Harley Davidson Performance & bolt on Upgrades in Brisbane
At Taverner Motorsports, we specialise in Harley-Davidson servicing and performance upgrades for Twin Cam and Milwaukee-Eight (M8) Harleys. Riders across South East Queensland choose us—from diagnostic servicing to powerful bolt-on upgrades, multi-stage builds, and premium A.P.E. kit installations.
Why Choose Taverner Motorsports for Harley Performance Upgrades?
Over 40 years of Harley specialist experience in Brisbane.
Full-service upgrades: bolt-on accessories, cams, exhausts, turbos, superchargers, and multi-stage kits.
A history of dyno-proven, race-tested performance (200 hp+ builds, drag success).
Proudly serving Brisbane, Gold Coast, Sunshine Coast, Ipswich, and wider SEQ.
Harley Davidson Performance Bolt-On to Full Builds
Bolt-On Accessories & Upgrades
Bolt-on upgrades are the quickest way to transform your Harley’s performance without major engine work. They’re perfect for riders chasing instant horsepower, torque, and throttle response.
Exhaust Systems
High-flow exhaust systems, especially 2-into-1 headers, improve airflow and scavenging. The result is better torque, sharper throttle response, and that signature Harley sound.
Air Intake & High-Flow Filters
Paired with a new exhaust, an upgraded air cleaner or high-flow filter gives your engine the breathing room it needs for stronger performance, forming the foundation of a Stage 1 upgrade.
Camshaft Upgrades
Performance cams like the Cycle Rama 483, APE Stump Puller, or Red Shift 468 optimize valve timing for smoother power delivery and stronger mid-range performance—especially when paired with exhaust and intake upgrades.
Big Bore Bolt-On Kits
Bolt-on big bore kits expand your Harley’s displacement without machining. Options like S&S Power Packages and Hammer Performance kits push your Twin Cam or M8 into new levels of horsepower and torque, with full reliability.
Sportster & Twin Cam Options
- S&S Hooligan Kit : Converts an 883 Sportster into a 1200 cc powerhousewith included cams and tappets.
- Hammer Performance Kits: Offer bolt-on solutions to take Twin Cams into 98, 107, or larger cubic inches.
The Layered Gain Strategy
For maximum impact, riders often stack upgrades:
Exhaust → Intake → EFI Tuning → Cams → Big Bore Kits
Each layer builds on the last, compounding your performance gains and ensuring smooth, reliable power.
Performance Upgrade Stages: Stage 1–5 Breakdown
A staged upgrade path helps you grow performance in manageable steps:
Stage 1- Intake, exhaust, and ECU tuning (~10–15% HP gain).
Stage 2- Cam upgrade plus Stage 1 (~15–25% gain).
Stage 3- Big bore kit plus Stage 2 (~30–40% gain).
Stage 4- CNC-ported heads, high-lift cam, throttle body, and earlier stage parts (~50% more HP, 24% torque gain).
Stage 5- Full custom build (high compression, aggressive cam, custom fuel delivery) for 70–80%+ gains over stock.
A.P.E (Alpha Performance Engines) Upgrade Options
We proudly offer A.P.E. M8 kits—premium Australian-designed bolt-on and big bore packages for riders who demand serious results:
A.P.E. Silverback 128 ci Package:
Ported heads, high-compression, heavy-duty valve train, and cam upgrades for massive top-end power.
A.P.E. Street Performer 128 ci Package:
Balanced torque and horsepower, valve-train-friendly, and capable of 150+ HP and torque while still running pump fuel.
A.P.E. Stump Puller 128 ci Package:
Retains stock heads but delivers huge torque with the CR485 cam and supporting upgrades.
A.P.E. Cam Kits & Ported Heads:
Popular cams like the CR483 and CR485 bolt-in for improved airflow and throttle response.
S&S Cam Chest Kits & Options for Milwaukee-Eight (M8)
1. Milwaukee-Eight (M8) Big Bore & Stroker Options
a) Cam Chest Upgrades (without cams)
- S&S offer cam chest upgrade kits without cams , giving you a durable, highflow foundation without forcing you into a specific grind. These kits include a precisionmachined oil pump and cam plate, upgraded pushrods, tappets, tappet cuffs, debris screens, and enhanced scavenging features
- S&S 129″ Big Bore Kit for 107″ M8 Uses a 4.320″ bore and maintains a stock stroke. Also
bolt-on with no need for case machining, this kit gives a significant bump in power while retaining engine
simplicity and reliability. - Improved oiling (≈44% more supply flow, ≈58% more scavenging) enhances reliability, especially under higher revs or more aggressive riding.
b) Cam Chest Kits with cams
- S&S 465 and 475 cam kits: Good entry-level options for milder builds or bolt-on power improvements. These are often available in chain-drive or gear-drive versions, with Quickee adjustable pushrods.
