



PST Carbon Fiber Driveshaft
Subaru STI 2015+
Features & Product Details
RallySport Direct is proud to provide you with alternative driveshaft options brought to you by PST.
On this page, you are looking at the PST Carbon Fiber Driveshaft. This is a great way to help relieve some of the rotational mass of the drivetrain so that you can transfer more power to the wheels.
DETAILS:
Product Video
Specifications
RallySport Guarantee - 30 Days
Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.
RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.
The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.
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REVIEWS & CUSTOMER MEDIA



The driveshaft it great and install was a breeze! Excellent quality, and can really feel a difference in drivability (2016 STI). However, after the install I was getting serious clunking (the only reason I downgraded the quality). RSD customer service was great in trying to help, and reached out to PST. In the end, we discovered the driveshaft was not compatible with my Group N transmission mount. The Group N tranny mount was thicker than the stock mount, which forced the transmission to sit up higher (closer to the cabin). As a result, the driveshaft was hitting my rear shifter bushing with every rotation. Had I not been concerned enough to tear everything apart until the problem was found, it could have caused some serious damage. Beware of that when going for this.
This drive shaft is advertised 2015+, however it did not fit my 2019 STI because it was too long. The slip yoke bottom out in the transmission and was over a 1/2" too long. It was unfortunate because the quality of the shaft was great. Very light and well manufactured. Not sure why it wouldn't fit as the measurements seem to match what the specs were from PST. I really wanted this on my car and thought about taking the car to PST to have them measure out my cars driveline specs and have one specifically made to my car but they are to far away. Rated the quality 5, value, performance and installation i couldn't honestly rate as i never got it installed.
Wether your bone stock or modified, you'll wonder why this driveshaft didn't come from the factory with one. I've had my PST shaft on my 2016 Subaru STI for about a week and all I can say is, the jerky 1st to 2nd gear shifts are gone, the car revs much more freely, and starting from a dead stop is a breeze. It might just be me but I also feel as if the turbo is spooling up a couple hundred rpm's faster. This is honestly one of the few modifications that doesn't require a tune and has none of the drawbacks of noise, vibration, or harshness. The only drawback is the price, which is a little steep, but luckily I bought this when it was on sale during Black Friday. If your on the fence about buying this shaft, don't think DO IT!
The best modification for your car is the carbon driveshaft.The jolting in the drivetrain from the stock 2 piece steel shaft is terrible. The shifting transition as well is better,I feel the car acelleration now is more connected with the one piece shaft, the rotating mass loss is also an extra bonus to.Install is a breeze, just be careful when inserting the shaft into trans housing respect the seal there.
The "install video" here is inadequate. The process is straightforward, but there's more too it than what's in the video. It took me 90mins with hand tools. 1. Safely jack car up on stands or ramps, all four corners will make life easier. 2. Get working on the six bolts holding your mufflers to the midpipe, leave the last one barely on. Remove the hanger from the rubber bumper. 3. Loosen the two bolts on the forward end of the midpipe at the cat, be nice to your donut gasket, and drop midpipe to floor, remove last bold on muffler side. 4. Get to work on the four heatshield bolts. They're easy but the O2 sensor wire goes though it. I made a small cut the the heatshield instead of taking the sensor out. 5. Loosen and remove the four bolts on the rear diff side of the driveshaft, and have something to rest that end on, as the shaft won't flex enough at the midjoint to touch the floor. Move on to the two large bolts at that mid joint and get ready to hold 30+lbs . Supporting the whole driveshaft, pull it out of the transmission, some fluid will leak. 6. Before reversing this process, put some grease or something in the spline of the new one. The four bolts you're reusing? Those heads are round with one flat side, to rest against a flat edge of the old knuckle. That doesn't work on the new one, you'll need an open ended wrench to hold them from spinning, while you tighten the nut. If you are re-using those crush washers, add some loctite and let it cure 24 hours. When you install the new shaft, you'll have to line it up on the spline, so that all four holes on the rear diff match. Or if e-brake is off, maybe just turn it. 7. Re-install heatshield, re-attach midpipe. You're done.
QUESTIONS & ANSWERS
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Q: 2019 STi fitment? Hazuki-San 11 months ago
In the description it says it fits the 2019 STi, however in the comments someone said it was a 1/2 inch too long. Can you confirm this one way or the other?
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0 of 0 people found the following answer helpful
A: It's a perfect fit on the 15-20 STI, I'm guessing that particular reviewer got either the wrong product or a defective one. Thanks!
Rick C. @ RallySport Direct 10 months ago
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0 of 0 people found the following answer helpful
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Q: custom order chrisb_one3 years ago
would I be able to order this drive shaft with the forged aluminum yolks vs the steel yolks? I'm concerned about the rusting from the steel yolks as someone else has stated.
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0 of 0 people found the following answer helpful
A: On any kind of custom order it's a case by case basis. You would need to reach out to our customer service department at 888-45-Rally!
Megan L. @ RallySport Direct 3 years ago
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0 of 0 people found the following answer helpful
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Q: PST Carbon Fiber Driveshaft eschellerup3 years ago
I read online that the DSS CF driveshaft comes with larger bolts that hookup to the rear diff and a workaround is needed to make it fit with the supplied hardware. With the PST, is that needed or it a direct fit with supplied or with original re-used hardware?
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0 of 0 people found the following answer helpful
A: Hardware is not included, this is intended to be installed the the original hardware on your vehicle and would be a direct install.
Evan M. @ RallySport Direct 3 years ago
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0 of 0 people found the following answer helpful
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Q: Carbon Fiber Driveshaft tonytony3 years ago
Does the PST Carbon Fiber Driveshaft fit JDM version of STI (model: VAB, EJ20)? thanks
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0 of 0 people found the following answer helpful
A: We cannot confirm these to fit anything other than USDM models. However, we can have PST make you a custom one. Please contact [email protected]rallysportdirect.com for more info.
Tyler A. @ RallySport Direct 3 years ago
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0 of 0 people found the following answer helpful
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Q: Driveshaft Mitchell 4 years ago
Is it safe to launch your car with this shaft ?
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0 of 0 people found the following answer helpful
A: Launching your car is never considered safe, however this driveshaft is designed to a huge amount of power compared to stock.
Jared A. @ RallySport Direct 4 years ago
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0 of 0 people found the following answer helpful