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Post by elitemkd on Oct 19, 2017 13:31:14 GMT -5
I upgraded my scooter to 70cc with gianelli reverse exhaust but it wont go past 65km/h at 11.000 rpm i have stock variator with 3.7 grams polini rollers and stock clutch with malossi green springs and also stock contra spring i dont really know how to tune the cvt so any idea is welcome !
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Post by edwardtennant on Oct 19, 2017 14:10:12 GMT -5
3.7g is waay to light. try upping it to 5 or 6 gram. it wont go faster as its revving its tits of out of its powerband
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Post by pinkscoot on Oct 19, 2017 14:12:48 GMT -5
Brent has a great thread on tuning your CVT here. |
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Post by spaz12 on Oct 19, 2017 15:07:32 GMT -5
40 mph does seem a bit low for a top speed, but 3.7 gram weights don't seem too light for a tuned pipe. Have you done the sharpie test on the variator to see how far the belt is traveling?  Draw a line on the variator like what you see in the pic above, put the cvt cover back on with a few bolts, go drive it up to top speed and then remove the cvt cover to see how much of the sharpie mark is still there. Optimally you want the belt to travel all the way to the top, removing all the sharpie. 1mm of sharpie left is somewhat OK, but I like mine completely gone. Anyway, do the sharpie test and come back and tell us the results. We'll help you figure it out from there. |
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Post by edwardtennant on Oct 19, 2017 16:10:26 GMT -5
40 mph does seem a bit low for a top speed, but 3.7 gram weights don't seem too light for a tuned pipe. Have you done the sharpie test on the variator to see how far the belt is traveling? Draw a line on the variator like what you see in the pic above, put the cvt cover back on with a few bolts, go drive it up to top speed and then remove the cvt cover to see how much of the sharpie mark is still there. Optimally you want the belt to travel all the way to the top, removing all the sharpie. 1mm of sharpie left is somewhat OK, but I like mine completely gone. Anyway, do the sharpie test and come back and tell us the results. We'll help you figure it out from there. Whoops thought i was in the 4 stroke section, where 3.7 would be too light. My bad! |
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Post by ThomasTPFL on Oct 23, 2017 8:26:42 GMT -5
What’s the final drive gearing? TGB Key West is geared so tall that all the power in the world makes it hard to get much over 40mph out of it without revving to the moon. Center stand, vario cover off, count how many times you have to turn the clutch bell to get the rear wheel to turn once.
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Post by ThaiGyro on Oct 25, 2017 3:06:34 GMT -5
Not sure if I am value adding or shifting this thread...
...but I have done quite a bit of tuning on Honda Gyro's and Dio's and similar. Some with Suzuki and Yamaha here. After seeing this thread and reviewing Trent's videos...I too have questions.
Trent did some simple mods with good results. My Thai buddy has spent untold funds trying to find the best combo for his liking.
We can all agree that there is no ONE answer to engine/transmission tuning.
That said, I often wonder if simple machining/tuning gives performance in the OK to fairly decent ballpark? I ask because we are developing a product line that the Thai people can get their minds into. We know that performance sells. We also know that discretionary money is hard to come by in any country.
We simply want to provide both sales and service that fits the market. In this case...CVT performance. I understand oversize applications for racing or possibly high performance street, assuming you really need higher speed. I am a form and function kind of thinker, so always want more usable power where I...ummm, use it! The Gyro is a delivery/grocery getter. I may do a trail version at some point, as we have many ugly dirt roads and hills to climb. For the street, however, things should be easier.
What are your opinions for performance applications?
Purchasing an aftermarket CVT? (Still must be tuned)
versus,
Making modifications to OEM CVT parts, like bells and housings? (Clutch spring, variator weights must also must be tuned)
Further, what kind of cost experiences do you have with either or both? (not including shipping)
We are looking for "the bang, for the buck" sort of comparison.
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Post by ThomasTPFL on Oct 26, 2017 12:27:52 GMT -5
I'm gonna drift this thread even more.... Products for CVTs? I'd love to see someone come up with a working "launch lever" sort of arrangement for a standard scooter CVT. You mentioning hills and rough roads popped that in my head. Being able to force a downshift when desired would be wonderful on a twist n go. J-Bot did lots of tinkering trying to get one set up on a (Hobbit?) but I don't think he ever came up with a solution he felt was worth running.
I kind of fantasize about a throw out bearing sort of arrangement tucked behind the rear pulley that would force those sheaves together when engaged but that would require a layout flipped from standard to where the inner sheave moves instead of the clutch side sheave.
I need to get my shop built so I can start hunting for a lathe.
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Post by Delpzie on Nov 16, 2017 11:18:24 GMT -5
Firstly that pipe is weak, after 8500rpm the pipe is dead.
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Post by repherence2 on Nov 20, 2017 22:06:47 GMT -5
Firstly that pipe is weak, after 8500rpm the pipe is dead. if that pipe drops off after 8500rpm, I think 3.7g roller weights might be too light. probably in the 4g-5g range.
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Post by Delpzie on Nov 21, 2017 10:46:34 GMT -5
Yea thats for sure way too light rollers but the pipe is weak too, low rpm low hp it makes about 6hp max.
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Post by benji on Nov 21, 2017 11:21:37 GMT -5
I think hp numbers rely on the bore AND the pipe. What kind of bore is it? I'm also gonna guess the rollers are too light, I'd go up to 4.5-5.5
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Post by benji on Nov 21, 2017 11:23:08 GMT -5
But with that pipe and a (I'm guessing) cast iron sport bore your gonna be limited to 10-11k or so.
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