Optimization of exhaustpipe tuning on a 4stroke engine using simulation 200202 engine performance simulation software has become an integral part of the engine designers toolkit. What this means is that stock cams, an exhaust cam on the intake, or high liftlong duration all tend to want similar specs on primary and secondary tubing. Mastering exhaust system math to build highperformance. A performance exhaust system is a characterizing element for any internal combustion conveyance. The first step in the 4stroke process is the intake stroke. Hi, its been a while sins i have posted here, occupied with a 4stroke engine development that was launched for rather small gas engines. North american twostrokes general twostroke discussion. Free 2 stroke expansion chamber calculator software update.
You can also save and load the data by using the provided functions. Pro circuit has built a reputation around our exhaust systems. Ive been tossing around some different ideas regarding mufflers exhaust systems for 4 stroke rc airplane engines. While twostroke engine development is on the rise again, the worldwide interest in a professional twostroke engine simulation is still limited. The bendtech exh is specially designed to aid in the manufacture of exhaust tubingpipe. Freeware 2 stroke expansion chamber exhaust calculator program. Tuned exhaust pipe length calculator for singletwinsfours. 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 opening angles of the cones should be 4 to 10 for the opening cone and approximately twice. Ability to use expansion chamber design software or, be really good at math or. I know the less exhaust pipe curves the better and where it does curve try and make them long and flowing. Next enter the cylinder bore and stroke which are 40. Split your calculated 2stroke exhaust up to 42 sections with regular length or even more with irregular lengths.
This is the place to talk about anything related to twostroke road race bikes. How to design a two stroke expansion chamber performance exhaust step 6 duration. The information used in the programs calculations was taken from the books the basic design of the two stroke engine and the book design and simulation of two stroke engines. How to design a two stroke expansion chamber performance. As with a twostrokes expansion chamber, a fourstroke exhaust system is tuned to. A yamaha yz400, 5valve, 4stroke cycle, motocross racing, motorcycle. Twostroke engines have different exhaust systems, but the basic muffler design is similar.
So overlap merely takes advantage of the inertia of the exhaust gases and the lowpressure region that it produces near the exhaust valve at the end of the exhaust stroke. Thanks so much for going to all the trouble and time doing this i cant afford to buy a pipe design program and im. Improve the performance of your twostroke engine with a torqsoft designed exhaust system. This is the length from the piston face to the end of the exhaust flange. 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. This software covers the 3 stage diffuser type expansion chamber exhaust as per equations provided in his book entitled design and simulation of twostroke engines published in 1996. For further investigate of the operation of twostroke engines with tuned exhaust pipes it is most appropriate to analyze actual test data. A twostroke pipe uses its reflective pressure wave to keep the fuelair mixture inside. Crankshaft rotation ratio buddy two stroke gas to oil ratio calculator. The higher the rpm we design for, the greater the intake and exhaust overlap we build into the cam lobes.
A simple 3 stage two stroke exhaust calculator based on formulas of g. 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. Twostroke waveaction engine simulation motion software. So whether you have a 50cc road bike, a 500cc motocrosser or a classic racer, we will design the perfect exhaust system for you. The calculations are assuming a speed of sound in the exhaust gas, which is not known exactly. I just started flying nitro powered warbirds foamies for 4 years before thatand nothing annoys me more than a ww2 warbird with sleek, beautiful body lines and a grotesque. You can also save and mota software, 2 stroke engine simulation software, 2. This coefficient kh is called the horn coefficient, with typical values between one and two. Any donations greatly appreciated, please use paypal link. By skinsfan6, january 15, 2005 in general dirt bike discussion. These bikes has been known to punch out big hp with twin carbs and exhaust. This small java applet uses design rules according to, and, to size a tuned pipe for a 2 stroke piston engine.
The exhaust system of a car is one of the most commonly modified areas when a gearhead gets ahold of their ride. Racingsm software for 2 stroke development, also for 4 strokes in some modules, create 2t exhaust, create 2 stroke exhaust toggle navigation. As a relatively new designer of the fourstrokecycle engine, design and simulation of fourstroke engines is by far the most important single source of information to me. Follow the link to my software site and go to the 2t exhaust calc menu item and download either the stand alone program or a installer package. That part of the overlap design is common to all 4stroke engines in order to gain additional charging of the cylinder with fuel mix at high rpm. Regular hours all times pacific more contact information. I just started flying nitro powered warbirds foamies for 4 years before thatand nothing annoys me more than a ww2 warbird with sleek, beautiful body lines and a grotesque exhaust wart sticking out of the cowl. Exhaust optimization for viking motorsports formula sae.
