Sierra Power Increases

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TWO WHEEL DRIVE CARS
The original 3 door Sierra Cosworth was produced by Ford to allow the car to compete in motorsport competitions, run to International F.I.A. Group N and Group A regulations. Group N regulations dictate that basically, the car remains in standard specification, with only safety modifications allowed.
For Group A, a large number of modifications are allowed. Suspension & braking components can be changed, as can the size of the road wheels. The engine may also receive further modification. 1987 regulations dictated a production run of 5000 cars with identical specification, all built within a set period, and the manufacturer must provide exact details of this specification to the F.I.A. This procedure is known as homologation.
The manufacturer must also homologate the modifications it requires for Group A. (Braking and suspension components for example can be substituted for the stronger or lighter parts that the manufacturer has homologated).
In Group A, the engine specification must utilise the parts from the original production car. Modifications to camshaft profile, inlet & exhaust port sizes and compression ratio are allowed, but details like turbocharger size and number of injectors used must be as the original 5000 production cars.
When the Sierra Cosworth was originally conceived, a basic engine specification was chosen that would be capable of giving up to about 370 BHP in Group A trim. When the four door Sapphire Cosworth was designed, although it was never intended for competition use, it retained the same fundamental mechanical specification of the original hatchback model.
270 BHP CONVERSION - REPLACEMENT WASTEGATE ACTUATOR & EPROM
Generally known as our level one conversion, its object is to produce the maximum power from the engine using the limited amount of fuel that can be supplied by the standard injectors, without using too much boost at higher revs and allowing the engine to run lean, with disastrous results.
In this conversion we use a replacement Garret wastegate actuator of the correct poundage, and a suitably re-programmed engine management eprom to suit the new parameters that the engine is now running.
Simple performance figures cannot really convey the experience of a conversion like this, but as a guide, the extra performance that you can expect is as follows:
0 TO 60 should improve by 0.8 seconds.
0 TO 100 should improve by 1.9 seconds.
60 TO 80 should improve by 0.6 seconds.
70 TO 90 should improve by 0.6 seconds.
As you can see from the figures above, the improvements are very significant, and will certainly be noticed.
320 BHP CONVERSION - REPLACEMENT WASTEGATE ACTUATOR, EPROM, AND A MATCHED SET OF HIGHER FLOW RATE FUEL INJECTORS
In the Level One conversion, the limiting factor is the relatively small flow rate of the standard fuel injectors. In the early days of Cosworth modifications, the only alternative injectors that were available were the huge Ford Motorsport Grey injectors. These large injectors can cause many unwelcome side effects when used in a standard specification engine, the most dangerous is bore wash, (the excessive levels of fuel injected into the engine, washing the lubrication oil away from the cylinder bores). Another less damaging effect of the Motorsport Grey injector is its relatively high cost price!
For this conversion, we have sourced a compatible Bosch fuel injector, that can flow the required quantity of fuel, but is small enough to ensure correct fuel atomisation at lower fuel delivery rates.
The Level Two (320 BHP) conversion consists of a matched set of these injectors, a replacement wastegate actuator, and a suitably re-programmed engine management chip.
Although the power figures show that this conversion only produces an extra 50 BHP when compared to the Level One conversion, this is just one of the many differences between the two conversions. The Level One conversion releases the maximum power available from the standard injectors, and, as such, it is a compromise. As the Level Two conversion uses larger flowing injectors, the complete engine management mapping has been altered suit. These alterations have transformed the way that the car drives, even before the turbo boost is produced, and then, because more fuel is now available, a higher boost pressure can now be used further up the rev range, resulting in more peak horsepower, but even more mid-range torque.
Please be reassured that by having your car converted in this way, it will not be transformed into a dangerous monster, a great deal of expertise has been used to ensure that the driveability of the car was not impaired, and that the road manners of the car are in fact better than the standard vehicle.
Please note that although the conversions described above were designed to work with the original exhaust & air filter systems, further improvements will be achieved if they are used in conjunction with the GGR 3" bore stainless steel exhaust and cone & trumpet induction kit systems.
PLEASE NOTE THAT THE CONVERSIONS DESCRIBED CAN MEET ALL CURRENT DOT EMISSIONS REQUIREMENTS.
More specific information on conversions and power increases:
RS 500
Four wheel drive Sierra Cosworth, (with green or red top engine)
Large turbo Escort Cosworth
Small turbo Escort Cosworth
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Correspondence/Requests
Sales Enquiries: sales@grahamgoode.com
Technical Enquiries: tech@grahamgoode.com
Tel: (+44) 0116 244 0080
Fax: (+44) 0116 244 0140

