discussion on wheel backspacing in general

[mightymidget]

1959 Pontiac introduced the widetrack by adding backspace distance on the factory steel wheel.
question? will your car handle the same if width is the same. but backspacing different? has in one rear end wider than the other.
will deep offset wheels handle jas well as wheels that are centered

 

[Guest]

I think I understand what you're askings. My opinion is, if the springs aren't moved further outward it'll be the same. If you move the springs out more it should handle better IMO. I've heard offset rims wear bearings more. It makes sense in a way. Unsure if it's true or not.

 

[jlaird]

I think changing the springs outward, or inward changes the roll center of the body but has little to do with handling.

I spent some years setting up stock cars and i could really care less about the body's roll center. Now the width of the track, darn right. If I can cheat there even a bit I can do wonders.

Sorry, Kelly. What you guys think.

 

[Guest]

I think changing the springs outward, or inward changes the roll center of the body.

The more body roll you had the worse it'll handle. The further inward you mount the springs, the easier it is for the body to roll and shift weight which affects handling.

From what I understand, moving the springs further outward has the same effect as installing a stiffer spring in the stock location.

Jack, what he's asking is if rim offest changes anything if track is kept the same. From what I read the springs are staying the the stock location.

 

[jlaird]

Aye Kelly. Body roll has nothing to do with where you have springs mounted, many ways to stop that, Shocks, several shocks. Painard (sp)bar, coil over shocks, etc.

However I do agree with your comment on moving springs outward if nothing else is changed of course. I suppose ideal position for springs is on center line of wheel. Think about that a bit, LOL.

I would think rim offset with track remaining the same changes nothing. In fact my first thought was why bother??

Someday Kelly we got to sit down and chat with a brew, in fact I look forward to it.

 

[mightymidget]

Kelly you are understanding my question. if you keep everything on the car the same but then replace wheels with a deep wheel. will the car handling improve? or since wheel is not center as designed will it cause a negative or postive results

 

[jlaird]

Answer: No change if track not changed. Change for better if track wider, even a quarter inch a side helps a lot.

 

[mightymidget]

is there a perfect ratio for width / height?
I am thinking about a car I want to hack together using very wide reverse wheels on a bugeye body with huge racing style fender overlays.

 

[jlaird]

I should not think it is quite so simple. Lots of math involved, way over my head.

However. concerning wide. The wider the better till you break axles. That would be my major concern unless you are going to change rear ends as well. Like a cut down something. Just for fun 8 feet is as wide as a vehicle is allowed to be on the road with out special permits. LOl

A Spridget is light enough and low enough just by nature that I expect it is fine for height ie weight distribution.

 

[Guest]

Jack, I look forward to it.

Think about it for a second, it's just like track. As you stated earlier, wider track= better handling. Who is easier to push sideways, a guy with his feet touching together or shoulder width apart? Same thing with a car, furniture or anything else with feet. The tires are the diff's feet and the springs are the body's feet. That is where they come in contact with the ground. (so to speak)

You decrease "tip ratio" with feet further out. Same way things are tipsier when they are higher. You lower a car to move CG lower which makes it tip less. Moving track out in effect does the same thing. The CG doesn't have as much leverage on the now wider track. CG is in the body, not the suspension. The CG leverage forces has to go through the springs...which if moved further outwards (springs), makes it (forces) easier to resist.

Draw a picture in you head of a triangle. CG is at the top and the springs are in each bottom corner. When the car goes into a turn, the lateral inertial forces of CG try to tip the triangle over. Move the feet out (springs) and it will take more force to tip.


The more weight on the outside of the spring give inertia more leverage when the weight shifts too.

You can look at it backwards too. It's simple leverage. The closer you put the spring to the "push" side of the lever, the harder it is to compress. (Push side could be either axle OR fender.

Ideal spring placement should be on the outside of the tire. :wink:

 

[mightymidget]

mustang 8.8 which is about 50" to backing plates. I was going to control track by wheel backspacing in rear and reversed in front. thinking about a 10" tire

 

[Guest]

The only loss I can see from a wider diff is if in fact more offset is bad for bearings. Jack mentions breaking axles so this may be true. Rim flex may be a consideration too if that exsists. Who knows, the moon may be made of green cheese but I can't tell you for sure 'cause I don't have knowlege of that either.

My philosiphy is, the parts should fit the car and not vice versa....unless you want wider rims or are buildinf for a particular purpose.

What you are proposing is what Nial is doing right now w/ the 210 diff.

 

[jlaird]

Hmm, take a Vet frame,suspension, etc. and park a Spridget body on it.

Now is wide, low, light. No clue as to how to get in it but....

 

[jlaird]

mustang 8.8 which is about 50" to backing plates. I was going to control track by wheel backspacing in rear and reversed in front. thinking about a 10" tire

Sounds like that might work. At least you would not break axles, etc.

Get a new camera, we are going to need lots and lots of pics.

 

[mightymidget]

I have actually thought about buying a totaled subura wax sti. cut the body off. shorten wheelbase and mate a bugeye body to body pan. all wheel drive 275 HP modern suspension and electronics??

 

[jlaird]

Thinking. HAHA. That's crazy. Have another Beer. Why not just a Spridget with a Wankel. Shucks that should be fast enough to scare you badly. In fact I rode in one and it will scare you.

 

[Guest]

Tunnel might be too big, unless you plan to straddle it like a motorcycle.

Jack, I did consider the buggy sprung Vette. I'm talking about a straight axle, not IRS. When you think about that, they ride rough and no one bugy springs anything anymore but them. ( that I know of.)

How wide is a spridget diff?

 

[jlaird]

I have no idea, don't remember. Can't seem to find it at the moment. Or something like that. However the front end is wider than the rear by a bit.

Later, dog out and bed for me.