Technical PtII-Ratio of Spring weight to unsprung weight unfavorable, what helps?

I don't agree in the least - All this discussion on this forum is not going to replace that.

An intelligent conversation is always helpful. it may not solve or satisfy all matters to perfection, but different viewpoints are almost always beneficial.

As far as trying then redesigning then buying more parts all on trial and error, well who in the hell is paying for that?

All I'm trying to do here is make better guesses? You don't feel this is helpful to accomplish this goal. It's a waist of time? It's better to build it, rethink and rebuild it than to put thought into what's going on or to try to think about the next few steps? Something wrong with planning past the end of ones nose?

It's really far and few between that I see an exceptionally well thought out hotrod. I see lots of costly mistakes and redesign because someone didnt do their homework and could have simply avoided those. I also see lots of copy cats that take a design that works and "do what they did", only they don't. They miss every damn detail along the way. There's some things that just take more work to make it better and 90% of the cars I see haven't had a builder go that extra mile. They just put up with the design flaw or bitch about it. Actually on a long term it's more energy and effort to put up with than to just do the extra work. I'm not a man who tolerates compromise well, because of that I've learned to make and chose my sacrifices well. Redos ain't one I'm fond of.

 

31Vicky, I really agree with your comment about "not tolerating compromise well" With that in mind ( a few years back) I decided to build a trailer for my dragster. IMHO one DOESN'T build a trailer to SAVE money - you build it to get features that YOU want. If you get a moment go to this video and pause it at 1:33.
http://www.youtube.com/watch?v=fhQYK8JaoAc
There you will see an example of "levers and springs" used to lift a load. Somewhere before building this I did scribble something down on paper to make sure I had the "math" figured right before I started cutting and welding. I think it's kinda neat to see it lift the front trailer tire off the ground - I tell people I set it up that way so I wouldn't need to carry a jack! But the real point of this is to echo your comments about "designing it" before building it. I always try to put a lot of thought into anything I build - whether or not it comes out good is another topic for debate, but I will never have the excuse for not giving it my best effort. I see you trying the same thing - seems perfectly logical to me. I don't know if any of my comments helped you much, but at least I tried I say keep going - doesn't hurt a thing to ask questions - so what if we can't always answer them - I say you and US will likely learn something. Engineering isn't about memorizing a bunch of answers that you can recite off the top of your head - it's about having the ability to figure them out based on something more than a "hunch". Of course you knew that already! Thanks for taking us along on your quest!
Now It'll be even more interesting to see how you resolve it all.

 

Vicky,

I don't think you will be happy adding weight to your car. You are limited with the rear buggy spring design. You could try taking the spring off and working the suspension thru its travel with the shocks to find out if you have binding.


Ago

 

This is better than reading science fiction novels and actually quite interesting reading other posters view points. 31Vicky, Now in some post the issue is brought out you have 5+ inches of chassis travel and only 3.5" body clearance. The body clearance is controlled by the spring displacement so your problem resolves around too soft a spring for good ride and clearance issues or tooo stiff a spring to prevent clearance issues and a lousy ride and no load transfer. This is an issue since the limiting factor is the ride clearance, you can control travel with an axle bumper set to min travel of 3" for safety because a spring spacer is going to raise the vehicle,change the COG and alter the stance look you want. 3-4" of axle displacement is quite a bit of travel, most cases only experienced when transversing curb cuts at an angle. Tannergang on post 58 is not far off base, I didn't realize engineering and politics were so closely related....

 

I've started a tangent engineering thread from this one.
Ill bring the info back here, but if you are following this thread and can answer some physics and engineering questions got check it out it's big fun for me . Probably not so much for the trial and error type guys.

http://www.jalopyjournal.com/forum/showthread.php?p=9686710#post9686710

 

LOL Engineering and Politics: They are now!

 

Thanks Dick ! I think

I'm hoping to get the spring dialed in an a progressive curve here.
So that the top 1/3 of its travel is pretty soft, middle third is medium and the bottom third of the travel is pretty stiff. I could be wrong but I thinking when it's into the bottom 1/3 ill not be worried about the ride. Ill be worried about turning into driveways or my foot on the floor keeping things straight.

Theres a laundry list of reasons why the chassis has 5" and the body has 3-1/2" not really important to this thread but ....
Without the gas tank and tank cover on the back the tail pan is up pretty far in relation to the rockers so I raked the frame tails up to fit the body better.
The the body has H U G E wheel well openings and I wanted bigger tires to fill it.
The tires are also pretty wide and I like them tucked a little so the center of the rear tracks closely with the center of the skinny fronts. Do do that I had to narrow the rear tails by 4" -2" on each side and narrow the rear end. Narrowed rearend lends itself to the 40 front spring very well. The step in just before the kick up was a perfect place to rake the tails.

Now all that being said, if I go racing and run smaller 28" slicks, instead of the 31.5 " tires I automatically get more clearance out back under the wheel well, a effectively better gear ratio. a level chassis, about 4* more camber.

 

I still want to see pictures of what your building....placed here where we can see what your doing......only picture I've seen is a transmission on a table.

