Short shift preference

[SCforme]

Looking to install a short shift kit on my '84 911. Any experience / preference with Rennshift sport shift or Wevo classic shifter? Thanks.

[freeform911]

I had the wevo..nice piece BUT a pain in butt to dial in..I gave up after 3+ years and installed a factory ss with a robotec.. Love the way it shifts now...and cheaper then both your options..not as pretty though..

[JJ 911SC]

I got the factory SS from Porsche, added the Seine System Gate Shift kit and the Stomski Shift Coupler.

Love it. Just about $525 and free shipping...

http://www.pelicanparts.com/cgi-bin/ksearch/pel_search_2016.cgi?command=DWsearch&make=POR&description=911-424-931-00-M260

http://www.pelicanparts.com/cgi-bin/ksearch/pel_search_2016.cgi?command=DWsearch&description=seine+gate

http://www.pelicanparts.com/cgi-bin/ksearch/pel_search_2016.cgi?command=DWsearch&make=POR&description=stomski+shift+coupler

[Trackrash]

I'm using a factory short shifter. I think from an '86. Not the kit, but the actual shifter. With a Seine gate kit it is the way to go IMO.

[cabmandone]

I'm running the same thing JJ and Trackrash are running. I thin my brother has the Wevo in his car. I have driven both and for the money like the factory short shifter with the Seine gate kit.

[Walt Fricke]

Me 4. If you also use tight round bushings in the shifter coupler toward the rear of the car, you'll wonder why Porsche didn't do all of this on its own long ago.
Lots of people like the Rennshift, and others the WEVO, but I don't see any real advantage for those other than a lighter wallet.

[merlinfe]

I picked up a Seine Systems setup a few years ago. Took the shifter completely apart and "blueprinted it" fancy way of saying I cleaned it, sanded a few bits, and put it all back together. When I installed the SS mechanism I also installed a slightly longer bolt to keep the tension exactly in the middle of neutral plain when not in gear. I then rebuilt the shift coupler with regular ebay bushings that I modified a bit to fit tight, and replaced all the bushing in the shift tunnel.

Zero slop. Love it.

Some may argue the 915 needs a little slop to work properly, but in the years since I did all this it's been fine.

I've driven many many stick shift cars and this one is now near the top. I get compliments from other 915 owners regularly.

-Steve.

[SCforme]

Thanks everyone. Great info.

[Trackrash]

Forgot to mention that I installed solid aluminum bushings in my coupler. IMO an improvement over the loose factory plastic ones.

[Arne2]

I'll be the naysayer. I had the factory SS in mine, also with Seine and delrin bushings. I was never happy with it until I removed the SS and went back to stock. There really isn't that much difference in travel, and the shift quality is much better with just the Seine and bushings, at least on my car. YMMV, of course.

[Walt Fricke]

Arne - that's not saying much nay, really. Short shifters are really a track modification, and may not be a very valuable one, because the synchro system pretty much limits sensible shifting speed (unless you keep rotating transmissions into and out of a transmission rebuild shop).

When you look at speed data from track driving, you can see where the driver is shifting up because the speed actually drops a little during the time the clutch is disengaged. Minimizing that time when there is no power to the wheels, and aero is slowing the car, is pretty useful there. But silly in daily or spirited highway driving - anyone care about a tenth of a second per upshift extra there?

Spring loading the shifter in the 3/4 plane is what removes much of the trouble and vagueness from these transmissions, and round bushings in back gets rid of the slop.

While I've never found much not to like about the factory short shifter, I can see how a person might see no improvement with one.

The things to avoid are the short shifters which just make the part below the shifter pivot longer. That narrows the side to side as well as the fore and aft, and you want the stock side to side separation to aid muscle memory. The factory SS changes one pivot point but not the side to side pivot.

[Discseven]

Would cutting then extending existing (stock) shifter rod between pivot and ball create short shift... or's there more to it? If this works, how much should be added? (Seems rod bushing bracket #24 would be lowered same measure as addition.)

