Actually, I dont wan t to be completly flamed, however, i would like to hear opinions, technical reasoning, and physics. What would happen if I were to weld in some crome moly tubing to make the rear beam solid? I have always driven a solid rear, rear wheel drive car until the cavy. i dont like the body roll the twist beam creates, so what would the ride feel like if i make it solid? how would it change the dynamics of the car: handling, contol, ride quality, noise, clearance, etc.


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

why not just add a good set of struts (koni or another kind), lowering springs, and sway bar, and perhaps even a tie rod too? That will tighten up the car alot more than you think and is by far easier than making the rear beam solid.

that still wouldnt make the rear beam solid though...


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

-A torsion beam axle doesn't contribute to body roll. Its entire purpose is to counteract it. (its only a big sway bar)

-You would be very hard pressed to actually be able to control the car if you were to have a completely solid rear axle. It would be like driving a 600whp RWD car on a skid pad.

-The difference you're feeling between the RWD car and the FWD car is just that- the difference between a RWD and FWD car. FWD cars are designed to understeer because the average driver can't handle oversteer situations, its a safety thing.

-You would never be able to make it completely solid. There has to be some sort of twist because the wheel centerline isn't on the same plane as the axle to body bolt centerline.

-It really wouldn't be any more noiser, but the ride quality would suffer.

If you're looking for better handling, upgrade the suspension. Even a simple tire upgrade would work wonders.

Isaak wrote:why not just add a good set of struts (koni or another kind), lowering springs, and sway bar, and perhaps even a tie rod too? That will tighten up the car alot more than you think and is by far easier than making the rear beam solid.

I'm with this. Who cares if it is solid. You can make it handle better than a RWD.



FU Tuning

John Higgins wrote:You can make it handle better than a RWD.

I don't know about that.

A Jbody with suspension done right, struts, springs, sway bar, camber adjustment, etc... it can handle very well... but if you want to go ahead and make your rear "axle" solid, go right ahead and let us know how it works out for ya.

It was fairly common practice to weld onto the old Dodge Omni rear axle to stiffen its action. Their rear twist axle was very similar to that of the Cavalier's.
It would very definately increase the roll stiffness.
That said, a bigger roll bar does the same thing.
I guess a few weldaments could be done lighter than a roll bar (if weight is an issue), but bolting in a bigger bar is just sooo much easier to install (and change!).

FWD and RWD IS different. Increasing the rear roll spring rate will not make your car act like a RWD. Cavaliers are sprung softly, and this causes the body roll you don't like. As mentioned by others here, spring and roll bars will help a lot.

stiifer springs or quality coilovers and or struts...

large addco swaybar....


prob less time, money than you will spend making a solid axle...


and even if you did place a REAL solid rear back there, your spring softness and weak struts will give body roll. alot of it.




learn more about your current suspension and mod it accordingly.


lets be realistic, AGX and prokits arent exactly that stiff.... my prostreets alone were stiffer than what you have on its hardest setting.



and to top it all off, you dont even have any swaybars..... aka the things tha reduce body roll.

for 130$ or so for a 1 inch swaybar, its a hella lot cheaper than trying to create a solid rear axle from a structure not meant to be one.

The Grand Am Cobalts are running an adjustable integrated "sway bar".

What I really like about a setup like that, is that it avoids bias towards one side. Being able to back the tension off in the winter months would be nice too.

I think this article talks about it. This buildup was featured on Street Tuner Challenge on Speed. I truly believe they did the best setup for small GM car suspensions.

Cobalt grand Am Car

I was just thinking of how much development GM has actually done throughout the years of the J-body and other so called grocery getters. GM can be pretty cool when you think about it.

Funky Bottoms (Event) wrote:and even if you did place a REAL solid rear back there, your spring softness and weak struts will give body roll. alot of it.

EXACTLY! I used to run with an addco sway bar in the rear and factory struts and springs. The body roll was still rediclious. Take care of the bread & butter before you start adding on the jam(meaning start by replacing your struts and springs and then move to sway bars).

well, i have agx and prokit, but like event said, it isnt stiff. I really dont like the setup. I was thinking of going to the new superstreet tein coilover system, however, i do not wan t coil overs. I dont need the ride hieght adjustability. I dont want that kind of adjustability. However, I want a suspension setup that will have the characteristics of coilovers. I was thinking of keeping the agxs because I like the comfort, and going with some stiffer springs. i think what i dont like on the car right now is the progressive spring rates. Who makes non progressive, stiff springs, that dont lower the car to a point of no suspension travel?

By the way, I own a 600 hp '65 el camino and an '88 5.0 mustang. This car is a commuter car and i want to keep it confortable to take the girls out in. girls hate getting into uncomfortable cars. i also want it to handle decent. I understand that control and comfort dont always mix, but there is a meeting point somewhere.


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

my bad everyone that was looking through my profile. The 5zignens are mounted and balenced with some zr rated sumitomo 225/45 17. The tires improved handleing by 10 fold.


