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

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:

S&S Cam Chest Kits & Options for Milwaukee-Eight (M8)

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

What’s the best first bolt-on upgrade for my Harley?

A Stage 1 upgrade air intake, exhaust, and tuning gives instant performance gains and sets the foundation for future mods.

Do bolt-on cam kits really make a difference?

Yes bolt-in cams like the CR483 or APE Stump Puller unlock mid-range torque and smoother delivery without major engine work.

How much horsepower can I expect from Stage 4 or Stage 5?

Stage 4 can deliver up to 50% more HP, while Stage 5 custom builds push gains of 70–80%+ over stock.

Are A.P.E. kits worth it?

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.

Are bolt-on upgrades reliable for daily riding?

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.

Testimonials

"Professional Service 10/10. I highly recommend any customisation to your bike by the crew - this lads know bikes - best in the business"

"The only people I would trust to service or build my Bike. 2 generations of experience. Old school knowledge and new school knowledge."

"Brought the bike in for a major service and new tyres. Brian and the team was excellent. Service was great and you can tell they really put in that extra bit of effort in there work. Thanks for making such a major job so easy guys."

Harley