Wow! What a great time it is for performance enthusiasts!! You have choices!! To turbocarge or supercharge or spray with nitrous or a combination of both!! Which is right for you, your car and your goals?? Nissan’s and Infinitis are great for power adding because they have bullet proof, over engineered engines and drive trains.

NitrousThis will usually be the cheapest power adder, and frankly nothing will give you more power per dollar.. The question is will it really meet your needs??? Here are the pros and cons of nitrous:

Pros:

adds lots of low-end torque

great for drag racing and lowering ets

allows normal engine operation when not in use

Can be adjusted for more or less hp

best bang for the buck

great intercooler for a blower

Cons:

Bottle doesn’t last long.

no room for spontaneity you have to know when you are going to race so you can open up the bottle the remotes do not work that well.

Nitrous is a lot of fun. You need to have a system that is well engineered so that your ignition timing and fuel injection are adjusted to accommodate the nitrous and you should make sure your system has a safety relay to kill the nitrous if fuel flow is shut off for some reason. I will be going onto all of this in more detail with a special article on Nitrous in the future.

SuperchargingThere are two basic types of superchargers; CENTRIFUGAL and POSITIVE DISPLACEMENT. The former gives most of its power addition on the high end of the power curve and the positive displacement gives most of its power on the bottom end and it is instantaneous. Both types have impellers that are driven off the engine’s crankshaft and thus siphon power from the engine. This is in contrast to turbocharging where the impeller is driven essentially for free by the exhaust gases. Still supercharging is a very worthwhile consideration. It is relatively simple and straight forward. The bigger the engine and the more cylinders, the less the parasitic losses matter. That is to say an Infiniti V8 is less likely to suffer from the power loss than a 2 liter, 4 banger.

Most people spend the majority of their time driving in the city..they stop and go (accelerate). If they want to enhance performance, they should plan to give themselves more low-end torque, not high end horsepower. This is where the positive displacement (pd) supercharger is most effective. It will give you a kick in the pants that you will not soon forget! This is really what most of you cruisers/ racers want and yet so many of the performance mods offered to you actually do the opposite!! Some engines lack low-end torque compared to their high end hp. These engine would do better with a pd supercharger, where as a small block Chevy has relatively good low end torque but because it breathes so poorly, it really needs help on the top end and this is where a centrifugal supercharger would be most helpful.. These days, most Nissan/Infiniti products breathe pretty well and where they need help is on the bottom end.

All supercharging requires that changes be made to the timing and fuel injection. I’ll go into the tech aspects of supercharging in a future article.

TurbochargingIn general, thanks to our current computer technology, turbocharging has the most versatile and awesome tuning capabilities . Twin turbos and or computer programming has all but eradicated the problem of turbo-lag. With proper programming and turbo selection., you can tailor- make your power band profile. With the proper software, you can, with the push of a button, go from your “daily driver” program of 6psi/210hp, to your “race” program of 16 psi and 350hp all with corresponding, automatic adjustments in timing and fuel injection. It is neat stuff!! Turbos are especially nice for small-displacement 4 cylinder engines where you can’t afford to lose parasitic power and where tailor- making your power may be more necessary.

ConclusionWell this is just enough info to answer some of your more commonly asked questions. I will cover each type of power adder in much greater detail in future articles. Feel free to ask me questions through the on-line mechanic forum. Needless to say, your choice of which power- adder to use, is in part based upon all of the above, but it will also be limited by availability.

Contributed by: Speeddoctor