Another question from a newbie

[Matt49]

Earlier where I said, "The measurement for motion ratio is from the lower ball joint to the inner pickup of the LCA divided by the lower shock/spring mount to the inner pickup of the LCA." That is backwards.
It is the distance from shock mount to inside of LCA divided by the distance from ball joint to inside of LCA.

[TLM4t4]

I've always noticed more of a difference on exit by adding the spacer than entry. Everyone told me it only tightens entry but from sitting in the seat I've felt more of a difference on exit. Now with that being said I'm confused as crap! What is it changing besides tracking, is it gaining leverage from LR?

[Matt49]

I've always noticed more of a difference on exit by adding the spacer than entry. Everyone told me it only tightens entry but from sitting in the seat I've felt more of a difference on exit. Now with that being said I'm confused as crap! What is it changing besides tracking, is it gaining leverage from LR?

Scrub radius. Moving the wheel out further from the spindle increases scrub radius.
Assuming you have some caster in the RF (which you should), more scrub radius increases the weight jacking effect of the the RF wheel. When you steer to the right, the RF tire is being pushed down into the ground which loads the LR which tightens on throttle handling coming off the corners.
If you really want to see caster and scrub radius at work, find somebody that races go karts. With the wheel turned hard to the right, the LF and RR weight virtually nothing.

[drtrkr244]

I've always noticed more of a difference on exit by adding the spacer than entry. Everyone told me it only tightens entry but from sitting in the seat I've felt more of a difference on exit. Now with that being said I'm confused as crap! What is it changing besides tracking, is it gaining leverage from LR?

My drivers have told me the same thing. After entering the new measurements on my front end software, adding the spacer has moved the roll center slightly higher and to the right, which would stiffen up the rf suspension somewhat. Just like Matt said, also, when back steering to the right, you are loading the lr more. This is why setting the caster is so important on these cars, plus you can use it to fine tune your setups. Just remember steering to the left, loads the lf and rr more also.

[TLM4t4]

May I ask drtrkr244, what software are you using? I know by adding the spacer to my car I either drop spring rate on RF, or open lock out nut up on my stack if not it would not get the amount of travel I want. Thanks for simplifying it Matt49!

[drtrkr244]

Bob Bolles. That makes good sense to soften spring some.

[jrkracing54]

Has anyone ever put a 1" spacer on the right front as well as one on the left rear for extreme slick conditions? Seems like it might be a huge adjustment but both have positive effects. John 1*

[BigNilla]

I want to thank each of you for your responses and additional questionsreally gives me stuff to think about

[MasterSbilt_Racer]

Has anyone ever put a 1" spacer on the right front as well as one on the left rear for extreme slick conditions? Seems like it might be a huge adjustment but both have positive effects. John 1*

I have put 2" at both locations in the leaf spring days. I have seen plenty of cars with 1" at both locations in the past couple of years. They may be there all the time and not an adjustment though.

[hucktyson]

Every newer rocket car I see always has a 1" spacer on the LR. Why don't they just run an inch longer axel tube ?

[tin man]

Keith Masters brought up an interesting point last week at the MBH chassis seminar with regards to suspension software. He said that most software packages on the market are written using symmetrical front ends. Very few, if any racecars on the market now a days use equal length suspensions.

[hpmaster]

Keith Masters brought up an interesting point last week at the MBH chassis seminar with regards to suspension software. He said that most software packages on the market are written using asymmetrical front ends. Very few, if any racecars on the market now a days use equal length suspensions.

I think you may be confusing asymmetrical and symmetrical. Symmetrical are the same on both sides, asymmetrical are different from side to side.JMHO

sym·met·ri·cal
səˈmetrik(ə)l/
adjective
made up of exactly similar parts facing each other or around an axis; showing symmetry.
synonyms: evenly shaped, aligned, equal; More

a·sym·met·ri·cal
ˌāsəˈmetrək(ə)l/
adjective
having parts that fail to correspond to one another in shape, size, or arrangement; lacking symmetry.
"the church has an asymmetrical plan with an aisle only on one side"
synonyms: lopsided, unsymmetrical, uneven, unbalanced, crooked, awry, askew, skew, misaligned; More
having parts or aspects that are not equal or equivalent; unequal in some respect.

[tin man]

You are correct. I stand corrected.

[jrkracing54]

Every newer rocket car I see always has a 1" spacer on the LR. Why don't they just run an inch longer axel tube ?

Yes you are right about that Huck. I was told they shortened that axel tube and put the spacer on but not quite sure why. I guess it must be there so they can take it off when the track is very heavy to help loosen the car. I have an older Rocket with the standard length. John 1*

[TALON75]

I know Rocket started running that rearend when they were doing the orange front cars, just not sure why they stick with it, almost everyone seems to run with the spacer.