For Distributor driven Type Engines

Part No. GRN 175 – D/Driven 967E (with optional lambda control)

Please read these instructions in full before attempting to fit your new system.

Group N kits have been designed for use in Rallying & racing cars where they are to be competed in showroom or near factory production classes. The biggest improvement these kits give apart from the extra BHP is the rapid throttle response. This is made possible by the use of throttle angle control which is instantaneous (as opposed to the standard airflow meter which is very slow & no matter what you do to your standard ECU it cannot overcome) & the speed that MBE ECU works at, which is up 10 time faster than the standard item. They can be used to upgrade road cars, but please note that although they are very smooth to drive, they don’t have all the functions of a road ECU e.g. they cannot drive the Idle control valves, which means starting especially from cold you may have to hold the throttle to maintain idle for a minute or two.

Notes:

A. Super-unleaded fuel must be used, otherwise damage MAY occur to engine. do not use normal unleaded fuel.

B. The Lambda sensor, on the outlet of the exhaust manifold (Bosch Part Number 0258 003 017) which is standard on Astra/Cavalier/Calibra -can be used for ideal mixture at idle. For an ideal mixture throughout the rev range, a wide range lambda sensor (as used on racecars) can be used. Please quote SBD part number LMBDA-11.

C. 6 pin throttle potentiometer, SBD Part Number PT-2, must be USED (Except for MK3 Astras with Traction Control they have this type of potentiometer already fitted as standard. The TC will no longer function after the GRN competition MBE System has been fitted. You will need to remove TC bulb from dash).

D. A digital voltmeter will be required for the set up.

E. White injectors, Bosch Part Number 0280 150 744 & a 2.5 Bar regulator must be fitted.

1. Remove SFI box from under bonnet.

2. Remove 3 pin throttle potentiometer(pot) and fit new 6 pin throttle pot in its place. Trim 3 pin socket to fit pins 4. 5 and 6 on new pot (ASTRA MK3 with Traction control should have wires modified as follows :-

a. Fold back boot on 6 pin connector

b. Cut wires about 2” from connector on pins 4,5&6 and fold back well out of the way as these Must not be used – Make sure you can not accidentaly use them

c. Cut wire about 2” from connector on pin 1 and connect to wire on pin no. 6

d. Cut wire about 2” from connector on pin 2 and connect to wire on pin no. 4

e. Cut wire about 2” from connector on pin 3 and connect to wire on pin no. 5

NOTE – Ensure that none of the wires cut in a. are not used

f. Re fit boot

3. Remove old ECU from drivers kick panel & fit new ECU and adaptor loom in its place-attach new to ECU to car.

4. With ignition on and throttle pot socket disconnected, probe the 3 wires on the loom socket for the throttle pot, 1 of them will be ground the other 2 approximately 5 volts. NOTE the lower voltage wire (this is the signal return to ECU) as this will be used to set the new throttle pot position.

5. Re-connect socket to throttle pot on pins 4. 5 and 6, peel back rubber boot and probe the wire carrying the signal return to the ECU noted in 3. and the ground . (the voltage will now be approx. 1 volt or less) Check socket is on the correct way by opening the, the voltage should increase. If it decreases the socket is on the wrong way round.

6. When socket is the correct way round., twist the throttle pot until a voltage of 0.690V is reached and then lock the throttle pot in this position.

7. Open and close throttle a few times and check voltage remains correct. If not, repeat 4 and 5 until correct. Then turn the ignition off.(On some pots it may be nessesary to slot the locating screw holes further)

8. Secure loom socket to throttle pot with a' ty-rap' or similar clamp and seal other pins using LM grease or Vaseline.

9. Remove old idle control valve & replace with modified one, supplied.

10. Re-fit SFIbox

11. Start engine, which may not idle correctly yet, and let engine warm up to normal operating temperature. When engine is at correct temperature, adjust engine revs to. 980 rpm. This is achieved by adjusting screw on modified idle control valve- DO NOT TOUCH THE BUTTERFLY SCREW UNDER ANY CIRCUMSTANCES. TAKE CARE AS ENGINE WILL BE HOT.

Please note that this kit is based on a racing management system. It does not have an automatic idle control valve, your engine may not idle immediatly from cold. For the first couple of minutes you may have to use the throttle pedal to maintain an idle but you may drive your car as normal from start up.

S B Developments

THROTTLE POTENTIOMETER AUTOMATIC SETTING

Group N 175 KIT

The THROTTLE POTENTIOMETER may be set automatically by means of the FAULT LAMP.

THROTTLE SENSOR SETTING ON THE CAR:

In order to replace the Throttle Sensor and to position it accurately on the throttle spindle it is necessary to adhere to the following procedure.

1. Ensure that the throttle is in the closed position.

2. Replace the Throttle Sensor as required and connect it to the wiring harness as described in the setting up procedure

3. Turn OFF the power to the ECU.

4. PRESS AND HOLD THE FAULT SWITCH WHILST TURNING ON the power to the ECU.

5. Release the FAULT SWITCH.

6. Carefully move the Throttle Sensor until the FAULT LIGHT is OFF. The FAULT LIGHT will remain ON until the sensor is correctly adjusted.

7. Tighten the holding screws.

The Throttle Sensor is now correctly aligned to the throttle spindle.

SB Developments

LIST OF FAULT CODES

CODES DESCRIPTION OF FAULT

2 - 1 Throttle Sensor or wiring to Throttle Sensor

2 - 2 Air Temperature Sensor or wiring to Air Temperature Sensor

2 - 3 Coolant Temperature Sensor or wiring to Coolant Temperature Sensor

2 - 4 Pressure Sensor or wiring to Pressure Sensor (if fitted)

2 - 5 Battery Voltage. This is triggered below 11.5 volts but not during cranking.

3 - 2 Crankshaft Sensor or wiring to Crankshaft Sensor.

Rapid No Faults recorded.

NOTE: After turning ON the power without the engine turning the fault system will show a 3-2 fault. THIS IS NORMAL until the engine has turned.

SB Developments

FAULT LIGHT FLASHING AND FAULT DIAGNOSTICS

The system incorporates a FAULT LIGHT for simple Fault Diagnosis and automatic Throttle Sensor setting.

When the ignition is turned ON and the engine is stationary the FAULT LIGHT is ON. As soon as the engine has started the light will go OFF provided there are no faults detected in the system.

Whilst a fault is detected the FAULT LAMP is ON. If a fault is intermittent then the FAULT LIGHT is only ON whilst the fault is present, i.e. the light will flicker with an intermittent fault. However, the ECU will remember the fault WHILST THE POWER REMAINS ON THE ECU. Once the power is turned off the recorded faults are erased.

Should a fault be present (fault light ON) or suspected, then the FAULT SWITCH should be pressed once and released. The ECU will then flash the codes of all faults, which have occurred since the power was last turned on.

If it is wished to erase all recorded faults manually, it is necessary to press and hold the fault switch for approximately 3 seconds. All faults will then be erased, thereby ensuring that should any fault that occurring after this is a true fault.

If there are no faults within the system, or all of the faults have been erased, then a press and release of the Fault Switch will cause the fault lamp to flash rapidly. This is the NO FAULT coded flash.