miuge
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Post by miuge on Apr 3, 2014 2:41:07 GMT -5
Hi John,
Just wondering what would be turbine's rpm for maximum output. I looked compressor- and turbine maps for similar Garrett models and end up to something below 30,000rpm. Since we got a 12" rear wheel, we need a greater reduction ratio than sprockets only would allow. My previous calculations show that 1400rpm at rear wheel equals 120kph. Maybe we could use karting chain in first stage reduction and then add a heavier chain for the final ratio..
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miuge
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Posts: 199
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Post by miuge on Apr 2, 2014 15:58:06 GMT -5
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miuge
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Joined: March 2014
Posts: 199
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Post by miuge on Mar 26, 2014 16:05:55 GMT -5
Okay, sounds interesting.. Yes we do have access to a lathe and CNC milling machine, but not constantly, secondly our machinist has a very limited time what makes creating things from scratch harder. It takes no time if I just draw a model for him. Could you perhaps reveal your solution? I was already thinking to make an axial fan by welding, but after a while found myself searching for a huge turbochargers again. I'm hoping to make a deal of one S500 turbine shaft..
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miuge
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Posts: 199
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Post by miuge on Mar 26, 2014 3:56:05 GMT -5
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miuge
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Joined: March 2014
Posts: 199
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Post by miuge on Mar 25, 2014 2:49:24 GMT -5
Hi John, Okay, that's pretty much what I was expecting Didn't notice those Garrett turbine dimensions were inducer diameters.. So it's not good to rise jetpipe PR? Does it cause too much temperature rise or choking the gas producer? Your calculations definitely help to perceive and develop our assembly. We still might go with the S300 first, and adjust the dump pipe size when things are bolted together. 18hp is a good start for the purpose, our baseline was to make it move... :-D I've done some gear ratio calculations for our desired 120/80-12" wheel: Freepower turbine 50,000rpm (or 25,000rpm and 10:1 reduction) Planetary gear 20:1 -> 2500rpm 13/45 sprockets -> 700rpm = 63kph 17/45 sprockets -> 900rpm = 86kph Freepower turbine 75,000rpm Planetary gear 20:1 -> 3750rpm 13/45 sprockets -> 1070rpm = 96kph 17/45 sprockets -> 1420rpm = 127kph Freepower turbine 50,000rpm Planetary gear 30:1 -> 1666rpm 13/45 sprockets -> 476rpm = nothing to mention.. 17/45 sprockets -> 640rpm = 57kph Have to keep an eye on eBay to get a suitable planetary gear. 10:1 reduction might be a good investment as it would take 25,000rpm easier than greater reductions would take 50,000rpm.. Slower acceleration, but much more reliability and margin for freepower rpm rise..
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miuge
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Joined: March 2014
Posts: 199
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Post by miuge on Mar 24, 2014 8:38:52 GMT -5
How did you bend the frame pipes? Just noticed few wrinkles.. Though I think it doesn't matter in this case. I used Biltema's hydraulic pipe bender when making a roll cage in my car project, it did wrinkles even with sand in the pipe, solution was to fill pipes with water and freeze them.. i187.photobucket.com/albums/x281/mice325/IMG_2615_zpse30cd6e5.jpg
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miuge
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Joined: March 2014
Posts: 199
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Post by miuge on Mar 24, 2014 5:56:22 GMT -5
Hi John! Nice calculations, I read it a few times to comprehend :-) Seems like the turbine is working pretty good indeed. Pitot entry was positioned between the turbine and half way of jet pipe. The S300 freepower turbine has a big A/R close to 1.30 if I remember right, that should take approx. 30lbs/min flow with our current nozzle pressure. If we can use a higher pressure for a freepower it could flow over 35lbs/min which is almost what our turbine produces. I think we'll also cut that S300 into half and remove the rib as our welds are still holding in the gas producer's housing.. What do you think John, should we use that maybe with a slight by-pass? Also what's the best rpm range for the freepower turbine.. There's plenty of planetary gears available from 2:1 to over 50:1 ratios, rated for only 8000rpm input but a little over revving can't be that bad Output rating of 60Nm should be enough, those bigger frames tend to be too expensive.. I was thinking to try revs up to 50,000rpm and about 20:1 ratio gear. We'd get some speed for the turbine wheel right from the start
