DTSFab.com (Desert, Trail and Sand)
UTV's Off Road ( RZR, YXZ, Mini Buggy, Carts,etc.) => UTV Motor and Drivetrain => Topic started by: Admin on January 01, 2009, 03:02:46 PM
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I know it has been gone over 1000 times, but what is the maximum torque number a busa puts out at the drive sprocket...Im trying to determine what my fnr has been proven to...They have been buas'd with 1:1 gearing to the trans input shaft, Just wonder how much reduction in my little motor i could achieve to the trans input shaft....
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the busa specs calls for 187 hp and 99 foot pounds of torque at the crank.
I have a dyno chart here with actual rear wheel numbers, 151.17 max hp and 86.14 max torque..
the red is the stock numbers, the blue was the initial pull on a motor I had built that ended up putting 220hp to the wheel, but I can't seem to find that sheet, although I have a sheet showing 212 and 105.96 foot pounds of torque, he had problems getting traction in 5th. gear over 3/4 throttle...
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the busa specs calls for 187 hp and 99 foot pounds of torque at the crank.
I have a dyno chart here with actual rear wheel numbers, 151.17 max hp and 86.14 max torque..
the red is the stock numbers, the blue was the initial pull on a motor I had built that ended up putting 220hp to the wheel, but I can't seem to find that sheet, although I have a sheet showing 212 and 105.96 foot pounds of torque, he had problems getting traction in 5th. gear over 3/4 throttle...
So the torque is figured thru the reductions etc? or is that the actual measured at the rear wheel?
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so the 80 some ft lbs of torque was at the wheel, what happens to the multiplication thru gearing to get what fabber always says torque is multiplied to?
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that dyno chart is measured at the wheel, the crank numbers are higher...
That is CALCULATED usable torque that is supplied to the rear wheel that takes into account parasitic losses through the geartrain due to it being measured at the rear wheel.The ACTUAL crank #'s would be higher only because they would not have the geartrain losses to consider. Since there is no way to couple a busa crank directly to the dyno ALL crank numbers stated are calculated approximations.
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So at the highest reduction, what would the 99lbs of torque equal at the drive sprocket?
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Your gonna have a lot higher torque number in the lower gears because the ratio is lower, but that ratio basically stops at the final drive, or actually the center of the wheel, you loose torque as you go farther out on the wheel. You would have a lot higher torque number if the drive train was hooked directly to the dyno, the 24" tall wheel eats up a big chunk of that torque.
Think of a wrench, you can put hundreds of pounds of torque on a 3/8 bolt by hand and spin it easily, even stripping the threads if you wanted, but if you had an adapter to attach to a 2 foot in diameter bolt head, and you still had the same torque wrench, which was a smaller than the wheel, you couldn't apply much torque at all and wouldn't get the bolt snugged very tight. That why you always strip smaller bolts a lot sooner than a bigger bolt. The high torque numbers are seen by the chain and gearbox which is why they always break, not the outside of wheel, ut given enough power and traction, you could break the studs attaching the wheel to the drive train because the closer you go to the center of that tire, the more torque you will see..
Yoshi your understanding is mostly correct but in red is not.Any torque multiplication stops at the rear wheel axle but with a 24" tire you only lose 1/2 of the actual FT lbs of torque at the rear axle...24" /12" =2:1. That is a lot but a lot to the extent that I felt the rest of the reply would indicate.
Say the ACTUAL measured tq at the rear wheel was 400#' the tq at the rear axle would be 800#'.
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Another easy way to think about it is a car, you can turn a tire by hand and cause the car to roll, but if you try to grab the axle and turn it by hand, the car won't roll. You may only need 50 foot pounds of human supplied torque to turn the tire and roll the car, but you will need a lot more torque to turn the drive train to roll the car. So it may take 50 foot pounds of torque to turn the wheel, and that may put 300 foot pounds of torque to turn the drive train (just like a wrench). The torque goes up when you use the bigger diameter tire to turn the smaller drive train, it goes down when you use the drive train to turn the tire....
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I don't have the true 1st gear ratio here but assume this scenario.80#'x1.596 primary reduction x2.5:1 first gear times rear axle ratio of 5:1=1596#'to at the rear axle/by 24"tire 2:1 RATIO increase=798#' AT THE TIRE SURFACE.
