Going to need engine dimensions sooner or later

Got a few things done. Worked a bit more on the frame just to get a rough idea of how the engine bay is going to be arranged. Thanks to Ryan by the way for digging up a couple driver models. Going to have to change the main and front hoop geometry to get the driver's head to pass the requirements in the SCCA GCR.



Unlike the CU Racing FSAE cars, the engine will not be a stressed element of the frame. Sportbike motors aren't designed to be stressed members of open-wheeler frames. As such, the mount points aren't really all that great for having the thing fully stressed. If you try to do it that way you either tend to get stuck with a rigid design where you can't get the engine in or out, or the engine can go in and out easily but you lose all your rear end rigidity from crappy mounts. On this go around the engine bay will be fairly wide and fully triangulated for hub-to-hub rigidity. The engine itself will have some simple mounts inside the bay to hold it in place and restrain it from drive torque.

Right now I'm just using a scaled 600RR model as a placeholder. Going to really need to CMM a 1000RR (or GSXR, whatever) block soon to get some basic dimensions to figure out how much room I need for the bay, intake and exhaust points, etc.

Speaking of exhaust points, threw in a few baseline parameters into my handy wave reflection tuning spreadsheet to get an idea for how long and what diameter the tubes will have to be. Right now it's setup for 4-2-1, though in the end it will likely be 4-1 out one side, or twin 2-1 collectors. I think the last time I talked to Caldwell (the veteran, retired 35+ year race engine builder) his thought was you do get a lot more "streetable" torque band from the 4-2-1, great for FSAE car, but you do ultimately lose out on some peak top end.



Found a couple places that do CNC mandrel bending of tubing. That'd be a great way to do the exhaust. If you haven't built an exhaust manifold before... it's a pain. Real challenging to do in CAD with 3d sketches woven through the frame while matching the right cylinders for the collectors, and keeping equal lengths. Likewise building it is a real bitch getting all the bend and compound angles right. Just building one "on the fly" with no CAD it would be impossible to get the lengths equal... then you have to go in and start to do individual cylinder trimming and all that BS. So yea, having the primaries seamlessly bent from continuous tube would rock.