Modern day Porsche enthusiasm has seen a massive upturn as of late with a whole new generation of bright-eyed, mod-happy enthusiasts—many of which have come from the Honda, Nissan and Toyota realm—eager to start building a 911 of their own. In its wake, the rush of new interest has helped outfits like Sleepers Speed Shop develop new parts and clever work-arounds in an effort to improve the overall driving experience.
Located in Costa Mesa, Ca, the group prides themselves on offering a variety of performance-based services, high-end custom parts and even offers goods and apparel based around their motorsport appreciation. Recently, Sleepers took a long, hard look at the all-to-common complaint from 964/993 owners about the almost comical shift throw length that seems completely out of character for the sporty icon. You've seen countless short throw shifters used in feature and track cars in the pages of Super Street over the years, but in the case of the 964/993 and, more specifically, the C4 model, a short shift conversion involves cutting the car's undertray—an act that most would prefer to avoid entirely. The Sleepers crew dissected a few different factory and aftermarket shifters and developed an ingenious solution which makes a significant impact on shift throws and shifter rigidity and does so without any needed modifications to the car's cabin or underside.
To understand just how clever this system is, you first need to understand how a short shifter typically works. For years people assumed that the shorter the shaft, the shorter the throw. Fortunately, that incorrect train of thought went out the window when various manufacturers began offering their off-the-shelf extended shifters that sat higher in the cabin and lower under the car as compared to their factory counterparts yet provided a shortened throw from gear-to-gear.
In the case of the C4 model, the factory shift throw is exaggerated and often cursed by owners, but in order to achieve a shorter throw action via the longer shifter that's required, additional length that protrudes under the car means cutting and modifying the undertray in order to function properly.
The car's undertray runs parallel to the driveshaft and covers the bottom of the OEM shifter. A scrap piece of metal is used here to give you a look at just how close the bottom of the shifter is to the tray that's been removed. Even in stock form, Sleepers says they've seen many cars come through their doors that have scrapped and damaged undertrays due to the OEM shifter showing signs of aging and developing play that results in metal-to-metal contact.
The magic in the Sleepwalker kit revolves mainly around the OEM "clamshell" that fits around the driveshaft and helps guide the shift lever through to the shift linkage. Sleepers flipped the entire unit upside down, which maintains the factory depth on the bottom of the assembly as to clear the undertray, while also increasing the length from the pivot to the shift linkage, giving the driver a true short shift action without the need to cut up their undertray.
The dual hole option allows the owner to opt for a 30 or approximately 40% reduction in throw, depending on their preference.
To get started, the crew removed the front undertray, pulled back the shift linkage rubber dust boot and released the four retaining screws that hold the factory clamshell together in order to allow the entire assembly to be pulled out from inside the cabin.
Inside, the center console that runs between the seats is removed and in the case of this 964, the shift knob's retaining screws are loosened to allow removal.
During the process of removal, the clamshell was unbolted from the bottom, but as mentioned above, the Sleepers version flips it upside down in order to gain some crucial space for the new pivot point. The screws are loaded from the top this time and secured.
The Sleepers shift forks are then fed from the top and carefully snake around the driveshaft and into position. The OEM-style or threaded billet shaft is then attached using a pair of bolts that are supplied in the kit.
The left and right sides of the 3-piece lower shift lever slide over the tabs on each side of the clamshell and are secured with press clips before the lower piece is bolted into place using the supplied hardware laced with Loctite.
The factory shift rod snaps onto the bottom of the OEM shifter assembly and an anchor point along the bottom of the car. The issue here is that "play" eventually develops over time and it becomes a nuisance.
Sleepers found a solution to that issue by employing a spherical joint that bolts onto their shifter with its other end attached to the car's frame using a plate that that mounts to the frame and is far stronger than the ball-type connector. The result being no unwanted slop and a precise, more rigid feel.
Regarding the shift rod that sits behind the shifter, the crew noted that early model 964s relied on a U-joint style connection, whereas more modern versions switched to a system that uses a rubber spacer sandwiched between two metal plates. Though it's not included with the Sleepwalker kit, its notorious for causing slop in the shift system so an older style or aftermarket version, like the example pictured, is highly recommended.
With the factory plastic reinstalled and this owner opting for the threaded billet shaft with aftermarket knob, the kit is complete. This version shows the factory shift boot reinstalled...
...while this version uses the factory rubber shift bellow surrounded by this slick filler piece offered by Swine Eleven.
A look at the complete kit
The Sleepwalker short shift kit starts with a set of stainless-steel forks and your choice of a standard shaft, which works with a factory-style shift knob, or a billet piece, which has a 10x1.5 threaded end to accept a number of different aftermarket shift knobs.
Those forks are bent to make their way around this multi-piece connector that was designed in 3-pieces to allow the end-user the ability to install it in the very small amount of space afforded by Porsche engineers.
Designed to work with the OEM plastic bushings, a fresh pack is included in the kit along with all necessary hardware.