Clutch Tuning Handbook by Olav Aaen: The Ultimate Guide for Snowmobile Performance
Olav Aaen Clutch Tuning Handbook FULL Version 32: A Comprehensive Guide for Snowmobile Performance
If you are a snowmobile owner or racer, you probably know how important it is to have a well-tuned clutch system. A clutch is a device that transfers power from the engine to the track, allowing you to control the speed and acceleration of your snowmobile. A properly tuned clutch can make a huge difference in your snowmobile's performance, efficiency, reliability, and durability.
Olav Aaen Clutch Tuning Handbook FULL Version 32
But how do you tune your clutch to get the best results? How do you know what settings and components to use for different snowmobile models and conditions? How do you test and measure your clutch performance and make adjustments as needed?
That's where the Clutch Tuning Handbook by Olav Aaen comes in handy. This handbook is a comprehensive guide that covers everything you need to know about clutch tuning for snowmobiles. It explains the theory and basics of clutch operation, provides detailed instructions on how to test and tune your clutch, and offers practical examples and applications for various clutch scenarios and setups.
In this article, we will give you an overview of what the Clutch Tuning Handbook is, who wrote it, what it covers, and why you should get it if you are serious about snowmobile performance. We will also show you how to use the handbook for your own clutch tuning needs and answer some frequently asked questions about it.
Introduction
What is a clutch and why is it important for snowmobiles?
A clutch is a mechanical device that connects or disconnects two rotating shafts, such as the engine crankshaft and the jackshaft that drives the track. A clutch allows you to engage or disengage the power from the engine to the track, depending on how much throttle you apply.
A snowmobile uses a variable speed belt transmission, also known as a continuously variable transmission (CVT), which consists of two clutches: a primary or drive clutch attached to the engine crankshaft, and a secondary or driven clutch attached to the jackshaft. The two clutches are connected by a belt that runs between them.
The primary clutch acts as a centrifugal clutch that automatically engages or disengages depending on the engine speed. As the engine speed increases, weights inside the primary clutch move outward due to centrifugal force, causing the clutch to close and squeeze the belt. This transfers power from the engine to the belt. As the engine speed decreases, the weights move inward due to spring tension, causing the clutch to open and release the belt. This disengages the power from the engine to the belt.
The secondary clutch acts as a torque sensing clutch that automatically adjusts the belt tension and ratio depending on the load and speed of the snowmobile. As the load and speed increase, the secondary clutch moves inward due to torque, causing the clutch to open and increase the belt diameter. This reduces the gear ratio and increases the speed of the snowmobile. As the load and speed decrease, the secondary clutch moves outward due to spring tension, causing the clutch to close and decrease the belt diameter. This increases the gear ratio and decreases the speed of the snowmobile.
A clutch is important for snowmobiles because it allows you to control the power delivery and performance of your snowmobile. A well-tuned clutch can improve your snowmobile's acceleration, top speed, fuel efficiency, belt life, engine life, and overall ride quality. A poorly tuned clutch can cause your snowmobile to bog down, overheat, slip, wear out, or break down.
Who is Olav Aaen and what is his contribution to clutch tuning?
Olav Aaen is a mechanical engineer and a snowmobile expert who has been involved in the snowmobile industry for over 50 years. He is the founder and owner of Aaen Performance, a company that specializes in high performance products and services for snowmobiles and all terrain vehicles (ATVs).
Aaen started his career as an engineer for OMC (Outboard Marine Corporation), where he worked on developing new clutch designs and computer programs for clutch performance prediction. He also participated in various snowmobile racing events, such as oval, snocross, drag racing, and speed runs.
In 1975, Aaen left OMC and started his own company, Aaen Performance, where he continued to innovate and improve clutch technology for snowmobiles. He also published his first edition of the Clutch Tuning Handbook, which was a small typewritten book produced on a copy machine. Since then, he has revised and updated his handbook nine times, bringing it to its current version 32.
