It was brought to our attention that certain Mini and Micro Max exhaust systems performed better than others or that well used exhausts perform better than new or repacked exhausts.
EMR has tested several new and used exhausts on its dyno simulator and confirmed that the variation is unacceptably wide – old burnt silencing wool versus a newly packed exhaust etc. This problem arises because the silencer is actually becoming a tuned pipe as the wool burns away by virtue of the fact that it is close to the exhaust port because there is no tuned pipe on Micro and Mini Max engines. Normally on racing two strokes there is a tuned pipe or expansion chamber first then the silencer fitted at the end - the silencer then has little or no effect on performance in this situation.
We have a solution and at no cost to competitors! An additional component consisting of a steel perforated pipe with a socket welded on one end will be installed into the existing exhaust – this is easy and takes less than 10 minutes. The additional component helps to deliver a very consistent performance - at least as good or better than the very best original systems and importantly the condition of the silencing wool new or used no longer influences the performance.
IMPACT ON THE JETTING
Many tests on the dyno simulator confirm that this has no effect on the lambda reading - in other words the jetting of the carburettor remains the same as before. The organizers reserve the right to exchange any competitors’ exhaust with a new EMR tested and sealed Version 2 exhaust during any event in the SARMC 2018.
Components will be available on or before Wednesday the 28st of March 2018 from EMR and we will assist competitors to install this. On Thursday the 29nd of March components and assistance will be available at iDube.
For more information, see MSA National Karting Circular 6 of 2018
Rotax Karting is about parity and fairness. This simple change is made to ensure that everyone is on a level playing field!