 2 front rods.

Yes I know what I am going to do
 

·
Registered
Joined
·
959 Posts
If you look at his design it's the same exact thing as I want to do minus the 2 front rods.

Yes I know what I am going to do

then it isn`t "the same" now is it?

knowing "what' your going to do and knowing "what you are doing" are two very different things.....at 16 years old do you really think you are a good enough fabricator to build the three critical components (times two) that make up the 5-link??
....redvetracr
 

·
Registered
Joined
·
2,366 Posts
Discussion Starter #10
All you do is make the 1 heim jointed tie rod parallel with the half shaft and with the same end points.

It like the the guldstrand set up but instead of using two tie rods they are using the halfshaft. There is no other way for it to maintain no toe.

And TT has said that the floating front bushing will work nearly as good. I just need to find where I can get one other than guldstrand. I may just have to do what 84rzv500r and cut the nose of the TA off

I would like to do the 2 front rods but I cant see cutting a set of 600 dollar trailing arms.

Edit: TT said it. I didn't notice it before


Because the whole suspension movement has no influence on the toe control, toe is now determined by the halfhsaft and toe control rods, those 2 angle the bearing block in or out for toe and if these are in perfect parallelism they will be a parallellogramme (sp?? damn what a word) and this means that effective toe does not change, sure the angles of these components will change but not relative to each other. THAT is the whole idea behind the 5 bar system where you use a set of sectioned forward rods to create a virtual swing arm but NOT to rigidly mount the bearing block to teh front with a fixed toe setting that changes (like a trailing arm) due to effective horizontal length of 2 components (the halfshaft and camber rod) moving the wheel in and outboard resulting in a toe change. Anotehr benefit of the 5 bar is that you have a virtual swing arm, not a true one like a trailing arm. This allows you to tinker with the anti dive/squat settings and virtual arm pivot height to tune the suspension. THIS is the reason why a 4 link setup for solid axles is so popular, it offers that same ability.
 

·
Registered
Joined
·
2,366 Posts
Discussion Starter #11
Heres another one with a picture :laughing:

marginal toe in does help w/ oversteer, but you can just set a marginal static toe in which will then be maintained throughout suspension travel. There's no need for a toe curve like there is for a camber curve because of body roll. You are comparing this to a solid axle, which is a much less rigid mounting option than a proper designed 5 bar or double a arm suspension (assuming you're using solid bushings and all) The flexing in a solid axle is what causes the brake toe out and the torque to in condition. This does not mean you can apply that to an independant suspension as something that needs to occur. Having said that, not even all live axles give toe in under power, some even toe out, especially those w/ weaker cases. Porsches had a similar problem w/ their semi trailing arms. They had terrible torque steer, something not very common in rwd cars but the semi trailing arm setup is notorious for this because of the arms being mounted on a diagonal axis towards the car centerline. This causes toe in under acceleration and toe out under deceleration 9letting off the gas or braking) because of the loading in the outer bushing and thus allowing deflection. Their solution was the weissach axle, basically splitting the trailing arm w/ a bushing in the front so that under deceleration the rear wheel toes in (especially important on the loaded outside wheel). These are all attempts to create a toe in situation to give understeer as understeer is much easier to control than oversteer.

What i want to illustrate is that you can just set a static toe in and have a suspension that does n ot change the toe so you wil never run into any toe control issues, especially toe out oversteer. However too much toe in is also not desireable. If you have a semi trailing arm suspension that does not use a sectioned arm like the weissach (and a lot of cars use the semi trailing arm) you will see a lot of static toe in being set just to counteract any toe change towards 0 or even out. This is not because more toe in is better but because they want to improve upon the shortcomings of the IRS design.

I agree on lowering the CG. I moved a lot of stuff aroudn on my car and think I lowered the cg quite a bit, my gas tank is about as low as it gets. By lowering the car you lower the CG but also the roll center, a higher roll center will reduce (weight shifting induced) body roll and this will let you run softer springs for a more responsive suspension and smaller sway bars (and thicker bars take away from the independence of the suspension), the only big drawback is that it puts more load into the tires however w/ modern tires in a wider size tat won't be a big problem. Given the same tire it would reduce the scrub angle significantly.

