Rf wheel spacer

[billetbirdcage]

i guess im still confused , if the wheel travels 1 inch up , then you move it out 5 inches and it moves up 1 inch , the ball joint is not gone travel up as much as it did to begin with before you moved the wheel out , this is what i would consider a change of rate at that wheel....

If you raise the ball joint 1" the spring will compress 1/2 that distance, since that crappy drawing I did has basically no camber gain the tire (blue or green) will still only move up that 1" regardless of which one you choose.

Now change the suspension so it has camber gain and you will see a difference.

[Austin34471]

If you raise the ball joint 1" the spring will compress 1/2 that distance, since that crappy drawing I did has basically no camber gain the tire (blue or green) will still only move up that 1" regardless of which one you choose.

Now change the suspension so it has camber gain and you will see a difference.

Billet is that Solidworks you are using for your 3d modeling?

[matchbox]

So if I move my mounting points out one inch. What does that do?

[fastford]

If you raise the ball joint 1" the spring will compress 1/2 that distance, since that crappy drawing I did has basically no camber gain the tire (blue or green) will still only move up that 1" regardless of which one you choose.

Now change the suspension so it has camber gain and you will see a difference.

so in your drawing , your saying if the ball joint travels up 1 inch , the blue tire is going to travel the same as the green tire? how can that be with it out 6 inches more than the other?

[billetbirdcage]

so in your drawing , your saying if the ball joint travels up 1 inch , the blue tire is going to travel the same as the green tire? how can that be with it out 6 inches more than the other?

The spindle never changes camber (snout will always be level as it is in the drawing), so it moves the same whether the tire is right at end of snout or 100 foot away from the snout.

*Note: This is with parallel and equal length control arms which a LM usually never has. I was only showing this because it shows what matt was saying with "no camber gain".

[fastford]

ok , i guess im not looking at it with both upper and lowers being identical in mounting points and length as with your drawing above.....

[Matt49]

Thank you billet for explaining what I was trying to explain so unsuccessfully.
As the old saying goes, a picture is worth a thousand words.

[Ghopper]

This tread got entertaining. More or less because it got heated in rhetoric. It is not good to be overly idealistic as the point can be lost and people mislead. I have been wrong many times because of simplifying the problem.

Wheel rate is vertical spring rate at the wheel center. All our current used suspensions have resulting camber components so it is a waste of time to not consider that. You guys can point physics fingers all you want at that....

A 1" wheel spacer on the RF of an XR1 will change the wheel rate ~10lbs/in. My example is with a linear 300lb/in primary spring. Wheel rate moves from ~103lb/in to ~94lb/in within the 3in of travel range. Tracking and steering influences will be easily noticed by the driver. I suggest you make this change only on a test track so you can back to back the resulting observation.

[billetbirdcage]

This tread got entertaining. More or less because it got heated in rhetoric. It is not good to be overly idealistic as the point can be lost and people mislead. I have been wrong many times because of simplifying the problem.

Wheel rate is vertical spring rate at the wheel center. All our current used suspensions have resulting camber components so it is a waste of time to not consider that. You guys can point physics fingers all you want at that....

A 1" wheel spacer on the RF of an XR1 will change the wheel rate ~10lbs/in. My example is with a linear 300lb/in primary spring. Wheel rate moves from ~103lb/in to ~94lb/in within the 3in of travel range. Tracking and steering influences will be easily noticed by the driver. I suggest you make this change only on a test track so you can back to back the resulting observation.

Long time no see, nerd! (grins)

Good to see you have a little time to race now and then, hope is all good.

[Matt49]

Nice CAD work ghopper. I've been working on simulating some front end stuff in Fusion 360 but have been encountering some challenges that may simply be finding the limits of what it can do. What did you use for this?

[fastford]

dont know about the " heated rhetoric " thing , if you do not question things , then you may never know if your right or wrong. I have gained a lot of knowledge from you guy,s and I appreciate it......what Ghopper has explained is what I was trying to say concerning wheel rate , just did not know how....

[Ghopper]

Nice CAD work ghopper. I've been working on simulating some front end stuff in Fusion 360 but have been encountering some challenges that may simply be finding the limits of what it can do. What did you use for this?

Siemens PLM Software's Simcenter 3D Motion. It is based on an NX CAD platform. I drew out some cars to get practice after being based in Dassault Catia V5 for a long time. Lots of holiday time with the wife sarcastically asking if I was drawing her pictures.

https://www.plm.automation.siemens.com/global/en/products/simcenter/simcenter-3d.html

Billet - It can be years between looking at this site. I should be at a race track a few times this year. Will probably be rusty as ever behind the wheel.

[Mr.Kennedy777]

This tread got entertaining. More or less because it got heated in rhetoric. It is not good to be overly idealistic as the point can be lost and people mislead. I have been wrong many times because of simplifying the problem.Wheel rate is vertical spring rate at the wheel center. All our current used suspensions have resulting camber components so it is a waste of time to not consider that. You guys can point physics fingers all you want at that....A 1" wheel spacer on the RF of an XR1 will change the wheel rate ~10lbs/in. My example is with a linear 300lb/in primary spring. Wheel rate moves from ~103lb/in to ~94lb/in within the 3in of travel range. Tracking and steering influences will be easily noticed by the driver. I suggest you make this change only on a test track so you can back to back the resulting observation.

That’s beautiful man. Lol. I’ve been using performance trends to map out the front, a little pre historic compared to that nice cad work, but it does tell a guy the same stuff. It’s nice they finally added a pitch setting and improved the four link aspect of their system a bit. Still do all the four bar and birdcage stuff on paper with separate drawings and then kinda mix it all together that way, so I’m always dealing with a certain amount of error based on scaling from iso paper to actual size. Need to invest in some new software lol.

[fastford]

dam , i may as well give up with my old school technology , i use strings and chalk and plum bobs , and a 4 ft by 8 ft white slick bathroom wall board to scale my front end out on , oh well........

[Matt49]

I agree, fastford. Some of this stuff is very difficult to explain through words alone. I think we all just get frustrated trying to get technical thoughts out in plain English. There is a reason why all college-level physics classes typically have a lab class married to them. It takes really doing it to understand sometimes.
Pretty much all of the regular posters on here have contributed quite a bit of valuable information over the years. Obviously not many of us are pros at this but this is FREE information and there a great many people out there that use it to help their racing program. And I learn stuff on here all the time.