Streetable would this be? What I mean is how would it handle curves ect.

Anyone every use one of these setups in steet/strip application? I realize I will loose some handling by going to one, but I seldom test the limits of the corning of the car on the street. I figure I test the car enough in a straight line and give it a break on the curves :D

I see most of the 4 link use a side to side, diagonal rod to reinforce corning stability, and i suppose it could be beefed up to improve corning.

I would like to hear is anyone has every done this sucessfully on a 4-link.

I have been looking at the possibility of a bolt in 4link for these cars. I have it pretty well hashed out, at least in my mind, and through pictures,but on of the big questions is corner stability.

I would like to hear from some that maybe had a true 4-link in cars and how they behaved on corners. Again, I am looking for something that can handle normal to moderate street cornering. No autocross actions ect.

Thanks! :cheers:

 

You mean a solid axle? I think it would be more stable in corners, because there is no suspension components that will allow toe or camber changes due to cornering load deflection.

Of course, it will make the car jumper overroad irregularities while in corners.

Think of it as turning your corvette into a camaro without a back seat. :D

 

4 links dont fare well in street use. Neither do Ladder bars. I have seen many primarily drag style cars break rod ends just cruising- not aggressive street driving. The reason is they dont allow body roll at all. The rods ends bind when the body tries to roll and if pushed hard enough they break. They sell poly bushed rod ends (non- spherical) that help on the street. The 4 link does allow some roll, but not much. The only way to help it is to have the uppers and lowers non-parallel (as viewed from the top) like the factory GM "four link"cars are.

 

Are you going to a solid axle? If you are then there would be alot of work involved but basically if you do then try to stick with a 4 link setup with urethane bushed rod ends like those from TCI, Art Morrison, or Alston. You'll also need some kind of diagonal link or panhard bar too and then some coilovers...if you're going that far you might as well back half the car and put some real tires on it but there goes the cornering...or you could use the adjustable heim jointed end links from Guldstrand and keep the stock IRS in the car.

 

If the links are not equal, does that mean that when the body rolls or even when the axel springs compress, the pinion angle tilts? :confused: :confused:

 

Here are some pictures of what I am looking at. They will obviously be modified from these slightly, but the 4 link will primarily be this configuration. The pan bar will have to be moved to the rear of the axle also to a fixed point on the car do to the lack of room in from of the axle, but I have seen them in that location before on cars that were pressed for room. Here is the 4-link setup:



Here is a shot of the rear housing I am thinking about having made up with the 4-link brackets located to proper spots:



I am also thinking about an 8.8 rear housing also. This might be easier and more cost effective since they are readily available in most junk yards. Brackets would also need added to the end, to allow use of the rear brakes/calipers. Not sure about the ABS still being able to be used, I have not got that far.

Ultimately I would like to see a complete bolt in setup, so if I wanted to change everything back to the IRS, it wouldn't be a total nightmare, and the car would not be altered beyond that possibility. Thus far its looking like its more than possible :cheers: :thumbs:




[Modified by ski_dwn_it, 8:44 AM 12/4/2003]

 

no permission to look at the pic's.

but a live axle is not better than IRS when it comes to cornering.

If live axle WAS better, then all the high end sports car makers never would have gone to IRS...

It is better for drag racing, tho... less parts to break.

 

The 4 link should be fine on the street, but don't expect it to handle like the stock suspension. However, you absolutely do not want the diagonal link as is shown in that picture; a panhard bar is neccessary for street use. The diagonal link in that pic is for drag racing only. Any large side loads will put too much strain on that bar and something will break.

 

Darcane,

What setup would you suggest? Just a beefed up bar? Or one that comes off the rear of the axle to tie it all together on a diagonal.

I realize it will not handle like the car does now. But most of my driving is just a cruise here or there, and seldom hammer on it on the street through corners. But I do not want to worry about damaging something or loosing control on the street with the car if something would be stressed enough to break. If someday the urge to drag race the car fades. Then I want to be able to easily change it back to IRS system for handling again.

I just think the benefits of the solid axle on the strip, for my use now would greatly outweight the IRS benefits I use on the street now. I would like to be pushing 1.3x 60' times or lower with the new setup. Somewhere around where Hooked Up is at now.

