Four stroke motorcycle exhaust design software

Howto how two stroke expansion chambers work, and why you should care. Extremely cheap poser exhaust for modern four strokes, enduro exhausts explained. Computer software can help you with the design, but dont expect super design from the software. Ive spent a lot of time looking for a performance related book that reflected both real world ideas and understanding with a hint of engineering in the explanations and the fourstroke performance tuning has met and exceeded what i thought was available. Improve the performance of your twostroke engine with a torqsoft designed exhaust system. There are many ways to boost the power, one of which is by installing a tuned pipe. I recently replaced the kit exhaust that came with the engine. Simply put, its because the two stroke exhaust system, commonly referred to as an expansion chamber uses pressure. In order to obtain maximum results matching the carbs. New feature of racingsm software, the 2stroke exhaust segment splitter. Fourstroke expansion chambers general dirt bike discussion. The frequency content of exhaust noise is dominated by a pulse at the firing frequency, but it also has a broadband component to its spectrum which extends to higher frequencies. Crankcasecompression twostroke engines, such as common small gasolinepowered engines, are lubricated by a petroil mixture in a totalloss system. Improve the performance of your two stroke engine with a torqsoft designed exhaust system.

These engine and pipe arrangements are now optimized using simulation to achieve several different performance goals. When attempting to tune up a motorcycle, consider these main points. Careful design of the manifolds enables the engineer to manipulate the characteristics. Its called exhaust scavenging and in automotive performance exhaust systems, most often folks opt for an h pipe and better yet an x pipe. Many had crankcases that were not part of the induction system and they had intake vales but the exhaust was a port in the cylinder wall, most required a blower to run. Split your calculated 2 stroke exhaust up to 42 sections with regular length or even more with irregular lengths. Assume the velocity of rotation of your engine in rpm dreaming doesnt help much though. This is beneficial for two stroke engines because unlike four stroke engines, they do not have dedicated intake and exhaust strokes and valves. With direct injection and no lubricant in the fuel a two stroke could be made to run as clean as a modern four stroke.

Stroking a fourstroke engine also increases the displacement making. Small values of kh are best suited to grand prix engines with narrow power bands, larger. Create your own calculated 2stroke racing exhaust system design database with this module. Exhaust and intake tuning this article describes the principles involved in using tuned exhaust and intake systems on twocycle and fourcycle engines. This coefficient kh is called the horn coefficient, with typical values between one and two. What exhaust modifications make sense on a 4 stroke. An engine simulation software, ricardo wave, is utilized in this research. Racingsm software has features for many different areas 2 stroke exhausts development, drag racing features, simulators, carburetor tuning, connectingrod analysis etc with all this knowhow along with lufo racing heritage, we believe this is a very fair price. Excessive exhaust restriction also adds to engine heat. On a 4stroke, the intake valve begins to open while the exhaust valve is still off its seat. Apr 28, 2015 the computation of what actually goes on during an exhaust cycle is a highly complex problem in compressible fluid flow, the details of which are explained in detail in several texts, my favorite being professor gordon blairs design and simulation of four stroke engines. Porting your cylinder head is a great way to increase power.

Ten things you need to know about mufflers motocross action. Freeware 2 stroke expansion chamber exhaust calculator program. Howto how twostroke expansion chambers work, and why you should care. These bikes has been known to punch out big hp with twin carbs and exhaust.

Ive spent a lot of time looking for a performance related book that reflected both real world ideas and understanding with a hint of engineering in the explanations and the four stroke performance tuning has met and exceeded what i thought was available. Engine geometry is modeled using commercial proe software. Flow restriction from the silencer, if not a completely flowthrough design, contributes to total exhaust restriction and to back pressure which restricts the engine a bit. Calculate your optimal airbox volume for a single, twin, triple and four cylinder 2stroke engines. With their much lower rpm and wider torque band 4strokes dont seem as sensitive to exhaust changes as with their 2smoker brothers.

