2 Stroke Pipe test! Homemade v shop bought Expansion Pipe - Dyno test - 100mph Moped

[@JoniK1]

I really enjoy watching this type of tests, thanks!

[@AutoBeta2T]

Cool, I'm pleased you are enjoying 😄 Lots more testing coming up.

[@Trevorpartington-yc6ri]

excelent vid mate....... I honestly can't wait for the final ! I Loved my little AR50, probally the mostt fun I've ever had on a bike ever.

[@AutoBeta2T]

Thank you Trevor 😊 I'm not sure if it will ever end. I'm sure there will always be some power available on the table. 😅

[@Fk8td]

Your videos are very informing and you do real testing. This us how info should be shared.

[@AutoBeta2T]

Cheers, this was always my intention: to share knowledge, successes and failures so we can all learn. Thanks for watching ☺️

[@LangstonPerformance24]

Hey Dave, good on you for making these videos, enjoy watching them 👏 Looking forward to seeing more vids on the EngMod. I'm looking at getting it seeing that I've been out of 2 strokes for quite some time.

[@AutoBeta2T]

Hi Andrew cheers and pleased you are enjoying the videos. I'm sure there will be some More EngMod stuff. It's a great piece of software.

[@halvorsonmx]

Awesome video. I really enjoy watching what you do!

[@AutoBeta2T]

Cheers buddy, thanks for the support, it helps to keep me motivated 😄

[@AutoBeta2T]

2 videos in two days. Pretty good for me 😂

[@sidecarbod1441]

It must be Christmas!

[@RACE.KART.PRODUCTS]

during the dyno pull the pressure is pushing your slippy pipe back. you need stiffer springs or a way to secure it better. It does this on the header on karts too. we use 4 mega stiff springs to combat this.

[@AutoBeta2T]

Yes, I need to address that and the leaking. I normally use lockwire but it wasn't doing it this time.

[@siem8160]

It doesn't get any better than homemade. Your welds look very nice. For the exhausts, I based myself mainly on the measurements of the best exhausts, which I modified to suit my needs (many thanks to Rhino 3D). I still have some old refrigerator sheet metal in reserve to help out a buddy, and of course my trusty 36 cm wide rolling machine.

[@AutoBeta2T]

Cheers siem :) I try to get the fit up as close to perfect making the welding easier I to have used well performing exhausts as a base in the sim then tried to finesse them before building. It seems to work. I found having the dimensions of a good exhaust (Dyno tested) really helpful. Can I ask: what or who Rhino 3D is? How do you find refrigerator steel forms? You can only get CR4 sheet steel in the UK. I believe that CR1 is more ductile (called superdraw in other countries) and is better for pipes - particularly hydroformed pipes. I believe fridges, car panels and other formed sheet steel objects use this type of steel. I have a dead fridge in the garden that I'd like turn in to a hydroformed pipe...? I have also heard the CR1 does work harden due to vibration?

[@siem8160]

@@AutoBeta2T I recycle refrigerator fairings thanks to an uncle of mine (he's also the one who gave me a lot of motorcycles) who owns a junkyard. These refrigerators come from old restaurants or canteens, and have excellent sheet metal. The 0.8mm sheet metal provides excellent resonance. Admittedly, it rusts very easily, but with a little oil it holds up perfectly. I have a Bidalot hydroformed exhaust, but I find that it doesn't sing the way I want it to. I tried to make one about twenty years ago, but it's extremely difficult to get something perfect. I had to cut out the header and weld it on to get it to fit properly. Objectively, by multiplying the number of cones by 3, and using precise welds, you can achieve a very fluid shape with very little effort. Builders can make hydroformed parts with the support of a 100 kg mold. A racing factory-style exhaust still looks good. Rhinoceros 3D is a 3D software that I have mastered. It allows me to calculate volumes, cone developments, draw or simulate cylinder diagrams. This software offers incredible precision and allows you to use mathematical curves (NURBS). When I want a 6mm circle to be tangent to 2 curves, it's done precisely and quickly. Last but not least, it helps to see possible breaking points or mismatched flows. I made 3D models of 4 of my motorcycles: RD350 LC; CF G2; Flandria 50; 250 YZ 94. It's a very long process, especially without a 3D scanner (my dream). This has enabled me to simulate and produce perfectly adapted exhaust, a longer aluminum swingarm on the CF; or to test a new steering angle on the racing version of the RD350 LC that I'm currently preparing. It's so much simpler, that every single bracket or pivot is made on Rhino first. No surprises during installation. Well, Rhino is certainly complex to start with. You can start with SketchUp, which will give you the basics, and then head for Rhino. If you need help, just send me a rough with dimensions and I'll do it for you with Rhino.

