Current ver. 4.8.2
Update info.

Let us introduce you to the Excel based software. Bimotion is currently the dominating software for passive engine tuning, i.e. time-area and parameter controlled. The program generates state of the art pipes with respect from exhaust- and transfer ports time-area and shape design. Since the exhaust port and the exhaust pipe should be regarded as one unit, this is the optimum user friendly way to do it with full control. The ports should be mapped on paper and measured. The data are then entered into the program and converted for 1D flow calculation.



The unique Bimotion features are:

* Arbitrary port shapes
* Dual exhaust port
* Auxiliary exhaust ports
* Port mapping translation
* Exhaust pipe and exhaust port dependence
* 3 to 8 ports
* Blair Pipe (Pre-parameterized 5-coned pipe)
* Custom pipe (2 to 6-coned pipe)
* Comparison of 2 exh. port sets (e.g. stock - tuned)
* Inside parameter recommendations dependent on
  engine size and tuning degree based on massive testing.
* Port layout development plot
* dxf cad drawings output on developed cones,
   hydro form and roll form.
* Language translation file import
* 4 years free support and updates.
* Portable, no hardware lock

System requirement:
Any system with installed MS Excel 2003 or later except Excel 2016 and any trial versions.

The program is divided into different pages that are accessed from the 'Pages' button. Different program sections makes the actual dimensioning work more efficient and less time is spent on searching after parameters in the program.

Two identical sections ('Exhaust Port #1' and 'Exhaust Port #2') are intended for one original configuration and one modified configuration  These two pages are transparent to each other in red and blue color, see below.

'Transfer Ports' handles 2-5 scavenging ports shape design.

'Custom Pipe' is a fully parametric flexible pipe model.'Blair Pipe' is an auto-generated racing pipe with certain built in dependencies.

'Port Mapping' is a table set to convert a paper mapped measure into a projected flow measure.

'Development Plot' is page where a developed plot can be printed for all ports or selected.

'About...' page connects and shows the latest released version, online manual access, etc.


The different pages are:

Custom Pipe, a flexible model with built in parameter recommendations.

Blair Pipe, a pre-parameterized 5-coned pipe for race engines.

Exhaust Port, one of two identical sheets. Two transparent configurations with auxiliary ports, arbitrary shapes.

Transfer Ports, 2 - 5 ports, arbitrary shapes.

Port layout plot. Two exhaust port configurations are overlaid for comparison in this plot example.

General Pipe manage pipes with coned header, 3-stage diffusor and 2-stage baffle for which any custom dimensions can be used. The user are guided by a lot of detailed recommendations from well known designs in real life. This works more or less as a 'pipe lab' page.

Bimotion Pipe

Design & Simulation of Two-Stroke EnginesThe other exclusive pipe model is suggested by prof. G.P Blair (QUB). This theoretically elegant pipe is described in the book "Design & Simulation of two-stroke engines" and is also designed from a time-area designed exhaust port. The program uses the mathematics and recommendations described in chapter 6 in the book.


The exhaust- and transfer ports shape design are made in a table and plotted in real time in a chart. For a chosen tuning degree, the port should be designed to reach the time-area target (decided by the tuning degree).

The exhaust port can be mapped inside the cylinder on a piece of paper, developed, measured, and entered in a column to be transformed to the port shape in flow direction. The reverse can also be done, i.e. adjust the port shape in flow direction and plot it as developed. The program also produces manufacturing templates as sheet cone developments in the same time. Very user friendly !! 

The plots are changed in real time when values in green cells are changed.
The modeling is very flexible with a lot of options to view the ports in charts.

         Dual exhaust port

The print function also include dxf cad drawings output of exhaust pipes !

- Ordinary layout drawing
- Cut out template for hydro forming
- Developed cones cut out templates for roll forming

Customized compensation for TIG weld seam and sheet thickness.

Read the KX500 case study and the manual for further insight in how to calculate high performance 2-strokes with Bimotion software!

You need Adobe Reader to open
the manual and case study.




Download the manual, click a flag !
(Man.ver.4.8.1)     (Man.ver.4.6.5)




US $ :249.00

Order is to be placed from Contact in the menu.
Please specify program and Excel version
(2003, 2007, 2010-2015 (except 2016) and 32- or 64 bit OS)