 

That's because you didnt look thru the whole thread. If that is all you saw you didn't look.

 

Hell, most rodders wear them like a badge of honor!

 

You haven't worked as an engineer then. It's been almost 40 years for me.

Once past the low-buck developer guys and one-man-shows, everything that gets built is squeezed through the filter of politics and finance.

Remember that o-ring on the Space shuttle? Engineers wanted 3, but the bean counters had an engineer who said that one would be OK if blah-blah-blah.

They pushed him to get the answer that saves money. That's how politicians and financiers think. They gamble with the lives of others and don't care a whit.

Every job goes like that. Cars, buildings, space shuttles...it's all the same.

 

What was that middle part again? When the paperback comes out, please let me know what the answer is... Iz be totally confused at this point. Gary

 

I went to the link....didn't find it again....I want to see them on this forum...not a link...here...right here on this one....so all can see.........

 

Dude, there's well over 100 pictures there.
Best thing is to go there and look at them.
They are in that link.
They are on this forum.
But hijacking my own thread just to make you happy?
Sure because I think you are pretty cool
But you should still go there. - http://www.jalopyjournal.com/forum/showthread.php?t=850807
And check out all 13 pages .

 

I am cool...hehehe........I found it...it wouldn't let me see anything but the transmission every time I'd go there...must have been something wrong with my computer...I will go back and look it over real good........make sure you engineer minded guys are doing it right..hehehe

 

Looks Good....especially like the rear spring hangers......neat....real neat....super neat....I bet they were built without any geothermal nuclear fusion divided by max force converted load bearing forceful leverage diagram........bet they work too....looks like plain old good sense red neck design..............you might make it yet...there is hope for you after all.....I knew you had potential.

 

Lmao !
Thanks.
There'd be alot of thought in those too.
But since it looks simple it must be simple right ?
Like I said before , making it look easy is the hard part.

 

True of nearly any profession or sport.

When I teach people to skate, they wonder how it looks so easy, and yet they struggle mightily to just keep erect.

But it didn't happen overnight. I've been skating since 1960.

 

I really appreciate the fact you are trying to build the best working car that you are capable of... It's pretty interesting to see all the argument and ideas , but with all things hot rod... Especially traditional hotrod you have a very small box that you have to build from, there is a certain aesthetic that you have to color in the lines of with out things looking wrong or off, your ford/Chevy/mopar truck/coupe is looking good and it will drive great as is... I wouldn't worry too much ... The only Time I have seen an unsprung weight issue was a very heavy champ rear, floaters the works... Heavy everything, big ass tires you name it.. Under a very light very short T-bucket... Your car is gonna be great , but if you are trying to squeeze every last % out of how good it can drive... Keep going the theory and solutions are certainly interesting and entertaining!

 

God Damn!!.....Where are you guys taking this thread Now??....What the hell does keeping erect have to do with motor mounts??....LOL This is better than watching Dr. phil.....LOL

 

Thats what everyone did with the old Holdens down under- stop 'em rollin' over- a 2250 lb traditional layout, with small inline six, like in my avatar.

 

Dr phil is for a mature audience,
I'd expect thinking like this from adolescents with a mindset of that like Beavis and Butt-head.

Huh huh ! He said erect huhuhuhuhuhuhuh

Brilliant my friend

here's another one for you to keep in your bag of party tricks and I can see you may be ready for things a bit more advanced.
Here's the set up-
you ask someone "what is that under there?"
When they ask back "Under where?"
You make laugh because you made them say "underwear"

 

added 1.5 degrees of pinion angle and pretty much cured the problem.......still think I'm about 1/2 degree off...at 50 I can still feel or hear a small bit of harmonics....at this point I think it is more MENTAL than a problem cause I've fought the problem so long........thanks for all the help.............I think the sprung weight of the u joints in a rotational mass at speed under diverse conditions caused the unsprung weight to mass such an amount of feel to it that it went away..........SOUNDS LIKE A DUMB ENGINEER DON'T IT....HEHEHEHEHE.......thanks again to you guys for the help

 

Sorry about the above post....it was supposed to be on the other post where we were discussing pinion angles and vibrations.

 

See what happens when you get all excited? I post one word with multiple definitions and right away you start posting "dumb engineer" comments; and here you're not even on the right thread.

Now, how can I possibly trust your opinion on pinions?

 

You can't..........but when you get old, you don't care either...hehehe....mistakes become a very common thing and memory loss too...."What were we talking about?"

 

Your signature line.

BTW, it may be time for Part -III of this thread.

 

Well, I've been toying with a few ideas that help with the ratio of sprung to unsprung weight. in my head & on paper it works well as a static concept, but hard to wrap my brain around the dynamics of it.
Scale model is in the works.
Interesting simple too.

 

Good deal.

My philosophy is, "Every time I do something, I learn something."

Planning is essential, but at some point ya just gotta get out there and do it.!

 

So, after reading all 10 pages of this thread, I'm convinced that the best vehicle will be a short heighth, longwheel based, six cylinder tractor with a high center of gravity but most or almost all of its mass underneath that line swinging like a pendulum.lol