Legality of crank swaps

[Z3_GoCar]

The S52 is 3152cc.

The S54 is 3246cc, which makes the whole concern moot. The S54 is too large for STU, even if 3.2L becomes the rule for 2012.

Nope, it's still a 3.2 as per the STCS:

I

.

Weights and Engine Allowances

Minimum weights for cars with normally aspirated piston engines will
be determined by 1.1 lbs/cc displacement for the installed engine (see
following table). Displacement is the factory displacement for the installed
engine. For

the purpose of weight assign ment, engine displacement will
be rounded to the nearest 100cc (e.g., 2150cc = 2200cc and 2149cc

= 2100cc).

[JS154]

Nope, it's still a 3.2 as per the STCS:


I

.
Weights and Engine Allowances

Minimum weights for cars with normally aspirated piston engines will

be determined by 1.1 lbs/cc displacement for the installed engine (see

following table). Displacement is the factory displacement for the installed

engine. For

the purpose of weight assign ment, engine displacement will

be rounded to the nearest 100cc (e.g., 2150cc = 2200cc

and 2149cc
= 2100cc).

Correct, but the rule specifially states "for the purposes of weight assignment".

it does not say that calulation is to be used for engine displacement eligibilty.

Reading the proposed rule strictly, "up to 3.2L" = 3200cc.

So the question then is what is the 3.2l cutoff? Is up to 3200 actual cc the ceiling for eligibility, or is 3200 calculated cc the cutoff? If the latter, the limit is really 3.249 litres, not 3.2litres.

The wording also says "displacement is the factory displacement". 3246cc is greater than 3.2l

for example: 5.0l (old old trans am limit) - Ford 302, Chevy 305. "5.0l" engines, but both were under the 5000cc limit.

I guess my point is the actual displacement limit should be clarified, assuming the proposed rule is adopted.

[Z3_GoCar]

My guess is the e-46 generation M3/S-54 is being brought into STU, because STU is being alighned to world challenge GTU, where this generation M3 and some of the pony cars are.

[Greg Amy]

My guess is the e-46 generation M3/S-54 is being brought into STU...

Don't overthink this. The car is NOT "being brought in", it just so happens to have a displacement that meets our stated philosophy for the class. And the philosophy for the class was changed from 3.0 to 3.2L because of the number of requests for exceptions we were getting for 3.2L cars, all of which we approved and expected to be approved going forward.

Nothing more, nothing less. No smoke-filled rooms, no dark ulterior motives to make the world great for Bayerische Motoren Werke.

We have demonstrated the will to exclude cars that exceed the performance expectations of the classes (see STL and Integra ITR and S2000, various Loti products). If you truly believe the performance of any of these engines is far and above the potential of its competitors, then put all your information together with a submission to the CRB. It will be seriously considered, but you better support the request; sending something like "exclude the 2012 M3 because it's too fast" will surely be responded with "we will continue to monitor the performance of the class".

It all starts with a well-written letter. Make your case, support it with relevant data.

GA