jcoahran
Scoot Enthusiast
89 zuma ii
Posts: 347
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Post by jcoahran on Mar 26, 2012 23:07:00 GMT -5
im 150 lb 6 foot tall, was wondering what weight roller weighs i should use to get maximum top speed, i have a gy6 50cc (maybe 60cc the original owner said it was, but i dont believe everything im told by someone trying to sell me something) i dont care about the acceleration (mainly just long open roads where i live) i just want MAXIMUM top speed, and if im getting 45mph with stock roller weights how much faster should i expect to go? :devil: :twisted:  :wheelie: |
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Post by larry001964 on Mar 26, 2012 23:12:38 GMT -5
Hi jtweak
ChinOmeters are notoriously inaccurate and has been the subject of many discussions here and on other forums, However if your getting a true 45 MPH verified by GPS or some other accurate means, Id say you have a 63 cc.. And 45 MPH is pretty good, and I doubt different weights will gain you that much more speed.. If it's truly 45 MPH then it sounds like your variator is opening up fully and your belt is traveling the full distance of the face ( Traveling all the way up )
You can perhaps get a different variator slightly larger, stock size for most iv'e seen is 87 mm, I had an NCY one that was 89 mm and it gained me a little, but I mean very little. Like maybe 2 or 3 mph faster was all.. And that was when my scoot was a 72 cc
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Deleted
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Post by Deleted on Mar 26, 2012 23:25:32 GMT -5
weights work like this..lighter raises rpm so your takeoff and hill climbing will be good but top end will suffer if you go too light.....heavier weights will give the best top gear but your hill climbing and acceleration will suffer if you go too heavy
assuming you are using the stock 1000 rpm torque converter spring get 5g and 6g. try 5g then do 3 and 3 that will give you 5.5g....then try 6g....see which works best....5.5g works best for me.
If you are seeing 45mph already i doubt you will see more. I had to build an 82cc to reach 50mph. Many are 44mm bore 63cc...my new bikes i sell are 72cc from the factory..if it does 45mph it sure isnt a 49cc.
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jcoahran
Scoot Enthusiast
89 zuma ii
Posts: 347
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Post by jcoahran on Mar 27, 2012 13:50:52 GMT -5
are you sure i can't get it a bit faster? when i get it fixed i was thinking maybe a turbo kit, a better variator, better gears, a new clutch, and maybe (if its not a huge hassle) 13 inch rims and tires, i mean...all that would have SOME gain....right? if so...about how much?
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jcoahran
Scoot Enthusiast
89 zuma ii
Posts: 347
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Post by jcoahran on Mar 27, 2012 13:55:51 GMT -5
just in case, if i can't get it above 55-60 mph, would anyone be interested in a 50cc (plus money) trade for a 150cc?....would a 150 even fit in a 50cc frame? (ill do frame mods if i need to) im a bit of a speed demon, and i'd never be satisfied with 45 mph lol
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Post by larry001964 on Mar 27, 2012 14:45:14 GMT -5
Ohhh we are not saying it can't be done. We are saying that the extra 10 to 15 mph you want will come with a hudge price tag. My build is 1400 dollars worth of parts alone, not including my labor.
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jcoahran
Scoot Enthusiast
89 zuma ii
Posts: 347
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Post by jcoahran on Mar 27, 2012 15:40:19 GMT -5
money isn't too much of an object, as im taking my time...one part at a time.
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Deleted
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Post by Deleted on Mar 27, 2012 17:46:00 GMT -5
are you sure i can't get it a bit faster? when i get it fixed i was thinking maybe a turbo kit, a better variator, better gears, a new clutch, and maybe (if its not a huge hassle) 13 inch rims and tires, i mean...all that would have SOME gain....right? if so...about how much? 'there is no replacement for displacement' if you want faster....it is time to build a bigger motor....like 50mm or 52mm....or go all the way to 52x44..which Larry did and i am planning to do. |
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Post by larry001964 on Mar 27, 2012 19:09:11 GMT -5
Ohhh my goodness, there are a lot of bugs in supporting componets, I can't recommend the stroker to anyone but the most seasoned mechanics, it's still new and component manufactures need to catch up.
