2 Stroke exhaust calculator

It does what it's supposed to do, except that you can't use decimals in some fields (like HP - I can't do any less than 1HP for a 5cc engine, so my total length comes out to 4ft). Everything is also in mm, no way to change units to in.

Total bugus, I admire people if they are able to make this app work, however I am a builder and have calculated my 2-stroke exhaust the hard way for a long time, the only way you can calculate a real expansion chamber is by entering in the width and Stroke of your piston chamber... That's the only possible way to know the proper exhaust chamber size. Any other way and it's not right.

I drive a it 490 hand built this ap0 produced a fantastic exhaust pipe for that runs great hell yea ⁴stars

Interesting program , Hope it works out, things I see that could be problems, tuned length is usually to the rear of the back cone, not to the end of the tail pipe , was made up to see the hydroform option, but no lengths shown, only the diameter are catered for and in blowing up a cone, the lengths get shorter, so this needs to be calculated in :) here's hoping this can be sorted :)

Needs to say what the mesurments are in! Is this imperial, metric? Centimeters milimeters!? Please make it show what the lengths and diameters are mesured in.

I will use it to make my 1st exhaust for RS 125

this really is a great app to have, all i have to do is punch in the engine specs and BAM, HP exhaust here i come!!

mooie auspuff voor kettingzaag

I think the funnest and most surprising bike i had was a Kawi S2 (3 cyl 2 stroke 250cc) It was a late 70's model i bought from a young guy who'd only had it 1 month and "looped it". he tried to ride a wheelie before he mastered his basic riding skills. The bike had chrome Denco pipes,clip-on's for handle bars and a good quality set of set back foot pegs.Whoever piped that bike installed a taller toothed rear sprocket and weisco short skirt pistons. When i got it i immediately installed new ignition points,

Is this for two stroke bikes with reed valves or for bikes with piston ports or both?

I will use it to make my 1st exhaust for RS 125

Works good simple to use

I think the funnest and most surprising bike i had was a Kawi S2 (3 cyl 2 stroke 250cc) It was a late 70's model i bought from a young guy who'd only had it 1 month and "looped it". he tried to ride a wheelie before he mastered his basic riding skills. The bike had chrome Denco pipes,clip-on's for handle bars and a good quality set of set back foot pegs.Whoever piped that bike installed a taller toothed rear sprocket and weisco short skirt pistons. When i got it i immediately installed new ignition points, condensers and spark plugs.changed gear box oil. The fun power band began around 8500rpm and HONESTLY pulled past burying the needle....the tachometers numbers only showed up to11,000rpm but that bike did not quit pulling until 16,000.I've had KH 500's and 750's also. A few RD's too. My next project is an Echo 63cc blower motor converted onto a beach cruiser. Im going to build my own pipe out of 18 gauge stainless steel and tig weld to perfection.

2 stroke exhausts are an art form , it is good to see this app. With pollution restrictions these days it will soon be hard to even find small 2 strokes.

The equation seems to be for single cylinder only. Would be nice to have a number of cylinders/pipes option

Its not too bad but the pipe diamensions are not what im used to for 25 - 30.5 cc motors. Would be good if you could have intake & transfere durations in the calc but also a reed option

How do u calculate coefficient?? Anyone other wise the app is great and does it calculate in mm?

Does exactly what most people will need. Cheers!

owsome.... helpfull for research 2t exhaust sistem

Please do more ! So handy to have

This app works great. The only problem is no exit.

But coeficient for what...i dont understand..

Started using it today and not sure if measurements are in millimeters or inches. Seems like its lacking some helpful information

Excellent Now i can finally tune my 2stroke exhaust perfectly!

have been waiting for something like this but please put more options

Im gonna use this for small business, im from Philippines, and in my town,there's a lot of people having two stroke motorcycle like, rs 100 yamaha,suzuki x4 and b120,x3,kawasaki xd2 and xd3,this is so usefull for me, ive been try to calculate it before how to get the exact mesurement, i even ask my engineer friend, i got 3 yamaha rs 100,im gonna use this up, mig weld and gauge of metal sheet i still have no idea, please help me.... Coz i know the temperatures of the expansion chamber core was important coz it effecting the sound waves travel inside it....

this really is a great app to have, all i have to do is punch in the engine specs and BAM, HP exhaust here i come!!

Awesome.....