[@AutoBeta2T]

Cool - 0.8mm is what I usually use any way. It will be interesting to use it. Maybe for the next pipe then

[@yogiguitar1]

nice 1 mate keep it going seems like she's getting stronger

[@AutoBeta2T]

Thanks... Yep it's going okay at the min. Hopefully some more progress today 🤞

[@yogiguitar1]

funny enough i had a dream this morning to start working on mine . i got an 88cc barrel to put on my am6 engined hrd (what became sherco) bike and a big fat chamber ive just not got round 2 it yet. gotta sort out the leccy system shorts first. and i gotta suzuki gt 125 that needs a box rebuild that i thought of trying to bore out and put some water cooled heads on but so far ive done nowt! @@AutoBeta2T

[@AutoBeta2T]

@yogiguitar1 did you get the 88cc barrel on? I did a few tests today but not as many as I'd have liked to

[@yogiguitar1]

nope ive had me boy over so we watched a film and ate pizza ! sunday innit. ill get round to it but i gotta get a longer throw crank first and grind out the cases a bit. ill prob have to work on the car first. or ill let me boy muck about with it he's a mechanic anyway it'll get done one way or another .eventually! . @@AutoBeta2T

[@marcusbrown2493]

Great job Dave👍

[@AutoBeta2T]

Thanks Marcus 😁 I need to pop up to see you at some point to talk CNC.

[@marcusbrown2493]

Anytime mate👍

[@cjclevenger7952]

Awesome 👍

[@AutoBeta2T]

Cheers 🙂

[@markaddy53]

gettin there lad sure ul crack it keep goin

[@AutoBeta2T]

Thanks Mark 😀

[@andycompton4885]

Sounds Sweet 🙂👍

[@AutoBeta2T]

Thanks Andy 😁

[@jritchiejritchie2687]

Just subbed... Great stuff 👏

[@AutoBeta2T]

Cheers and welcome to the channel ☺️

[@alerusso5356]

does that jan thiel book give some technical informations about 2 strokes or is it just a biography?

[@AutoBeta2T]

Hi, it's more of a biography, there is some information about engines in there but it's more about Jan's journey.

[@alerusso5356]

@@AutoBeta2T thank you 😊

[@robertbekoscke988]

What are you seeing exhaust temps stock vs now I’ve been building a few pipes for my 50 and I seem to be off slightly on my calculations and I think my guess on temps are off thanks awesome videos

[@AutoBeta2T]

Cheers Robert. I don't really use a temperature as such. I work backwards from a known tuned length that gives the peak rpm I am after and fudge the temp to give the tuned length. That said I am trying to collect exhaust temperature data to help with its refinement.

[@robertbekoscke988]

@@AutoBeta2T ok I don’t have a dyno so i drive the bike and seeing how it reacts to changes it seems like I make a pipe off the calculations and it’s not giving me what I want so I cut the pipe or lengthen the pipe to get better results I may need to do what you did and make an adjustable one to dial it in thanks for the reply love the videos

[@AutoBeta2T]

@@robertbekoscke988 glad you are enjoying. Ultimately it's the real world performance that counts.