Two stroke engine and exhaust design software north. In a normallyaspirated spark ignition engine burning gasoline and operating at high bmep, the pressure can be 7 bar or more, and the pressure in the exhaust port at the valve is somewhere near 1 bar atmospheric. Ive long felt that some features of car muffler design could be applicable to fourstroke model engine muffler design. This software work on all 4 stroke engines from 49cc capacity and up, any rpm to 19k max. I know next to nothing about 4 stroke modifications i am thinking of a lake pipe or poohpooh type pipe on a 4 stroke and wondering what harm it might cause i am more interested in lowering the pitch and possibly volume of the engine as well as the eye candy effect than performance, but certainly do not want to harm performance. Properly tuned systems can increase the charge of fuel delivered to the cylinders and a related phenomenon can aid in the extraction of exhaust gases from the cylinders. Jan 15, 2005 four stroke exhausts can work in similar ways, but because the four stroke is more like a positive pump, and not so dependent on the dynamics of gas inertia just to even run, the effect an exhaust system will have on them is going to be more subdued. Notes 2 a reduction in primary pipe diameter of 18 of an inch will move the torque peak down by 650800 rpm. Tuned adjustableexhaust pipe for use on two stroke motorcycle was designed and tested. The pipe in the pic is a different design and designed in the sim differently than the pipe tested. This small java applet uses design rules according to, and, to size a tuned pipe for a 2 stroke piston engine. This is often referred to as geometric compression ratio but is also known as the static compression ratio. Twostroke engines have different exhaust systems, but the basic muffler design is similar.

They are so simple and fun that ive always enjoyed tinkering with them. North american twostrokes general twostroke discussion. The exhaust designer programme enables the user to design a twostroke exhaust system with ease, then with one click of the mouse, create a pdf document in any of the common paper sizes a4, a3, letter. I am currently working on building a high performance free flow exhaust for my bike yamaha fz16 single 153cc engine.

North american twostrokes general two stroke discussion two stroke engine and exhaust design software this is the place to talk about anything related to two stroke road race bikes. How to design a two stroke expansion chamber performance. Dedicated to the free exchange of information among twostroke road racing motorcycle enthusiasts around the world. Great exhaust, average fit i had this exhaust on my 2009 honda crf450x and ordered the same for my 2017 450x. Considering component one, when the exhaust valve first opens in a 4stroke piston engine, the incylinder pressure is still well above atmospheric.

In fact, your standard motorcycle exhaust will house a catalytic converter which helps convert the carbon monoxide expelled from the engine into carbon dioxide which at least makes it slightly more environmentally friendly. Im now using a 78 id stainless steel flex pipe purchased from memory lane classics. A two stroke pipe uses its reflective pressure wave to keep the fuelair mixture inside. Exhaust tuning of an internal combustion engine by the combined. In a four stroke engine, there is only one working stroke against three. Pdf improving the performance of twostroke motorcycle with.

I know the less exhaust pipe curves the better and where it does curve try and make them long and flowing. A previous paper by blair et al 2, presented to the society at setc 2001, demonstrated the ability to predict the behavior of tuned exhaust systems on a single cylinder 4 stroke motorcycle engine using virtual 4 stroke. If the negative wave arrives back at the exhaust valve just before it closes, it will suck more of the exhaust gases out of the cylinder. Engineering acousticssonic supercharging of 2 stroke. This is the place to talk about anything related to twostroke road race bikes.

Outlaw racing or2034 4stroke atv dirt bike exhaust silencer. Improving the performance of two stroke motorcycle with tuned adjustable exhaust pipe. Mufflers free delivery possible on eligible purchases. Discussion in 2 smokers started by chillis, jan 22. Unlike formula 1 or road racing exhaust pipes, a fourstroke motocross bike has to develop a broad and usable powerband instead.

