HOW TO: Modify a factory S4 or S5 shifter to a Short Throw
 

I know the engineers will chime in and say this is not a 'real' or 'proper' short throw shifter, because it doesn't change the relationship between the ball and the shift change rod in the tranny. My reply (and many others') is this: This how to produces a cheap, well functioning shifter with shorter throws (about 40%), no rattles, and shift force is no more than about 40% more, not 'double' (100% increase), as some say.

The pictures tell the whole story...I didn't do some of the work, since I have access to a metal shop with very qualified people and machinery (i.e. for the initial cut, the hole and tapping)...but you can do this with a few hand and electrical tools. If you need me to tell you what to use, you probably want some help with this (honest advice).

Disclaimer: If you end up with missing appendages or no shifter on the car, don't blame me, do at your own risk, educational purposes only, blah, blah, blah.

See this if you're wondering what thread size (tap) your factory shifter is. Use another tap for shifters with other threads (duh!):

https://www.rx7club.com/2nd-gen-archive-72/master-list-thread-sizes-2nd-gen-nuts-bolts-367392/ (search if this link ever goes down)

On to the pictures:

http://s218.photobucket.com/albums/c...er%20How%20To/

I think you should re-title it to "HOW TO: Cut a factory S4 or S5 Shifter" so people don't get confused, since, the throw remains the same as before, it's just the shifter length that has changed.

:werd:
Not to mention the heat transfer, the rattles, the bearing feel on the shifter, and if you drop the top of the shifter to exactely 1/2 of the original hieght from the pivot the force required will be exactely 100% more. There is no escaping physics in this world - sorry. How do I know all of this? I was a poor HS kid with more time than money ~ 11 years ago too ;)

A+ for effort and documentation though. Some people I'm sure will do it and love it. I was glad I had 2 shifters.

i did somthing very simular but heated it with a torch and the top finally pops off. no cutting. then grind off the black sealant crap then just grind down the top an inch of so..basically the same results without cutting

Oh god, here we go again...and I started it this time... :)

Roen: Define "throw" please. Is it not the relative change in position of the shift knob? A short throw shifter changes the shift throw by angle by changing geometry, a shortened shifter changes the throw because it's closer to the pivot point.

TitaniumTT: The car is stored for the winter, so I can't test it for now. I'll buy some of your arguments regarding bearing feel and some heat transfer. As far as rattling, I don't see how the insulating rubber would prevent rattles. I thought rattles were transmission dependent, and only affected aftermarket shifters (some). The rest is unchanged. Also, the distance from pivot to shifter knob only changed about a third, and therefore the force isn't up 100% (which is accurate if shortening the length to pivot to half).

Because you didn't change anything but the length of the shifter after the fulcrum point. If you move that fulcrum point, then you change the throw. I have done both and a 'short' shifter is worthless and actually requires more effort. The short 'throw' shifter I have now is 100 times easier to shift with and requires less movement to achieve the same action.

Duh.

hmm...someone beat me to my response.

What he saod.

I wonder if you guys are just skimming over posts...

Djmtsu - so you're saying the throw is the same, but the force required changed? Something's wrong with your physics. Remember, M = F x d; in this case, F went up, d went down. Shift throw is the relative displacement of the shifter between neutral and the gears.

I'm not saying modifying the shifter this way is equivalent. I'm just saying it will shorten shift throw by sacrificing some additional force.

Unless you're looking at shift throw in terms of angle, which this doesn't change, but it's the movement of the shifter knob that matters.

I see what you're saying, by changing the whole length of the gear shift, you decrease the distance traveled. I think that some people (myself included), don't equate that to shifter throw.

Actually, you're not wrong.

"Levers" are defined by X length versus Y length in relation to the pivot point.
You are, technically, changing the length on one side.

Moving the pivot point changes both the throw and the force.


-Ted

http://i11.photobucket.com/albums/a1...ce/shifter.gif
Quick example representing 40% reduction in throw. On the left shows how throw distance changes by shortening the stick, on the right shows how it changes by raising the pivot point as "true" short shifters do. Throw at the bottom needs to remain the same since you can't make any changes to the actual linkage throw.

Fake but correctly proportioned numbers because I don't care to go remove my shifter and buy a short throw to make a completely accurate representation for a forum post, and I represented straight measurements because I don't feel like doing the math for a curve when they're going to be pretty much the same anyway. It's basic math people.

The only reason the "true" short shifter feels better is because the angle of the knob rotates less as you throw it (distance travelled by the top of the knob vs bottom of the knob), so effort is directed in a straighter line to move the knob.