TWO WHEEL DRIVE CARS
	The original 3 door Sierra Cosworth was produced by Ford to allow the car to compete in motorsport competitions, run to International F.I.A. Group N and Group A regulations. Group N regulations dictate that basically, the car remains in standard specification, with only safety modifications allowed. For Group A, a large number of modifications are allowed. Suspension & braking components can be changed, as can the size of the road wheels. The engine may also receive further modification. 1987 regulations dictated a production run of 5000 cars with identical specification, all built within a set period, and the manufacturer must provide exact details of this specification to the F.I.A. This procedure is known as homologation. The manufacturer must also homologate the modifications it requires for Group A. (Braking and suspension components for example can be substituted for the stronger or lighter parts that the manufacturer has homologated). In Group A, the engine specification must utilise the parts from the original production car. Modifications to camshaft profile, inlet & exhaust port sizes and compression ratio are allowed, but details like turbocharger size and number of injectors used must be as the original 5000 production cars. When the Sierra Cosworth was originally conceived, a basic engine specification was chosen that would be capable of giving up to about 370 BHP in Group A trim. When the four door Sapphire Cosworth was designed, although it was never intended for competition use, it retained the same fundamental mechanical specification of the original hatchback model.

270 BHP CONVERSION - REPLACEMENT WASTEGATE ACTUATOR & EPROM
	Generally known as our level one conversion, its object is to produce the maximum power from the engine using the limited amount of fuel that can be supplied by the standard injectors, without using too much boost at higher revs and allowing the engine to run lean, with disastrous results. In this conversion we use a replacement Garret wastegate actuator of the correct poundage, and a suitably re-programmed engine management eprom to suit the new parameters that the engine is now running. Simple performance figures cannot really convey the experience of a conversion like this, but as a guide, the extra performance that you can expect is as follows: 0 TO 60 should improve by 0.8 seconds. 0 TO 100 should improve by 1.9 seconds. 60 TO 80 should improve by 0.6 seconds. 70 TO 90 should improve by 0.6 seconds. As you can see from the figures above, the improvements are very significant, and will certainly be noticed.

320 BHP CONVERSION - REPLACEMENT WASTEGATE ACTUATOR, EPROM, AND A MATCHED SET OF HIGHER FLOW RATE FUEL INJECTORS
	In the Level One conversion, the limiting factor is the relatively small flow rate of the standard fuel injectors. In the early days of Cosworth modifications, the only alternative injectors that were available were the huge Ford Motorsport Grey injectors. These large injectors can cause many unwelcome side effects when used in a standard specification engine, the most dangerous is bore wash, (the excessive levels of fuel injected into the engine, washing the lubrication oil away from the cylinder bores). Another less damaging effect of the Motorsport Grey injector is its relatively high cost price! For this conversion, we have sourced a compatible Bosch fuel injector, that can flow the required quantity of fuel, but is small enough to ensure correct fuel atomisation at lower fuel delivery rates. The Level Two (320 BHP) conversion consists of a matched set of these injectors, a replacement wastegate actuator, and a suitably re-programmed engine management chip. Although the power figures show that this conversion only produces an extra 50 BHP when compared to the Level One conversion, this is just one of the many differences between the two conversions. The Level One conversion releases the maximum power available from the standard injectors, and, as such, it is a compromise. As the Level Two conversion uses larger flowing injectors, the complete engine management mapping has been altered suit. These alterations have transformed the way that the car drives, even before the turbo boost is produced, and then, because more fuel is now available, a higher boost pressure can now be used further up the rev range, resulting in more peak horsepower, but even more mid-range torque. Please be reassured that by having your car converted in this way, it will not be transformed into a dangerous monster, a great deal of expertise has been used to ensure that the driveability of the car was not impaired, and that the road manners of the car are in fact better than the standard vehicle. Please note that although the conversions described above were designed to work with the original exhaust & air filter systems, further improvements will be achieved if they are used in conjunction with the GGR 3" bore stainless steel exhaust and cone & trumpet induction kit systems. PLEASE NOTE THAT THE CONVERSIONS DESCRIBED CAN MEET ALL CURRENT DOT EMISSIONS REQUIREMENTS. More specific information on conversions and power increases: RS 500 Four wheel drive Sierra Cosworth, (with green or red top engine) Large turbo Escort Cosworth Small turbo Escort Cosworth

Back to Power Conversions · Back to FAQs & Features · GGR Home
Correspondence/Requests Sales Enquiries: sales@grahamgoode.com Technical Enquiries: tech@grahamgoode.com Tel: (+44) 0116 244 0080 Fax: (+44) 0116 244 0140