My Short Shift Plate

Those of you looking to shorten shift throw without cutting into anything stock, or adding a midget short shifter, I got a plan.

Following on the obscenely expensive Jazzy shift plate, hovering around $105 for a cut out of aluminum with some holes punched in it, I decided to make my own. I've even improved on the idea by incorporating a shift throw length adjustment! (we'll see how that works)

I'm making it out of old 1/4 steel plate, because I have some scraps and, here's the kicker: After my production run of...one... is concluded and I have determined success or failure, I'll provide dimensions and specs to anyone who wants them, free.

How this works is the old fulcrum crap you learned in Grade school. If you shorten the distance between the pivot point and the end of the lever, you shorten the throw, at the expense of added effort. Any short shifter is using the same principle, as is the Jazzy plate.

Technology involved for me? A 4-1/2 inch grinder with a cut-off wheel, a drill press, a vise, a few drill bits and a tap but, at a pinch, a hand drill and a hacksaw is all you really need.

I'm not looking for another business opportunity, I got plenty to do but, I can't stand seeing people get bent over for something so stupid easy to make.
 
Those of you looking to shorten shift throw without cutting into anything stock, or adding a midget short shifter, I got a plan.

Following on the obscenely expensive Jazzy shift plate, hovering around $105 for a cut out of aluminum with some holes punched in it, I decided to make my own. I've even improved on the idea by incorporating a shift throw length adjustment! (we'll see how that works)

I'm making it out of old 1/4 steel plate, because I have some scraps and, here's the kicker: After my production run of...one... is concluded and I have determined success or failure, I'll provide dimensions and specs to anyone who wants them, free.

How this works is the old fulcrum crap you learned in Grade school. If you shorten the distance between the pivot point and the end of the lever, you shorten the throw, at the expense of added effort. Any short shifter is using the same principle, as is the Jazzy plate.

Technology involved for me? A 4-1/2 inch grinder with a cut-off wheel, a drill press, a vise, a few drill bits and a tap but, at a pinch, a hand drill and a hacksaw is all you really need.

I'm not looking for another business opportunity, I got plenty to do but, I can't stand seeing people get bent over for something so stupid easy to make.
(headbang)(popcorn)
 
Woot! Was going to do it with the extra tow plate material that I have but its a bit too thin. Can't wait for the info and pics!
 
Massive success! I took home the tap set from my shop but, otherwise I made this thing using a hand drill and a bench vise, just like you might. I wanted to prove you don't need a machinist's workshop to manage this.

Shift throws are...2.5 inches!, down from the 5+ the stock thing did. That's Miata close...with a stock height shifter.

Videos of before and after:

Gargantuan, flobbery shift throws: http://www.youtube.com/watch?v=nyewmWgHcIM

microscopic new shift throws: http://www.youtube.com/watch?v=jTHo2vIaF_U

The adjustable idea went by the wayside, as the distance between the new and old locations was about a CM and you can only drill and tap so many holes in that space.

This transforms the car totally. Shifts are rock-solid and direct...at least as much as the cable shift will allow. I think it's worth a tenth at the track, from not having to throw the knob into the back seat on 1-2 and 3-4. Efforts are minimally increased but, the shift action was too soft and girly to begin with.
 

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I took a rubbing of the finished plate top and bottom. Tomorrow, I'll get my caliper, etc. out and start measuring things up, plus adding instructions.
 
I have drawn up a plan in Google Sketchup. If you don't have it, you can download it for free from Google. Just type in "Sketchup download" and you'll get there. Shoot me an email addy by PM as 247 doesn't allow .skp files to be attached. File is 21Kb so, should be ok for regular email, I think. I sent it to myself as a check and it's ok. This plate alters nothing in stock hardware and can be removed in minutes.

Instructions/recommendations:

Cut a 2" by 3-3/4" piece of 1/4" plate steel. Drill the holes as the plan indicates. I tapped the hole for the ball stud using a 17/64" tap drill and a 5/16" NC tap. You could just drill it a little bigger and nut it from the bottom if you don't have and tap and die set.

The ball stud can be sourced at an RV parts place. They use these 10mm ball studs as mounts for hydraulic hatch struts.

The placement of the ball stud can be moved around a bit to alter the centre point of the shifter. I placed it just so when the shifter in going into second, fourth and sixth it's just a little past vertical. If you want more rearward centre point, move the ball stud a touch forward (toward front of car) of my location. A little means ALOT here.

The relief hole in the middle of the plate gives room for the stock ball stud and helps locate the shift plate. Don't drill all the way through here, just til you reach the flutes of the drill bit. The stock ball stud will sit in that recess and locate the shift plate more securely.

You can use stock bolts to mount this, either with the weight on or nuts to replace but, they are a touch short. I'd recommend getting some longer ones to account for the thickness of the shift plate.

I have set up this plate to move the cable as far to the driver's side as possible without fouling the other cable or wearing away the rubber sheath on this one.

Bracket holes are 21/64ths to start and open to 11/32 if tight. Relief depression is made with a 3/8ths drill. Ball stud hole as indicated above.

You're going to have to pull the airbox...if anyone still has one...to do this but, with a CAI, I didn't even have to take that off. Just be careful not to ding your nice aluminium CAI pipes with your steel tools.

That's all I can think of now.
 
A little update:

In the interests of shortening the the throw as much as I could, I put the ball stud hole as far from the mounts as possible. I see that in the back gears, the ball end very slightly touches the other shift lever. Nothing untoward happens but, if you want that contact eliminated, best move the ball stud hole in another 1/16" or 1/8", at the expense of a bit more shift throw over mine.
 
In Jazzy's defense $85 is not much to ask. This is not as easy to make as it looks.
I designed mine in Auto-CAD and cut 15 out on a wetjet. Reduced the throw by 35 - 40%.
I also made a new weight to replace the factory shifter weight.
This is the way the car should have shifted from the factory.
It's really nice now.
It was like driving a slot machine before.
IMG_6574.jpg
 
Supposed to email him for it and he will send the google sketchup file for it.

I have it and will turn it into a template for download once I get some dimensions straightened out. I will look at the stock piece tonight and take some measurements too.
 
It is nice having machine tools at work

This is a nicer way of doing the mod rotus came up with!

reversable and adjustable. and if you don't like where the shifter sits or feels, just drill up another plate

what kind of shop you guys work at?

I did a little of everything back when I made chips for a living
 
Small typo on the templates already sent out. There is one hole marked 1/2 X 1-15/16ths. It should 1-5/16ths.

It actually is just as easy as it looks. Cripes, I made mine at home with a bench vise, a hacksaw and a drill. I didn't even use the shop tools for this one.
 
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Another little point. Due to the closeness of the ball stud hole to the adge, I didn't measure centre on that one like I did the others. Just drill it so the edge of the hole is at least an 1/8th" from the edge of the plate.
 

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