Sample Apps

  XR650 Tuning

    Input file

  Shim ReStackor

    Clicker map

    Valve Tuning

    Trail Stack

  ReStackor pro

    Clicker map

    Valve Tuning

    Damp Coeff



Shim ReStackor Valve Port Diameter Calculations

The input file for the XR650 ReStackor calculations was setup here. The first thing we want to do is run the stock valve stack configuration at a couple of different clicker settings to create a map of stack flow area vs clicker setting. Instructions for creating the clicker map for the stock valve configuration are here.

To determine the effect of different valve throat diameters all we have to do is change the D.thrt parameter in cell H8. The stock valve port diameter for 2000 to 2004 bikes is 2.65 mm. Borynack reports that the 2005 XR650 is using a port diameter of 1.96 mm. We want to run both of those diameters and the 3.64 mm port diameter recommended by Borynack and determine the point where the valve port diameter limits the flow. For the first calculation we will run the stock 2.65 mm throat diameter as setup below.

After clicking on the run button and the Load_Output button the ReStackor calculation results are loaded into the "ReStackor" tab of the spreadsheet and the plots are automatically updated. 

ReStackor Output

Results from the calculations are loaded into the "ReStackor" tab of the spreadsheet when you hit the "Load_Output" button.

Shim ReStackor calculation results are in columns A through E and columns G through M are ReStackor pro calculation results. For the Shim ReStackor outputs "Force" is the force applied to the shim stack face. ReStackor runs about 20 points between zero and the force requested in the input file, in this case 7 lbf. The calculation points are closely spaced near zero force to accurately describe the shim stack deflection as the stack is cracked open. The ReStackor output parameters are:

  •  Yport is the deflection height of the outside edge of the shim stack in inches. 

  • Aclsd is the fluid flow area in square inches between the shim stack and valve face with the bleed clickers in the closed, 0 click, position. 

  • Aclk is the shim stack plus bleed circuit flow area at the requested clicker position.

  • Awo is the flow area with the clickers wide open. 

Valve Port Throat Diameter Effects

For this exercise we want to compare a couple of cases with different valve throat diameters and plot the results to see where the valve throat diameter limits the flow area through the shim stack. On the ReStackor spreadsheet every time you click on the Load_Output button the data columns in the "ReStackor" output tab are overwritten. To save results between calculations we need to copy the outputs in the ReStackor tab to another worksheet.  

To do this a new worksheet tab named "D.thrt" was added to the workbook and the Shim ReStackor results in columns  A through E copied to it. Subsequent calculations with the throat diameter set to 1.96 mm and 3.64 mm were made and the results pasted into the "D.thrt" work sheet. With these results the effect of valve throat diameter was plotted as shown in the worksheet below. 

The instructions here assume you are somewhat familiar with excel and how to run and manipulate data within spreadsheets. The instructions do not go into how to create a plot in excel. If you need help with that check out the microsoft excel website. 

RETURN to XR650 sample case.