[@TEAMVISKAT81]

It's great to see that your home-made exhaust gave one more hp. do you have the option to make your exhaust port wider? then you can also achieve more port area. but no more blowdown area :(

[@AutoBeta2T]

Thank buddy. I'm just packing up as we speak to head to the Dyno. I'm going to widen the exhaust port first then head upwards raising the port. Hopefully more blowdown will help. I just don't want to go too far and make the power band too narrow.

[@davidwickboldt712]

Maybe a divergent cone and header need to be shorter/more angle to empty the cylinder faster. Instead of increasing blow down.

[@AutoBeta2T]

Hi David, possibly but this pipe is pretty angley already. From what I can see the current blowdown time area limit is 15 hp which is the same as the power I'm getting.

[@freddykoopmans6985]

Hi where did you get the book about Jan and does it has a ISBN number?

[@AutoBeta2T]

Hi Freddy, it's ISBN is: 978-88-7586-727-0 You could aski via this email address: [e-mail]

[@AutoBeta2T]

Freddy - I just saw this link from Jan on Facebook: 📸 Look at this post on Facebook facebook.com/groups/671081149638729/permalink/6915535795193202/?ref=share

[@ugandansupakicka1367]

does longer stinger affect performance

[@AutoBeta2T]

It can if there isn't a more restrictive area at the exit of the pipe.

[@andrewhambelton8209]

What carb are you using, I used to run in moped mayhem, the carb to have was a semi flat side from a KR1S.

[@AutoBeta2T]

Hi Andrew, it's a Kawasaki KX 80 carb which is 28mm. What size was the KR1S carb?

[@captroft]

Standard is a 28mm pwk

[@sidecarbod1441]

Just out of interest and I know that the blowdown angle is important but what is the current exhaust port duration?

[@AutoBeta2T]

Hi Pete, that's an interesting question... I thought it was about 197 but after a remeasure today it's quite a bit lower. 186-194 depends how you measure it. I'd go for 190 as an average

[@AutoBeta2T]

It's more than that now... But that's for another vid.

[@sidecarbod1441]

@@AutoBeta2T 190 is not excessive but I'm guess you will need 5 to 10 degrees more. I have found that if you go just a couple of degrees too far it can ruin the feel of the engine, work up to it slowly! I guess the pipe will need tweaking too after any exhaust port changes. I'm sure you are aware of all of this anyway!

[@AutoBeta2T]

Yep, I think duration will be in the 200s. Luckily the pipe is adjusted so can be lengthened.

[@Jonathanbaker]

What’s that my fav compressor 😂

[@AutoBeta2T]

I effing hate that thing. It's like it knows when is a bad time to start... And starts.

[@Jonathanbaker]

@@AutoBeta2T

[@vikingjohansson8986]

What is diy and bdk

[@AutoBeta2T]

Hi, DIY is: do it yourself - so home made me. BDK is a company in the UK that tuned Kawasaki ARs and this is the pipe they developed and sold. Cheers for watching ☺️

[@bertlilley4988]

Would someone run my bike details ?

[@AutoBeta2T]

Hi, what bike is it?

[@wtm7554]

Hello, you haven't work the ignition,stinger, head,... So for me just make this type of test is not complete. 👀

[@AutoBeta2T]

Hi, WTM I did actually play with the ignition a bit but did not show it. It's quite difficult recording everything and doing the testing too I just wanted to show the difference a pipe can make. I don't think that testing will ever be completed as there is always something else to try 😉 And like you say, stinger and head changes could be tried but that takes time and testing after work limits the time I have (I like to do a set of tests the day session as I don't fully trust the correction factors used). It's going to be a long process I think. I definitely want to try other heads as I think a lower compression one will work better. There's endless things in my head to try but I just need some more time.

