Supercharger Performance and Engine Performance Parts

Posts Tagged ‘intake’

I’m going to talk about my own car for a bit here… I’ve been in the performance scene for a long time and have helped a lot of people fix, repair and build up their cars from being a stock neglected and abused second hand car into being a gem of a dual purpose daily driver and weekend racer.

One of the things that I’ve learned through experience, is that unless you have the ultimate in tenability on your car, with a control system that is able to compensate for barometric changes, varying load conditions, rapid temperature swings…etc then it is best to get a car that is very close in stock form to your desired power levels and use the minimal number of power modifications required to reach your ultimate power goals.

This path of 20/80 *using the 20% of the modifications that will give you 80% of the results* usually leaves you with a very reliable car, with proven power potential; a car that you don’t need to give your mother a pre-race briefing on how to drive it before she borrows it to go to the grocery store, and a car that you will never be reluctant to take on a long weekend road trip out of town. After all, the point of having an enjoyable car is being able to spend as much time enjoying it, rather than working on it and having it break down. This is especially true on a dual purpose car that spends a lot of time serving you in your battle against the daily grind of school, college or work.

So, in looking a car to buy as my daily driver after college back in 2005, I was looking for a car that was already supercharged (taking away the headache of finding a reliable supercharger kit and an intelligent engine management system that I could rely on). I also wanted a car that had potential to be slightly modified to make it more engaging and that had good handling from the get go.

In doing my research I landed on the 2005 Mercedes C200 Kompressor equipped with the M271 engine. The m271 engine is an impressive factory engine equipped with a lot of things that we usually upgrade on factory supercharged cars. The car utilizes a 4^th generation eaton MP45 supercharger utilizing Teflon coated rotors for higher thermal efficiency and an increased maximum rpm range of 16000 rpms and a peak power capability of 240hp or ~360cfm. Even in a low boost package of 4psi on the C180 and 6psi on the C200, the car is still factory equipped with a front mount air to air intercooler to cool the air charge down. On the intake side, the car is equipped with a generously sized air-box with a cold air duct to the front grill.

The engine itself is equipped with dual variable valve timing on the intake and exhaust cam for optimized power delivery, better emissions. The ignition system is factory fortified with a coil over plug setup but with generic Bosch platinum spark plugs.

As far as tuning goes, the car is equipped with an MAS air flow sensor and a MAP pressure sensor, as well as a transmission slip and wheel spin sensor. The combination of all these sensors is that the factory computer can very accurately distinguish between boost pressure and load by comparing actual acceleration with the acceleration demand. This load sensitive ECU also uses dual knock sensors equipped on the block to detect individual cylinder knock. The result of these factors is an ignition timing optimized for each cylinder based on boost / rpm / load and air flow with individual cylinder timing retard to keep as much timing in the engine as possible for peak power delivery, while retarding timing in the offending cylinder to prevent the engine from detonating itself to pieces in case of a bad fill of gas or a clogged injector..etc

Over all the car is an impressive factory package. However, a 1.8 liter engine in a heavy chassis with 10 factory air bags, fully adjustable front seats, xenon lighting, a sunroof, and other heavy Mercedes amenities leaves the car slightly underpowered and requiring modification.

Below is a list of minimal modifications that have proven power potential as follows:

1. Carlsson CK20 kit
2. Remus 60mm Catback exhaust system
3. ported factory throttle body

Read the rest of this entry »

Technorati Tags: eaton, exhaust, HKS, intake, M271, Mercedes, MP45, Ported throttle body

This is the triple distilled guide on engine performance parts to help you make the most power with the least effort. There’s an abundance of bolt on and custom application engine performance parts available for any vehicle, and the internet is full of advice, trials, and feedback from enthusiasts, brand promoters, magazine editors, and even racers about which performance parts are best for your car. 

Engine performance hinges on one of THREE general factors:

1-      raw power factors

2-      efficiency factors

3-      Power boosters

3-      Power Boosters:

Typically called forced induction, power boosters include serious modifications to your engine that can result in a 30 to 400% power increase while maintaining the same raw power and efficiency figures (i.e. at the same peak rpm and with the same displacement).

