Untitled Document Untitled Document
Untitled Document Untitled Document
Untitled Document
Untitled Document


 
Untitled Document Untitled Document
   Valving Info 106
 

 

Base shim

The base (clamp) shim supports the entire stack.  Diagram 13 shows a typical stack with a 40mm main, 30mm separator and 20mm base shim. 


Diagram 13

 

As previously demonstrated, the low speed circuit does not act independently of the high speed circuit if the separator shim is a larger diameter than the base. 

 

Table 12 contains the stock compression valve stack for a 2004 RMZ 250.  Using both the Shim Program and dyno, we will compare the stock valving with a 23mm base vs. a 25mm base

  • As shown below, changing the base shim diameter from 23mm to 25mm has an affect on both low speed and high speed.
 Stock comp valving - 2004 RMZ 250  
11 - 40.20 11 - 40.20  
34.12 34.12  
30.12 30.12  
40.25 40.25  
38.20 38.20  
36.20 36.20  
34.20 34.20  
32.20 32.20  
27.20 27.20  
23.30 base 25.30 base  
     
Shim Program loads (lbs/in) Shim Program loads (lbs/in)  
def load
.003 11.7
.006 23.4
.009 35.3
.012 47.3
.015 59.6
.018 73.4
.021 88.1
.024 103.3
.027 119.1
.030 135.4
.033 152.3
.036 170.0
def load
.003 14.2
.006 28.5
.009 43.0
.012 57.7
.015 73.3
.018 90.9
.021 109.1
.024 127.9
.027 147.3
.030 167.5
.033 188.6
.036 210.7
% diff
122%
122%
122%
122%
123%
124%
124%
124%
124%
124%
124%
124%
11-29-05
04 RMZ 250
stk39s v4
11-29-05
04 RMZ 250
stk39s v9
 
Dyno force (lbs/in) Dyno force (lbs/in)  
ips force
5 130
10 237
20 437
30 619
40 782
50 927
60 1053
70 1161
80 1250
90 1321
100 1374
ips force
5 159
10 254
20 422
30 569
40 701
50 827
60 952
70 1084
80 1231
90 1399
100 1595
% diff
116%
121%
124%
125%
125%
124%
124%
123%
122%
121%
120%
Table 12

 

The Shim Program shows the loads to increase an average of about 23%, and the dyno shows the force to increase about 23%.  The difference in these numbers appear to be very close, but this may just be a coincidence.  The Shim Program load differences generally do not mirror the dyno differences.  From previous experience, the Shim Program loads follow one curve, and the dyno forces follow their own curve.  The curves do not always match.  We are currently working to define the exact relationship between the program and dyno.

In this example, we changed the base diameter from 23mm - 25mm, and noticed an increase in both low speed and high speed forces.  The low speed forces will also increase if any other shim changes are made to the high speed stack.

 

[top]     [next, 107]

 

 
Untitled Document Untitled Document
 
  valving info
valving 001
valving 002
valving 003
valving 004
valving 005
 
  complex stacks
complex shim stacks
 
  more valving info
valving 101
valving 102
valving 103
valving 104
valving 105
valving 106
valving 107
valving 108
valving 109