MembersPage/PelleWallberg (2008-02-18 21:26:15)

The car is a Mazda RX3-1973 with a 13b engine that is being built by a friend. The current engine is balanced, has lowered compression, is street-ported and has new hurley apex-seals. This is accompanied by a Garrett turbocharger to get some more power from the available 1.3 liter.

Right now the engine is fitted with 2 x Weber 50 carburettors and a distributor from a newer Mazda with built-in ignition-coil drivers.

My part of the project is to hopefully adapt the VEMS firmware to work with two separate igntion tables for use with the wankel-engine. This is needed because the wankel engines have 2 sparkplugs per rotor to overcome the 'not-so-optimum' combustion chambers and help burn all the fuel.

With the current firmware, 1.1.x, it is possible to have the VEMS controlling both the leading and trailing spark with some restrictions. It is only possible to have the trailing spark at 1 tooth (or N teeths) after the leading spark. I.e. with a 24 tooth wheel we get a fixed 15 degrees (or 30, 45 etc.) between leading and trailing spark.

I've divided this task into subpages for better readability,


Some pictures of the setup so far

rx3_turbo.jpg

rx3_sideview.jpg

rx3_runners.jpg