- Why do your ignitions cost more than those from other suppliers?
- Why don’t most M&W ignition systems include a multi spark?
- I recently installed one of your ignition systems to cure a full boost misfire with inductive ignition. Why do I now have an occasionally misfires at part throttle?
- Will your CDI ignition make more power?
- Why can’t I use your drag race ignition on my street car?
- Why do your ignition systems out perform others with larger (advertised) energy levels?
- Which ignition coils work best with your CDI systems?
- Why don’t you advertise the output voltage for your ignition coils?
- Why do your instruction specify inductive ignition coils be wired in reverse?
- Which is the best configuration for waste spark installations, dual outlet coils or single coils wired in pairs?
- Why do I need to change my timing after installing your ignition?
- Why are there no ignition delay figures quoted for your CDI systems?
- We have conducted direct back to back comparisons between your ignition and other systems without seeing a discernable differences in performance.
- Why does my spark look weak?
- Why do my spark plugs appear to have burn marks or cracks down the outside?
- How do I determine if my trigger edge selection is correct?
- My ECU has igniters built in, will it work with your CDI systems?
Q1. Why do your ignitions cost more than those from other suppliers?
A. M&W products are designed, assembled and tested in Australia using components and processes equal to and often exceeding OEM and Mil-Spec standards. Unlike manufacturers of similar products we do not outsource work to cheap overseas labour. The build quality is reflected in our customer base which consists of end users from Formula 1 down.
Q2. Why don’t most M&W ignition systems include a multi spark?
A. Multi spark ignition is not required for correctly designed & tuned performance engines. Additionally ignition systems are unable to independently determine engine load, crankshaft position or engine rpm therefore it can be harmful to allow uncontrolled multi spark firing. If multi spark ignition is required the safest option is to use an ECU with multiple ignition triggering functionality. Multi sparking is generally effective only when the primary and secondary ignition events are separated by less than 7 crankshaft degrees. Above approximately 1,500 rpm there is insufficient time for an ignition system to recover before piston travel makes a second event ineffective.
Q3. I recently installed one of your ignition systems to cure a full boost misfire experienced with inductive ignition. Why do I now have an occasionally misfire at part throttle?
A. High horsepower street vehicles, particularly those running alcohol based fuels, have a fuel flow range such that single injector systems are incapable of correct metering under light load conditions. Further, the replacement injector spray pattern may wet down the manifold port walls rather than keeping fuel in suspension. Either of these factors or poorly optimised injector phasing will create a non homogeneous fuel mixture at part throttle difficult to ignite which may be masked by inductive ignition.
Q4. Will your CDI ignition make more power?
A. Factory ignition is often marginal and regularly becomes inadequate when increasing engine performance also the use of alcohol base fuels will place additional strain on the system. Using a high energy CDI system will enable the engine to develop its full potential through consistent and complete combustion while tolerating less than ideal air/fuel mixtures.
Q5. Why can’t I use your drag race ignition on my street car?
A. Ignition systems are unable to sense engine load and provide maximum energy whether free revving or under full load. M&W drag race ignition systems were designed to provide ultimate energy in a compact light weight package, street driving would push them beyond their intended duty cycle limits. We do however customise some 250mJ drag race units with a selectable power level function for street use.
Q6. Why do your ignition systems out perform others with larger (advertised) energy levels?
A. The advanced technical design used in M&W systems is more efficient at transferring stored energy into the combustion chamber resulting in consistent complete combustion tolerant of wider air/fuel ratios.
Q7. Which ignition coils work best with your CDI systems?
A. M&W CDI’s can be used with almost any ignition coil and will drive into a short circuit without damage however maximum performance and energy transfer will only occur when using coils specifically designed for CDI use such as our COI-006. On-plug ignition coils were not intended for the energy levels developed by M&W products and may overheat or fail prematurely.
Q8. Why don’t you advertise the output voltage for your ignition coils?
A. There is a general misconception that ignition coils 'develop' a set maximum voltage and feeding on this myth unscrupulous supplier’s quote ever increasing numbers to gain sales. In reality coil voltage will only reach that necessary to initiate ionisation and break down of the spark plug gap. At part throttle this might occur at several thousand volts whereas idle and full power may require tens of kilovolts.
Q9. Why do your instruction specify inductive ignition coils be wired in reverse?
A. Coil primary polarity is determined by manufacturers expectations of ignition type to be used. Spark plugs work more efficiently with the correct polarity (centre electrode negative), to achieve this it is necessary to swap primary wires when using indutive coils with an M&W CDI ignition.
Q10. Which is the best ignition coil configuration for waste spark installations?
A. Dual outlet coils were never designed for performance applications and their inherent design makes it impossible to achieve correct spark plug polarity in both cylinders (see Q9). Using two individual coils wired in parallel will allow both spark plugs to achieve optimal performance however due to load balancing issues it will never perform as good as a direct fire ignition setup.
Q11. Why do I need to change my timing after installing your ignition?
A. Different ignition systems have varying ignition delays (time between commanded ignition point and rise of cylinder pressure). High energy ignition systems will often significantly reduce combustion delay therefore it is important to re tune ignition timing and fuel curves to optimise engine performance.
Q12. Why are there no quoted ignition delay numbers for your CDi systems?
A. M&W recommend using zero ignition delay when istalling a CDI system as the actual combustion delay may be significantly reduced and this will provide a safer, slightly retarded, initial timing curve (See also Q11).
Q13. Why do we find no difference in performance when conducting back to back comparisons between your ignition and other systems?
A. Due to changes in combustion delay engine tune of both fuel and timing must be optimised for each different type of igntiion system. Please read questions 3, 4, 9 & 11.
Q14. Why does my spark look weak?
A. CDI ignition provides a very fast rise time, short duration, high energy pulse. The human eye response makes this appear completely different to that of an inductive igniton with it's slow rise time, long duration and relatively low energy. Spark appearance will also vary from cylinder to cylinder due to burning contaminants in the arc gap.
Q15. Why do my spark plugs appear to have burn marks or cracks down the outside?
A. The burn marks or 'cracks' are caused when ultra high cdi ignition energy finds it easier to travel down the spark plug exterior than through the centre. This is generally caused by a damaged spark plug resistor, excessive spark plug gap or dirty spark plug insulator or dirty/loose spark plug boot.
Q16. How do I determine if my trigger edge selection is correct?
A. Lock the igntion timing (most ECU's have a function for this) and rev the engine while monitoring it with a timing light. If you are on the correct trigger edge the engine timing will appear relatively static however if you are on the wrong trigger edge it will move with changes in engine rpm.
Q17. My ECU has igniters built in, will it work with your CDI systems?
A. An intermediate ignition system in circuit will cause additional trigger delays which manifest as varying timing values depending on engine rpm. Although not optimal it can still be made work by selecting risising edge triggering on the CDI then check using the procedure from Q16 above. When correct operation is confirmed adjust igntion timing to suit engine performance do not tune to the advance value reported by the ECU as this may be incorrect due to introduced timing delays!