Short-shifter physics question. Confused...
#1
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Short-shifter physics question. Confused...
So I was thinking about short shifters, and I have a few questions. I will ask the questions in a certain order, because the early questions might negate the need to answer the later ones. Please help, if you can...
1. Is the distance between the pivot point on the shifter (the ball) and its mounting point in/on the transmission a FIXED DISTANCE?
2. Are the adjustable short shifters designed such that the pivot point moves up or down in some fashion? If so, how is this accomplished? And if the pivot point DOES move, how does that NOT change the distance between the pivot point and the mounting point in/on the transmission?
3. IF there is a fixed distance between the pivot point and the mounting point, and IF that distance cannot be changed, then HOW does a short shifter actually shorten the throw?
4. Does a short shifter not simply shorten the length of the lever (distance from the pivot point to the end of the lever [where the shift **** is located]) to accomplish a shortening the throw? Simply bending the lever to a different angle would accomplish nothing but to change the location of the lever, so where is the shortening of the throw being accomplished? This question is particularly aimed at fixed-throw shifters such as the B&M and the Courtesy parts shifter.
5. IF it is simply a shortening of the lever that is used to accomplish the shortening of the throw, why is a cut stock shifter not the same as an STS, except for finish and POSSIBLY a better pivot and bearing system to make things move more smoothly?
Sorry, all of this is confusing to me. I don't mean to be asking about what amounts to physics, but I am perplexed...
Words to aid in searching down the road: STS Short Throw Shifter Short-Throw
1. Is the distance between the pivot point on the shifter (the ball) and its mounting point in/on the transmission a FIXED DISTANCE?
2. Are the adjustable short shifters designed such that the pivot point moves up or down in some fashion? If so, how is this accomplished? And if the pivot point DOES move, how does that NOT change the distance between the pivot point and the mounting point in/on the transmission?
3. IF there is a fixed distance between the pivot point and the mounting point, and IF that distance cannot be changed, then HOW does a short shifter actually shorten the throw?
4. Does a short shifter not simply shorten the length of the lever (distance from the pivot point to the end of the lever [where the shift **** is located]) to accomplish a shortening the throw? Simply bending the lever to a different angle would accomplish nothing but to change the location of the lever, so where is the shortening of the throw being accomplished? This question is particularly aimed at fixed-throw shifters such as the B&M and the Courtesy parts shifter.
5. IF it is simply a shortening of the lever that is used to accomplish the shortening of the throw, why is a cut stock shifter not the same as an STS, except for finish and POSSIBLY a better pivot and bearing system to make things move more smoothly?
Sorry, all of this is confusing to me. I don't mean to be asking about what amounts to physics, but I am perplexed...
Words to aid in searching down the road: STS Short Throw Shifter Short-Throw
#3
after install my sts a few weeks ago, this is my take from it:
its not the relative distance from pivot ball upwards to the top of the shifter, that would not reduce "throw" because your still moving the same amt from pivot ball to the bottom where it connects to the shift linkage and then to the tranny
from what i've noticed on the stillen one is two things:
1. the distance from the pivot ball downwards to the end of the shifter where it connects to the shift linkage is shorter.
2. the stillen sts is a full sts with new bracket, metal pivot ball, etc. Its designed so moving x (pivot ball to top of shifter) reduces throw to y (pivot ball down towards shift linkage)
its not the relative distance from pivot ball upwards to the top of the shifter, that would not reduce "throw" because your still moving the same amt from pivot ball to the bottom where it connects to the shift linkage and then to the tranny
from what i've noticed on the stillen one is two things:
1. the distance from the pivot ball downwards to the end of the shifter where it connects to the shift linkage is shorter.
2. the stillen sts is a full sts with new bracket, metal pivot ball, etc. Its designed so moving x (pivot ball to top of shifter) reduces throw to y (pivot ball down towards shift linkage)
#4
Yes, the distance between the trans and the shifter is fixed. But, the angle of the rod that connects them isnt fixed since there are pivots at both ends.
But, that's not really relevant.
