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

31Vicky, I hope you appreciated my humor. This is a very interesting topic. However, I've been around here long enough to know that "popular"....well I won't go there.
Instead might I suggest that the FIRST place to look is the PRIMARY shock absorber system - namely your TIRE. A stiff tire (lots of air pressure) would more readily transfer that chuck holes energy to your suspension - resulting in that "hop" mentioned earlier. Another area you may have to interpret is spring rates. When a guy tells you that "hey I used a so and so rated spring on my identical car" I have to wonder what angle was it mounted on? Potentially a huge difference. I'll leave the rest of the discussion to the experts - as an admitted amateur I know I do not effectively express my thoughts via the typed word. Good luck solving this - and I mean that sincerely.

 

You can shave a lot of weight off the brakes if you're careful. Taking off weight close to the ends of the rear axle will help more that removing the same weight from the middle (not that you can't do that too...)

Using lowering blocks? (I know you're not. Just an example.) get rid of them and de-arch the springs.

Of course lighter wheels and tires if you can find/afford them.

 

There ya go. If you just move the "engine" the overall weight doesn't change. The CG will move though.

And If the engine doesn't move, the CG doesn't move. It doesn't matter what the engine mount looks like.

 

It's best to have a thick skin if around here,
I have no idea clue if your idea works or not, you say it does so I want to find out. I learned along time ago that its not what you don't know that gets you into trouble, its the things you know for sure that just ain't so.
I've thought many things were impossible and had my**** handed to me a few times because of that.
As you can see, I come up with some stuff, ideas here. not only here buy other places that others have thought impossible, I handed them their**** more often than ill say thru my carrer because it just is what it is and I just do what I do.

Giving up isn't one of my better qualities, nor do I think you should throw in the towel. There's all different types of backgrounds here and no one person can know everything. But as a group, I bet this place is damn close to knowing most of everything there is to know. Some play a part sharing, some play a part absorbing and hopefully they will share when it's appropriate, some observe and are spectators, some provide amusement, some provide a target, some provide doubt, some provide encouragement. Out of all that, don't give them a target or spread doubt and all should be well. Right ?

 

500lbs is too much!

 

I like the idea........I look at it this way........a vehicle launches hard leaving the line...follow the path of energy and torque from the engine block mount location and follow it all the way to the back..........sure you need the correct spring rates ect.....that is a given......its an entire package that needs to work in concert......I can see the energy moving thru the mount location at the point it meets the chassis.......I made my moves just recently, but I was after a particular % of weight on my rear wheels w/ me in the car and playing w/ the CG...............Dave

 

"Around here" of course being the whole internet.

It's difficult to communicate some things clearly and politely when people are not face to face, because we don't see the body language and facial expressions.

That problem has cause more ticked off forum posters than than than the NHTSB and the DOT combined.

Tanner, you should grit yer teeth and hang on for the ride. After a bit you'll get more comfortable with the problems of forum life. It's worth it, particularly if you've come here for help, or to help others.

Either way, it's a rewarding, educational, and inspiring business.

 

Not sure when you started reading here, but I see your join date is 2014.
The Hamb used to be the ultimate "thick skin required" place. The knowledge, content and abrasiveness have been deluted. It was quite a bit rougher around here and its a bit more politically correct and people's feelings are at least considered once in a while.

Anyway what do you know about things that help with unsprung weight?
That's the question here right, not what I mean or don't mean or if its specific to the Hamb & traditional hot rods or the whole*****ing Internet. Don't derail this thread and get all it Facebook and squishy. You ain't here to hold anybody's hand you damn sure ain't going to do it here and get this deleted. just kidding, the old Hamb was great IMO, and I miss it.

 

I guess I'm getting too old for the Bull...my skin is pretty thick, but my patience is very thin...Every day I get up with the goal of telling someone how good of a job they did or trying to help someone if I can...at 62 years old and been into racing since age 16, I've learned some things the hard way and I hate to see someone spend extra money and time when I might be able to help him.....I guess this new generation don't give a Hoot, they'd rather argue or insult someones intelligence.......I'll try to help the ones I know that appreciate whatever little help it may be....31 Vicky has the start of a Super Nice car....I really don't think he needs the help of anyone really...looks like this ain't the first horse he ever rode....You hang in there and post some pictures when you get it further along.

