PST, Inc. is a state of the art Manufacturer of Driveshafts for applications ranging from "Critical Link"™ carbon fiber driveshafts to the Super Spline PTO shaft.
The plant has been located in Clearwater, Florida for over 20 years and PST takes pride in serving the U.S. as well as foreign markets with driveline products.
PST, Inc. has been an innovator in the high performance driveshaft business and keep striving to maintain their excellent reputation for driveshaft engineering, technical support and service.
Reasons for Carbon Drive Shafts:
Carbon shafts in case of a fracture will separate into tiny little fibers. For you as a driver its a huge safety factor as unlike a metal shaft you dont have to worry about a 20+ lb shaft flinging around under the car damaging the underbody of the car or going through into the cabin.
The Carbon shafts are a 1 piece design that eliminates the center carrier which is used with the OEM driveshaft. This allows for energy to be quickly transferred from the transmission into the rear differential, and not wasted rotating the carrier and flexing the bushings around it. After install on our 2011 STi we noticed a increase in throttle response at low RPM driving and acceleration at partial throttle.
The Critical speed is just over 9500 for WRX Shaft, and close to 10,000 on the STi shaft.
The bonding area is 40" and the epoxy used is rated at 3200 lbs per square inch. PST have seen guys break joints and shear the ears off the yokes in some drag race cars that had diff or tranny failure and the bond was still intact!
The shafts are balanced on a Stewart Warner computerized industrial balancer. And the shafts are balanced to under 1/8 in/oz.
These results are gained from our 2011 STi, Stag2.
Stock Driveshaft: 27.6lbs
PST: 14.2 lbs!
Weight Savings of 13.4lbs means that your engine spends less energy rotating the driveshaft and more energy on spinning the tires. This in turn decreases drivetrain power loss and increases power at the wheels. So even though your car is not making more power, its able to transfer more of it to the wheels increasing performance, drive-ability, and response.
After installing it on our 2011 STi shop car, we where nothing short of amazed. The fitment was spot on and was a direct factory replacement. Install time was about 10 min after the mid pipe was removed off the catback.
Test Drive Results where nothing short of AMAZING! The vehicle was much more pleasant to drive in very low RPM with no more bucking or shacking, and it was much more eager to accelerate even at partial throttle. Throttle input response was also drastically increased with less "dead" time between when the throttle was applied to when the vehicle started to accelerate. As for all out acceleration, well the thing is MUCH faster then compared to the way the car was with a stock driveshaft. The vehicle is much more eager to go through the RPM range at a much faster rate, meaning that its accelerating faster. The shifts where also crisper and faster as up shifts and down shift delays where cut to a minimal in terms of hard downshifting and fast upshifts. Overall this was by far the fastest stg2 STi any of us have felt at the shop!
We where curious to see the results the addition of the driveshaft made, so we did a quick dyno comparison of before and after.
Performance Mod List:
PST Carbon Drive Shaft
Cobb Tuning Accessport Running the 91 octane AEM Stage 2 map
Cobb Tuning Catted Down pipe
Invidia Q300 Catback
Temps: High 30's
Fuel: 91 octane winter blend (talk about bad fuel)
As you can see, consistently through out the entire powerband both Tq and Power increased!
*sorry about the starting RPM range, it was getting later in the day and we didnt think twice about the starting RPM of the initial pre-driveshaft starting point. But you can see that after 3000RPM the gains are nice and constant.