Nizpro's marketing philosophy has and always will be to promote product on its merits, and whereas it is of course understandable that there must be comparison with others, we are not in the business of embellishing facts in an attempt to discredit. Instead, we like to let our product attributes and results do the talking for us.

As this is not the way some others go about marketing their product, we decided to create this Question and Answer sheet whereby we hope we have covered most of the points others use as criticism.

Q; Given that the Stage One and Two Cobra kits utilize the factory exhaust system, is it true that as a consequence of massive exhaust back pressure it results in burnt out exhaust valves?

A; The results of significant testing on our engine dynamometer including the undertaking of a 100-hour endurance test while retaining the factory exhaust system indicated no sign of damage to the exhaust valves, exhaust manifold, turbo wheel or turbine housing. Furthermore, Ford understand the heat potential with turbocharging, hence the XR6 Turbo engine is equipped with Inconel exhaust valves.

Q; It has been suggested that multi orifice 4 valve injectors must be used with these engines. What do you use in your Stage Two and higher kits?

A; The injectors used in all Nizpro kits, as has been proven through exhaustive testing, provide optimum fuel burn that not only ensures factory fuel consumption figures and clean burning are maintained, they also deliver the best power figures of every available kit. We also recommend that with any injector that a customer makes sure that a four-squirter injector is exactly that and not a dual squirter with the orifices directed towards the top and bottom of the combustion chambers!

Q; You run a thinner intercooler than some I have read about.

A; When designing an intercooler for the Cobra kit, we called on our many years of intercooler construction experience to create a core that although thinner than some others, is still happily capable of flowing 560 flywheel kilowatts. Significantly, the thickness of the core also plays a significant role in how the radiator cools the engine, with the Cobra core ensuring exceptional flow characteristics.

Q; I've heard that the stock valve springs can be problematic.

A; This is true, however it only comes into play with Cobra Stage Three and above kits. This is because Cobra kits are designed to run relatively low boost pressures, hence the limited pressure on the back of the exhaust valve doesn't push the valve open.

Some other kits run higher boost levels yet deliver lower power outputs, with the higher boost having a direct effect on holding the exhaust and inlet valves open which results in valve spring problems. We accept that over time the stock valve springs - even with Cobra's Stage Two kit - may weaken over time, a situation applicable to any automotive part. With other high boost kits you would be lucky if the springs worked at all. Also, whereas you can fit a larger exhaust system that lowers the backpressure from the back of the turbo to the exhaust tip, it doesn't stop the build-up of pressure between the back of the valve and turbocharger.

Q; It has been suggested that the stock Ford catalytic converter fails when faced with higher than stock power levels due to massive restrictions and high exhaust temperatures.

A; Out of the dozens of Cobra kits already fitted to cars across Australia, we have had only one catalytic converter fail, with testing proving it to be a manufacturing fault.

Q; Are Cobra kits Vic Roads approved?

A; From the outset a decision was made to complete all Cobra stages before presenting them for emissions testing. In turn we expect to have finalised this in a few weeks.

Q; I have been told that the Cobra plenum is simply a marketing exercise, that it doesn't in fact do anything.

A; Cobra didn't simply create a plenum, we used our experience along with computer aided design software to establish a volumetric efficiency far in advance of anything else on the market. Proof of its success can be seen in the fact that when compared to the stock inlet manifold, the Cobra plenum requires 3 psi less boost at the manifold to achieve the same power output.

Q; I have a manual car, how long will the clutch last?

A; With the Cobra Stage One package, you can expect good service from the stock clutch, unless of course you treat the car quite badly. However, with the 290 rwkW Stage Two kit, you would literally only expect the stock clutch to last five (5) minutes. The torque output is far too great for the stock clutch to cope with.

Cobra has a clutch to suit each stage.

Q; I have a manual car, how long will the transmission last?

A; How long is a piece of string? It really comes down to how a vehicle is treated. That said, the factory T5 is only rated at 450Nm and will, given time, break with anything from Cobra Stage Two upwards. The best-case scenario is that through gentle launches and easy gear changes, a transmission could last as much as 100,000 kilometres. Push the envelope and it is best to consider a transmission upgrade. Cobra can assist with a transmission.

Q; Will my auto cope with the increased power?

A; Succinctly, no. That is to say that in the short term and with up to the Stage Two kit, we have seen many of our customer cars run faultlessly for many thousands of kilometres, yet others who perhaps due to quality control issues with the transmission build, have run into problems after as few as 5,000 kilometres.

Cobra offers a fix as follows; The transmission is removed, stripped, and fitted with larger quantity clutch packs, a custom hydraulic servo and custom valve body. This improves lubrication, repairs inherent faults and provides for more much more secure faster shifts.

Q; Does the increased boost of the Cobra kits have a detrimental affect on intake temperatures?

A; To the contrary, our tests have shown that with our Stage One, Two and Three kits, intake temperatures typically run at more than 25 degrees below a factory system. Furthermore, with some other kits we have seen as much as 65 degrees above ambient and this can be quite dangerous.

Q; You don't offer an exhaust system with your Stage One and Two kits. What if I still want to use a modified system?

A; No worries, with all Stage Three and higher kits we always supply an exhaust system and have spent some months working with Remus (one of the world's largest OE and aftermarket exhaust system manufacturers) on suitable systems. With a full replacement system you can expect around a 10-15kW power increase (at the wheels), and if this system is fitted to a Stage Two vehicle it then starts pushing the power output to a level that threatens the integrity of the factory connecting rods.

Q; Cobra has suggested that the factory connecting rods are not particularly strong, when would these need to be changed?

A; Cobra will not supply a Stage Three kit for all of the reasons established in including our 100-hour endurance test without connecting rods for the simple reason that at this level, and depending on driveline integrity (whether the owner has also undertaken a transmission upgrade) the kit can develop as much as 825Nm of torque which is 60% greater than any engine available in an Australian vehicle.