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Deleted
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Post by Deleted on Mar 27, 2012 20:00:21 GMT -5
Ohhh my goodness, there are a lot of bugs in supporting componets, I can't recommend the stroker to anyone but the most seasoned mechanics, it's still new and componet manufactures need to catch up. oh i agree. the point was that there comes a time when a 60cc..or 72cc...or 82cc.... just isnt going to go any faster no matter what you do...and its time to go bigger. and the faster you go the more money it takes to go just 5mph faster. and it seems the next 5mph costs twice as much to obtain as the last 5mph....and the knowledge base tends to be like that too. |
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Post by larry001964 on Mar 27, 2012 20:12:20 GMT -5
I agree, sometimes I think many don't know how much more power each 1 mph over 40 takes. And many dont realize that going bigger does not change the rpm's. It changes torque.
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Post by 90GTVert on Mar 28, 2012 11:29:38 GMT -5
You'd have to know a lot of info I don't know to get accurate numbers for what it really takes, but just as an example of how power demands increase at speed...
Using the same coefficient of drag, frontal area, and vehicle weight :
30MPH requires 1.5 HP to overcome drag.
40MPH requires 3.4HP.
50MPH requires 6.3HP.
60MPH requires 10.7HP.
70MPH requires 16.9HP.
80MPH requires 25HP.
Again, I have no idea what the real numbers should be, but there's an idea of just how much power it takes to go fast and why fast scoots are a challenge. If you want an example of how much drag really affects your scoot, try running into a 20MPH wind and then with a 20MPH wind. Most scoots will see a helluva difference in those 2 scenarios. I've ran into winds so hard that a 50+MPH scoot couldn't get over 30.
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Deleted
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Post by Deleted on Mar 28, 2012 15:05:29 GMT -5
You'd have to know a lot of info I don't know to get accurate numbers for what it really takes, but just as an example of how power demands increase at speed... Using the same coefficient of drag, frontal area, and vehicle weight : 30MPH requires 1.5 HP to overcome drag. 40MPH requires 3.4HP. 50MPH requires 6.3HP. 60MPH requires 10.7HP. 70MPH requires 16.9HP. 80MPH requires 25HP. Again, I have no idea what the real numbers should be, but there's an idea of just how much power it takes to go fast and why fast scoots are a challenge. If you want an example of how much drag really affects your scoot, try running into a 20MPH wind and then with a 20MPH wind. Most scoots will see a helluva difference in those 2 scenarios. I've ran into winds so hard that a 50+MPH scoot couldn't get over 30. ...and along with that here is what you can expect out of stock 49cc all the way up to 150cc 49cc-82cc 49ccscoot.proboards.com/index.cgi?board=4ttech&action=display&thread=2758100cc-150cc 49ccscoot.proboards.com/index.cgi?board=4ttech&action=display&thread=2953so if you take all the info you can see what its gonna take to get you to the desired mph...more-or-less. Remeber this....the charts are STOCK motors. stock carb jetting and air boxes..stock air filters and everything...just like they come in the bikes from the factory....they will be a little stronger than whats on the chart with the right mods. Both my 82cc bikes run @ 50mph with stock size valves...much is in the tuning....but this info gives an @ baseline. |
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Post by 90GTVert on Mar 28, 2012 17:03:32 GMT -5
Also remember when you are looking at the manufacturer info it's bhp. The figures I guessed on would be how much power it puts to the ground (less than bhp). Not that it matters, I'm sure my numbers are wrong. You'd have to put the scoot in a wind tunnel to really know. Got tied up in the other part of the conversation and just noticed this... i was thinking maybe a turbo kit Do not turbo it unless you are a great fabricator and tuner. Even then, don't expect a lot for all the money and hard work. Basically what you wanna do with the weights in the variator is get them setup so you are within your powerband as much as possible. Too light and you'll rev over your peak output, too heavy and you'll never reach it. Get them just right and acceleration and top speed should be good. There's usually a little range of weights that will work well and sometimes the lighter side of that will sacrifice a little MPH. Just takes time and trial and error from my experience. For you, stick to the heavier side of that. If what you have works well now I'd suggest weighing them and picking up something close to what you have. Heavier or lighter just depends if it seems to need to rev more or less. You can mod the faces of the variator and try to get more belt travel, but mods sometimes lead to ruined parts (trust me). Also when you go changing things for top speed, sometimes the engine doesn't like to pull it and you end up going slower. That's where all that horsepower talk really comes in. You can try to find aftermarket variators that might give you more speed. I didn't have any luck with the one I tried on my GY6 giving me any more top end, but it kept acceleration RPM more linear (stayed in the powerband more). Had great luck with them on my 2Ts though, so I know they can work. |
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Deleted
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Post by Deleted on Mar 28, 2012 20:29:51 GMT -5
I guess the right way would be get a tinytach and tune the rollers so that the motor runs 6500 rpm all the way through
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:wheelie: 
