Replacement Upgrade Ignition for Porsche 911 Carrera and Turbo Engines
Ignition performance is the most important component of an engines performance. It is the last function that happens before power is produced. Powerful and reliable Ignition is critical in making your engine perform at its best.
A little history. Porsche 911 and 911 turbo engines produced during the late 70’s and through to the late 80’s all had Bosch CDI ignition. In the early 90’s the requirements to meet tighter emissions regulations and higher fuel mileage required the ignition systems to change. However, there was a time where the hemi combustion chambers used in Porsche engines had Inductive ignition. The larger combustion chambers and long flame travel required these engines to have dual spark plugs fitted to shorten the burn travel. Inductive Ignition is not the best choice on large hemi chambers and works better on modern, smaller volume pent roof style chambers.
Performance Developments believes that the more ignition power you can generate within the combustion chamber, producing a higher level of temperature, will always result in the highest level of engine torque. We have proven this many times with these engines. Engines that have very large hemispherical combustion chambers and operate at the lower end of compression ratios have shown huge gains in engine performance. The response is dramatic, especially when compared to the stock and aftermarket Inductive or older CDI systems. The Porsche 911 based engines will idle smoother, have better throttle response and will have a little more performance. How much extra performance? That will always depend upon the state of the engine.
Today, many will install coil on plug (COP) ignition coils with the idea that it will produce more performance. It may if the system you are replacing is poor. Although, COP inductive coils will never out perform a good CDI ignition, even one that still uses the distributor. We believe that any system works best if it is kept simple and in good condition.
What are the advantages of CDI? Other than producing a “hotter” spark, over time a CDI ignition will overcome many of the issues an Ignition system has to overcome due to plug fouling, carbon build up, plug wear, plug wire deterioration, etc. A CDI system stores the energy created in the system during the “off time” in a capacitor, then sends approximately 250 volts through a low resistance coil that steps up that volts to over 100:1 times the initial voltage. The spark generated is very accurate and quite short in duration. About 10 – 12 micro secs. This higher voltage creates a higher in chamber temperature which is the element that ignites the fuel mixture.
Why does it make more torque? Simple. The spark timing can be later or closer to TDC on the combustion stroke, thus generating more dynamic compression before the ignition point occurs. The CDI system produces higher energy levels which generate higher in cylinder temperatures, faster burn rates over less crankshaft degrees, thus producing higher in cylinder pressures upon the piston faces, turning chemical energy into kinetic energy at the crankshaft.
The faster burn rate condition happens as the pistons go over TDC and descends on its power stroke. As the piston travels to BDC, the cylinder pressure drops. This drop in pressure then has less effect on the crankshaft, so the faster the burn rate verses piston position in the cylinder will always make more torque.
With an increase in energy comes some draw backs. Spark plug life will be shorter. You will see some degradation on the center electrode and ground straps. A nice advantage of CDI ignition is it will fire fouled plugs where Inductive ignition will not even attempt to fire.
Choosing a good Ignition system is very important. This is why Performance Developments is proud to be associated with M&W Ignitions. We have been a user and supplier of this great Ignition system for over 20 years. We believe any engine is only as good as the sum of its parts. Remember, the Ignition system is the most important part of any engine. It is the last function to happen before the engine makes power.
The Pro 10R and Pro 10E single channel systems are perfect for the older Porsche engines that incorporate a distributor with either triggers. These two systems can generate 115mJ of energy and up to 150mJ of energy when the high power switch is activated. Each unit comes with this option, however, this is for short time use (push to pass) and not for continuous use. Multi spark feature is also available on the Pro10 unit.
The complete kit comes ready to install with CDI unit, isolation mounts, a short adapter harness to factory wiring, CDI coil, plug and coil wire(s) and new spark plugs.
Pro 10 E. All engines with points triggered Ignitions. Most early 911 engines.
Pro 10 R. All engines with reluctor triggered Ignitions. Later 911 Carrera and Turbo engines.
To determine which Ignition you have, remove the distributor cap and look if your Ignition is switched via points or a reluctor star shaped wheel.
After installing the system, always check your ignition timing and adjust if required. This system may allow you to retard the timing a little and still have the same or better performance. Also check your AFR numbers to ensure you are still running safe. The spark plugs supplied in the kit are a colder heat range than standard and should always be fitted.
Seek professional advice before and after installation if you are unsure about your engines running condition.
For further information and support, call 949 646 7461