How eccalc agrees with the real life exhaust pressure graphs from blair. You know that changing the exhaust pipes on your two stroke motorcycle can have a marked effect on the engines power characteristics, but do you know why. Ive read on this forum that dynamometer testing by. Optimization of exhaustpipe tuning on a 4stroke engine. Mar 27, 2010 i have just got my son an old 1985 xr 250. A high intensity pressure wave generated by combustion in the engine cylinder propagates along the exhaust pipe and. Thruhub boat props consist of a round barrel the hub to which the blades are attached. Jul 25, 2007 exhaust pipe design with cone layout software by paul crowe if you have ever tried to layout a conic section on sheet metal, cutting just the right piece, that when rolled over and joined on edge, you have a cone with the exact shape, size and angled openings desired, you know its not easy. You only have to put one cylinder value in, note from eliot. Look very good and i understand this program gave excellent performing pipes to others.

For four stroke engines it is standard practice to calculate compression ratio based on the full swept volume of the engine. Attached is the cad design i made for the exhaust i am not a professional cad designer but do it as a hobby by the way this is my first cad drawing. And there have been expansion chambers built for four strokes for years. Nov 02, 2019 for further investigate of the operation of two stroke engines with tuned exhaust pipes it is most appropriate to analyze actual test data. A yamaha yz400, 5valve, 4 stroke cycle, motocross racing, motorcycle engine is instrumented to provide pressure diagrams in the exhaust system which are recorded over the usable engine speed range at full throttle from 5000 rpm to 1 rpm. Mar 18, 2016 warning you may be offended by this video. We cover that, as well as other mods on a four stroke engine. On four stroke racing bikes that pipe could be a long straight pipe or a short header pipe and a megaphone. The opening angles of the cones should be 4 to 10 for the opening cone and.

Buy outlaw racing or2034 4 stroke atv dirt bike exhaust silencer spark arrester muffler packing repack. The developed simulation software is focusing on design and optimization of powertrain systems and. A yamaha yz400, 5valve, 4stroke cycle, motocross racing, motorcycle engine is instrumented to provide pressure diagrams in the exhaust system which are recorded over the usable engine speed range at full throttle from 5000 rpm to 1 rpm. We shall send you a pdf document with the templates for manufacturing your exhaust. We offer fourstroke exhausts for all the popular motorcycles and atvs. As with a twostrokes expansion chamber, a fourstroke exhaust system is tuned to produce the optimum powerband. Avl needed an optimized exhaust system for this engine. Exhaust pipe design with cone layout software by paul crowe if you have ever tried to layout a conic section on sheet metal, cutting just the right piece, that when rolled over and joined on edge, you have a cone with the exact shape, size and angled openings desired, you know its not easy.

Pipe looks and sounds great, but getting it to line up with the mounting holes was not so easy. Expansion chamber exhaust design software i have just bought and installed this 2 stroke wizard tuned pipe expansion chamber design software package. Properly tuned systems can increase the charge of fuel delivered to the cylinders and a related phenomenon can aid. Exhaust and intake tuning building, tips and techniques. In a twostroke engine, the exhaust gasses transfer less heat to the cooling system than a fourstroke, which means more energy to drive the piston and, if present, a turbocharger. This app can be use for finding inside diameter and length of four 4 stroke exhaust pipe with specifictype of an engine e. Engineering acousticssonic supercharging of 2 stroke engines. Aug 02, 2012 also, the definition of good design depends on what you want to do with the engine. Your exhaust system with the help of the muffler also reduces noise. You can also save and load the data by using the provided functions.

A performance exhaust system is a characterizing element for any internal combustion conveyance. Regular hours all times pacific more contact information. The calculated compression ratio is usually referred to as the trapped compression ratio. Question basics of 4 stroke muffler design engines.

The formulas on this page were taken from fourstroke performance tuning by a graham bell. Engine performance simulation software has become an integral part of the engine designers toolkit. Tuned adjustableexhaust pipe for use on twostroke motorcycle was designed and tested. The complete engine geometry together with these two exhaust systems is simulated using an engine simulation software package virtual 4.