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Yoshi your understanding is mostly correct but in red is not.Any torque multiplication stops at the rear wheel axle but with a 24" tire you only lose 1/2 of the actual FT lbs of torque at the rear axle...24" /12" =2:1. That is a lot but a lot to the extent that I felt the rest of the reply would indicate.
Say the ACTUAL measured tq at the rear wheel was 400#' the tq at the rear axle would be 800#'.
I believe I am correct. Lets make it simple, if you have a 14 tooth front sprocket and a 60 tooth rear sprocket, you have a 5:1 ratio, which means you are putting 5 times the amount of torque to the center of the 60 tooth sprocket as you are the 12 tooth sprocket, correct? Since your putting the highest number of torque at the center of the biggest sprocket, a straight line from the center of that sprocket via a drive axle to the wheel will see the same number of torque, putting the highest number of torque at the center of the wheel, you then loose torque as you go out to the edges of the wheel.
Granted the most torque is only applied when the axle is straight to the wheel, since you loose hp and torque as you have angle, but worse case senerio, there will always be points where the axles is straight and applying th most torque possible to the wheel...
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I just want it at the sprocket, the motor i am debating using is 80 lbs at the crank, Im trying to figure out how much i can gear it into the trans, 1.2:1 1:1 etc.... I dont want to expierment with any more torque than i know has been put thru them....But at the same time id like to take advantage of every bit of gearing i can...
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WHich sprocket? Countershaft I assume?
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WHich sprocket? Countershaft I assume?
You think? ;D
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I believe I am correct. Lets make it simple, if you have a 14 tooth front sprocket and a 60 tooth rear sprocket, you have a 5:1 ratio, which means you are putting 5 times the amount of torque to the center of the 60 tooth sprocket as you are the 12 tooth sprocket, correct? Since your putting the highest number of torque at the center of the iggest sprocket, a straight line from the center of that sprocket via a drive axle to the wheel will see the same number of torque, putting the highest number of torque at the center of the wheel, you then loose torque as you go out to the edges of the wheel.At a ratio of 1:2 using the 24" tire as an example.So as I said you lose 1/2 of the torque that was available at the center of the rear axle.I'm not muddying the discussion with taking into account the losses in the axle angles.Maybe we were saying the same thing tho as your post indicates to me we do.
Granted the most torque is only applied when the axle is straight to the wheel, since you loose hp and torque as you have angle, but worse case senerio, there will always be points where the axles is straight and applying th most torque possible to the wheel...
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so 413 lbs of torque coming from the engine...
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Are there any reductions between the crank and the countershaft?
ya why you think i am asking?
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busa crank torque 99
Primary Reduction Ratio 1.596 (158.004 foot pound of torque at the clutch basket)
1st Gear 2.615 (413.18046 foot pounds of torque in 1st. at the output shaft/front drive sprocket)
2nd Gear 1.937 (306.05374 foot pounds of torque in 2nd. at the output shaft/front drive sprocket)
3rd Gear 1.526 (241.1141 foot pounds of torque in 3rd. at the output shaft/front drive sprocket)
4th Gear 1.285 (203.03514 foot pounds of torque in 4th. at the output shaft/front drive sprocket)
5th Gear 1.136 (179.49254 foot pounds of torque in 5th. at the motor output shaft/front drive sprocket)
6th Gear 1.043 (164.79817 foot pounds of torque in 6th. at the output shaft/front drive sprocket)
so, in first, with a 5.5:1 gear reduction after the motor, your looking at 2,272.4925 foot pounds of torque coming out of the final drive to the wheels, the torque number will go down depending on your tire size)
in 6th., with a 5.5:1 gear reduction after the motor, your looking at 906 foot pounds of torque coming out of the final drive to the wheels, the torque number will go down depending on your tire size)
Yes we agree and the actual measured tq on the dyno takes into accounr the ACHIEVED tire radius to calculat the REAR WHEEL TQ NUMBERS. In the case of a theoretical 24" tire it would be in 1st gear 1136#' at the tire OD.We are in agreement yoshi,I just must have read your post wrong.
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ok, there is a possibility I did that wrong. The primary reduction is the clutch basket off the crank, I am assuming the transmission gear reductions are running off the primary reductions so when I multiplied the gear reduction for say first gear, I didn't do it off 99 foot pounds, I did it off 158.004 foot pounds of torque after the primary. I can't seem to find any info to be more clear on where the reductions are coming from. But if the tranny numbers are reductions off the crank, not the primary, you'd be at 258.885 foot pounds of torque in 1st. gear off the motors output shaft...
