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WARmaro

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I have a tillotson 212 stage 1 with a juggernaut converter i just installed on my dingo. I've taken it for a few test runs and it runs great, but my top speed on my GPS says I'm only hitting 36 mph. my max rpm is 5890, I have 10 tooth on my jackshaft and 54 tooth on axle with 18' tall tires. The carburetor is stock and I adjusted the idle screw slightly. The speed calculator on bmi karts says i should be getting around 50 mph. Any tips on getting more top speed?
 

madprofessor

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Here's a tip, don't use either one of the free GPS speedometer apps downloaded onto my cellphone. Both of them read out only 80% of what the speedometer in my van reads. Different apps, read the same.
No idea what to trust now, and hooking up some kind of real speedo, mechanical or otherwise, is out of the question for me right now.
Going to assume you mean your expensive Juggernaut CLUTCH, not a "torque converter" (CVT or Constant Variable Transmission). The belt drive CVT's can't be figured in to a calculator for a mathematical answer to output, as the ratio is constantly changing.
If a clutch (high stall Juggernaut) can be assumed to not be slipping once it's engaged, the speed calculator should be accurate if figuring in your engine rpm's. Any decent little cheap induction tachometer can get you the rpm's.
Just figuring that in to your 5.4:1 gear ratio, and the rear tires diameter (18" tall diameter x pi, or 18 x 3.14 = 56.52" circumference) will give you the speed. 5,890 rpm's div. by 5.4 ratio gives you about 1,090 rpm's of rear axle, Translates to 61,607 inches per minute. Div. by 12" = 5,134 feet per minute. That's 308,040 feet per hour. Div. by 5,250' in a mile, that's 58.67 mph.
At least that's my desk quarterbacking on paper. I know that's not real world numbers, and there's a huge unknown about the loss from tire compression at speed, just rough calculating. You know, even if 36 mph. were only 80% real speed like my 2 apps would read, you'd still only be getting 45 mph.
I will say this, everybody agrees that right out of the box a Tillotson 212 will blow away a Predator 212, but of course both can be hotrodded up to similar results. I'd be willing to accept that your stage 1 Tillotson at that ratio could top 50 mph.

About getting more speed, I'd advise against increasing your gear ratio for less low end torque but more top end. People do that all the time, and burn up clutches all the time too.
I heartily recommend replacing the clutch with a CVT. Bought 2 from China, average about $60 each, never had a problem with them. Bolts right to the case w/4 bolts, where the clutch is now. Wheelie popping low end, scary top end.
You could probably sell the used Juggernaut online for enough to buy a CVT.
 

WARmaro

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Here's a tip, don't use either one of the free GPS speedometer apps downloaded onto my cellphone. Both of them read out only 80% of what the speedometer in my van reads. Different apps, read the same.
No idea what to trust now, and hooking up some kind of real speedo, mechanical or otherwise, is out of the question for me right now.
Going to assume you mean your expensive Juggernaut CLUTCH, not a "torque converter" (CVT or Constant Variable Transmission). The belt drive CVT's can't be figured in to a calculator for a mathematical answer to output, as the ratio is constantly changing.
If a clutch (high stall Juggernaut) can be assumed to not be slipping once it's engaged, the speed calculator should be accurate if figuring in your engine rpm's. Any decent little cheap induction tachometer can get you the rpm's.
Just figuring that in to your 5.4:1 gear ratio, and the rear tires diameter (18" tall diameter x pi, or 18 x 3.14 = 56.52" circumference) will give you the speed. 5,890 rpm's div. by 5.4 ratio gives you about 1,090 rpm's of rear axle, Translates to 61,607 inches per minute. Div. by 12" = 5,134 feet per minute. That's 308,040 feet per hour. Div. by 5,250' in a mile, that's 58.67 mph.
At least that's my desk quarterbacking on paper. I know that's not real world numbers, and there's a huge unknown about the loss from tire compression at speed, just rough calculating. You know, even if 36 mph. were only 80% real speed like my 2 apps would read, you'd still only be getting 45 mph.
I will say this, everybody agrees that right out of the box a Tillotson 212 will blow away a Predator 212, but of course both can be hotrodded up to similar results. I'd be willing to accept that your stage 1 Tillotson at that ratio could top 50 mph.
The juggernaut is a cvt just like chimmike said. and i'll try to find a more reliable means of getting a more accurate speed measuring tool. what i dont understand is, how are people running 45mph on a stock ungoverned predator and im just getting 36 at max. The math says it can do it but its just not. I'm trying to understand if i need a better carb, or just better tune, i have both the stock huayi carb, and a tct carb which i need to adjust to get to work, or do i need more hp to actually reach 50+ mph. I dont want to change the gearing for it because i'd like to keep a decent balance of hp and torque. thank you for replying i really appreciate it.
 