Aaen is widely recognized as one of the leading authorities on clutch tuning for snowmobiles. He has contributed many articles on clutch tuning to various snowmobile magazines and websites. He has also sponsored and supported several snowmobile race teams and drivers over the years.
What is the Clutch Tuning Handbook and what does it cover?
The Clutch Tuning Handbook is a comprehensive guide that covers everything you need to know about clutch tuning for snowmobiles. It explains the theory and basics of clutch operation, provides detailed instructions on how to test and tune your clutch, and offers practical examples and applications for various clutch scenarios and setups.
The handbook is divided into four main sections: Clutch Theory and Basics, Clutch Testing and Tuning, Clutch Applications and Examples, and Conclusion. Each section contains several chapters that cover specific topics related to clutch tuning.
The handbook covers both Comet and Polaris clutches, as well as other brands and models of clutches that are compatible with snowmobiles. It also covers different types of snowmobiles, such as trail, mountain, racing, vintage, etc.
The handbook is written in a clear and concise manner that is easy to understand and follow. It includes many diagrams, charts, tables, graphs, formulas, calculations, tips, tricks, recommendations, warnings, cautions, etc. that help you learn and apply clutch tuning effectively.
Clutch Theory and Basics
How does a variable speed belt transmission work?
A variable speed belt transmission works by changing the effective diameter of the belt on both clutches according to engine speed and load. This changes the gear ratio between the engine crankshaft and the jackshaft that drives the track.
The gear ratio is defined as the ratio of input speed (engine crankshaft) to output speed (jackshaft). A low gear ratio means that the input speed is higher than the output speed, which results in more torque but less speed. A high gear ratio means that the input speed is lower than the output speed, which results in less torque but more speed.
A variable speed belt transmission allows you to have a wide range of gear ratios without having to manually shift gears or use multiple gears. It automatically adjusts the gear ratio according to your throttle input and riding conditions.
Clutch Testing and Tuning
How to measure and analyze clutch performance?
One of the most important steps in clutch tuning is to measure and analyze your clutch performance. This will help you determine if your clutch is working properly, and if not, what adjustments you need to make.
There are several ways to measure and analyze your clutch performance, such as using a tachometer, a speedometer, a stopwatch, a belt temperature gauge, a clutch alignment tool, a belt deflection gauge, a spring scale, etc. However, one of the most effective and convenient ways is to use a computer program that can simulate and predict your clutch performance based on your input data.
One such program is the Clutch Performance Analyzer (CPA) by Olav Aaen. This program allows you to enter various parameters of your snowmobile, such as engine power curve, track size and type, gearing ratio, clutch components and settings, etc. and then calculate and display your clutch performance in terms of engine RPM, track speed, belt ratio, belt slip, belt temperature, etc.
The CPA program also allows you to compare different clutch setups and see how they affect your clutch performance. You can also print out graphs and tables of your clutch performance for reference and documentation.
The CPA program is included in the Clutch Tuning Handbook CD-ROM that comes with the handbook. You can install it on your computer and use it anytime you want to test and tune your clutch.
How to adjust and optimize clutch settings?
Once you have measured and analyzed your clutch performance, you can start adjusting and optimizing your clutch settings to achieve your desired results. There are several components and settings that you can adjust in your clutch system, such as primary spring tension and preload, primary flyweight size and shape, secondary spring tension and preload, secondary helix angle and shape, belt tension and deflection, etc.
The Clutch Tuning Handbook provides detailed instructions on how to adjust each component and setting in your clutch system. It also explains how each component and setting affects your clutch performance in terms of engine RPM, track speed, belt ratio, belt slip, belt temperature, etc.
The Clutch Tuning Handbook also provides general guidelines and recommendations on what components and settings to use for different snowmobile models and conditions. However, these are only starting points that may need further fine-tuning depending on your specific snowmobile and riding style.