Short shifters shorten the throw by changing the length of the lever, that is the shifter itself. If you make the portion above the pivot shorter and the portion below the pivot longer, it requires fewer degrees of lever rotation to move the rod connected to the trans the required distance to change the gear. This equals shorter throw.
But, that's not really relevant.
Short shifters shorten the throw by changing the length of the lever, that is the shifter itself. If you make the portion above the pivot shorter and the portion below the pivot longer, it requires fewer degrees of lever rotation to move the rod connected to the trans the required distance to change the gear. This equals shorter throw.
#5
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Originally Posted by I30tMikeD
Just cut your stock one and same your self some thinking.
Does anyone have a pic of the stock shifter out of the car? What does the transmission mounting end look like? Is it a bearing?
#6
Originally Posted by phenryiv1
Does anyone have a pic of the stock shifter out of the car? What does the transmission mounting end look like? Is it a bearing?
The OEM shifter looks just like the pace setter STS, just the geometry is different and it's higher quality.
#7
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Originally Posted by Larrio
after install my sts a few weeks ago, this is my take from it:
its not the relative distance from pivot ball upwards to the top of the shifter, that would not reduce "throw" because your still moving the same amt from pivot ball to the bottom where it connects to the shift linkage and then to the tranny
from what i've noticed on the stillen one is two things:
1. the distance from the pivot ball downwards to the end of the shifter where it connects to the shift linkage is shorter.
2. the stillen sts is a full sts with new bracket, metal pivot ball, etc. Its designed so moving x (pivot ball to top of shifter) reduces throw to y (pivot ball down towards shift linkage)
its not the relative distance from pivot ball upwards to the top of the shifter, that would not reduce "throw" because your still moving the same amt from pivot ball to the bottom where it connects to the shift linkage and then to the tranny
from what i've noticed on the stillen one is two things:
1. the distance from the pivot ball downwards to the end of the shifter where it connects to the shift linkage is shorter.
2. the stillen sts is a full sts with new bracket, metal pivot ball, etc. Its designed so moving x (pivot ball to top of shifter) reduces throw to y (pivot ball down towards shift linkage)
So the Stillen, to accomplish its adjustment, moves the pivot point, right? (based on your point 1 and point 2 information) It gets shorter by relocating the pivot point to a spot determined not by stock parts, but by the new bracket, right?
#8
Originally Posted by phenryiv1
So the Stillen, to accomplish its adjustment, moves the pivot point, right? (based on your point 1 and point 2 information) It gets shorter by relocating the pivot point to a spot determined not by stock parts, but by the new bracket, right?
The levers that are adjustable allow the user to move the pivot point along the length of the shifter, thus altering both critical dimensions.
#9
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Originally Posted by mzmtg
Yes, the distance between the trans and the shifter is fixed. But, the angle of the rod that connects them isnt fixed since there are pivots at both ends.
But, that's not really relevant.
Short shifters shorten the throw by changing the length of the lever, that is the shifter itself. If you make the portion above the pivot shorter and the portion below the pivot longer, it requires fewer degrees of lever rotation to move the rod connected to the trans the required distance to change the gear. This equals shorter throw.
But, that's not really relevant.
Short shifters shorten the throw by changing the length of the lever, that is the shifter itself. If you make the portion above the pivot shorter and the portion below the pivot longer, it requires fewer degrees of lever rotation to move the rod connected to the trans the required distance to change the gear. This equals shorter throw.
Am I crazy? (<--Don't answer that part!)
(Edit: This ties into your response immedately above, as well.)
#10
Originally Posted by phenryiv1
Does lengthening the rod below the pivot point cause the problems that people have with stiff or notchy shifting, because the longer rod effectively "rubs" at the highest part of its arc between the gears? Meaning, the components are designed Xmm apart, and the stock rod is Xmm long. Now we have a rod that is (X+?)mm long trying to pass through a distance of Xmm, resulting in resistance.
Am I crazy? (<--Don't answer that part!)
(Edit: This ties into your response immedately above, as well.)
