lift blocks on the front of a straight axle gasser, yes or no?

I need the 1.5 to get to level.
My avatar looks good, but that is photo angle.

 

Old thread, I know.

Hell no. Blocks on a front axle are what would be best described as weapons-grade-stupid (not to mention illegal in many states). If you don't understand why, then you just don't understand physics.

Those laws are not negotiable, and you don't get tickets, you get killed.

Just it because it was done on a dedicated strip car, back-in-the-day does not mean that it was a good idea now.

Just my $0.02, but I am just a Master Mechanical Engineer, with an automotive specialty, and an experienced professional ch***is and suspension builder.

 

When you set up a car as a g***er, with a nosebleed stance, you are forcing the weight bias to the rear of the ch***is. On a dedicated drag car, this is to provide maximum traction.

Under hard breaking, you are shifting weight bias to the front of the ch***is. Unlike most other cars, which already have a lot of weight bias there, g***ers have a lot more available to shift to the front.

This makes for a much more pronounced shift. This will create dive in the nose. No matter how deep you set your caster angle, this will move it far toward, if not all the way to straight-up. That will make the steering twitchy under hard braking, and this is without blocks.

Add blocks into the mix, and you increase the leverage available for wrapping the springs. Wrapping the springs under braking further pushes the caster angle. Once you are past the point-of-no-return, no amount of steering input will keep the wheel from being ripped from your hands, as the tires go wherever m*** and momentum take them.

Oh, and depending on the design of your steering, and how the links run, this spring wrap will actuate the steering without your consent, and you will be powerless to stop it. Don't wrap your thumbs around the steering wheel, or you are going to be in for a painful recovery.

Unless you are planning on not running front brakes, and using a parachute at every stop light, you are on shaky ground with your reasoning.

Trying to prevent these conditions by using springs too stiff to move is an alternative, but not for anywhere but a perfectly paved 1320 (or 660) foot strip of isolated road.

 

Gimpy, by all means dont stop there!
What would you do?

Is there a difference whether the spring shackle is in front or back of the front leaf springs?
Or are they all shackled in front?

What do you consider minimum acceptable caster? 4 degrees? 5?

 

Will the lift blocks get your crank center above 24"? if that is the case then no to lift blocks unless you are building a mud bogger and want to run slicks to get to and from the bog.

 

Have springs made that properly do the job. Most major cities, and numerous smaller ones have spring shops. They can hook you up with the proper deal. They will need to have a stout lower leaf.

Not every vehicle with parallel leafs in the front has shackles in the rear of the springs.

The pre-TJ Jeep Wrangler comes to mind. Of course, having driven brand-new ones, and modified ones, I can say with authority that they handle very poorly. I would strongly suggest shackles in the rear of the spring. The Jeep folks even employ shackle reversal kits to put them on the back, where they ought to be.

A front-shackle spring is effectively a leading-link, and those can have very strange character flaws. Just ask the Jeep folks about "death wobble" and how hard it is to make it go away, on a vehicle designed by a major manufacturer.

It is hard to pick out a caster angle on a car that I have not seen, or put across scales.

For instance, I run 2º on my '60 Falcon, but it is set up like a road-race car. If you run 2º on a g***er style street car, you might stack it in the first corner.

Somewhere around 4º or 5º would likely be in the range, but there are too many unknowns for me to pick an exact number.

 

After seeing two g***ers go on their lids I figured what not to do building mine, as I did not what to have mine wrapped around my neck

Like I said I took a few leafs out of the stock springs, had a tube axle made with 4 degrees caster and at 120 in the lights it went straight arrow for four years and never felt un-safe

Ran the car at 2300 lbs and 3000 lbs and safe at both weights

DND

 

wry
rī/
adjective

1. 1.
   using or expressing dry, especially mocking, humor.
   "a wry smile"
   synonyms: ironic, sardonic, satirical, mocking, sarcastic;

 

Most states have laws against using blocks on a front axle.

 

My start states that no blocks in allowed on my axle ......