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

Demonchild wrote:well, i have agx and prokit, but like event said, it isnt stiff. I really dont like the setup. I was thinking of going to the new superstreet tein coilover system, however, i do not wan t coil overs. I dont need the ride hieght adjustability. I dont want that kind of adjustability. However, I want a suspension setup that will have the characteristics of coilovers. I was thinking of keeping the agxs because I like the comfort, and going with some stiffer springs. i think what i dont like on the car right now is the progressive spring rates. Who makes non progressive, stiff springs, that dont lower the car to a point of no suspension travel?

By the way, I own a 600 hp '65 el camino and an '88 5.0 mustang. This car is a commuter car and i want to keep it confortable to take the girls out in. girls hate getting into uncomfortable cars. i also want it to handle decent. I understand that control and comfort dont always mix, but there is a meeting point somewhere.

everything is a give and take...

you arent gonna get a stiff ride, and not sacrifice comfort.

you wont get 1000hp and not sacrifice longevity and possibly streetability.

you wont get rich and have no one know who you are.

pretty much everything you do to a car or anything else in live, theres a fine line between luxury and performance....

all on a scale and its a balance.

the softer the suspension, the more comfortable it is..... the worst it handles...

the harder the suspension, the better it handles the more comfortable it is....


pretty much you are asking for a coilover setup. especially with spring rates stiff enough to produce what you are asking.




also not sure if you mentioned it or not, but what are the agx set on? front and rear?

agx are 5 on the rear and 2 on the front. drifting, set 8 rear 4 front.

so is it not possible to get the coilover handleing without the ride hieght adjustability?


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

also, here is the other prob im having. event, remember my other post that i said it was making noise at the top of the travel and i thought that the spring were unseating from the mounts? well, i have a theory. I here the noise, but i took the suspension apart again and didnt find anything wrong. The springs are tall enough that there is seat pressure unloaded, however, not that much. i was able to put them together without compressing the springs.

Here is my theories. The springs are progressive.

1) the springs are shorter than stock. The agxs technically are not made for the shorter springs, therefore, effecting the handling negatively.

2) the progressive rate is really low at the side of the spring that isnt wound hard. When i go over a speedbump of rain gutter that intersects the intersection, the suspension is coming back faster than the spring velocity rate can handle, therefore, momentarily unseating the spring from the mounts.

i would probably be semi happy with the setup if i could make them quieter and not pop when i go over bumps.

Also, IT IS NOT THE MOUNTS THEMSELVES. they are good. I have had the same problem on two different sets of mounts.


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

1. AGXs are made for springs shorter than stock. Give them credit where credit is due, AGX and even GR2 are very high quality struts, just not made for everything.

2. No way. Gravity is the only thing pulling the suspension down. Gravity acts basically equally on both the suspension and the springs. Unless there is something restricting the spring's movement they'll move at the same speed. (I know air friction plays a part, but I think we can safely ignore it given the springs have not only gravity, but also the spring rate pushing them down).

What size rims do you have on that? What brand/type of tires? What air pressure?

Sumitomo's suck.

Try driving around with the AGX's on full firmness. My car handled bumps much better that way with AGX's and H&R springs.

Your poping sounds could be coming from other suspension components. You may want to inspect all your ball joints, tie rod ends, etc.

the popping is only coming from the rear. There isnt much moving back there is there?


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

cut your strut mounts

i was thinking about that. I was looking at the long piece of rubber that sticks down against the rod coming out of the strut. What does everyone think about this. I was thining about an inch. I no longer care if i blow these struts. If they blow, im going coilovers...


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

Cutting the mounts will not blow the struts. Cutting those should lower your car an inch, and cause the mounts to wear out very quickly.

What worries me the most is your apparent lack of understanding of suspension dynamics. It seems that you need to read more about suspension, a couple of books maybe.

Have you checked your spare, and tools, lately? Maybe they're loose and making the noise.

C.T.S wrote:. It seems that you need to read more about suspension, a couple of books maybe.

Quote:



i agree. Im good with mechanics but no where near some of the people on here. Most of what i know is from trial and error. I try things until it works.

and yes, lowering the car an additional inch will have a lot of effects. two i can think of is possibly positive rake and lowering the strut below warrenty and its useful travel, so yes it is possible that the struts will blow fairly quick.


2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP

Demonchild wrote:i was thinking about that. I was looking at the long piece of rubber that sticks down against the rod coming out of the strut. What does everyone think about this. I was thining about an inch. I no longer care if i blow these struts. If they blow, im going coilovers...

would be alot smarter to simply go coilovers, sell what you have and put the money to the coilovers rather than blow and damage close to 300$ worth of parts and not be able to sell it, rendering it junk.

personally i wouldnt cut a strut mount. something about weakening a mount doesnt sit right with my logic on things.

it would be like having a shoe not fit, so cut out some of the soles inside, so it does fit...

which would make the foot fit, but essentially take away shock absorbing material.

Go for the coilovers, thats what I'm gonna do, try the TeIn SS with EDFC, which has apperently just been released. As for cutting the strut mounts, I only cut whats going in the dumpster, nothing else. Well mabe the fenders on my old Jeep but that was for a diferant resone


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