We have made extensive use of various computer-aided engineering tools in 2-stroke and 4-stroke engine projects. The most extensive use has been for the engine development of our 95Racer project, which has resulted in a reliable engine that now produces over 95bhp at the rear wheel, up from the 67bhp of the standard engine. This gain has not come easily, requiring lots of effort. However, we can categorically say that without the use of extensive simulation, it simply would not have possible. Our experience has clearly shown that knowing which part of the engine represents the next bottleneck in terms of extracting power and torque saves an enormous amount of time wasted in "dead ends".
For instance, we simulated:
- Over 500 different exhaust configurations
- Over 100 different camshaft profiles
- Over 100 variations in cam timing
- Over 50 intake runner geometries
- Over 50 throttle body geometries
- The valve train dynamics to determine the required valve spring rate and pre-load (The standard spring showed lots of valve float above 8500 RPM)
Here are some examples of the cam timing simulations. You can easily see the effect that cam timing has on performance, not all of them positive! Intake is on the left and exhaust on the right.
Quite obviously, it simply wouldn't be practical nor possible to fabricate these permutations of parts and test each one on a dyno. Also, quite clearly, not every project requires, or can afford this level of effort, and so we provide two levels of service.
This is a service that focuses primarily on the dimensions of the exhaust system. It requires a minimal set of parameters to be supplied by the customer, yet provides useful information about how to build a higher performance exhaust system. This service is especially popular with our 2-stroke customers who have a tuned or otherwise non-standard engine. We usually charge £150 to perform this service and here is an example (from our Yamaha TZR-250 Hyrbid) of what you receive in return.
It is this same service we supplied to Stan Stephens to get his Yamarilla Banshee race bike good enough to get it banned from competition!
Full Engine Simulation
This provides the level of service similar to what we used on the Kawasaki ER-6 engine in our 95Racer. The cost of this service usually entails 2-3 weeks of work and is priced accordingly. Still, if you're serious about building a special engine, this is by far the most economical route.
An extensive set of parameters is required and the task of obtaining this set of data through measurements and calculations can be significant in itself. We are happy to have the customer undertake this effort to keep cost down. In brief, this service analyses the following areas:
- intake system
- combustion process
- cam profiles
- valve train efficiency, incl. valve float and bounce, and valve spring rate and preload sizing
- exhaust system including silencer
- flow coeffients
Here is an example of the type of information this simulation provides, in this example the outcome of a set of exhaust configurations.
This level of service is quoted on an individual basis and requires a close interaction with the customer throughout the process. Please get in touch to discuss your requirements.