2015 Canadian Rotax Max Challenge Regulation – Presentation

13 March 2015

This year will mark the introduction of the new EVO engines family and the possible upgrade on the current engines family. The introduction of the new EVO engines family to the Canadian Rotax Max Challenge will be done according to the principle of “EVO or non EVO”.  This means that drivers will use EVO (or engine upgraded to the EVO package completely) or non-EVO engines « as is », except for some specific parts which will be mandatory in Micro and Mini (see the Micro & Mini Appendix for more details).  Here is an overview of the 2015 regulation with the introduction of the EVO engines.

For 2015 regulation, important elements are:

  1. Visual presentation of the sporting regulation have changed.
  2. Visual presentation of the technical regulation have changed, Max engines and DD2 engines are not separated anymore.
  3. Minimum squish gap of the Mini-MAX will go down from 2,80 mm to 2,40 mm.
  4. Minimum squish gap of the DD2 engines will go up from 1,10 mm to 1,30 mm.
  5. Minimum spacing between the reed stoppers will be defined for all classes (similar to Mini-MAX last year).
  6. Mini-MAX, non EVO and EVO engines, will use the 22 mm old exhaust socket.
  7. Mini-MAX: no more intake restrictor for the EVO engine. Old one will still use the intake restrictor.
  8. Allowed engines will be « EVO or NON EVO ». This means that drivers will use EVO (or engine upgraded to the EVO package completely) or old engines « as is », except for some specific parts which will be mandatory in Micro.
  9. EVO engine will not be allowed to use old parts (EVO components).
  10. Only old engine upgraded with the EVO package will be allowed to use the new exhaust pipe.
  11. New exhaust pipe is not mandatory to upgrade your old engine to EVO but mandatory for EVO engine.
  12. Micro & Mini EVO upgraded and New EVO Engines will only be allowed to use cylinders marked with lettered production code.
  13. Cylinders marked with a numbered production code (produced before 2011) will not be legal anymore in 2016.
  14. Carburetor: VHSB QS and QD for DD2: only floats 5.2 gr are allowed.
  15. Carburetor – all versions: For the Needle jet, additional measures for technical inspection purposes with jet gauges (go-no go gauges).

Questions and answers:

 1. Should I buy and EVO upgrade kit for my engine even if I plan to use my old engine « as is »?

We strongly recommend it. Just to keep the resale value of your engine, you should buy the upgrade kit at the special price for a limited time. The ease of use of the new carburetor is worth the purchase of the upgrade kit.

2. I want to use my old engine, is there any new EVO parts mandatory to buy.

Yes, for Micro-MAX only. New exhaust socket, gasket ring and perforated tube are mandatory. This solves the leakage problem.

For Micro and Mini, if you upgrade your old engine to EVO, you must use a cylinder marked with a lettered production.

3. I want to upgrade my actual engine to transform it in EVO status. What should I buy for this?

See this chart according to each class:

4.  My son is going senior this year and I will buy a new EVO engine. I love my actual carburetor. Can I use it with my new EVO engine?

No. If using a new EVO engine or and upgraded EVO engine, you must use only EVO components.

5.  My existing exhaust pipe is broken, can I buy the new pipe and use it with my old engine?

No, you must have and EVO engine or EVO upgraded engine to use the new pipe, except for the Micro MAX which should use the new perforated exhaust tube.

6.  Can I use the new carburetor with my old engine?

Only if you convert you convert your engine to the EVO status.


This document is just for your information and has no legal value. For the complete regulation, please visit

PDF file of this presentation is available here.

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