CPI sand pipe vs ProCircuit
Posted: October 18th, 2011, 4:40 am
Hey, today I can test the CPI sand pipe in my ´94 CR500. I have rebuilt and tuned the engine recently:
-Rebore the cylinder to 90mm and new Vertex piston.
-190/126 porting, widening the exhaust port, grinding the exhaust port flangle, ...
-V-Force 2 reed cage.
-41mm PWK by Sudco.
-´86 cylinder head cutted to attain 2.5mm squish height.
-HPI 2 curves programmable CDI from www.hpi.be
-Hinson clutch basket with EBC disk.
-`92 CR500 closed ratio trans.
Before rebuild the engine I have a ProCircuit. When I tuned the engine, it lost some low end but the mid-range and top was much better. I can do wheelies in mid range in 5th gear with 15/49 gearing only with the throttle. But I felt the engine wants to pull harder in top-end and the PC don´t allowed it.
Today I put the CPI in my bike and It fits perfect. The sound was very good. The change in power delivery is radical. The bike feel like a 250 with the 500 power.. Again I have lost low end comparing with the PC (and this exhaust isn´t the best in low end ). The midrange is slightly better than the PC with more torque, but the top end was amazing . With the PC I can´t do wheelies in 5th in top end, only in mid range, and now I can´t open full throttle. I can do the backflip in 5th with 15/49 only with the throttle .
If you need low end, please don´t buy this exhaust. If you ride SM, dunes, drag,... and you need amazing power in top end, this exhaust is made for you.
-Rebore the cylinder to 90mm and new Vertex piston.
-190/126 porting, widening the exhaust port, grinding the exhaust port flangle, ...
-V-Force 2 reed cage.
-41mm PWK by Sudco.
-´86 cylinder head cutted to attain 2.5mm squish height.
-HPI 2 curves programmable CDI from www.hpi.be
-Hinson clutch basket with EBC disk.
-`92 CR500 closed ratio trans.
Before rebuild the engine I have a ProCircuit. When I tuned the engine, it lost some low end but the mid-range and top was much better. I can do wheelies in mid range in 5th gear with 15/49 gearing only with the throttle. But I felt the engine wants to pull harder in top-end and the PC don´t allowed it.
Today I put the CPI in my bike and It fits perfect. The sound was very good. The change in power delivery is radical. The bike feel like a 250 with the 500 power.. Again I have lost low end comparing with the PC (and this exhaust isn´t the best in low end ). The midrange is slightly better than the PC with more torque, but the top end was amazing . With the PC I can´t do wheelies in 5th in top end, only in mid range, and now I can´t open full throttle. I can do the backflip in 5th with 15/49 only with the throttle .
If you need low end, please don´t buy this exhaust. If you ride SM, dunes, drag,... and you need amazing power in top end, this exhaust is made for you.