Q. Will the Rimmer Supercharging System fit my pre-1989 Land
Rover, or non-V8, carbureted or diesel engine?
A. Systems are applicable to port-fuel-injected (EFI) engines only; 1989 and
later. Each vehicle model installation must be tested for hardware and software
compatibility before it is released for sale. All Range Rover and Land Rover systems
offered have been verified and have received California Air Resources Board (CARB)
exemption orders (certification).
Q. Do the injectors or the ECU (computer) need to be changed to install the
A. The Rimmer Supercharging System uses the maximum number of
original equipment components, including the fuel injection system and engine controls.
Supplementary fueling and spark control (knock sensor) equipment are included in the
system if needed for a particular engine. These modules are designed and programmed to
work with the factory fuel and ignition timing controls, providing adequate adjustment
characteristics to accommodate the supercharger installation as supplied in the package.
Q. How will installation of the Rimmer Supercharging System
affect my new vehicle warranty?
A. An auto manufacturer cannot legally void your new vehicle warranty merely
because you have added other equipment to your car. For example, they cannot void an
engine warranty unless they can prove that the supercharger was the cause of the problem
or failure you are attempting to have repaired under warranty. However, a supercharger is
considered "speed equipment" and therefore, you are putting it on your vehicle
at your own discretion and liability. (The supercharger unit is warrantied by the
manufacturer for three years. The other components of the Rimmer Supercharging
System are warrantied by Rimmer Engineering, Inc. for a
period of 12 months or 12, 000 miles. Consequential damage, personal or property damage is
not covered under this warranty.)
Q. Does the Rimmer Supercharging System require upgrading of the
engine or other parts of the powertrain?
A. The supercharging system is designed to work with the existing factory
powertrain as supplied by the vehicle manufacturer. Your personal driving style or vehicle
use profile may make certain upgrades desirable in order to take full advantage of the
power and performance increases that become available when the Rimmer
Supercharging System is installed.
Q. How reliable is the supercharger?
A. The Eaton supercharger has been designed to qualify as original equipment
by manufacturers of new vehicles. Because of the very high standards necessary to meet
these requirements, the Eaton supercharger has very high reliability. Eaton says,
"... strict customer durability test criteria have been achieved. Successful
completion of numerous 500 hour durability tests established a firm grasp on achieving a
reliable product. In addition, numerous vehicles have successfully completed 100,000 mile,
OEM (original equipment manufacturer), vehicle durability tests. Improvements in bearing
and seal designs also aided in a product which meets all OEM durability criteria."
Q. How difficult is it to install the Rimmer Supercharging System?
A. The mechanical installation process is a true "bolt-on" and does
not require any engine internal modifications, welding or fabricating. Typical
installation times should be in the four to six hour range for a moderately experienced
Q. Does the addition of the supercharger require use of premium grade
A. It is possible to run the vehicle on a lower grade of fuel, but the engine
control computer will automatically dial back the ignition advance to eliminate knock
(pre-detonation) in order to prevent engine damage. To obtain the designed power potential
of the Rimmer Supercharging System, premium fuel should be used.
Q. What is the effect on fuel economy?
A. The biggest effect on fuel economy is caused by greatly increased driver
enthusiasm. Because the supercharger is equipped with an automatically-actuated bypass
valve, loads on the system are drastically reduced during low power demand conditions
(such as at cruising speeds or while idling). Eaton Corporation, the supercharger
manufacturer, states that "a typical domestic vehicle ... shows no fuel economy
penalty for highway driving and only a one mile per gallon penalty for city driving."
And that "during typical driving conditions, the engine is under boost around 5% of
the time, which means the remaining 95% of the time the engine is under vacuum..."
Our experience is that the "grin factor" will result in your engine being under
boost more than 5% of the time, so there will probably be some fuel mileage penalty but
this will occur mostly under city or heavy off-road driving conditions, is usually
nominal, and can be adjusted easily by decreasing the drivers right foot pressure.
Q. What about "throttle lag"?
A. The Rimmer Supercharging System uses a
mechanically-driven, positive displacement supercharger, which is coupled directly and
proportionally to the engines crankshaft speed. The bypass valve system, which opens
automatically when boost is not needed, also closes immediately when you press the
accelerator pedal. Unlike a turbocharged engine, boost is right there when you want or
need it...no lag.
Q. Is an intercooler required?
A. While desirable from a performance standpoint an "intercooler"
(or, more properly, an aftercooler) is not a necessity. The Rimmer Supercharging
System is designed and configured to work very well without one. We expect,
however, to offer an optional charge air cooling system in the near future, for those who
want even more power.
Q. What comes in the package?
A. The Rimmer Supercharging System is a complete
installation package, except for tools, skill and labor time. It includes the supercharger
assembly with bypass valve, belt-drive equipment and accessories, manifolding and plenum
components, necessary sealers and gaskets, hoses and clamps, hardware, etc. required to
connect the package components to the engine, to each other, and to the factory air filter
and inlet system. Complete, illustrated installation instructions are provided. Fuel
controller and knock sensor modules are included as required by the particular vehicle
Q. Where is the throttle control valve (throttle body) located?
A. The original Rover factory throttle control valve assembly is remounted on
the "upstream" side of the compressor, providing air inlet control for the
entire supercharging system. This design eliminates the driveability, reliability and
safety concerns present in arrangements that place the throttle control on the
"downstream", or outlet, side of the supercharger. Combined with the
automatically-actuated bypass valve, this configuration results in precise control of
Q. What sort of performance improvements can I expect with a Rimmer
A. Results will vary, depending on the driver, the condition of the vehicle,
gearing and other factors. Our test results show an average reduction in 0-60 MPH
acceleration times of approximately 2.5 to 3 seconds, more as altitude increases. You can
imagine what effect a 30% increase in torque will have in off-road operation.
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