Frame strength plans{Dave Severson}

This is what I'm planning for the 65 Ranchero frame.
Dave do you think this looks ok?

Thanks ~ Vegas ~

I'm going for this type look in the back, If you remember Dave.

~ Vegas ~

I'm not Dave, but I have a couple of thoughts - if you don't minde me crashing the party, that is. What size tubing are you using, and what wall? 2 x 4 x 0.125? I'll defer to Dave on the strength, but it looks good to me. Using the 4-link plates as gussets is a good idea. I have a couple of other comments though.

Your 4-link plates are spaced quite a ways apart. The Heim ends will move around unless you put in some spacers (DOM tubing?).

It looks like you're centering your 4-links under the frame rails. Do you have enough room for suspension travel?

Same question about shock mounts. If the 4-links are centered under the frame rails, have you got a plan for the shocks. They usually are bolted in the same plane as the 4-links. That would put your top shock mount directly under the frame. Do you have enough clearance?

Henry brought up all the good points. If the clearances and travel is ok, it should work. Mine will be running ladder bars with the adjustable lower link, I can make them hook hard and not have to constantly tune to track conditions. Ooops, that's the drag racer in me coming out!! I will get some pics up on mine again when we start caging it. My frame rails are only 1 1/2" X 3", but it is all braced with a 12 point cage. It should be 2" X 4" rails to be NHRA legal, but there aren't a lot of rules where I race!!

Dave and Henry; I was thinking of putting the springs inside the frame.
Now the 4 link I'm not sure about? I would like to bring those
inside the frame too, but I'm not sure if that will work right?
I'm trying to fit some 50's in the back,but the car is not that
wide. But I want the tires inside the fenders. The beds getting torn out and new tubs and sheet metal will be put in. In the
very back in the center of the bed I'm gonna install a fuel cell.
I am open to any good suggestions or advice since this is going to be the first car frame, I've done.


~ Vegas ~

The 4 bar mounted to the frame is ok, as long as the kick up on the frame is high enough to clear the bar mounts on the axle housing when the suspension is compressed. You can mount the forward mounts of the 4 bar to a crossmember between the frame rails. Either way will work fine.

Ok Dave; I need tech 101. How do I figure out what spring
I should use? I can measure the spaces for the 4 link rods,
but I'm not sure about how much travel I should have?
Now under heavy torque should the drive line be in line with the diff and the tranny? {like when Launching} or in line after you have allready left the line????????
Do you get my Meaning? Hopefully you understand what I'm
trying to say.
Thanks

~Vegas ~

Calculate the weight of the car, when you order your coilovers tell them what this weight will be, they can spec the coilovers accordingly. You will only have about 4 or 5 inches of travel with coilovers.
Set your pinion angle at 3 degrees down with the car at ride height.

Dave,

Since I generally set my transmission output shaft at 3 degrees down bubble, I set my pinion angle at 3 degrees up bubble. Of course, that's with ladder bars. I've installed 4-links, but my partner always adjusted them. Could you update me on the 3 degrees down?

I'm not questioning your advise - just trying to learn a little more.

Henry: I think thats so when the car is under Heavy torque It
will bring every thing in line. At least thats what I've heard,
Some of my friends also said this also helps pull the front
end up and transfer the weight to the rear wheels for launching
the car hard! Hopefully I'm right, what you gotta say Mr.Severson.


~ Vegas ~

Yup, I do it for the launch. Not sure if it is scientifically or geometrically correct, just know that it works. I still prefer ladder bars. A 4 link is more tuneable, and that is both the good news and the bad news. I suppose for the street it is a much better unit, but for a predictable and repetive hard hit on the drop of the clutch it is hard to beat a set of ladder bars.

That's pretty much what I thought. I do it differently on street machines because they don't "launch" all that often. Also, setting up the trans at 3 down and the pinion at 3 up keeps the u-joints exercised.

No disagreement on special setups for heavy launch though. It's amazing what a 4-link can do - raise the front, raise the rear, make the rear squat, make the whole car rise. All depends on the relationship of the instant center and the CG of the car.

Dave ; You got any photos of your set up on file.
I want this thing to hook so hard that it peels the
pavement back. If ladder bars hook better I'll change
my plans around. I've got a buddy thats been using
my car trailer talking smack. He's running a hopped up
302, And thinks I don't know it's been stroked. So he
wants to run my 351 cleveland. Now heres the kicker
I'm gonna be running a 400M, HE! HE! HE!
He Does'nt know anything about clevelands, I think
I've got him. His car is fast but It's not running right yet!
He's having converter problems right now.


~ Vegas ~

It's not that the ladder bars hit any harder, they are just easier to tune and stay more consistent as the track conditions change. A 4 bar will actually hook up better, I just hated having to adjust them all the time.

Well I am not gonna be ajusting them all the time either.
Bootlace butt will be, thats my sons nick name. HE! HE!
My son asked me why I called him that one time, and I told
him thats because if you don't start behaving thats the
only part of my boot you'll be able to see! {laces}


~ Vegas ~

Dave or Henry; Do you know what gage the frame rails should
be for NHRA rules? Thanks


~ Vegas ~

ummm. not sure. I would think 11 ga, but better wait till Pro or one of the others more current on NHRA stuff comes along this evening.

Thanks Dave;

~ Vegas ~

Come on Pro wear you at buddy I gotta get some facts,
sose I can buy some steel and get started on my frame.

Thanks
~ Vegas ~

Vegas~

Without trying to be a smartarse, it might be worth your time to drop by the local speed shop or go to the NHRA site and pick up a 2005 rule book.

I don't have one either . . . or I'd look it up for you.

Thanks Henry

~ Vegas ~