Your outer rod end is most definitely not in the same position as the greenwood one. Take a closer look at the sketched drawing and the picture. They use a chopped off trailing arm. The rod is about mid plane in relation to the spindle. It looks like it's a bit lower

Yours is significantly lower. This is the main reason for the geometry misalighment w/ the halfshaft. I'm willing to bet that the stock eaton type diff has a u joint center in the stub axle that's 8.25" off center or very close to that.

Have you even seen that the drawing depics WHERE to weld the center bracket? 8.25" from the centerline.

Here's a little sketch I made of that later type susp. See where the u joints and pivots line up and are all parallel w/ the driveline axis?
This was the latest version of that greenwood 5 bar system.



The other picture is just an installation drawing, I feel the picture of the real thing is a lot more valuable source of info.
 

·
Banned
Joined
·
1,873 Posts
I said nearly as hood. You will have some toe change due to angular difference between the 2 lower toe control rods (if you do it like that), if you sue a rear control rod the setup will work a little better, you won't have the angular problem then.

Yellow, that's a greenwood 5 link that you're showing. It has sectioned forward rods for axle placement, not a floating trailing arm.

This is the floating arm with the dual lower rods, you can see the angular difference in these drawings, that gives a little to change but nothing nearly as bad as teh stock setup and if you have a limited suspension travel it's hardly an issue







If you use 1 lower rod and 1 in the rear like the greenwood setup you posted then you're golden. It won't give you the benefits of adjsuting the anti squat w/ the virtual swing arm that the 2 forward rods make but from a toe control standpoint it's just as good.

You can just order the johnny joint from curry and use a hole saw w/ oversized pilot drill to drill out your trailing arms. i assume those arms you have use a stock front bushing?

You are right about the rear rod, it has to be placed parallel and behind the halfshaft w/ equal length. This way, when you adjsut it out or inboard it's still got the right geometry (since the trailing arm is aiming in a different position), it will always be spot on.
 

·
Registered
Joined
·
2,366 Posts
Discussion Starter #13
Thank you


I figured I would do the greenwood set up. I guess that wasn't the 5 bar.

I would really like to find a front bushing where I don't have to cut the nose off.
 

·
Banned
Joined
·
1,873 Posts
You do not have to cut the nose off, just get the 2" joint from curry.
 

·
Registered
Joined
·
2,366 Posts
Discussion Starter #16
Why did 84rzv500r cut his off?

the 2 inch joint would fit inside the current TA sleeve? With out the provided sleeve of course. I could swing 60 bucks for the 2. :D
 

·
Banned
Joined
·
1,873 Posts
I don't know. The joint somes w/ an outer sleeve, you can just weld that in. The guts are held in by s tepped ridge on one end and a snap ring on the other.

The 2" won't fit the sleeve, you have to cut a 2"hole w/ a hole saw, insert the outer sleeve and weld it in.
 

·
Registered
Joined
·
550 Posts
Because I used Vansteel offset trailing arms their was no "meat" around the pivot like on the stockers.

I made an aluminum guide that located the holesaw in the existing bushing....

I may still "strap" the front with some 1/8 stock...





 

·
Registered
Joined
·
1,196 Posts
I don't know. The joint somes w/ an outer sleeve, you can just weld that in. The guts are held in by s tepped ridge on one end and a snap ring on the other.

The 2" won't fit the sleeve, you have to cut a 2"hole w/ a hole saw, insert the outer sleeve and weld it in.
Marck you guys are getting me thinking. Where do I get those joints from?? Do they need to be aircraft quaility? I remember Herb Adams saying they are the only ones that stand up.
A link to where I could get a set would be appreciated.
 
1 - 20 of 35 Posts
Top