 

correct me if i am wrong, this works as long as some of the engine weight is forward of the front king pin?

 

Vicky (I sure feel funny calling a guy Vicky...) It couldn't have been any worse than the motorcycle forums or computer forums or skateboard forums, etc.

...And I saw the same issues on all of them, because people are all people. Whether skateboards or hotrods or choppers is the topic it don't make a difference.

Different people make a difference though.

Now personally I understand being short on patience. It happens to me too. I empathize.
If I get bent up and hold grudges over this stuff, I really only hurt myself.

It'd be nice if more folks realized that.

And yeah, I just stumbled across this place a couple months ago. I've got very little idea who's who and what's what yet.

Now cars I've been fixin' since the 60's. I have a good idea what's what there.
I come here to help a bit. But mostly because guys far better than me are posting here, and it's worth a lot to me, what you all are putting out gratis.

 

I may not agree with some of your logic but your illustrations are superb. Not like the ones that hack 31Vicky scribbled out.

 

lmfao.

Wait am I supposed to get offended instead of laughing.
I wish somebody would tell me

 

Here's the picture:

 

Perhaps the motor mounts or the chassis are flexing and acting like a spring. If so, your car would have two suspension systems. The regular one - which allows movement between the wheels and chassis, and the long motor mounts - which allow movement between the chassis and engine/transmission. That may account for the better cornering. The wheels may be better able to stay in contact with the ground because the chassis was not following the weight of the engine quite as much as other the cars.

That may account for your experience vs. everyone's replies about leverage.

If everything's stiff, than your experience doesn't make sense. The distance between the engine and the suspension is what determines the size of the lever. Moving the motor mounts around only changes the shape of the lever's handle.

However, if things flex around like a secondary suspension, that would allow the wheels to stay in contact with the ground longer and your experience would make sense to me.

 

Thanks. It's no different than if the frame itself had an inward jog at that location. Other than a bunch of extra stress points where the angled mount would attach.

 

If real life experiments and experiences show results, there's an explanation.
So there's one of two possibilities, Tanner's trick shows results or Tanner's telling stories. I do not believe that tanner is telling stories and that his trick does show results. So that leaves the "why" and how part of the explanation. The physics experts say that it could not possible be from altering the weight bias. I'm still not convinced of this one way or the other yet. So maybe that's not part of the how, but since it was posted on this thread about helping sprung vs unsprung weight that is what got hammered on. Rolling over scales before and after would put that to rest.

I do know that where you hold weight makes a big difference. Think of choking up on a ball bat vs letting your pinky wrap over the stop. Or where your grip is on a hammer. Moving the frame connection should have some of the same reasoning behind it, because the mounts and chassis will be holding the weight differently.

Also the motor mounts and engine create almost a solid member. if you move the location of a solid member it's going to have some effect. Moving the frame mounts will be moving that created solid member's effective position.

The other side of this is the changes might not do much even though they are obviously different. Much the same as******** in the ocean changes the volume of water. Clearly it does change it, anyone could see liquid being added, but it doesn't matter much.

Don't forget what littleman said- everything needs to work in concert

So maybe these changes are the little tweak to the guitar strings that make it just a little bit better.

 

Well the hemi is sprung weight unless you are running a rigid front end.

Light wheels, lightened brakes lightened brakets on the axles. There really isn't much you can do with your rear end. You may save a bit on a drop out chuck by using an aluminum chuck.

So I got a question that falls into a gray area (not to hijack) suppose you are running a trailing arm or a ladder bar or other link type of suspension. Are the links sprung weight or unspring weight? What about the springs themselves?

Just something to ponder. I have heard it told both ways by people way more advised than I am.

 

I liked your experiment.
And not sure if you caught my post.
A 1/10 scale mock up would have about 80lbs on a 12" rail.
A 1/2 scale would have 400 lbs on a 56 inch rail
Full size would be 800 on 112"

Looks like you had 3 lbs on 16" maybe?

