Suspension woes, I have found that the 2007 R1 shocks are far too stiff for my needs. I will be exploring other options from Ohlins, Penske, etc. for the next while. Jan 2015.
Found some one-offs from Ohlins that I got new for 40% off, they are extended versions of the TTX25 MKII. After a bunch of math and a lot of miles in rFactor I chosen a couple sets of springs to go with the shocks. March 2015.
Also have been spending time on system design and modeling for electric reverse which could double as an assist for launching from a stand still. Yet to be determined whether the system will be effective for launch assist. Will likely get a lower first gear ratio to help, regardless of the outcome. The left image below shows the initial ScicosLab/Coselica model for a launch assist system, the only control loop is the clutch actuation. The intent is to learn and understand the Coselica modeling libraries while also preparing an acceptable basic ICE only launch assist model.
This next group shows development of the CAD model as more details are attended to. These were added 2014-Oct-11.
A bit of a no brainer, but lowering the weight became a focal point for performance enhancement. I began looking into the parts for which weight was something I could control, these are the structural parts of the car. The structural stress analysis is on going but there is some information available here, or click the image below.
This next group shows development of some details now that the concept is frozen. Concept resembles an Ariel Atom, with a motorcycle engine. At that time the engine was a circa 2007 Yamaha R1 engine. This is around 2012.
This blog documents the evolution of the car design and some studies I have completed along the way. Most pictures can be enlarged and have a captions with more details, click to enlarge.
This first group shows the evolution from the very early stages. Very conceptual. This spans 2009-2011.
It was about this time when I did some CFD to optimize aero loads and fix the outer boundary of the design. Click here or the image below to see the webpage about that experiment. In parallel with several other deisig activities, this took about a year starting in the summer of 2012.
This group shows the fuel system design and some parts purchased. Also bought the bronze 13x8 TrakLite Launch wheels, 11lbs each I believe. This was early Nov 2014.
Although I had been developing a race sim model since about 2010, the majority of the work was done Jan-Feb 2014. Watch the video to see what it looks like.
This group shows CAD images and the first mock up of the engine sub-frame that is made from cardboard and the mounting bolts. The fit of the cardboard parts made from the CAD parts was better than expected. The wood mock up is coming soon. Details like these also lead to increasing fidelity of the race simulation model. Also Nov 2014.
With a detailed CAD model I was able calculate all these parameters and to fully populate the physics and graphics files needed for a race simulation model. I used this race sim model to investigate the performance effects of several primary vehicle parameters: weight, engine power, downforce, and aero drag. Click here to read more about that study.
With areo boundary fixed, I could explore the internal systems in more detail. This allows for detailed measurements of vehicle parameters such as weight, inertia, suspension parameters, etc. Also, I bought a 2007 Kawasaki ZX10 engine in the summer of 2013. You can see the updated engine+exhaust model in the images below. I plan to use the engine entirely stock.
The middle image above shows some simulation results from the ICE only model. The left plot shows, from top to bottom: crank shaft speed (rad/s), crank shaft torque (Nm), wheel speed, wheel torque, vehicle speed (m/s), vehicle force (N), and clutch normalized actuator signal (0=disengaged, 1 = engaged). The right plot shows some clutch details: clutch input speed, output speed, input torque, output torque, and the lower three are the same as the left plot. Looking at the top 2 graphs in left and right plots, we can see that the controller modulates the clutch to maintain engine speed while the vehicle accelerates, which is the intended outcome.
The electrical side of the reverse system has not yet been modeled. Some work is required here to better understand electrical power and energy during an aggressive launch event. March 2015.
Found a potential inspector for the car, so now its time to add some of the finishing touches necessary for inspection according to the CVSE inspection manual. The images below show mirrors, lights, properly sized wheels with street tires, and bumpers. Clearly the rear bumper concept doubles as tire rack for hauling the race tires to the track. March 2015.
The images above also show preliminary model of the rear wing. rFactor trials in early 2015 demonstrated instability during braking and corner entry. Moving brake bias to >70% on front helped, this suggests that under heavy braking, rear end grip was insufficient. A rear wing and some weight adjustments has significantly improved stability; however, the car tends to understeer now. This result is not ideal, but easier to handle in the simulator. As a result, I purchased a used rear wing from a Stohr Gen 1 car which has similar physical shape to the wing used in CFD simulations, images coming soon. Jan- Mar 2015.
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