Am I crazy? (<--Don't answer that part!)
(Edit: This ties into your response immedately above, as well.)
#11
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Originally Posted by mzmtg
The very idea of doing the same work (moving the shift rod) with a shorter lever means that the effort is going to go up. It's like using a cheater bar on a ratchet. The longer the lever, the less force is required at the end of it to generate the required torque. Shorter lever, more effort. This higher effort can be percieved as effort (hard to push) and/or notchiness (pops into and out of gear more noticeably).
As a next logical step, would you say that my analysis about the lengthening of the rod creating some additional resistance might have some merit?
To that end, think about a see-saw. Longer lever on the input side requires less force to move the output side through its full range of motion. Shortening of the input side (what you just explained) increases the force needed to move the output side through its FROM. Now, if you keep the input side at its original length and lengthen the distance from pivot to the end on the output side, that increases the amount of force required on the input side to take the output through its FROM, right?
What a short shifter seems to do is shorten the input lever (increasing necessary force) AND lengthen output rod (also increasing necessary force) to create a sum effort that is much greater than that required in the initial configuration.
Compounding this (in my head, at least) is the additional resistance created due to the whole "Xmm rod through (X+?)mm distance" that I explained a few posts up.
(I am not really sure why this conversation fascinated me, but I have been thinking it over for months.)
#12
Originally Posted by phenryiv1
What a short shifter seems to do is shorten the input lever (increasing necessary force) AND lengthen output rod (also increasing necessary force) to create a sum effort that is much greater than that required in the initial configuration.
Compounding this (in my head, at least) is the additional resistance created due to the whole "Xmm rod through (X+?)mm distance" that I explained a few posts up.
(I am not really sure why this conversation fascinated me, but I have been thinking it over for months.)
Yeah, you've got it now.
#13
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Originally Posted by mzmtg
Yeah, you've got it now.
Am I correct?
#15
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Thanks, Ben. Nice to knwo that you care.
ONE LAST THING (seriously)- If I do cut my stock shifter, would it benefit me to replace those bushings- or anything else- to smooth things out? I have 110,000 miles. I know that synthetic fluid will help, but is there any maintainence or replacement that I should make at this point?
Should this post be distilled down to its basic concept and put in the FAQs for future information?
ONE LAST THING (seriously)- If I do cut my stock shifter, would it benefit me to replace those bushings- or anything else- to smooth things out? I have 110,000 miles. I know that synthetic fluid will help, but is there any maintainence or replacement that I should make at this point?
Should this post be distilled down to its basic concept and put in the FAQs for future information?
#16
the stock shifter has a plastic pivot ball and plastic bushing and bracket. The stillen replaces all of it with metal, hence ppl argue that its the only true sts out there. I don't experience the stiffness or vibrations caused by other sts' that I have driven on maximas.
there isn't a need to replace the bushing, its the plastic makeup of the stock parts that make it the way it is.
i'll try to PM you a pic of the stock sts when I took it out this weekend
there isn't a need to replace the bushing, its the plastic makeup of the stock parts that make it the way it is.
i'll try to PM you a pic of the stock sts when I took it out this weekend
#17
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Originally Posted by Larrio
the stock shifter has a plastic pivot ball and plastic bushing and bracket. The stillen replaces all of it with metal, hence ppl argue that its the only true sts out there. I don't experience the stiffness or vibrations caused by other sts' that I have driven on maximas.
there isn't a need to replace the bushing, its the plastic makeup of the stock parts that make it the way it is.
i'll try to PM you a pic of the stock sts when I took it out this weekend
there isn't a need to replace the bushing, its the plastic makeup of the stock parts that make it the way it is.
i'll try to PM you a pic of the stock sts when I took it out this weekend
Just email it there, please!
#18
#21
Cutting the stock shifter does shorten the shifts a bit, I cut mine 3" and there is a bit of a difference. Compared to my buddy with a STS his shifts seem to take half the time. You just nudge the shifter a bit and you're in or out of gear. There really is no comparison.
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