[@D.Technical.S]

suggest from a novice 😬 Adjust the ignition timing a little later , thats why you have a the power drop in over rev .... just saying 😋 Do that before messing with the spacers

[@AutoBeta2T]

Cheers, I'll give it a go 🙂

[@MrTench8]

@@AutoBeta2T No, on a two stroke the ignition timing needs to retard at high rpm to raise the exhaust gas temp, this changes the speed of sound in the hotter gases in the expansion chamber effectively shortening the exhaust to better suit high rpm which extends the power band. A 4 stroke benefits of increased advance at high rpm but a 2 stroke is very different!!

[@AutoBeta2T]

MrTench, yep. that's what I though D Technical was saying... Cheers :)

[@D.Technical.S]

exactly 🙂 you just have to try and find the sweet spot , every engine is different and for sure when you start messing around with timings and exhaust . you have the benefits of having a test bench ... so would love to see a movie where you play around with the ignition timings . can you program the CDI of that ignition ( i preusme it's a batterie ignition ? ) ? you maybee would benefit a higher curve , like 30-35 degree advance , dropping from 6000rrpm to 5 - 10 dergee on top RPM ... @@AutoBeta2T

[@AutoBeta2T]

@D.Technical.S I'm just about to start editing a video of ignition testing... Hopefully out by tomorrow.

[@AnaAjaksi]

Do you know why AFR is very lean at 7000 rpm, I had similar results, video: kzbin.info/www/bejne/f2nbqnaabdWJfs0 5 min from start. I haven't got time yet time ti investigate further. I have almost similar setup, engine is standard (not tuned) Piaggio scooter.

[@AutoBeta2T]

Hi, no I'm not totally sure. I do know that lambda sensors are prone to error on two strokes and only really accurate around peak torque. I believe it's something to do with how they measure the oxygen and the fact that a two stroke can over-scavenge and have a lot of unburned fuel air mixture in the pipe at off design rpm. I believe that the sensor can get fooled into thinking the mixture is lean when it is in fact rich. I read about this many years ago but I'm struggling to recall the full facts so take what I say with a pinch of salt.

[@andrewallen9993]

Instead of all this fooling around with hacksaws and welders by guess and by god just do what Mr Kaden did and work it out mathematically.

[@AutoBeta2T]

Hi Andrew - I do work everything out but there are so many variables in a two stroke engine testing is the only way to get it dialed in correctly. Even if I did get it calculated correctly I'm not good enough to ensure that the pipe is exactly as calculated, particularly as I've hand cut each section plus there could be a certain amount of shrinkage from the welding - times that by 20 separate pieces there is plenty of scope to be 10 mm off. I hope that explains my approach. Basically I need to get better at welding and fabrication. :)

[@andrewallen9993]

@@AutoBeta2T 😁Every time MZ changed the ports,carb jets, fin size etc. etc. etc. Mr Kaden had to do his sums again. Though they did have former V1 fabricators I believe.

[@Intesanoga]

Found this channel yesterday had to binge watch almost all the AR50 videos. I really like your scientific approach and its easy to follow along and understand. I like how you show the programs, notes and the work and thinking behind it all not just the result. How does the lamda sensor cope with the oil two stroke exhaust? If you haven't seen int before i can recommend a other fellow youtuber www.youtube.com/@ASoftaaja Its a Finnish guy tuning an am6 50cc to get 20hp form 50cc. He has really good eng subs in his videos. Greetings from Sweden.

[@AutoBeta2T]

Hi, I'm pleased you found the channel, and you are enjoying 😀 Hopefully I'll get to do some more videos this year looking at some of the details of two Stoke as the exhaust duct. Personally, I find the lambda works, but I know you have to be cautious of the reading when not around peak torque as rich can show as lean. In terms of reliability I've had a few fail but they weren't being heated as I had a wiring issue. The one I use now seems to work fine. I also got the same reading from another dynos lambda too. Yes, I've seen quite a few a Asoftaaja's videos - a really cool project and hopefully he gets to 20hp soon ☺️