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miuge
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Posts: 199
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Post by miuge on Mar 23, 2014 14:13:01 GMT -5
Don't get bored, I've got more info and video to offer Here's some numbers, what do you think? It has a jetpipe with 51mm diameter out. Video of making a log: youtu.be/Kzu5FZ8TT9oWalkaround, water spray, glowing metal.... youtu.be/3VVrrdszFyo
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miuge
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Posts: 199
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Post by miuge on Mar 22, 2014 18:00:51 GMT -5
Here's a short clip: youtu.be/lbzgT4o5WrsLike said, we made it run clean with no problems. You might see the happiness in the video Today temperatures were even lower than earlier, TOT was 350°C at idle (from 0 to 0.5bar) after that it started to climb but stopped at 650°C at 2.5bar. Tomorrow we'll add a pressure gauge to the jet pipe so we can make an inclusive log of running. After that, maybe adding the freepower turbine?! Can't wait!
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miuge
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Posts: 199
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Post by miuge on Mar 22, 2014 8:58:04 GMT -5
Thanks John for the great tips! Turbine now runs perfect, no more flame outs or hard starts TOT also did decrease.. I'll post more info later.
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miuge
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Posts: 199
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Post by miuge on Mar 19, 2014 16:49:28 GMT -5
Thanks guys! Some further planning before next tests.. Like I said earlier, we did some testing with an old Bosch EFI pump and 1.5GPH oil heater injector. Pump gave 7bar pressure and then it faded, at 6.5bar it ran smoothly. We modified one injector which gave about 11GPH, just to see if the pump can keep the pressure with a larger injector. And it did it good It should be good for our purpose when converting to diesel. Injector size for maximum air flow of 50lbs/min should be 7.2GPH for my calculations and that's at 100psi/7bar fuel pressure. Then we should notice the P2 and our lower fuel pressure which means injector size should be around 8.5GPH. To be sure we got enough fuel 9.5GPH injector should be worth of testing too.. Correct me if I'm completely lost with the sizing... :--) Oil pump is also under construction, my friend will machine casing for oil pump rotors from a 150cc 4-stroke engine. An electric motor needed to power it. Then the freepower unit. We got this S300 turbo with 72mm (out) turbine wheel, had a little damage but we did grind it "better": i187.photobucket.com/albums/x281/mice325/Project%20Jatkettu/WP_002360_zpse4b4116c.jpgi187.photobucket.com/albums/x281/mice325/Project%20Jatkettu/WP_002358_zps8e7765e4.jpgClosest turbine map I could find is this Garrett GT3782 map: www.turbobygarrett.com/turbobygarrett/sites/default/files/default_images/turbogroup/performance_maps/452195-3turb.jpgAny good? Thought was to replace the compressor wheel with a sturdy planetary gear and maybe a centrifugal clutch after it... Just thinking by far
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miuge
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Post by miuge on Mar 18, 2014 15:37:45 GMT -5
We used shims to keep the clearence the same If tangential delivery tube ain't good, then it has to be fixed: Positioned between secondary and tertiary zone: i187.photobucket.com/albums/x281/mice325/Project%20Jatkettu/WP_002432_zps2d21aa81.jpg3 of the primary holes also opened to 10mm and all holes now got a little tapering if it helps air penetration.. Should test this version by the weekend, hopefully we get better results
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miuge
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Post by miuge on Mar 17, 2014 14:35:26 GMT -5
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miuge
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Post by miuge on Mar 15, 2014 5:21:43 GMT -5
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miuge
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Posts: 199
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Post by miuge on Mar 14, 2014 14:01:56 GMT -5
Very nice work with the bike! Waiting to see it run
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