What is a 5AS Unit and where is it?
The 5AS Unit is part of the Rover K series Engine Management System. It is a Rover part and is configured with your ECU to work as a security (anti theft) device. The ECU and 5AS Unit are security coded as a pair and so must be kept together. The 5AS Unit is often confused for the MFU (Multi Function Unit) as they look similar, both are black, and similar size. The MFU is a switching unit with relays inside. It is often mounted with the ECU and has a taper to its shape. The 5AS unit is mounted behind the speedo on a Lotus Elise. The 5AS Unit is approximately 12 cm long 8cm wide and 3.3cm deep. If we need to test your engine we must have the ECU and 5AS unit with its key fob to test your ECU. if there is still any doubt bring all three units with the engine.
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Why should an oil cooler be fitted?
Dynamometer tests show the engine operates best within a certain temperature range, see our engine data pages. The oil cooler will assist in control of the high oil temperatures often seen in track use.
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Why should an up-rated radiator fan be fitted?
Temperature control is key to engine performance and reliability. The Engine Control Unit (ECU) can enable the fan to operate at a specific temperature range, therefore reducing the risk of the engine reaching higher, detrimental temperatures.
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Why should a modified air-intake be fitted?
The engine charge (air/fuel mix) temperature is very important to be cool; therefore it is advantageous for the air to be drawn in from outside the enclosed bonnet, as this will benefit performance
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When fitting a new or rebuilt engine should the oil system be cleaned?
Yes, it is very important to thoroughly clean the pipes and oil cooler (if fitted) before the engine is fitted.
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How often should the oil level be checked?
The oil level should be checked when refueling.
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Does the oil level need to be checked more frequently if used on track?
Yes, it should be checked before every half-hour of use.
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Does the oil/filter need to be changed more frequently if on track?
The oil/filter should be changed before track use.
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Is there any particular oil I should use?
We recommend a 15w/50 good quality oil e.g. Mobil 1 Motorsport.
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What is the required minimum oil temperature?
See Engine Running Data pages specific to your engine.
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What is the required maximum oil temperature?
See Engine Running Data pages specific to your engine.
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What is the required minimum water temperature?
See Engine Running Data pages
specific to your engine.
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What is the required maximum water temperature?
See Engine Running Data pages specific to your engine.
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Should an antifreeze/corrosion inhibitor be included in the coolant?
Yes, it is very important to ensure the correct strength is used. Back to top
Does the cooling system need to be bled?
Yes, stringent bleeding of the cooling system is vital to the performance and reliability of the engine.
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What is the required idle speed when engine temperatures are at the correct level?
The required idle speed should be 1000 RPM ± 100 RPM.
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Does the engine need running in?
Most engines are run in on our Dynamometer before power-cycles are commenced. However, we strongly
recommend close observation of oil/coolant levels etc. in the early usage.
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Can the engine be used without an air filter?
No, it is important an air filter,in good condition, is used at all times.
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Does the throttle cable need adjusting?
To get the best driving position, you may need to adjust the throttle pedal, however you must ensure a throttle
pedal stop is used in order not to stretch the cable.
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What is the MAX RPM of my engine?
See Engine Running Data pages specific to your engine.
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