• Turblown Engineering Mazda RX-7 Stud Kit — FD3S 13B rotary engine
  • Turblown RX-7 FD3S stud kit — angle 3
  • Turblown Mazda FD3S stud kit — angle 2
1 3

Turblown Engineering Rx7 Stud Kit

$619.00
$619.00
Sale Sold out
Shipping calculated at checkout.
Fits the Mazda RX-7Engineered for the 13B-REW · 13B
  • Fitment guaranteed
  • Fast, tracked shipping
  • Price-match guarantee
  • Authorized US retailer

Select items are stocked in the USA — others ship from the manufacturer. Delivery calculated at checkout.

The Turblown Engineering Rotary Engine Stud Kit is designed for High Horsepower applications. These studs are available for all 13B engines including the MSP-13B Rx-8 engine. This stud kit is a more linear, and precise medium of torquing the engine compared to stock tension bolts. Torquing the stock bolts creates friction at both the threads, and head of the bolt. This unnecessary friction promotes false torque readings and the result is reduced and uneven clamping force. Instead of twisting a bolt to achieve a desired torque reading, studs are stretched in a static position. Furthermore and more importantly these studs are made from far superior material & manufacturing process which increases clamping force evenly, and limits engine expansion. The OEM bolt material stretches under high boost and in turn, reduces clamping force. An engine using the OEM bolts will expand several thousands, as measured with a strain gauge on an engine dyno. This expansion can damage to the engine's internals. Common harmonic, and resonance issues are reduced due to the superior material used in the stud manufacturing. Installing these studs will reduce engine expansion and movement which is a must for a high powered rotary. 


Turblown Engineering has been manufacturing these studs since 2006. These studs are precision ground from aircraft quality forged steel. The threads are hot rolled, not just cut with a die or a lathe. The course end is embossed with a allen head for easier installation. They are rated at 195000 PSI tensile strength after the heat treating process. One can torque these much higher than the OEM bolts without any breakage( maximum of 77 ft lbs for studs, please be aware front iron might break near this limit). The studs are finished in a black oxidation coating. No machining is required for installation.

Read more about the manufacturing process & testing here. 


Studs are compatible with OEM or aftermarket flywheels( S4 flywheel will require a bottom end tap to be used on front iron to achieve as much thread depth as possible) Replaces all 16 inner tension bolts for 13B engines, Rx-8 engines kits replaces only 13 tension bolts. Service life will not reduce like OEM bolts, these are re-usable. Studs should be torqued to 3 inch lbs, and the nuts to 40 Ft lbs( in 4 ft lbs increments using the OEM torque pattern). Lubricate the front iron threads, and use a silicone sealant near the OEM sealing washer threads(OEM sealing washers not supplied). If using lubricant on the OEM sealing washers, use brake clean and wipe the studs clean once the sealing washers are installed. Let the sealant on nuts setup overnight and pressure test engine coolant system to confirm proper adhesion of silicone sealant. Pineapple Racing Pressure tester or equivalent is recommend to use before engine installation.

The Black Mamba Racing Beetle runs the Turblown 13B stud kit with zero other modifications. It makes in excess of 900rwhp and has run a best of 8.5 @ 153mph in the quarter mile! 
Bacon Sports Racing 13B FD runs an 8.25@167 with the Turblown 13B stud kit. 
NTB Tire FormulDrift Rx-8 ran the Turblown 13B Stud kit in every engine.

Specs & fitment
Brand
Turblown
Platform
Mazda RX-7
Engine
13B-REW, 13B
Category
Rotary Engine Parts
$619.00
View full details

What customers say

Trusted by JDM builders

  • J-Spec Garage is my first stop for JDM parts now—fast shipping and no surprises.

    Alex M.

  • They actually took the time to help me choose the right setup for my GT-R. That alone won me over.

    Brian S.

  • Everything arrived well packed and exactly as described. You can tell car people run this shop.

    Chris D.

  • I've ordered three times now and it's been consistent every time—accurate, quick, and hassle-free.

    Daniel R.

  • Customer support answered my fitment questions in detail instead of just sending a link. That meant a lot.

    Jason L.

  • Parts for my Supra showed up on time and bolted right up. No guessing, no drama.

    Kevin P.

  • Site is easy to navigate and checkout was simple. Whole experience felt dialed in.

    Nate H.

  • Communication was excellent from order confirmation to delivery updates. I always knew what was happening.

    Ryan F.

  • These guys are clearly enthusiasts. The brands they stock and how they talk about them says everything.

    Tyler N.

  • I've dealt with plenty of parts shops—this is one of the few I trust with big-ticket items.

    Zach W.

  • My 240SX build depends on good vendors. J-Spec Garage has delivered every time so far.

    Cody J.

  • You can tell they care about the scene, not just sales. That's why I keep going back.

    Dylan P.

  • I had an issue with a manufacturer drop-ship and J-Spec Garage handled it for me. That's real customer service.

    Josh H.

  • The coilovers for my S13 came packed perfectly and ride exactly how they advertised. Super happy.

    Kyle M.

  • Grabbed both parts and merch—quality on both sides. Cool to support a shop that supports the community.

    Sean L.

  • I recommend J-Spec Garage to anyone building a JDM car. Solid parts and people who know the platforms.

    Omar V.

  • The RaceOnly parts I grabbed for my RX-7 were top-notch. Fitment was perfect and the car feels night and day better.

    Aaron F.

  • Finding legit rotary parts is tough, but J-Spec Garage came through with RaceOnly gear that actually delivers.

    Blake S.

  • Finally found a shop that understands rotary builds. The RaceOnly pieces I ordered have held up great under real abuse.

    Jake P.

  • Everything for my FD—from RaceOnly parts to small accessories—showed up clean, labeled, and ready to bolt on.

    Mason K.

  • I've ordered RaceOnly gear from other places before, but the service and communication from J-Spec Garage were on another level.

    Noah V.

  • The RaceOnly pieces for my RX-7 build fit exactly like they should. No grinding, no modifying, just bolt-on and go.

    Owen T.

  • It's hard to find a shop that really understands rotary builds, but J-Spec Garage clearly does.

    Caleb M.

  • Real rotary parts, solid communication, and no nonsense. Exactly what I want from a parts shop.

    Isaac R.

  • The Supra parts I ordered were clearly not cheap eBay stuff—quality brands and everything matched the listing perfectly.

    Adrian C.

  • I've been slowly building my MK4 and every order from J-Spec has shown up on time and ready to install.

    Carlos N.

  • They actually understood what I was trying to do with my Supra build and suggested parts that made sense, not just the priciest options.

    Derek W.

  • The turbo-related parts for my Supra came exactly as described and have held up great under boost. Zero complaints.

    Javier S.

  • I appreciate that they stock real-deal brands for Supra builds instead of filling the catalog with questionable stuff.

    Miguel R.

  • I'm picky about what goes on my MK4. J-Spec Garage earned my trust with accurate listings and solid communication.

    Steven D.

  • I've had a great experience ordering Supra parts here—accurate listings, fair pricing, and quick shipping.

    Marcus D.

  • It's refreshing to buy Supra parts from a shop that actually knows the platform.

    Preston G.

  • The turbo and supporting parts I got for my Supra were exactly what I needed. Everything matched the listing.

    Trevor M.

  • If you're building an RX-7 or Supra, this is a shop you want to know. RaceOnly parts for the rotary and quality Supra gear in one place is a win.

    Victor H.

  • It didn't feel like I was buying from a generic online store. It felt like a shop built for enthusiasts.

    Wyatt N.

  • Good communication, real brands, and parts that showed up when they said they would. Hard to beat that.

    Zachary R.