Swapped out my stock 30mm/18mm sway bars with WS6 36mm/24mm. Installed a Spohn adjustable wonderbar and Founders Performance panhard bar and replaced my stock steel driveshaft with an LS1 aluminum one. My '91 Firebird feels more stable, doesn't squat during takeoff, and seems to attain cruising speed much quicker than before. Just my imagination? Will installing the quick ratio steering box, 2 turns LTL, make it perform any better?

 

My car has the quick steering gear so I cant really compare but,,, I LOVE IT!!!!

My daily driver Mercury Sable has nothing on it. LOL

 

What's the purpose of an adjustable steering brace/wonderbar?

 

Preload?

 

Thats what is says on Sphons website. IIRC

If its that important weld something in there. It would probably cost less than any of the aftermarket wonder bars.

If it ever quits raining I am thinking of doing that. I just need to get a better look and make sure I will never have to remove it where ever I weld one in. If I cant find a way to do that there is an IROC sitting at a local yard I will get one off of.

I know if I weld mine it will only cost some wire and a little gas. But even if you took it to a shop I cant see them charging more than $50.00 to do it including the steel.

 

As long as the bolts are torqued, welding them in isn't going to do anything different than bolting them in.

What are you trying to achieve that bolts aren't doing for you?

The concept of pre-loading a structure is unrelated to bolting vs welding. The idea is to take pre load a structure in the opposite direction of loading. This reduces the net stress on the part. A common example is pre-tensioned cables in concrete. Concrete is terrible in tension, it just falls apart. It is great in compression. In order to improve the tension properties of a concrete structure you can run cables through the slab. Then stretch the cables to the cables are clamping the concrete in tension. Now when the loading on the structure sees tension, the tension has to overcome the tension in the cables before the concrete itself sees an tensile load.

You could use this to your advantage in cars if you fully understand the loading.

 

The only reason I am thinking of welding a brace in instead of the wonder bar is more ridged like welded in SFC compared to bolted in ones.

I don't plan on welding in a wonder bar. I am going to look and see what I can do with out making it impossible to work on the car later.

I will say I don't see how pre-loading your frame rails (together or apart) will help any more than locking them together in their correct place with proper bracing so they never flex again.

Witch way would you pre-load them and how will that help?

 

why not just get a thick bar of steel and weld it to the bottom of the radiator tray then?

 

Bilstien shocks and subframe connectors will help alot.

 

Except its not. The bolted joint is effectively rigid if torqued the spec. The reason why SFCs are typically welded in is because the frame rails and thin and would crush when tightening the fasteners to spec. A solution would be to first weld in inserts that would prevent the frame rails from crushing. You would also have to do analysis to make a single bolt of that size at each corner is sufficient. Luckily in the case of the wonder bar, GM has already done the engineering for you.

That is the problem, the car sees loading both directions, so you are out of luck.

 

STG back when he was VETRUCK spot welded them in and the spot welds broke. That is proof it moves and I am 100% sure he tightened them correctly.

Here is the post. https://www.thirdgen.org/forums/post...19-post19.html

Bolts will always give vs welding. IMO GM engineers built it for a daily driver just like our rear suspension that we have all tore up. I know I have a bent GM designed rear torque arm on my car as I type this. Thats what started my suspension rebuild.

My car is a 100% bolt on 305 TPI with a 700r4. If I can bend one anyone can.

So why pre-load them then if you need to load it both ways? Makes more sense to makes them rigged and take all movement out of them.

I'm really just trying to understand the advantage of the adjustable wonder bar. I have searched this forum and I would guess 99.9% of the people do not see an advantage. Very few post seem to think there is an advantage but none explain why. My guess is they spent money on one and don't know the difference.

I am not trying to be a smart *** I just want to understand this.

 

Today is the first day it's not going to rain in 4 days here so I will know later today what if anything I come up with.

Finally get to start my suspension rebuld.

 

Were you there when they were tightened?

I would not trust some random person on the internet, myself including. If you choose to trust one member over another, that is your call. I would suggest taking a class on bolted joints to gain a better understanding.

The wonderbar is attached by two bolts on both sides. Torqued to spec, each bolt produces about 9000lbs for preload resulting in about 3600lbs each or 7200lbs of shear slip resistance per side. Assuming your frame rails have no additional support and assuming all the weight is over the front wheels, you are good for a 2g lateral load without the joint slipping. Pretty conservative if you ask me.

Designing a bolted joint is quite different than the rear suspension. I guarantee all the bolted joints in the rear suspension are overkill. Did you upgrade your hardware when you replaced all those parts? Why not?

You wouldn't preload them. Its going to make the loads in one direction better and the other direction worse. If you could determine the crack initiation location in the sub frame rails, you could perhaps figure out which direction of preload is better. Until then you are just guessing.

John

 

If the welds broke it was the welders fault.

 

VETRUCK added ANOTHER bar in addition to the wonderbar if i recall correctly. He also had a brace underneath the tranny (similar to the kenny brown one), and his car also handled at 1.07g's according to him.

 

No he spot welded it. The point was the bar slipped in the bolts enough to break the spot weld.


But no I was not there when he tightened it.

 

Thats my point also. If your just going to be guessing like 99.9% of us would be there is no point in an adjustable wonder bar.

I am sure there is some engineer on here that actually could use one but the rest of us would be buying one just to add adjustable wonder bar to our mod list.

And you know I will argue with STG faster than anyone else on this forum. LOL I don't give a crap how many NASCAR wins he has.

 

Yea I never seen the pictures. I sent him a PM to see if he would share them but I don't think he wants anyone seeing them anymore.

 

Yup, we agree on that point for sure. If you are trying to stiffen the chassis for handling then the preload provides to improvement. If you are trying to reduce the risk of the sub frame rails cracking, then you need to know where the cracks start. My car doesn't have the cracking, so I can't help.

 

I don't have crack, either