- S&S 540 cam kit: A popular midrange option designed especially for M8 engines. Comes as a complete cam chest kit with stronger springs and pushrods, and works well with S&S 124″ and 128″ big-bore kits
- S&S 550 cam kit: Geared towards larger displacement builds. Suitable for riders who want more airflow and rev capability, especially when combined with ported heads or larger bores.
c) M8-Compatible S&S Power Packages
- For riders seeking a complete upgrade solution, S&S offers 129″ and 132″ Power Packages for 2017up M8 engines. These include big bore cylinders and matched cam chest kits, giving a reliable, high-output bolton solution with good value. Shape
2. S&S Cam Kit Options for Twin Cam Harley Engines
a) Common Performance Cam Choices
- S&S 583 cam kits: Available for many older Twin Cam models. They strike a balance between good midrange torque and easier installability.
- S&S 585 cam kits: One of the more popular choices for 20072017 Twin Cam bikes. Generally available in gear-drive versions, these offer smooth power gains and are suitable for higher performance applications.
- S&S 640 cam kit: For serious builds, this high-lift gear-drive cam offers higher horsepower at revs between ~3,000–6,000 RPM. Ideal for riders looking for strong power increases, often used in conjunction with other supporting mods.
b) Power Package Options
- The S&S 100/110″ Power Package includes big-bore cylinders and a matched cam chest kit, often built around the 585 cam. It’s a well-regarded entry-level package for those upgrading their Twin Cam for more displacement and torque.
c) Installation Considerations
S&S Big Bore & Stroker Kit Options for Harley Engines
1. Milwaukee-Eight (M8) Big Bore & Stroker Options
a) Bolt-on Big Bore Kits (No Case Machining Required)
- S&S 124″ Big Bore Kit for 107″ M8 This converts a stock 107″ to 124″ using a 4.250″ bore forged-piston kit with ~11.1:1 compression. No crankcase machining is necessary, making it a straightforward upgrade for more
- S&S 129″ Big Bore Kit for 107″ M8 Uses a 4.320″ bore and maintains a stock stroke. Also bolt-on with no need for case machining, this kit gives a significant bump in power while retaining engine simplicity and reliability.
- S&S 114″→128″ Big Bore Kit Comes in various finishes, retains stock engine height, and works cleanly with factory parts.
- S&S 132″ Big Bore Kit for 114″ M8 This is one of the largest bolt-in bore kits available for M8 engines, typically using a 4.320″ cylinder setup. Installation requires no crankcase machining; the kit retains stock internal components and engine height. b) M8 Power Package Kits
- 124″ & 128″ Winter Power Packages These are bundled kits that include the big-bore cylinders, matched cam chest kits (often using the S&S 550 cam), upgraded cam plates, oil pumps, valve springs, lifters, and supporting hardware. They’re marketed as costeffective, bolt-on performance upgrades for 2017on M8 models, designed for reliability and value.
2. Twin Cam Big Bore & Stroker Options
a) Bolt-on Big Bore Kits
- S&S 88″ → 97″ Conversion Kit Allows older Twin Cam engines (1999–2006) to increase displacement from ~88″ up to ~97″ without requiring crankcase machining. Comes as a complete top-end kit with pistons, cylinders, and necessary gaskets
- Other Twin Cam Big Bore Options S&S offers cylinder kits for larger displacement increases (e.g., going up to 100″, 110″ or more), often without needing internal case modifications. The bigger step-up kits may complement matched cam and head upgrade packages. b) Stroker Kits
- S&S 106″ Stock Bore Stroker Kit (2007–2017 Big Twins) This kit adds displacement via a stroker-style flywheel assembly with a longer stroke, using the stock bore. It’s designed for ease of installation, using tapered bearings and minimal machining.
Taverner’s results speak for themselves—engineered for both street reliability and racing pedigree:
- The Golden Child – 200 hp Supercharged M8 Fatboy (featured on Heavy Duty magazine cover).
- The El Chappo – 140 hp Custom Build with ported heads and cam upgrades.
- 24K V-Rod – mid-140 hp show build with gold finish.
- Joseph Taverner’s JIMS FXR – 11.1 sec quarter mile in drag competition.
Performance Tuning (Dyno)
Every upgrade—whether a bolt-on exhaust or a full Stage 5 build—benefits from dyno tuning. Proper mapping of fueling and timing ensures:
- Maximum horsepower and torque.
- Smooth throttle response.
- Engine safety and long-term reliability.
Local Expertise – SEQ Coverage
Serving riders across Brisbane, Gold Coast, Sunshine Coast, Ipswich, Toowoomba, and regional South East Queensland—Taverner is your destination for high-performance Harley builds.
FAQs
A Stage 1 upgrade air intake, exhaust, and tuning gives instant performance gains and sets the foundation for future mods.
Yes bolt-in cams like the CR483 or APE Stump Puller unlock mid-range torque and smoother delivery without major engine work.
Stage 4 can deliver up to 50% more HP, while Stage 5 custom builds push gains of 70–80%+ over stock.
Absolutely A.P.E.’s bolt-on big bore and cam kits deliver dyno-proven 150+ HP and torque, designed specifically for Harley Davidson M8 engines.
Yes—with quality parts and proper dyno tuning, bolt-on upgrades provide both performance and reliability for everyday use.
Ready to transform your Harley? From bolt-on Stage upgrades to A.P.E.’s and SnS big bore packages, Taverner Motorsports delivers power and precision.