Hey guys...

We've got a couple of bolt holes that are in use, sway bars, motor mounts... and a couple other bits through out the car at our disposal... to build spreader bars!

From the from of the car back:

We've got the frame horns on the front, with square nuts holding helping hold the front clip on... a flat bracket, some heim joints and a some threaded tubing... some tension!

We've got the front sway bar, it has 2 bolts on each of the brackets. A bracket sandwiched between the frame and the sway bar, and you have a new mount for another reinforcement.

We've got the big hole behind the steering box.

I believe twin turbo was working on an engine locator that would bolt to the frame on one end and the bellhousing on the other.

The front body mounts under the front of the doors, the body mounts in front of the rear tire... maybe with some work welding a bracket could be made to install a bolt in triangulated frame. Something that would tie into the front and rear mounts, along with the transmission crossmember.

The rear swaybar holes are already there, those of us not running a bar might be able to stiffen up the back half of the car with a bolt in bar...

Just doing some pondering, stuff that is easy enough to fabricate... that might improve our frame stiffness.

I read in an army welding manual that its not all that good for you, to weld a foam filled metal part... It releases all sorts of nasty chemicals! That put an end (almost) to my pondering of structural foam!

Dont know how well it'd work... but the spreader bars sound like they do a decent job of keeping the shock towers from folding up! Maybe something similar will work elsewhere on the car!

 

I would like a spreader bar that can be used with the stock fan and fan clutch.

I always see them on cars with thermofans but not on factory fans.

 

The welds on the U channels are poor and this channel pulls off the crossmember. Weld it in solid, this is not easy because grease keeps comming out of the crack messing up the weld. For the first pass don't worry about it, the heat will help draw the grease out. Hopefully the second pass will be better.
They also recommend gusseting the corners both front and back around the lower A arm mounts.

 

Grease??? I would not weld over grease, even if the weld heat pulls it out your welds will be brittle. The trick is to scrub & clean that area as thoroughly as possible and strip it down to bare metal.

 

Well ZD75blue we posted about the same time it looks like in the origin of the two threads, yours on frame stiffness and mine on cross members. We are going in the same direction and looking for the same answers.

I guess it boils down to a happy medium. I want frame stiffness and handling in my car without the addition of a roll cage because of insurance issues. I may however gusset, weld seams, brace, structural foam and as tall a cross member as I can get in front of the firewall or at the rear of the seats across the car inside the battery/storage compartments.

Clutchdust built a cross member as you described between the frame rails and the bell housing on his car. I think an aluminum plate between the engine and the bell housing attached to a tall cross member that runs to the cockpit frame corners may be a consideration.

Some of these are just ideas to incite brainstorming of the topic that may result in a viable idea.

GM used some subtle ideas on the Grand National Buick and the Monte Carlo SS. I have an SS in the shop we are dismantling at this time. It uses a small lightweight tube that runs from the center of the front cross member to the front frame horn to triangulate this area. Then a set of 1/4" rods are used in front of the radiator cradle creating an X. The cradle had another lightweight tube that went from the middle of the fender top lip to the edge of the radiator to further attempt triangulation. These parts were never noticed by many people that owned the cars or even knew of their existence.

Some of these ides are expandable and could be used in our C-3 cars. This is what I'm looking for. Simple ideas that some can use and an intermediate system that is useful but still not a roll cage. Jim

 

Same thought process...

THought process is as ittle weight, with as much gain as possible.

I'm putting in a roll bar, but only for just that! The stuff I'm pondering is ONLY frame stiffening, not human protection.

I've seen strut tower braces on unibody cars... I'm going to bet our cars bodys dont do much when it comes to adding structure to the frame. I wonder if a brace of sorts could be used, like foam filled ribbing on cheap boats ( ) to stiffen the "hull." With some work, and thickening up some portions of the body... maybe it could be the "composite" strength, much like late model cars!

Is there any way of testing where the frames flex? I cant figger a way to do this, while in motion. All I can guess is we have to try something... and see if the seat of the pants improvement is there. Either that or use some real easy to break string and tie between the points of intrest... stuff that would snap if it flexes hardly at all. But even then, you cant exactly tie a line front to back on our cars, bumper to bumper and say, "It flexes!"

 

On the topic of the sway bars... If you could bolt through the bar to the car, and use the twist from the mounting point to the A-arm instead of the whole thing, you could use the bar as a brace to the frame.

Wonder if anyone has tried this?

 

The torsional constant requires a length X diameter. Translation, it would be way too stiff.

How about going to solid motor and tranny mounts. Thats solidly connecting the frame rails and cross member through a block of iron and aluminum. Whats better than that?

 

Not much... But I wouldnt want to twist on say... the transmission case!

I think the flimsy engine mounts are to keep the motor from rockin the car around on the C3's. From where I'm sitting, the mounts going to the frame, are just stamped sheetmetal, very little welding, no boxing at all.

Maybe boxing the frame mounts, and then going with solid motormounts would help?

 

HELLO?

Its enough to hold a big block and the torque from dumping the clutch with slicks.

Its just amazing how everyone wants to get out the welder and start putting braces all over the place but something so simple and basic that can be done in an afernoon is shunned because it might cause too much viberation. Is it gonna upset the poodle? Wimps i tell you. Wimps.

 

Well... if you have to install a chain from the alternator bracket to the upper a-arm shaft, and you crack the paint on the front fenders because of the torque twist... my thinking is the front end needs help!



Nova's can take a 5k drop of the clutch with slicks and a big block, they dont ever track straight afterwards, but they can take it!

 

Years ago I ran a big block Duster and before we went to a full frame and 10 point cage you could spit out the rolled up window when it was launching. lol now that's twist.

I am looking at my Chevy Power book from 1980. It is showing several areas that need welding, plating, gussetts and reinforcments. So there TurtleVette the General has spoken so drop down and give me twenty!

lol jim

 

yep, i have the chevy power manual too. Not a whole lot of ideas in there.

you see... i'm cheap and lazy. A $60 set of solid mounts and 4 hours would do more to stiffen things up than lifting the body to cover a few holes in the frame.

i tend to be road course oriented rather than drag race.

 

a few holes? There's a whole lot of holes and some are really large also.

 

Same way...

IRS rear suspension is better at curved tracks than straight lines...

Anyways, what do yall think about using the bellhousing bolts to attach a second set of engine mounts?

 

That is what Clutchdust did.

I am going to use a blow proof on this car and they have a mounting pad for the 55 Chevy style mounts on the bell housing.

I think the key is height of a cross member.

TurtleVette, There are some good ideas in the GM Power Book, several in fact. Is it posted anywhere electronically? If not I may scan it in and send it to Terry to post.

Have you guys read all of the post at Corvettefaq.com under suspensions?

 

Life is simple!!
a. buy a chevy power book
b. do what it says, EVERYTHING it says...
...redvetracr

 

Howard is my old 1980 Power book still current information? j

 

It is already available at www.corvettefaq.com

For those that don't have it...

Go to the "misc" section. You will find the link to it in the column on the left side.

About 1/3 of the way down the page is the link entitled "Chevy Power Book on Corvette - In PDF format (caution: over 8 megs!)"

 

Any area I weld I remove all paint, any rust? anything down to bare metal BUT old seams have oil wicked into them from years of accumulation. It seeps out of the seams when heating in the welding process and destroys the weld.
Stick is not quit as bad but mig really hates this oil.
I certainly have had my share of problems welding seams and it takes a couple of passes before it is clean enough to get a good top coat.