[cabmandone]

I guess like Gordon I should mention that I have brass bushings in my shift coupler.

[Bill Verburg]

Originally Posted by Discseven

Would cutting then extending existing (stock) shifter rod between pivot and ball create short shift... or's there more to it? If this works, how much should be added? (Seems rod bushing bracket #24 would be lowered same measure as addition.)

Short shifters were extensively analyzed bu Russ Dickerson and Bob Gagnon back in 1987, The full articlces canbe found in Panorame 5/87 & 2/88
Here's a suynopsis of their work

The ratio of R2 to R1 is the same as the ratio S2 to S1


thru '84
R1 42mm R2 292mm
factory semi short shifter became standard in 1985
R1 46mm R2 288mm
Factory short shift, option M241
R154mm 280mm

amount throw is shortened
FSemiS 10%
FSS 20%

[Discseven]

^^^ Thanks for both top and bottom measures Bill.

...As shift lever is moved side-to-side, am wondering what happens to shaft #33 at the bushing #24-25? Seems shaft would be moving laterally slightly yet the bushing does not allow for that. I'm seeing something wrong here... what am I missing?

[Walt Fricke]

What you are missing is the movement of the white nylon (if stock) cup receptacle which inserts into the metal ball cup holder (sort of L shaped piece). When the shift lever is moved side to side, the plastic holder part moves up and down in the steel receptacle.

The inexpensive commercial kits which do basically what you are thinking of consist of a longer steel end piece, which replaces the stock one. The stock end piece is held to the shift lever by glue - heat things and you can pull off the old. Glue the aftermarket piece on. Then add the spacer which goes under the whole tower to lift it up so the long shaft and its bushing are still lined up as they need to be. May or may not require some longer bolts.

Cutting and welding is going to require regluing, which doesn't work all that well (in fact, the factory glue job can fail - if you can twist the shift lever, it has). You can solve that by soldering or brazing or welding the shaft to the bottom piece, but be careful - a welder who tacked mine also burned a hole through the thin walled shift lever, which eventually broke off starting with that point.

The factory short shift is a far far better mousetrap for changing the throw, including the previously mentioned side to side unhelpful issue for these low buck short shifters. Not all that expensive.

[Discseven]

Originally Posted by Walt Fricke

...When the shift lever is moved side to side, the plastic holder part moves up and down in the steel receptacle.

... so the shaft rotates rather than moving laterally.

Thanks Walt.

[Walt Fricke]

Yes - back in the transmission, for 1/2, and 3/4, there is a sort of short stubby analog of the shift lever. Moving the shift lever from the 1/2 position in neutral to the 3/4 position allows something called a dongle to position itself within an open notch in a shaft. Pushing the shift lever forward will move the shaft forward, which engages 1st. Back is 2d. If you move it to the 3/4 plane, same thing. When you move the shift lever all the way to the right, a finger attached to the shift shaft in the transmission (which is what the coupler connects the long shift tube from the shifter to), is positioned to drop into a slot in a shaft in the nose housing, and that shaft engages 5th or reverse.

So it is rotation of the shaft which decides which pair of gears you can engage. The shafts always remain in alignment, between the holder piece in front with its large plastic bushing, to the bushing in the nose of the transmission, which keeps the stuff inside the transmission in line.

[Bill Douglas]

I don't want to be a killjoy, but around here there are always a few second hand short shifts for sale

So I'm guessing it means not everyone who has installed one likes it. It would be nice to test drive a car with one. My thoughts are it's not the length of the throw but the slowness of the syncros.

[Walt Fricke]

As you might expect, my take would be that if the car is just street driven, add the Seine and the round hole bushings (I see Pelican sells the brass ones, but a clever fellow can make his own easily enough). Tightens things up a lot, and the synchro system (and your wallet) pretty much put a limit on how fast you can upshift anyway.

However, were I to convert my track car back to a street car, I'd leave my factory short shift and the Seine stuff there. It is what I am used to, and there is really no downside with the short shifter on the street - I drove it to work for years despite stiffer and stiffer suspension, and a roll cage and so on.