:cheers:

 

You're getting into what I'm dealing with right now, Jesse... I've looked at three different solid setups; a ladder bar, 4-link, and Watts linkage for the C4's... All of them have inherent problems when you start dealing with the C4's design. I was hoping to utilize the OEM trailing arm mounting points for a 4-link setup but the bars would be too short. That throws suspension travel and the "instant center" point off. A ladder bar setup (check out Bob Curran's GS PRO/X-Treme Street racecar) would also be a good system; it doesn't allow the adjustablity of a 4-link...It also requires the bars be around 30" for correct instant center; there ain't 30" to spare going forward in the C4 with the OEM floor pan. Check out the 4-link setup on HookedUp's car; they cannibalized the floor pan from the rear bulkhead (behind the seats) back...The same was done for the ladder bar setup in Curran's car; NMCA EZ Street and PRO both require stock frame rails, ie., no back-halved cars. In order to have all of the correct mounting points for a 4-link or ladder bar setup you have to have a new rear crossmember (ya know C4's don't have ANY friggin' crossmembers past the firewall). That's where I'm running into problems right now in designing a "bolt-in" solid axle setup for C4's...Where the "F" do I mount whatever linkage system I desire to use (probably a 4-link) without cutting the car up and adding bracing and a crossmember??? The last option is a Watts linkage; it uses a trailing arm system and then a complex linkage system that attaches to the center diff to control both up and down and lateral movement...Well, the linkage could theoretically be attached to the stock "batwing" mounting points but then where in the "F" would I put the new coil-over shock mounting assembly????

See the conundrum I'm in?? As for lateral movement for a 4-link or ladder bar what you're referring to in the "diagonal bar" is a Panhard bar...It positively locates the rear in the center of the car and prevents lateral movement. The Panhard is the simplest way of doing this; a more complicated but better way is a Y-shaped sliding locater that has it's two legs of the "y" attached to the diff and the center pole (which slides back and forth to allow vertical movement) is attached to the rear crossmember (there's that DAMNED crossmember that DOESN'T exist, again)...

As for handling, a properly setup 4-link or ladder bar will handle better than most people are capable of driving...Remember, NASCAR's are solid axle setup and they handle pretty damn well...
-Jeb

 

Ladder bar setup is easier to tune because there are fewer options. But, on the other hand, you have fewer tuning options. Four-link can be a can of worms, but if you go thte time and know-how and it's installed correctly it is definitely the best way to go. Something to think about as well. :seeya

 

Check out this site for a reference: http://www.myphotosonline.biz:8080/p...Id=833&curDir=

 

are you talking about the track locator bar breaking? i've never heard of the ladder bar breaking. The main reason the track bar breaks is people use the weakest stuff to make it. Just look at the JEGS track locator bar, thats a pencil. get some chrome molly 1" dia. won't break easy.

 

First of all, I would recommend getting "Doorslammers: the Chassis Book" by Dave Morgan. There's some stuff in there I don't entirely agree with, but it's an excellent book overall and focuses mostly on drag racing.

If you are going to be doing mostly drag racing (I assume you are, otherwise why bother?) just do a four-link with a panhard bar and you'll be fine. This pic shows both: The diagonal link is the one in front of the axle at about a 45 degree angle to it, the panhard bar is the one parallel to the axle. The panhard bar is the one you want.

I would stay away from ladder bars because they bind when the axle is not parallel to the body (i.e. when one wheel hits a bump or when the body rolls going around a corner). It basically uses your axle as a sway bar. It's fine most of the time, but can fail with a lot of street use. Non-parallel four links can bind a little too, but it's not as problematic.

jburnett: The Watt's Linkage can be used with any of the other suspension, it is just the lateral locating device. You could also get a Shaw Link to do the same thing, but like the Watt's Linkage I think they are both overly complex for anything that isn't going to be set up purely for road racing. A panhard bar isn't perfect, but it's simple and doesn't take up much space.

As for NASCAR, they handle well, but they don't have to worry about irregularities in the track either. Their suspension is just a refined version of what's in my '68 pickup, two long trailing arms that angle inwards towards the front and a panhard bar.