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Yes we agree and the actual measured tq on the dyno takes into accounr the ACHIEVED tire radius to calculat the REAR WHEEL TQ NUMBERS. In the case of a theoretical 24" tire it would be in 1st gear 1136#' at the tire OD.We are in agreement yoshi,I just must have read your post wrong.
and that's off a 24" tall tire for a street bike, there is even less torque put to the ground with the 31's we run in a sandrail....
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And that 413 is at MAX tq in first gear.Somewhere you will spend VERY LITTLE time at.Time and tq are interrelated as far as durability is concerned.
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Try stating wtf you want man!LOL!!! Are you talking busa or not??? If so yes 413 in FIRST GEAR if that is what you are asking!!!
Read the very first post you dipshit...
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ok, there is a possibility I did that wrong. The primary reduction is the clutch basket off the crank, I am assuming the transmission gear reductions are running off the primary reductions so when I multiplied the gear reduction for say first gear, I didn't do it off 99 foot pounds, I did it off 158.004 foot pounds of torque after the primary. I can't seem to find any info to be more clear on where the reductions are coming from. But if the tranny numbers are reductions off the crank, not the primary, you'd be at 258.885 foot pounds of torque in 1st. gear off the motors output shaft...
Stop thinking.You had it right to start with.
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And that 413 is at MAX tq in first gear.Somewhere you will spend VERY LITTLE time at.Time and tq are interrelated as far as durability is concerned.
And that's why most people break their drive line off the line, when all the torque is applied to the wheel from a dead stop and you get hella good traction, that's when it's gonna happen, just like twisting the head off a 1/4" bolt with a 2 foot breaker bar......
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Stop thinking.You had it right to start with.
I thought I was right, but I seem to recall someone once saying in the highest gear, your spinning at roughly the same 1:1 ratio as the crank, and seeing a 1.043 ratio for 6th., I started thinking if that was the 1:1 to the crank i'd heard in the past, oh well......
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My calculated torque is 357.97 so effectively i could gear to my trans input shaft 1.12:1 so i could do a 17/19 sprocket combo and not see more torque than it has been proven to... 400.93
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And that's why most people break their drive line off the line, when all the torque is applied to the wheel from a dead stop and you get hella good traction, that's when it's gonna happen, just like twisting the head off a 1/4" bolt with a 2 foot breaker bar......
Depends on traction and how many milliseconds it takes for full tq to be delivered to the shaft.If it happens as all shock you get snapped shaft.If it occurs over a longer timeframe ,such as is accomplished with a cushion drive,(tq converter,cvt), you will have a much tq capacity of the same shaft.Time IS relevant.Off topic ,I know, but relevant nevertheless.
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How would that alter my final ratio tho? 4.75:1 would i multiply that by 1.12?
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Yep
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ok, I found a chart for the gear teeth, so I know I was right the first time
Transmission Gear Teeth
1st: 34 / 13 (2.6153846 reduction in 1st. after the final drive ratio.)
2nd: 31 / 16
3rd: 29 / 19
4th: 27 / 21
5th: 25 / 22
6th: 24 / 23
the new 08/09 busa has 114 foot pounds of torque, so that baby is putting out 475.78356 foot pounds of torque to the output shaft, and over 2,616 foot pounds of torque as a final output to the axle number through a 5.5: ratio....
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ok, I found a chart for the gear teeth, so I know I was right the first time
Transmission Gear Teeth
1st: 34 / 13 (2.6153846 reduction in 1st. after the final drive ratio.)
2nd: 31 / 16
3rd: 29 / 19
4th: 27 / 21
5th: 25 / 22
6th: 24 / 23
the new 08/09 busa has 114 foot pounds of torque, so that baby is putting out 475.78356 foot pounds of torque to the output shaft, and over 2,616 foot pounds of torque as a final output to the axle number through a 5.5: ratio....
Where is the reduction from the crank to the clutch figured in? I think the number is even higher.
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so at 13000 rpm the max speed the counter sprocket can turn is 7757 rpm correct?
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Your on the right track here bug...
I could use a smaller engine and get even a larger final gear reduction....