I also own blairs design and simulation of twostroke engines. We offer fourstroke exhausts for all the popular motorcycles and atvs. Two stroke engine and exhaust design software north. New feature of racingsm software, the 2stroke exhaust segment splitter. 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. In this example the dimensions are 45mm and 27mm respectively. After a while i became more and more convinced that the technology we are using to obtain a higher volumetric efficiency could be used in low revving boat 4stroke diesel engines. The complete engine geometry together with these two exhaust systems is simulated using an engine simulation software package virtual 4stroke and the experimentallyrecorded exhaust pressure diagrams and performance characteristics of power, torque, etc. 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 twostroke engine. Mastering exhaust system math to build highperformance engines january 24, 2015 by muscle car diy exhaust systems dont generally invoke the glamour and gut level appeal associated with many highperformance induction systems, but they certainly play a critical role in the performance of every engine. Optimization of exhaustpipe tuning on a 4stroke engine using simulation 200202. Create your own calculated 2 stroke racing exhaust system design database with this module. Considering component one, when the exhaust valve first opens in a 4stroke piston engine, the incylinder pressure is still well above atmospheric. The main interface of bendtech exh gives you the ability to recreate the critical components of a vehicle axles, mufflers, gas tanks, etc and then properly route the tubing around them.
Near the end you will be presented with the latest and best software for design and analysis of 2 stroke pipes. Advanced twostroke tuned exhaust system the challenge the society of automotive engineers clean snowmobile challenge 2002 sae csc 2002 is an engineering design competition for college and university student members of the society of automotive engineers sae. There are many ways to boost the power, one of which is by installing a tuned pipe. Small values of kh are best suited to grand prix engines with. Scientific design of exhaust and intake systems engineering and performance philip hubert smith, phillip h. I personally wouldnt own a 4 stroke, they came into existence only to meet environmental rules, but the new evinrude direct injected 2 strokes are cleaner and better. We shall send you a pdf document with the templates for manufacturing your exhaust. I think mota is a good program for the money, but dont think the results from any engine modeling program are carved in stone. Every manufacturer has some form of reprogramming software that allow the consumer to. Exhaust manifold is made up of cast iron or stainless steel. Engine performance simulation software has become an integral part of the engine designers toolkit. To achieve the optimal geometry for the low backpressure and.
The way a two stroke motor works causes them to be f. Engineering acousticssonic supercharging of 2 stroke. Blair of queens university belfast, and published by the society of automotive engineers. Scientific design of exhaust and intake systems engineering and performance. You could create a hardcopy of the program window, though, using your systems suitable tools. Free 2 stroke exhaust expansion chamber calculator youtube. With the intake valve open, the piston travels down the cylinder pulling a fresh air and fuel mixture into the cylinder intake stroke. This small java applet uses design rules according to 22, 23, and 24, to size a tuned pipe for a 2 stroke piston engine. Exhaust and intake tuning building, tips and techniques. 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 bad thing. Pdf design of exhaust silencer muffler for transmission. It collect gases from different cylinders and supply.
In a motorcycle we aim the gases out the exhaust port and into the exhaust pipe. The intent of the competition is to provide universities with an. The diameter is the internal diameter of the exhaust flange. The exhaust pipe works because of the pressure waves generated when the exhaust valve opens. The frequency content of exhaust noise is dominated by a pulse at the. Newpipe will probably generate an ok pipe but knowlegde, experiance and testing is better. However, optimization of a particular design using such. Most exhaust companies and formulas tend to treat a 3cylinder engine the same as a v or inline4. Optimization of exhaustpipe tuning on a 4stroke engine using.
Motion software offers performance engine and vehicle simulation software for the automotive enthusiast. In order to explain the effect of exhaust tuning on performance, lets take a quick look at the 4stroke engine cycle. Since 2005 4t header wizard have a new homepage click here. On four stroke racing bikes that pipe could be a long straight pipe or a short header pipe and a megaphone.