British Touring Car Championship organisers TOCA have responded to Team BMR by issuing a statement, regarding the engine equalisation the row, as the furore rumbles on at Rockingham.
While the question of boost levels has simmered for most of the season, the equalisation row boiled over last time out at Knockhill following comments made by Jason Plato.
BTCC series director Alan Gow then responded to Plato's claims - branding them 'borderline offensive' - which then triggered the Subaru outfit into releasing a statement, regarding the situation, of their own.
BMR went on to re-issue a slightly amended statement [on Thursday]. They argue that the calculus of engine power, determined under test conditions, doesn't translate into 'on-track straight-line speed performance' - and therefore speed equalisation.
BMR and TOCA's views also differ surrounding the circumstances of BMR's Homologation Extension, which allowed the team to change the Levorgs inlet manifold earlier in the year - something TOCA say was a unique occurrence.
"Silverline Subaru BMR Racing made a transparent application for a Homologation Extension to change the design of its inlet manifold based on a reliability issue and performance benefit," the BMR statement reads.
"The BTCC Technical Working Group including the TOCA officials agreed the Homologation Extension as permitted by the Championship Regulations for the Oulton Park round onwards albeit subject to an initially conservative base boost setting. Other teams and manufacturers have also made similar proper Homologation Extension applications also in accordance with the Regulations.
"Silverline Subaru BMR Racing understand and support our drivers' frustration on power levels and boost adjustments that did, in some circumstances, not seem logical given the objective of equalising engine outputs across the championship. This concern was also expressed by senior personnel and high profile drivers from some other teams throughout the season.
"Since these comments were made the calculus used in determining the resultant boost pressure and any adjustments has been presented to us and all other engine manufacturers. It is clear to us that the methodology used is based on raw data taken from each and every vehicle in the championship. The maths and processes are in fact a remarkably accurate judgement of the power output of each engine at the test conditions.
"However, we believe these test conditions do not translate to actual 'on track' straight line speed performance and recommend revisions moving forward if we are to achieve the common goal of 'on track' speed equalisation. We are looking forward to working with TOCA, the engine builders and all other teams to achieve this common goal."
TOCA, on the other hand, describe BMR's comments as 'incomprehensible' and state the sole intention of the regulations is to equalise engine power, not straight-line speed as other factors can influence the overall top-speed.
TOCA's statement is as follows:
Following an additional amended statement issued by Silverline Subaru BMR Racing earlier today (27 August), Series Organiser TOCA is disappointed that it finds itself having to further clarify and correct some of the points raised.
To suggest that their statement has been issued to 'avoid confusion' has unfortunately merely added to it;
Stating that 'other teams and manufacturers have also made similar proper Homologation Extension applications also in accordance with the Regulations' is factually incorrect. This comment was made in relation to the BTCC Technical Working Group agreeing to Silverline Subaru BMR Racing's request for a waiver to change its inlet manifold earlier this season.
For the avoidance of doubt, the waiver given to BMR was a unique occurrence – in fact no BTCC team has ever before been granted a waiver during the course of the championship to change a major component that will substantially improve their performance.
We are pleased to note that BMR, after seeing all engine power data calculations, agree with those calculations and state that they are a 'remarkably accurate judgement of the power output of each engine at the test conditions'.
However it later continues 'we believe these test conditions do not translate to actual 'on track' straight line speed performance and recommend revisions moving forward if we are to achieve the common goal of 'on track' speed equalisation'.
This we find incomprehensible. There has never been a common goal of 'on track speed equalisation'.
As BMR acknowledge and agree, each engine's power is equalised. But how that then converts to on-track performance is entirely up to each team and subject to a great many variables in each car – such as aerodynamics, weight, engine cooling, differential settings, drivetrain format, gearing, corner exit speeds, rolling resistance and many more variances.
In fact, even engines producing the same power can have differing performance characteristics, by altering their ECU mapping, using different camshaft profiles to achieve a different torque curve and such like.
Therefore like all other major motorsport championships, we have never sought to equalise straightline speed performance. It is simply not part of the equation – in fact we do not know of any major championship (particularly one with such a great variety of engine types, drivetrains and body shapes as ours) where this is done.
To think that all cars should be subject to a 'speed equalisation' is nonsensical, in our view. To attempt to match each and every type of car to achieve identical top speeds is a naïve and virtually impossible goal – particularly with the diversity in our championship.
Our proven and acknowledged process simply provides each team with an engine of an equal power factor. How this then relates to on-track performance is entirely down to each team and the way in which they build, develop and race their cars.
The incredibly close lap times produced throughout the BTCC field this year (26 cars covered by less than a second at the most recent event at Knockhill), clearly demonstrates the veracity and success of the BTCC's rules and regulations.
To now introduce unachievable 'speed equalisation' of top speed times into the equation is one that won't be pursued.