Shifters

[eronbo]

I have a 1967 911S that I am vintage racing. I have the factory shifter and am seeing WEVO and have read about RennShift. Does someone have experience with either and an opinion on the best? Are there others?

[hesaputz]

The options are;

Factory shifter
Factory shortshifter
Rennshift
Wevo
Fabcar
Stock shifter modified with Seine gateshift

The Wevo and Rennshift have less play, but also less of the synchro feel in a stock shifter. If you like and are used to the way a 911 shifts and feels, use a factory shortshift with a new tunnel bushing and a good coupler like Stomski or Wevo (or Ed's from the Pelican forum). If you like a more conventional, other car feel to your shifter, use the Wevo, Rennshift, or Fabcar - they're more positive, and have a strong centering action that helps prevent the dreaded 5-2 downshift.. The Seine kit is a good comprimise - uses the Porsche shift housing with modifications to give you a reverse lockout, plus a stronger centering in the 3-4 plane.
Don't bother with the Weltmeister slickshift.
I'm giving you the conventional options for the 915 - if you're running a 901, most of it still applies.
BTW - I have a new Rennshift for sale if you get interested - from an aborted racecar project.

[smedley]

Keep in mind the mechanical aspects of a "short shifter." all of them function by changing the fulcrum and relative length of the levers on either side of the pivot point of the lever. A shorter throw is an advantage in racing situations, but there are two trade offs for a shorter throw. First of all the shorter throw requires signifigantly more physical effort. So keep that in mind...more effort may not be "quicker" for your arm/hand strength. Secondly, the mechanical advantage change of the short shifter puts an additional load on the synchos with accelerated wear. If you are a big budget racing effort the gearbox would be torn down every race for inspection/service or ratio changes for the next race. So, wearing out the synchos is no big deal. However, if you are the typical vintage club racer on your own budget, R&R-ing the gearbox every couple of races becomes a pain!

Try doing fresh factory tunnel bushings and either the Stomski or WEVO rear connector first...this alone makes the shift action more precise, eliminating the "stiring a bowl of oatmeal" feel.

All of this applies to 901 or 915, although things are more robust in a 915. 901 synchros do NOT like short shifters. If you go with short shifter double clutch going up and down..things will live longer.

[JohnT]

Having been through this with a 901 (well technically a 902 box) my experience is this.

First the motor and transmission mounts must be good and tight. Whatever that is done to shift linkage and couplers won't really help as long as the engine and transmission are rotating on the mounts each time one steps on the clutch. I began with solid mounts (which shook every fastener in the car loose - but then the 4 cylinder does have more vibrations than the 6) and eventually changed to Hayden's (Wevo) semi solid mounts to control the engine/trans movement (the Blue pillows worked fine for me).

Once the engine/trans are properly mounted and controlled I'd change the shift coupler. I believe these are all equal. If the price hurts too badly, you can buy a coupler from Aircraft Spruce and rework the ends to fit your Porsche.

http://www.aircraftspruce.com/catalo...es/ujoints.php

Now the shift selection should be under control and one can decide on the pattern & feel one wishes. 901 factory short shifters are like hen's teeth. I've been looking off and on for 10 years and have never seen one. I use the Wevo 901 short shifter which uses a 915 base and like it a lot. If your sanctioning body is strict, they may frown on this because of the newer 915 base. I simply cover it up with a 915 rubber boot so as not to call attention to it. I've seen several of Sherwood's (Seine Systems) gated shifters and the people I've talked to like them. I have no experience with the Rennshift solution and I certainly agree with hesaputz about the Weltmaster.

good luck with your project

johnt

[eronbo]

Thanks for the prompt replies and the information. I loved the "stirring a bowl of oatmeal" line. I have found that, when shifting from 4th to 3rd, sometimes 3rd is elusive and can't be located.

[edmayo]

I don't think you have ever driven a properly bushed and adjusted 901 shifter, too bad you don't live a little closer than 2,000miles, you could come drive my 71. Every gear is right where it's supposed to be with no guess work. Like the previous posts have indicated there are drawbacks to "short shifters" The synchros can only work just so fast, doesn't matter how fast you move the lever.

[kissov356]

I have a 915 trans in my 70T with the Wevo shifter and I cannot say that its any "better" than the stock. I've also tried the aftermarket couplers and have always gone back to stock.

[hesaputz]

Yeah - I have to agree with Ed. Aftermarket units have their strengths, but I grew up driving 911's; I like the way they shift when set up properly - especially the 901. The leverage and gating of the stock unit is well- harmonized with the forces and speed required to shift balk rings smoothly, and to feel the synchros engage as you shift; they encourage the 'tick tock' shifting rythm thats so much a part of the 911 experience.

[lexatola]

I just returned my 1970 901 back to the stock shifter with the wevo coupler and boy what an improvement from the short shift setup that was in there. 100% more pleasant experience.

Best,

Alex