Because of this serious increase in power, power boosters are the great equalizer that allows smaller engines to simulate and exceed the performance of a much larger engine. Originally these technologies were developed for conditions where more power was needed with a limitation on the physical dimensions of the engine. A prime example for this would be requiring more horsepower for a plane that would see most of its usage in high altitude thin air. The engine for this type of aircraft faces the difficulty of having to carry its weight and still maneuver with high performance and accuracy, which places maximum weight and size requirements on the engine and complete aircraft. Furthermore, the engine would have to operate efficiently and produce power in thin air which is less dense and thus less oxygen rich making it have less power potential.

After time these technologies moved into automotive racing and from there into aftermarket modifications and finally into production automobiles.

There are three types of Power boosters I want to mention here:

Engine Compression ratios:

Some may argue that this is an efficiency modification, but since this modification actually ADDS more horsepower rather than freeing up system inefficiencies I have chosen to set it apart here.

The addition of 1 compression point typically results in a 4% power increase and reduced fuel consumption. Bumping up a car’s compression ratio from a typical 9:1 compression ratio to a more performance oriented 15:1 for example is a potential power increase of 24%. I don’t think this kind of power increase can be considered an ‘efficiency’ upgrade but rather a legit power boost.

Let me disclaim here that increasing the motor’s compression ratio , as well as using all the other power booster modifications in this section, significantly increases the final combustion pressure produced inside the motor (especially when using more than one power booster in tandem), and thus there is definitely a need for:

1-      Higher octane fuel requirements to prevent preigntion detonation and reduce the speed of the flame front for normal ignition events.

2-      Heat management, through increased head cooling, using aluminum heads, colder spark plugs, and upgraded cooling system capacity to be able to cope with a significant increase in power (and its co product which is heat).

3-      A more conservative retune to a richer air fuel ratio that helps maintain stable exhaust gas temperatures that indicate a sustainable combustion process rather than an explosion occurring inside the engine

4-      A more conservative retune to for ignition timing and cam overlap that helps maintain stable exhaust gas temperatures that indicate a sustainable combustion process rather than an explosion occurring inside the engine.

Chargers (weather they are turbochargers or superchargers)

Turbochargers and superchargers intercept air in the intake system before it reaches the engine and compress it making it denser leaving more oxygen per volume of air. If the air is compressed to half its size for example then we will be able to fill a 2.0 Liter engine with 4.0 Liters of air per revolution. If we also make available double the fuel injection coupled with proper tuning, then we can successfully produce double the horsepower because there is literally twice as big a combustion occurring inside the engine.

Of course under normal conditions the engine would never breathe 4.0 Liters of air on its own, and thus charger works as a pump that keeps the engine pressurized by overfeeding or force feeding it with more air than it would have ingested under normal conditions.

The term boost or ‘psi’ (pounds per square inch) is a measure of how much pressure is placed on the motor and thus boost is highly related to how much more air is ingested into the motor. Every 1psi of boost is equivalent to a power increase of 7% over what the engine would make without a turbocharger, so increasing the pressure of an engine by just a few psi can show a significant increase in power and torque.

With 93 octane gasoline and proper tuning, boosting an engine to 15 to 18psi is pretty safe and thus increasing an engine’s power by 120% is not uncommon with a ‘street’ friendly turbo system. More power increases can be seen with race setups and higher octane availability.

One of the advantages of turbochargers and superchargers is that since the air is compressed (for example to half its original size at 14psi) then  a conservatively sized 45mm throttle body looks to like a 63mm throttle body from the point of view of the compressed air. In this way, turbochargers and superchargers can overcome inefficiencies in the design of the engine’s intake path because compressing the air makes it occupy a smaller volume (for the same oxygen content) which makes the intake system seem like less of a flow restriction.

This also makes some of the efficiency modifications (namely those between the charger and the intake valve) less in need of being modified as they are less of a power restriction.

