The Variable Pressure Clutch (VPC) by Tak's Performance Parts is not 'just a lock-up clutch'. The VPC is a system that reduces spring pressure at idle, and as the centrifugal force increases in line with rising engine rpm it provides the clutch with the required pressure to match engine torque.
Adjust the clutch cable. Ensure free play of 1/8in or more at the clutch lever pivot between the clutch holder and lever without pulling ths cable. Install derby cover gasket (Parts#AIM003-003) and derby cover. Tighten bolts to 84-108in-lbs (9.5-12.2 Nm). Tech Note: You can use 18mm spark plug socket to tighten locknut. Barnett news; barnett universal internal throttle cable more barnett ep kit and h-d diaphragm spring video more barnett coil spring conversion kits- install video. One of the less desirable byproducts of increased power is the need for a clutch spring upgrade, and the additional lever effort it requires. By adding the Variable Pressure Clutch (VPC) devise, clutch plate holding pressure is reduced at lower RPM’s, and increased as RPM rises, reducing the chance of clutch slippage as power builds. The VPC system reduces initial pressure and uses weights.
AIM strongly recommend VP Performance Kits to upgrade '98 and later Harley-Davidson stock clutch for any performance engines, even a Screamin Eagle Stage 1 Kit (Exhaust pipe, Air cleaner, EFI tuner). Because as you know Harley-Davidson has reduced clutch lever effort from 2006 Big Twin model by reducing clutch spring pressure about 10%. Even though clutch performance is 10% less than before, the current engine size has been increase to 96ci. That means clutch performance may not be enough when you do any engine performance modifications.
VP Performance Kits are the best product to upgrade Harley-Davidson stock clutch and eliminate unnecessary heavy clutch pull (not like a regular heavy duty spring), but add up to 40% additional pressure to clutch as engine RPM increases (Centrifugal Force) to make very strong clutch clamping force. VP Performance Kit is including VP92T and Clutch spring.
Note: In the Chart, The clutch will not slip when there is your engine torque curve below the clutch pressure curve. These pressure and handling torque in the chart are calculated with stock primary and final gear ratio. These numbers will be change by primary and final gear ratio.
Variable Pressure Clutch (vpc By Tak's Performance Parts Oem
S&S has a long history of making a lot of power, and a lot of stock clutches have been sacrificed to the “Gods Of Speed”. S&S has come up with a couple of economical ways to beef up your stock clutch so it can handle the power an S&S engine can throw at it.
This Variable Pressure Clutch gives you up to 40% more additional pressure for clutch engagement. Fits behind a stock derby cover and primary cover with NO modification required. The upgrade is a 10 minute installation…
Variable Pressure Clutch (vpc By Tak 27s Performance Parts Catalog
For 1998-up Big Twins with 6 Stud Clutch Hub (Does not fit: ‘13 and later CVO™ and Tri-Glide™, ‘15 and later Ultra Limited Low and Electra Glide Classic Low Models with New H-D® Assist and Slipper Clutch: 3 Stud Clutch Hub) Only $284.95.
S&S also offers a Transmission Mainshaft Bearing Race that won’t “walk” on the shaft when you pour the coal to it. The improved S&S bearing race is a must for any high performance application. Fits 2006-2007 & 2010 – up Big Twins. $51.95.
Variable Pressure Clutch (vpc By Tak's Performance Parts Distributor
And to make your stock 1998-later Big Twin clutch a contender, install the new S&S Heavy Duty Diaphragm Spring. And if that isn’t enough, put the squeeze on your clutch pack with the S&S Variable Pressure Plate. The weighted clutch fingers use centrifugal force to increase the pressure on the plates. The faster you spin your engine, the stronger your clutch engagement, all without increasing the clutch lever pull at idle. 380 lbs pressure, 25% stronger than stock. $32.49. More info at S&S Cycle Go Fast.