EXHAUST DURATION
RPM DURATION
10000-11000 194 ° - 196
11000-12000 196 ° - 198 °
12000-13000 198 ° - 200 °
13000-14000 200 ° - 202 °
14,000 -15,000 202 -204
EXHAUST DURATION FORMULA
T² + R ² - L².
2 x R x T
LONG PISTON handlebar
EXHAUST DURATION = (180 ° - CO) X 2
T = R + L - E
R = STROKE DIVIDED 2
L = LONG PISTON handlebar
E = HIGHER THAN hole EXHAUS T.M.A
Example: YAMAHA F1Z-R
STROKE: 52mm HIGH EXHAUS: 26mm Conrod LENGTH: 96mm
R = 52: 2 = 26mm E = 26mm L = 96mm T = 26 + 96-26 = 96mm
6² + 26² - 96².
2 X 26 X 96
D = (180 ° - COS) X 2
D = (180 ° - COS O, 135 416 666) X 2
D = (180 ° - 82.217) X 2
D = 97.782 X 2 = 195.565 DURATION → 196 ° → EXHAUS = 11,000 RPM
Example 2:
STROKE: 52mm HIGH EXHAUS: 25mm Conrod LENGTH: 96mm
R = 52: 2 = 26mm E = 25mm L = 96mm T = 26 + 96-25 = 97mm
97² + 26² - 96².
2 X 26 X 97
D = (180 ° - COS) X 2
D = (180 ° - COS O, 172 283 901) X 2
D = (180 ° - 80.079) X 2
D = 99.921 X 2 = 199.842 DURATION → 200 ° → EXHAUS = 13,000 RPM
* EXHAUST PIPE *
L = ED X42545
RPM
L = LONG IDEAL KNALPOT. (From PISTON until mid CONE BAFLE).
ED = Exhaust Duration
The engine RPM = Round Exhaust Duration
Example: EXHAUST: 26mm DURATION: 196 ° RPM: 11,000
L = 196 X 42545 = 758mm
11,000
Example 2: EXHAUST: 25 mm DURATION: 200 ° RPM: 13000
L = 200 X 42545 = 654.5 mm
13,000
* HEADER *
Ø Port in exhaust: 34mm 140cc 100cc → → 40mm
→ → 175cc 140cc 40mm 46mm
Header length: 7.8 → 8.8 x Ø Port exhaust
Header angle: 1 ° → 2 ° max (road race). 2 ° → 3 ° max (motocross)
* Flank *
The distance between the piston and the header: 60mm - 80mm
* Diffuser *
Angle Diffuser: Stage 1 = 6.5 ° → 7.5 °
Stage 2 = 4.5 °; 7.5 °
Stage 3 = 4.5 °; 7.5 °; 9 ° → 10 °
* BELLY *
Ø Belly 2 → 3 x Ø Port exhaust belly length = L - (Header + Diffuser + ½ Bafle)
* BAFLE *
Bafle angle of 9 ° - 12 °
* STINGER *
Ø LONG PIPE IN PIPE
125cc - 145cc ------ 150mm - 265mm 19mm - 23mm
145cc - 175cc ------ 150mm - 320mm 22mm - 27mm
