Technical spring behind the axel head scratch questions

There's a build thread index as a sticky at the top of the thread listing. Might help?

Chris

 

Why would someone stretch a wheelbase? To gain space and/or for looks.

 

that makes sense, but why woulf you want 12'' of space between the radiator and the engine???

 

thanks so much.... found the build thread....

 

The reason mine was "stretched" 13 " longer than stock was to make room for everything. The original plans would have left only 13 inches between the firewall and front crossmember with a sedan body on it, no room for an engine or rad.

 

Good thing we don't build anything exactly as the cartoonish world of nomenclature & assembly diagrams . Particularly the ones coming from asia

 

I don't know what car you're looking at, but usually people do it for looks. Not everyone has the same eye for proportion.

 

Exactly. It's almost like that drawing was a crude example for demonstration purposes. Weird.

 

Why do you think others tastes should mirror yours ? There's a word for that ....

 

You raised an interesting point though. This was a good image to mock up the principles of a panhard bar. Pay attention to the arcs on the left between the red "suspension travel" lines. The "problems" you mentioned with the panhard not being parallel to the axle is that if it is parallel to the axle at ride height it is at the furthest point in its arc of travel and will only travel one direction with suspension travel (green arc) which is more predictable from a handling perspective. If it's not parallel (as you mentioned in our exaggerated example), then it travels both ways and the distance of axle travel is more exaggerated (orange arc). However, between the red lines (approximate suspension travel) shortening the link distance by 50% (purple arc) gives very little additional axle movement at the ends of its travel. The length of the panhard is MUCH less important than it being parallel to the axle.

 

this where my eye lands on a 27 roadster...32 rails.. stretched to fit a hemi, stretched one piece half hood... front wheels centered to the grille.. pie crust bigs and littles, might as well add buick brake drums also..

 

but thats pretty evident with this pic of my 34 that I sold to this guy when my doc said , get your affairs in order, and do what ever you want... you won't live much longer and won't make it to the new year



oh, and no death wobble or any other ill handling..

also there is a stretched hood... but I kinda like it without , the hood on really shows the stretch..

 

I'd roll this one , green , pin striped and all. probley adios the 4 bar,.. and I like the slight radius windshield... which brings up another preference of mine.. I like the radius better than flat on the windshield, but the radius has to be less than the cowl radius... but to each his own...



but, and then this is just me.. before I would buy this car I'd request a pic of the owner sitting in it, anything past head and nect sticking out would be a deal killer...that and if holding the steering wheel @ a quarter to three, hands are above the shoulders, I'd hit the brakes also

 

Light bulb moment? Makes sense, doesn't it?
The dance of the 'sagitta'.
This is a great tutorial video:

 

Light bulb moment? No. I know how it works, but I see it referred to erroneously a lot online, and thought that was a good image to demonstrate on.

The video you posted is okay, but they make a few comments that seem more specific to air suspension. For a static suspension, I would put the rear end centered at ride height. That way it's not dog tracking most of the time. With air ride you probably want clearance so that the axle can move both ways.

 

If you have the rear end centered at half travel/ride height, any suspension cycling in compression or rebound will push the rear end to one side only. The whole point made at the 2:45 mark in the video is so suspension cycling will move the rear end to each side an equal amount. That is how to get things properly centered, and is why they make the comment "(this is critical!)".

 

They make the comment that it's critical because they're talking about air suspension design. Your air suspension will be cycled over a much larger range than your static suspension will. They even try to sell an air suspension design book.

Either way you can believe what you want, I know what works for me.

 

WOW! This sure stirred up a hornets' nest. I like Illustrious Hectors' version much better. The position of the perches makes a lot more sense as there is solid metal behind the perch welds, meaning not as much tendency to flex and break. The ones in the original pictures are too far back, too poorly done and bending stress could cause failure. Now, for my idea of doing it that way would be to make wedge shaped 1/8" V shaped plates about 12" long, narrow ends pointing away from the shackle mount and wide enough hanging down to drill holes for the shackle bolt at the height desired. Welded to the wishbones all around. That would be enough to safely reinforce the bones and eliminate the bending stress at that point. The (reverse) leverage laws come into play here, also. A short lever trying to move a long lever would mean that the up/down stress on the rear (bung) would be negligible. It would look better and be strong. Hope you can understand the reasoning for this.
I'm out ............................
Another edit: I noticed the spring eye position on the original picture. Not good. The spring eye could hit the mount on the wishbone when hitting a bump or dip in the road, thus breaking the mount off the bones. They should be more like Hectors'. Springs get longer as they bend, ya know.

 

I'd roll that one too, and anything else Pete Chapouris built.

 

It's just discussion about proper process. By all means, you do it however you like.

 

In fact I have one that the adjustable panhard centers the rear end at ride height where it wasn't centered previously.

You realize that you're talking about a tiny amount of travel? I'd much rather center my rear at ride height than have it off-center because of suspension travel. For example, Welder series sells a 29" long panhard kit. On a 3" suspension travel with that length of link at the extreme end of the travel, we're talking 0.155" of lateral movement. That's 5/32" or less than 4 mm. If your axle can't take that in one direction on the odd giant bump, that's the least of your worries.

If your axle movement is that critical you should be using a watt's link anyway.

 

What a great idea. Must be why virtually all of them are length adjustable.......
As for the Watt's link, they work very well, but are not typically used on the type of builds here.
Definitely not on a front axle, which is where this all started, isn't it?

 

You're claiming traditional now after you posted a link about air suspension design?

Yes, one of mine had a non-adjustable panhard bar. Now it has an adjustable one so I could re-center the rear end after it was lowered. What a novel idea. After you were claiming that the rear end shouldn't be centered. This all started because you didn't like a rudimentary image of a rear suspension. Your nonsense is making my head hurt. See ya.

 

A simple name database search disagrees.

 

I think he’s referring to the lead singer in Guns and Roses. <spelling on the bands name>

Edit: Google says it’s Guns N’ Roses.

 

My apologies. I should have known better...........

 

Axle, Axl, Axel... I have met 3 individuals with these variant spellings. Seeing as we're wandering all over the road.

 

Vintage Anglia..... spring in front. Always Wondered about methodology in designs.
Guess you had to be there... when the senior Engineers wadded up paper and bounced off your head.. OK Einstein..