For example my suzuki 100 gained 10kph more top speed when the silencer was removed. In a motorcycle we aim the gases out the exhaust port and into the exhaust pipe. The analysis is conducted on a 1d model of a ktm 510 cc single cylinder, fourstroke. A twostroke pipe uses its reflective pressure wave to keep the fuelair mixture inside. Ability to use expansion chamber design software or, be really good at math. The calculations are assuming a speed of sound in the exhaust gas, which is not known exactly. The software uses mathematical formulas that are approximations of reality, and the. Near the end you will be presented with the latest and best software for design and analysis of 2 stroke pipes. May 03, 2018 freeware 2 stroke expansion chamber exhaust calculator program. The book was published 25 years ago and is still published.

I understand how exhaust back pressure works on a 2 stroke, but can someone please explain why it would be desirable on a 4 stroke reading up ive read that back pressure keeps the fuel mixture from escaping the combustion chamber before it can be efficiently ignited but why would any fuelair mixture be escaping on an exhaust stroke. Defining the acoustic profile and influencing the powerband exhaust design is a more dynamic science than stringing together a few pipes and tacking on some mufflers. A previous paper by blair et al 2, presented to the society at setc 2001, demonstrated the ability to predict the behavior of tuned exhaust systems on a single cylinder 4stroke motorcycle engine using virtual 4stroke. Every manufacturer has some form of reprogramming software that allow. In this video we look at the very basic concept of how back pressure works in 2 stroke expansion pipes. Calculated by dynamic flow simulation modules to match your engine specs. You know that changing the exhaust pipes on your twostroke motorcycle can have a marked effect on the engines power characteristics, but do you know why. Four examples showing how accurate eccalc is compared to dyno graphs. It helps to loosen the headpipe nuts, slide the q4 on and install the midsection bolt and then align the rear mount to get the bolt installed. Why 2 strokes can rev higher than 4 stroke engines and what limits engine speed. Design of exhaust silencer muffler for transmission losses with the performance of a four stroke diesel engine with and without muffler section.

So whether you have a 50cc road bike, a 500cc motocrosser or a classic racer. Pdf design of exhaust silencer muffler for transmission. I was looking in to details about how to make a ffe. Torqsoft twostroke exhaust system designer programme. A simple 3 stage two stroke exhaust calculator based on formulas of g.

The exhaust gases travel down and out the pipe, but as the pressure pulse moves through the exhaust plumbing it encounters various design features. For this we can go to the tfx website where they demonstrate their testing and data analysis software, or read the paper referenced below titled exhaust gas flow behavior in a two stroke engine. This is because four cylinder engines have a 180 crank, whereas virutally all v8s have a 90 crank the angle between the crankpins and so the order in which the exhaust pulses come down the pipes is different. The exhaust pipe works because of the pressure waves generated when the exhaust valve opens. Exhaust and intake tuning this article describes the principles involved in using tuned exhaust and intake systems on twocycle and four cycle engines. Every performance exhaust for 2 stroke multis has an expansion chamber for each cylinder. Exhaust tuning theory and system design weve all heard the magazines talk about back pressure and most of what they say is utter cac so how do we ensure we have a good, efficient, exhaust system bearing in mind that back pressure, any back pressure, is a. Measurements of the exhaust pipe pressure pulse on a continental o. Great tool for those who are building exquisite format exhausts, one of the largest benefits of this module is that it can be used with any exhaust formula results.

The engine produces a maximum of some 34 kw 46 hp power. Advanced twostroke tuned exhaust system the challenge the society of automotive engineers. Optimization of exhaustpipe tuning on a 4stroke engine using. These engine and pipe arrangements are now optimized using simulation to achieve several different performance goals including maximum power and torque over. Two stroke engines have different exhaust systems, but the basic muffler design is similar. Simply put, its because the twostroke exhaust system, commonly referred to as an expansion chamber uses pressure. What is the exhaust temperature of four stroke bike engine. Jun 15, 2015 in fact, your standard motorcycle exhaust will house a catalytic converter which helps convert the carbon monoxide expelled from the engine into carbon dioxide which at least makes it slightly more environmentally friendly. So whether you have a 50cc road bike, a 500cc motocrosser or a classic racer, we will design the perfect exhaust system for you.