The best way to adjust and optimize your clutch settings is to use a trial-and-error method. You can start with the recommended components and settings from the handbook or the CPA program, then test them on your snowmobile and measure their performance. If you are not satisfied with the results, you can make small changes to one component or setting at a time, then test them again until you find the optimal combination that works for you.
How to use computer programs and tools for clutch design and prediction?
As mentioned earlier, one of the most effective and convenient ways to test and tune your clutch is to use computer programs and tools that can simulate and predict your clutch performance based on your input data. These programs and tools can save you a lot of time and money by allowing you to test different clutch setups without having to physically change them on your snowmobile.
Clutch Applications and Examples
How to choose the right clutch for different snowmobile models and conditions?
One of the most common questions that snowmobile owners and racers have is how to choose the right clutch for their snowmobile model and riding conditions. There is no one-size-fits-all answer to this question, as different snowmobiles have different engine characteristics, track sizes, gearing ratios, etc. and different riding conditions require different clutch performance.
However, there are some general principles and guidelines that can help you choose the right clutch for your snowmobile. The Clutch Tuning Handbook provides a comprehensive list of clutch components and settings for various snowmobile models and conditions, based on Olav Aaen's extensive experience and testing. You can use this list as a starting point for your clutch selection, but you may need to fine-tune it according to your specific snowmobile and riding style.
Here are some of the factors that you need to consider when choosing the right clutch for your snowmobile:
Engine power curve: This is the graph that shows how much torque and horsepower your engine produces at different RPMs. You want to match your clutch components and settings to your engine power curve, so that your clutch engages at the optimal RPM for maximum power output and efficiency.
Track size and type: This is the dimension and design of your track, such as length, width, lug height, pitch, etc. You want to match your clutch components and settings to your track size and type, so that your clutch provides enough traction and speed for your track.
Gearing ratio: This is the ratio of teeth between the sprockets on your jackshaft and driveshaft. You want to match your clutch components and settings to your gearing ratio, so that your clutch provides enough torque and speed for your gearing.
Riding conditions: This is the type and quality of the terrain and snow that you ride on, such as hardpack, powder, ice, etc. You want to match your clutch components and settings to your riding conditions, so that your clutch adapts to the varying load and speed demands of your terrain and snow.
For example, if you have a high-performance snowmobile with a powerful engine that produces a lot of torque at low RPMs, a large track with deep lugs, a low gearing ratio for quick acceleration, and you ride on deep powder or steep hills, you may want to choose a clutch setup that has:
A stiff primary spring with high preload and tension to engage the clutch at a high RPM and prevent bogging.
A heavy primary flyweight with an aggressive curvature to shift the clutch quickly and maintain high RPMs.
A soft secondary spring with low preload and tension to allow the belt to slip slightly and prevent overloading.
A shallow secondary helix with a straight angle or a single-angle helix to provide a smooth backshift and prevent binding.
On the other hand, if you have a trail snowmobile with a moderate engine that produces a steady power curve at mid-range RPMs, a medium track with moderate lugs, a medium gearing ratio for balanced performance, and you ride on groomed trails or flat fields, you may want to choose a clutch setup that has:
A medium primary spring with medium preload and tension to engage the clutch at a medium RPM and provide smooth throttle response.
A medium primary flyweight with a moderate curvature to shift the clutch gradually and maintain mid-range RPMs.
A medium secondary spring with medium preload and tension to provide enough belt tension and prevent slippage.
A steep secondary helix with a multi-angle helix or a progressive helix to provide a fast upshift and a responsive backshift.
How to troubleshoot and solve common clutch problems?
Sometimes, despite choosing the right clutch components and settings for your snowmobile model and conditions, you may still encounter some problems with your clutch performance. These problems can be caused by various factors, such as wear and tear, dirt and debris, improper installation or adjustment, etc.