itsid

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what i dont understand is, how are people running 45mph on a stock ungoverned predator and im just getting 36 at max
****ty gear ratio and suboptimal drivetrain (the juggernaut doesn't do well for you)
gear lower and or swap back to the original series 30 driverthe math on BMIs website is as dumbed down as possible.
it ONLY calculates rpm times ratio to _guess_ a top speed.. if you cannot reach the rpm you put in, it simply puts out a wrong answer.
(you can put in a 1:1 ratio and 15k rpm and reach hundreds of mph if you so desire.. it doesn't care)

and the juggernaut.. don't get me started.
the last time I remember someone using it he finally reached the 50+ mph he was after with his ****ty gear ratio...
at some insane rpms (7500 rpms or such) BUT math wise that rpms should have propelled him to upwards of 70mph..
sooo some of the rpms got lost in translation so to speak... and it's been the juggernauts fault I bet.
if you shift up your engagement speed to 4k and beyond you'll have to expect some nastyness
So yeah same exact result could be achieved with the original driver and a lower ratio (and less wear on all parts)

since you haven't told us what weight the engine has to deal with...
I go out on a limb and assume some things (like 200 kg worth of vehicle)
a stage 1 should hit about 6k if done right..
the engine should INDEEED be good for roundabout 54mph
and to reach that you need the standard 30 series driver and 66 teeth on the rear axle sprocket

then the engine has enough power to move 200kg at that speed (440 lbs roughly)

'sid
 

madprofessor

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Oops! Only learned about the Juggernaut from a Cars and Cameras video on youtube, something sent to them by their sponsor. Thought they were only referencing the fancy clutch, not the whole drive unit.

Update: Downloaded another GPS speedometer to my phone out of curiosity and boredom. Same result, only reads 80-85 % of what the vehicle's speedo says.
 

itsid

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the juggernaut is actually just a driver true..
that's why I said you might have better results with the original series 30 driver once you fixed your gear ratio

but it must be part of a CVT (torque converter here) to make any sense, otherwise it can't do anything
(hence it needs a series 30 driven)

'sid
 

rockman96

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Update: Downloaded another GPS speedometer to my phone out of curiosity and boredom. Same result, only reads 80-85 % of what the vehicle's speedo says.
I'd be suspicious that your vehicle's speedo is out of whack. The GPS speedos I've used were dead on with my truck's speedo.
 

madprofessor

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Thanks 4 info jamyers, that Cool Niks is the second one I downloaded. Also have a SoloTechApps one. Just uninstalled the first SpeedView, because it's complicated getting it shut down once opened, have to Force Stop. My chief concern now after having 3 different ones doing basically the same is that my bottom-of-the-line el cheapo "A502DL" smartphonewith Android version 8.1.0 is the culprit itself.
It is after all responsible for receiving and calculating the satellites for all apps. Going to get a match to a friend's car's speedo before doing anything else, highly unlikely my van's speedo is the problem, but that will eliminate it.
Just too dang cheap to buy something to put on the kart.
 

jamyers

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I'd love an actual speedometer I could mount on a kart, and calibrate for tire size or whatever. Of course, I also want it to be cheap. And work. LOL
 
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