 

When does this get back on topic? Question 31 Vicky what are you attempting to accomplish or determine, a ride issue or a bottom out issue?

 

Yeah that's about what I had but don't you think there should be some result regardless if the theory were true? Or would the difference in my test be too insignificant to measure on my scale?

There must be some engineering data somewhere on this subject. I would love to use it if it worked. But for now a full tank of gas helps..

 

Yes, that is what I'm wondering. You guys are thinking about this too much. Do you wan't to shift the motor back and loose interior room, or what. A sorted out 34 with a Hemi will be a nice car to drive and ride in. Get it on the road and then modify it. Run the chassis in primer. Then it is easy just to pull the body off and make changes. real simple.

Ago

 

Here's the topic ,
its a general question and discussion topic.

its a general question and discussion topic.

Now as long as people keep asking about my particular set up, or what im working on and what I want to know for or why I'm asking, then we keep going there. Since this a traditional forum we should stick to traditional chassis design.
The one I've been staring at recently is a 33/34 slightly modified. Pinched at front cross member for an A front member. widened at B pillars and the rear is stepped in with the rear tails raked up 2" at the rear crossmember. The 40 rear crossmember I got from you was narrowed and flattened slightly so the 40 front spring gives the ride height with the spring hangers I made.

So what I'm really working on is my own edification
Attempting to be a student and find a teacher by drawing from the great knowledge base located within the Hamb. Then when I know a more than I did before ill apply what i learned to my vehicles.

So how's this for a fresh start.

general question and discussion topic.

Reduction of un sprung weight is pretty popular but if that's already been done and the only options left are incredibly expensive, else what helps?

Altering the weight bias, or increasing the sprung weight ?

I'm really just working on is my own edification
Attempting to be a student and find a teacher by drawing from the great knowledge base located within the Hamb. Then when I know a more than I did before ill apply what i learned to my vehicles.

Any and all chassis designs welcome
Tips and tricks are a plus

 

I'm not sure how that all works, but 2 weight scales may or may not make a difference.

I doubt 80 lbs on 12" will show anything difference between scales.

Physics is going to rule here, but if there's a difference in handling of a stock car, and better balance like tanner says, then there's a reason for that and physics should root it out too.

 

I am not very sharp........... but ...........I say build an old Keith Black aluminum block and heads (they held water) ........... take 300 bounds off the front. Attach this monster to your chassis with a front and rear motor plate in whatever position you choose.......... the building of long motor mounts (in any direction) creates leverage ......let the clutch out and I would not want to the the frame rails that were responsible for trying to hold the torque .......... out 8" , 12" , or 18" . The further out you go the weaker any given frame becomes ........... for the same reason that the toughest bolt gets the longest wrench ...........

 

Yeah, I'll just start over
Them iron 392s don't work in a hot rod anyway.

 

Ok question posed is relation to unsprung weight of rear axle. Ok you have a heavy rear axle, so what. The heavy engine in the front offsets the heavy axle in the rear to balance the overall weight front to back. A scale reading gives total weight, rear bias and side to side bias so scaling the car will give you the front and rear weights and overall combined. What is your priority now ride or high speed handling? The way I look at it is the difference in sprung and unsprung really affects the spring rate option right now.

 

If you are running radius rods at the rear (?) then the pivot point should be at or slightly higher than the center line of rear axle...Hard to do with old style radius rods but you can get there with angled four bars to project the center [called instant] to a suitable point...Run around a bumpy area with a wheel barrow for a bit, push and pull with the handles at different heights and you will see that it does make a difference to what impluses you feel in your hands [pivot point] as the barrow wheel follows the ground...

 

Hummm,
Have Pete and jakes style ladder bars with dipped crossmember.
I fabbed the crossmember but followed their dimensions on it.
Not sure I can gain much here now.

 

I did leave myself room to play with this- 1 "exactly to come up.
Lots of ways to raise it and change the spring rate.
The 4O front spring rides almost flat so there's not a lot of eye to eye growth in the travel, that growth bottoms the spring eyes into the hangers.