22nd December 2021


Balance of Performance (BoP) assessment to be used in the search for better parity between engines for TaG 125 (Open) and TaG 125 Restricted Classes in Karting Australia competition.

Karting Australia is employing its own simple BoP assessment as the mechanism by which a variety of competing engines can compete on a more level playing field on any given Track in 2022.

TaG has traditionally been balanced, seeking parity by the use of weight.

TaG 125 Restricted has traditionally been balanced seeking parity by using a combination of exhaust restrictor size and weight.

The performance of each of the TaG engines varies – not just on straight out horsepower, but also torque, top end, mid-range and bottom end characteristics. Some engines have better performance on the straights, other accelerate and drive out of the corners better. Weight affects karts differently at different parts of a Circuit. Power restrictions react as being almost the same across the entire lap or a Track.

Karting Australia has been closely following and assessing the relative performance of the IAME X30, PRD Galaxy and Rotax engines in different competitions and at different circuits throughout 2021.

In preparation for 2022 we have conducted circuit testing of all engines (including the new Vortex Rok GP engine) that form those Classes following dyno analysis during the past 15 months.

In striving to achieve parity and BoP for TaG and TaG Restricted Classes, we have settled on a system that uses a variation of weight and power restrictions (created by exhaust restrictions) across each engine used. This is the first time that such a combination has been employed in the TaG 125 (open) Class.

Weight as a form of equalisation is the ultimate ‘blunt instrument’ when it comes to kart/engine performance. Yes – it is definite that more weight slows a kart down more. It clearly changes the ‘power to weight’ ratio but it is arguable that it is where it slows a kart down the most (on corner exists under acceleration) that matters the most. This results in a significantly greater impact being felt, and significantly differently outcomes being achieved depending upon the characteristics of the track layout upon which you are racing. I.e., the parity outcome is different depending upon the combination of long straights, steeper inclines, high speed sections and slower, more technical corners.

A parity system that utilises a simple BoP system is intended to allow for a majority of competing kart/engine combinations to utilise their relative strengths throughout each lap thereby creating better racing and overall closer competition in each Class.

Obviously, driver ability and performance also plays a very important role in determining the actual on-track performance, but that is completely beyond our control other than through permitted licence gradings.

While added weight will alter the overall performance of the kart/engine combination, any exhaust restriction that we can utilise will change the horsepower and torque that the engine produces and that it produces consistently across each lap regardless of the complexities of each circuit layout.

The various adjustments work together to ensure that each kart/engine combination can compete more equally and removing the notion that a particular circuit is an “X30 Circuit” or a “Rotax circuit”.

By using an engine restrictor as a means to achieve parity and BoP it is aimed at ensuring the speed trajectory of each engine is similar.

Weight will always play its part of in the simple BOP assessment in the search for performance parity, but we will increasingly look at relying more and more on engine restrictions as our primary BOP tool.

Drivers are advised, that in accordance with the Rules, if, through on-going monitoring of performance KA considers that any further adjustments are required either through restriction or weight or a combination of both, that we will act to further refine the current BoP tools that are available to us.