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Where is the reduction from the crank to the clutch figured in? I think the number is even higher.
no, I gave all the numbers on page 2, the one you quoted was just the gear teetch count which told me what the ratio was which told me the reduction was after the primary, not off the crank. I multiplied all the tranny numbers off the 158 foot pounds after the primary....
busa crank torque 99
Primary Reduction Ratio 1.596 (158.004 foot pound of torque at the clutch basket)
1st Gear 2.615 (413.18046 foot pounds of torque in 1st. at the output shaft/front drive sprocket)
2nd Gear 1.937 (306.05374 foot pounds of torque in 2nd. at the output shaft/front drive sprocket)
3rd Gear 1.526 (241.1141 foot pounds of torque in 3rd. at the output shaft/front drive sprocket)
4th Gear 1.285 (203.03514 foot pounds of torque in 4th. at the output shaft/front drive sprocket)
5th Gear 1.136 (179.49254 foot pounds of torque in 5th. at the motor output shaft/front drive sprocket)
6th Gear 1.043 (164.79817 foot pounds of torque in 6th. at the output shaft/front drive sprocket)
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If you go back to the beggining he is trying to setup his gear ratio so that the MINI-Mite motor that he is using will not exceed the torque output of a busa, which has been proven to work with his FNR. And he is assuming that the Busa was geared to the FNR at 1:1.
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what wouldn't see more torque, a gearbox your attaching?
My Drakart gearbox, they built them with hyabusa engines before, so i know its capable of that much torque, I wont use a busa engine, as i cant afford to for 1... If i use a smaller engine i can gear it deeper in the back, as it is geared to high now....
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If you go back to the beggining he is trying to setup his gear ratio so that the MINI-Mite motor that he is using will not exceed the torque output of a busa, which has been proven to work with his FNR. And he is assuming that the Busa was geared to the FNR at 1:1.
I know it was geared 1:1... ;D
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Here we go...... :police:
3:
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Where is the reduction from the crank to the clutch figured in? I think the number is even higher.
It's in there just not stated. Once again
dyno tq# times primary reduction times 1st gear =countershaft tq.
80x1.596x2.615=338.8 at the CS Plug in any tq# you wish at the first to get what you want bug.
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We had the chassis dyno discussion here before......... Tire sizes and gear ratio's should have no affect on the numbers, because it is always figured back to motor RPM.
If it wasn't, then you could just put the vehicle in a lower gear and get a better number because you would have more torque, and then a higher HP.
;D ;D ;D ;D ;D
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It's in there just not stated. Once again
dyno tq# times primary reduction times 1st gear =countershaft tq.
80x1.596x2.615=338.8 at the CS Plug in any tq# you wish at the first to get what you want bug.
I think he has his answer.........
A clutch petal and shifter is in Bug's future...... That is how real men drive. :o :o :o
;D ;D ;D
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If you go back to the beggining he is trying to setup his gear ratio so that the MINI-Mite motor that he is using will not exceed the torque output of a busa, which has been proven to work with his FNR. And he is assuming that the Busa was geared to the FNR at 1:1.
But that won't work as the countershaft in first gear assuming 11500 for a redline the CS rpm would only be 2755 . He loses any mechanical advantage when he gears UP the trans. No win there.
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I think he has his answer.........
A clutch petal and shifter is in Bug's future...... That is how real men drive. :o :o :o
;D ;D ;D
Actually REAL MEN just roll off the throttle,grab a handful(of whatevers handy) and keep on going.Clutches are for women and putting around camp.Hehe
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But that won't work as the countershaft in first gear assuming 11500 for a redline the CS rpm would only be 2755 . He loses any mechanical advantage when he gears UP the trans. No win there.
explain this more please...
I understand there is a huge disadvantage.. as i will loose speed...right now the 600 doo motor makes about 90lbs of torque im guessing, but at the same time i am doing it at 8600 rpms on the crank, assuming i am shifted "cvt" 1:1 my trans input shaft will be spinning 8600 rpms as well.... were the bike motor torque will be at 7700 rpms or so... my max torque is nothing comparable to a bike in first gear, but in 6th gear i out weigh it substantually at the same rpm...
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I better just put a bigger 2 stroke in it and call it good i guess... ;D
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But that won't work as the countershaft in first gear assuming 11500 for a redline the CS rpm would only be 2755 . He loses any mechanical advantage when he gears UP the trans. No win there.
I don't understand the problem.