Nitrous Oxide Injection

Nitrous oxide injection is similar to turbochargers and superchargers in that it delivers more oxygen to the fire in the same volume of air and thus in the same engine displacement. Nitrous oxide does this in two ways:

1-      Rather than compressing air to a smaller volume to increase oxygen density, nitrous oxide is composed of two nitrogen molecules and 1 oxygen molecule. This composition makes nitrous oxide 33% oxygen rich by volume compared with normal air which is around 16% oxygen by volume. What this means quite literally is that if we had an engine breathing pure nitrous oxide flowing at room temperatures and atmospheric pressure then the horsepower output would simply be doubled.

2-      However nitrous oxide is delivered to the engine in compressed form (as it is compressed to 1000psi when it is packaged into the bottle). Using the same formula for pressure and volume that we used for turbochargers, a 1000 psi pressurized bottle is compressed 70 times or to 1/70^th its original volume. This  means that feeding an engine purely with nitrous oxide at the temperature and pressure at which it comes out of the nitrous bottle, we could potentially produce 140 times more horsepower from that engine than we could having it breathe normal air! How is that for a replacement for displacement?

Practically speaking, nitrous oxide is usually used for a power boost of 50 to 100% depending on how prepared the engine (and the user is) for the power boost, and depending on the style of nitrous delivery (for example progressive direct port nitrous injection is the most reliable type of injection for 100% or more nitrous power boosts).

So in summary of the whole article…. Here’s what I recommend:

1-      Figure out how much horsepower you want to achieve

2-      As stated in part 1, figure out the engine combination with the highest potential that is allowable for you in the rule books.

3-      Look at how much boost you will need if any with that engine combination to reach your power goals

4-      Depending on weather you need a 20% power boost or a 200% power boost, pick your power adder (from a small compression increase, to a small nitrous shot, to a larger supercharger or turbocharger setup, to a combination of power boosters) that will allow you to reach your goals.

5-      Last (and not first), plan out the supporting and efficiency modifications that are required for that engine and power adder combination (from part two of this article). Basically you want to install the efficiency parts that will allow you to flow the amount of exhaust gas that you need at your peak power level, and optimize your entire engine package around your target peak PRM, anything else would be a waste of money.

6-      Understanding that upgrading engine efficiency is limited to a 10-20% power increase over stock as well as performing modifications planning in the sequence that I have just described, may save you TENS of THOUSANDS of dollars from being wasted upgrading a motor that just frankly doesn’t have the raw power potential (in terms of displacement, RPM or stroke) to meet your power requirements, or requires an unrealistic power boost combination (such as a 400% power hike using an exotic turbo setup) to reach the power goal requirements that you have.

I know that most of the advertising and development in performance modifications spent on things like intakes and exhausts (covered in part two of this article), but that is easily explainable:

1-      Those parts although they don’t add much horsepower to your car, are exactly what 80% of the people are willing to install on their cars because they sound cool, are cheap, may require no tuning at all, and are fairly easy to install.

2-      Those parts are also a gateway modification to more power modifications in the future, and so come at a smaller entry price and smaller install complication to get you willing to work on your car and purchase parts (basically a marketing ploy). If everyone were chucking their stock engines for a larger big block grabbed from the junkyard then all the shallow aftermarket performance companies (producing only efficiency parts) would go out of business leaving only the companies that have the depth of experience and science to build crate engines and power adder kits. So for these companies to stay profitable they need to keep you invested in your stock engine which allows them to secure their place in the industry, weather that wins you races or not.

However if you are serious about modifications, you will use my 3 piece guide to start your modifications plan with the end in mind. If you really want 700hp then you are much better off with a 500hp engine running a measly 6psi of boost than you are trying to boost a 150hp 4 cylinder to 54psi or trying to feed it 550 horsepower worth of nitrous.

Technorati Tags: compression ratio, Displacement, engine performance parts, exhaust, intake, N2O, Supercharger, turbocharger