The Clutch Tuning Handbook provides detailed instructions on how to troubleshoot and solve common clutch problems that may affect your snowmobile performance. Some of these problems include:
Clutch slipping: This is when the belt does not grip the clutch sheaves properly and slips, causing a loss of power and speed. This can be caused by a worn or glazed belt, a dirty or damaged clutch, a loose or broken spring, a wrong or misaligned belt, etc.
Clutch binding: This is when the belt does not release the clutch sheaves properly and binds, causing a loss of backshift and deceleration. This can be caused by a dirty or damaged clutch, a tight or broken spring, a wrong or misaligned belt, etc.
Clutch overheating: This is when the belt or the clutch gets too hot and melts, causing a loss of performance and durability. This can be caused by a slipping or binding clutch, a dirty or damaged clutch, a wrong or misaligned belt, a lack of ventilation, etc.
Clutch noise: This is when the clutch makes abnormal sounds, such as squealing, rattling, grinding, etc. This can be caused by a loose or broken component, a dirty or damaged clutch, a wrong or misaligned belt, etc.
The Clutch Tuning Handbook provides detailed instructions on how to diagnose and fix each of these problems by checking and replacing the faulty components, cleaning and lubricating the clutch, adjusting and aligning the belt, etc.
How to use the Clutch Tuning Handbook for specific clutch scenarios and setups?
The Clutch Tuning Handbook is not only a guide for general clutch tuning principles and guidelines, but also a resource for specific clutch scenarios and setups that you may encounter or want to try on your snowmobile. The handbook provides several examples and applications of how to use the handbook for different clutch situations and goals.
Some of these examples and applications include:
How to tune your clutch for racing: The handbook provides tips and tricks on how to tune your clutch for different types of racing events, such as oval, snocross, drag racing, speed runs, etc. It also provides examples of racing clutch setups for various snowmobile models and conditions.
How to tune your clutch for mountain riding: The handbook provides advice and recommendations on how to tune your clutch for mountain riding, where you need more torque and traction to climb steep slopes and deep powder. It also provides examples of mountain clutch setups for various snowmobile models and conditions.
How to tune your clutch for vintage snowmobiles: The handbook provides information and suggestions on how to tune your clutch for vintage snowmobiles, which have different engine characteristics and clutch components than modern snowmobiles. It also provides examples of vintage clutch setups for various snowmobile models and conditions.
How to tune your clutch for custom snowmobiles: The handbook provides guidance and ideas on how to tune your clutch for custom snowmobiles, which have modified engine or track features that affect the clutch performance. It also provides examples of custom clutch setups for various snowmobile models and conditions.
Conclusion
Summary of the main points and benefits of the Clutch Tuning Handbook
In conclusion, the Clutch Tuning Handbook by Olav Aaen is a comprehensive guide that covers everything you need to know about clutch tuning for snowmobiles. It explains the theory and basics of clutch operation, provides detailed instructions on how to test and tune your clutch, and offers practical examples and applications for various clutch scenarios and setups.
FAQs
Here are some of the frequently asked questions that snowmobile owners and racers have about clutch tuning and the Clutch Tuning Handbook:
Q: How do I know if my clutch is tuned properly?
A: The best way to know if your clutch is tuned properly is to measure and analyze your clutch performance using a tachometer, a speedometer, a stopwatch, a belt temperature gauge, or a computer program like the CPA. You can compare your clutch performance with the optimal performance for your snowmobile model and conditions, as provided by the Clutch Tuning Handbook or the CPA. You can also check for signs of clutch problems, such as slipping, binding, overheating, or noise.
Q: How often do I need to tune my clutch?
A: The frequency of clutch tuning depends on several factors, such as how often you ride your snowmobile, how hard you ride your snowmobile, how much you change your riding conditions, how much you modify your snowmobile engine or track, etc. Generally speaking, you should tune your clutch at least once a season, or whenever you notice a significant change in your clutch performance or condition.
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