solid mounted front axle. . . pros and cons?

im getting DEEP into planning it out and getting some things down on paper before i go all out and pull a "ready, FIRE, aim!" kinda deal with the build. . .

i'd like to know from the guys that are running a solid mounted front end if its a good idea to go that route? or if i should actually take the time and spring suspend the axle up there?

thanks fellers

 

Kinda curious of that myself. Most I've seen have had front suspension of some kind.

 

Fiddy-

In researching the build of my proposed car, I went thru all the mags to see what the issues were, and:

1) Short wheelbase cars (like the Bean Bandit and the Bug) were a no-no; at 100+ trap speeds they were skittish as hell.

2) somewhere around 1960 or so, the NHRA outlawed solid fronts due to the car's tendency to swap ends when the pilot backed outta the throttle.

The reason for this is the track ain't exactly 100% flat; any variation from side-to-side causes loading and unloading of the front end. when this happens, the toe-in will make the rail 'dart' away from the loaded front tire - a bad thing, especially when you're most likely designing for a 110+ MPH trap speed!

I was looking into a torsion bar setup for my 'potential' build, but it appears that TB's really didn't hit until the slingshot era - so a buggy spring setup suicide style seems to be the hot ticket.

One last 'trick' (for safety's sake) - period racers often ran a dirt-track buggy spring perch - that is, one side of the spring was firmly mounted to the front axle and the other side was allowed to float conventionally. Looks unorthox, but the setup supposedly eliminates the high speed shimmy some rails (and rods) experience when you roll off the throttle and dip into the brakes.

If you suspend, I'd recommend trying different spring packs. I'm planning on a softly sprung front end in an attempt to promote what little weight transfer that can be affected - those skinny rears need all the help they can get!

 

I think that one or maybe two of the ones running now are ridgid mounted fronts.
I am running a Model A front end, complete with the buggy spring. I even have some old ford shocks on the front that I intend on hooking up. I may end up removing some of the stock springs, depends on how the first couple of runs feel like.

 

hey fiddy, there was some talk on this awhile back about this on an HA/GR thread... im not going to recommend anything because i dont have any real world experience with it.

the BFD runs a solid mounted rear and a lot of FED's and altereds run solid mounted front and rear.

we are building ours up with solid rear, and a transverse spring up front.

edit - better answers above... when i was answering, no replies were made just yet

i should add, that the projected wheelbase of our rail will be about +/= 107"... so, a normal early ford wheelbase... goal MPH 100 mph +

 

We run a solid frunt end and it works well for us. It gets down the strip striaght and the ride's not bad until you hit the return road. If I were to give advice on a new build, I'd say to install a sring up front.

I believe the shut down shimmy comes from frame flex. After I strengthened the frame, that went away.

 

We run solid on both ends,have no trouble at all. You saw the video I presume. Too all the new guys keep one thing in mind,Weight Weight,no horsepower you dont need the weight.

 

thats kinda what i had in mind. . . put the thing on a strict diet, seein as how i sure as hell cant seem to myself

 

You know! Thats what the crew keeps tellin me,Mac you loose 30lbs, we'd go faster. Damn them

 

reply with the following:

"If you'se guys'd make dat sumnabitch go faster, i wouldnt need to drop any of this here relaxed muscle"

 

Hell yes! I'll tell dem guys dat.sumnabitchs,especially Larry he's fatter than I am.

 

On solid front ends what caster spec are you guys running?

 

5to7 degres if my memory serves me right.