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Discussion Starter #1
Does anyone know if cutting down and re-threading your shifter in the B-14 sentra is an option in creating a short shift? will this be just as good as purchasing a short shifter?
 
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Discussion Starter #5
woooooooo there hold on just one sec. Cutting down your shifter does not make it shorter in throw. If you just want a shorter lever just bust out the hack saw and then go buy a real nice momo universal knob that does not go on buy threads... If you want a real short throw spend the bucks and get yourself a B&M short throw.... If you want to get into who makes the best one use the damn search button... Every week i think we have this discussion on this board.......... Buy the way the the B&M short throw is a little shorter than stock....
 
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Yes it does!

Think of it in the extreme, cut the shaft so it only sticks out 1" above the pivot ball.

You telling me that the throw will still be the same distance?

You can prove this to yourself. Instead of shifting by grabbing the shift knob, grab the shifter halfway up.

Yes, this comes up ALL the time. Why buy something when you can mod your own for FREE by moving and pinning the pivot ball and if you desire also cut the shaft shorter.
 
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Yes but you still have the same amount of distance to travel on the fulcrom point.... If you did that to a REAL short throw it would be impossible to shift it because the axis along the fulcrum point would to short........ There Is more to a short shifter then fooling your mind into thinking your getting a shorter thow........
 

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Well if you decide to get a short shifter, we've got a group by goin on!!:D Check my sig.
 
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Discussion Starter #10
ok gents... this isnt a difficult concept if you cut the shaft it does not lessen your throw it is basic geometry with e leaver... the part of the shifter that makes for a shorter throw is the throat... or rather the part under the ball... that mounts... if you want a shorter throw the ghetto way cut that.. then you will have a shorter throw.. most of the time if you ge a short throw shifter the accual top part of the shifter is not shortented however its the throat...
 
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Discussion Starter #11 (Edited)
200sx se-r-t said:
ok gents... this isnt a difficult concept if you cut the shaft it does not lessen your throw it is basic geometry with e leaver... the part of the shifter that makes for a shorter throw is the throat...
Oh geeze, if you're going to use the line "it isn't a difficult concept" at least get it right guys, this is not hard but yes you are all screwing it up.


The end of the rod BELOW the ball will ALWAYS travel the same distance because the throw your shift forks and rods in your transmissions move will never change. Agreed?

So, how you make the end of the rod ABOVE the ball move a shorter distance and have the end of the rod BELOW the ball move the same distance is either by
1- increasing the length of the rod that is BELOW the ball or
2- shortening the length of the rod ABOVE the ball or
doing both #1 and #2.

You can move the pivot ball higher (shortens rod above ball and lengthens it below.)

You can cut the rod ABOVE the ball

You can cut the rod below the ball and weld in an extension.

Most aftermarket short shifters extend the rod below the ball to retain the stock height of the shift knob. My 1991 the shift knob is way too tall stock. I cut out 1/2" of the shaft above the ball (removed below the threads to retain the stock knob - re-tig'd), and then relocated the stock pivot ball 1/2" higher and pinned it.

Ended up with a really short throws AND a shorter shift knob in height too . ( a whopping 1" shorter in height)




Can't do word problems? How about some math.

L1 = length above fulcrum
D1 = distance end above fulcrum moves

L2 = length below fulcrum
D2 = distance end below the fulcrum moves (which is a constant in this case because of the tranny shift rod /forks.)

equation for lever arms about a pivot is
L1/L2 = D1/D2
Again D2 is a constant because of the tranny.


Solving for D1, you get D1 = (D2*L1)/L2

So if L2 remains constant (you don't change the length below the ball) and if L1 decreases (you cut the shaft above the ball) then D1 decreases.
 

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You're both right in your own ways....

The distance your hand will travel will decrease as you cut down the shifter. So, if that is what you consider a shorter throw, you are correct. You are physically moving your hand a shorter distance. If you need proof of this, simply use your imagination and lengthen the shifter by 10 feet. The distance of the "throw" would be rather large. ;)

However... cutting down the shifter will not change the angles involved. Only the lenght of the shaft. So if you consider a shorter throw to be a reduction in the angle of the shifter... you are also correct. Cutting the shifter down will not produce a different angle only a reduction in travel.

The only way to do both is to move the pivot point which is what good aftermarket shifters will do for you. This allows you to not only have a shorter "throw" but also a reduced angle allowing you to use less force than would otherwise be needed.
 

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Just to clarify... an aftermarket shifter does both. It reduces the "throw" by moving the pivot point higher on the rod. It also reduces the over all length of the rod. So it does both.

By moving the pivot point it is able to offset (somewhat) the increase in force required to move the shift rod through it's range of motion. This allows the overall length of the rod to be shorter without a significant increase in force.

;)
 
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