In the motorcycle world nearly every modification has its own nomenclature, but what does it really mean? Much of this is marketing but it can really serve a purpose and can actually be helpful when interpreted correctly. OEM’s and aftermarket companies have been very successful using the term “Stage” with their kits, for many companies it’s a way to help educate customers on performance levels as well as how complex or comprehensive a set of modifications may be. We’re going to talk a bit about “Stages” in the traditional sense, as well as how Fuel Moto will be referencing our own kits as we move forward.
Some of the first companies to offer components in Stages was Kerker and K&N in the 80’s, they offered exhaust systems and jet kits at different levels ranging from semi restrictive exhaust & stock airbox, up to full open headers with the airbox removed. As performance changed with each combination they referred to the kits as Stage 1, 2, 3, etc. These terms were very successful as they allowed customers to better understand what they were buying. The same could be said in todays V-Twin performance market, as in many cases the term “Stage” is applied to various levels of performance.
As you can see in the examples listed below as the various Stages increase the amount of necessary modifications increase exponentially, as does the necessity of the components to support a given power level. For example an exhaust system that is capable of 90-100 horsepower is not going to work on a 130Hp build. While a Stage 1 build can be fairly forgiving on the exhaust & intake, a Stage 3, 4, 5 build requires a very specific recipe. The components used WILL make or break the entire combination.
The following descriptions could be used to generally describe the various performance levels:
Stage 1: these are generally considered exhaust and intake modifications to an otherwise stock engine along with the appropriate EFI Tuner.
Most Stage 1 type modifications are typically in the +10-15% power increase over stock.
example: 2018 Road Glide, stock 107” engine, Jackpot 2/1 exhaust, FM AC/DC air cleaner, Dynojet Power Vision tuner
Stage 2: this is typically referred to an engine with a performance cam upgrade as well as the other components within a Stage 1 combination. A typical Stage 2 has generally +20-25% more HP than stock.
example: 2018 Road Glide, Wood WM8-222 cam, 107” engine, 2018 Road Glide, stock 107” engine, Jackpot 2/1 exhaust, FM AC/DC air cleaner, Dynojet Power Vision tuner
Stage 3: most normally refer to the Stage 3 type build as a mild big bore & cam upgrade and included the other components of the lower Stages. These kits in most cases use the stock throttle body and most of the other stock components. HP increases can be +30-40% or more from stock
example: 2018 Road Glide, 117 big bore kit 10.8 comp, Wood WM8-222 cam, FM AC/DC air cleaner, heavy duty clutch springs, Dynojet Power Vision tuner
Stage 4: this would be a moderate compression big bore combination. It includes headwork and more cam than a Stage 3. In many cases it would include a larger throttle body & injectors (depending on the specific model). Additional supportive mods would be required such as clutch and other upgrades.
Power levels can be +50-60% or much more over stock
example: 2018 Road Glide, 120 big bore kit 11.4 comp, Wood WM8-999 cam, FM Level B CNC heads, 64mm TB, 5.5 injectors, Jackpot 2/1 exhaust, FM AC/DC air cleaner with larger element, AIM SDR lock up clutch & springs, Dynojet Power Vision tuner
Stage 5: this would be a custom high compression big bore combination. It includes comprehensive headwork and aggressive cam. Requires larger throttle body & injectors as well as additional supportive mods. Would be considered fuel & tune sensitive.
Power levels can be +70-80% or much more over stock, in some cases even more.
example: 2018 Road Glide, 124 big bore kit 11.9 comp, Wood WM8-9F60 cam, FM Level B heads w/oversize valves, 64mm TB, 7.3 injectors, custom exhaust with large primaries, custom air cleaner, Dynojet Power Vision tuner