Had a chance to record some new footage of the exhaust. XForce Varex VMK51-250 variable volume exhaust – it’s pretty much straight through when it is open. Here’s a few runs with the back boxes set to closed and open for comparison. The engine is a BMW M20B25 with a crank from an M52B28 making it an M20B28. It has a dbilas 282°/272° camshaft. It’s running the original 80’s motronic from Bosch with a chip map design for the stroker conversion. It does pop a bit when the exhaust is warm and you change down. Would benefit from a more modern ECU and tuning (someday!)