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Additional parasitic losses both in the busa trans and the final gear ratio increase
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if your gearing it lower, you will not loose speed, you will gain speed and lug the motor more off the line.
do you know the hp/torque specs for the motor your wanting to use, if not, what's the make and year so I can look up the reductions, we need to figure out how much torque you have at the output shaft to figure out what you need to do......
01/03 gixer 750 here is what i came up with for torque after primary reduction and in 1st gr...357.97
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Additional parasitic losses both in the busa trans and the final gear ratio increase
What are you refering to?
b:1
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He needs to state what his objective is so we can understand this.I think I know and there will be no increase in performance and likely a decrease. Whatcha you really thinking bug?
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Objective, remove the 2 stroke, replace with 4 stroke bike motor, Hope to gain performance...car is geared to high right now, can not be changed in the gearbox...
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But you will only be turning maybe 3-3500 rpm at the CS in first gear.You WANT that?
I just figured maximum torque to trans is all...I explored the option of cvting a bike motor, but at redline in 6th gear i can only see 7500 rpm, not enuff IMO to make speed with a cvt...
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I guess i'm confused, you wanna pull a 2 stroke motor, stick in a motor that's smaller than a busa, but your worried the smaller motor is gonna be too much for a transmission that holds up behind a busa, did I leave something, or possibly everything, out?...lol.......
yes, the gearing between the engine, and the fnr input shaft....I dont wanna fxxk up the fnr... question, can i effectively change the gear ratio between the engine and fnr from 1:1?
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But you will only be turning maybe 3-3500 rpm at the CS in first gear.You WANT that?
Then he could shift......... LOL
Hes not going to leave it in first, he just wants to find out the maximum torque in 1st, then he will put more reduction in between the motor and the FNR to get the equivalent maximum torque not to exceed that of the BUSA.
He is going to Gear deeper than they do when they use a Busa.
Geeze 5 pages later.........
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current fnr gear ratio is like 4.67 or so to one, I have to take it apart and count the teeth, cant remeber the exact number, current setup with engine, the gearing is to high...
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Any idea what the CVT ratio is when it first engages?
Doesn't really matter cause its not apples to apples. Even if the ratios were the same, the bike 4 stroke will have more low end than the 2 stroke IMO.
approximately 3:1
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Then he could shift......... LOL
Hes not going to leave it in first, he just wants to find out the maximum torque in 1st, then he will put more reduction in between the motor and the FNR to get the equivalent maximum torque not to exceed that of the BUSA.
He is going to Gear deeper than they do when they use a Busa.
Geeze 5 pages later.........
Just put the effin busa into 6th gear then. Adding additional gear reduction/increases will just add up to more parasitic losses as I was referring to earlier engineer.Still have to run a jackshaft or some other crap to spin the primary.It won't mate to the busa.
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were talking chain drive to the fnr, not cvt... clutch pedal and shifter...
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Just put the effin busa into 6th gear then. Adding additional gear reduction/increases will just add up to more parasitic losses as I was referring to earlier engineer.Still have to run a jackshaft or some other crap to spin the primary.It won't mate to the busa.
I think he is shit canning the CVT with this idea! ;D ;D ;D
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I was 21 seconds late on that one. ;D
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hell you almost have me confused to what i am doing... ;D
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I am tossing around ideas, read carefully,
Option 1...remove cvt and 2 stroke, put chain and sprokets with a bike motor, how much torque can my fnr handle, it has been proven to the torque of a stock busa geared 1:1 with the trans, 421 lbs in 1st gear... I dont want to exeed them numbers...
Option 2. Buy a bigger engine and keep the cvt, gas sux and its a pain in the 2 stroke ass...
Option 3, cvt a bike motor, to be discussed elsewere...I dont belive it would work well off the primary reduction and 6th gear, would work great off the primary reduction alone, target rpm range max 8500 rpms...
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WHat fnr you talking about then ? A TW?
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Option 1 and be done..... If you can learn to shift hehe!
Option 3 would be a pile of work......
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WHat fnr you talking about then ? A TW?
My drakart box, fxxking transworks, you smoking crack?
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WHat fnr you talking about then ? A TW?
WTH?? Have you ever seen a Drak?? Where did TW come from cept Yoshi's joke?
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11 seconds late that time.
You must think like a Bug Fabr......
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I'm home on fxxking dialup! I think fine! LOL!!!
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The drak with the busa motor was chain driven, 1:1 gear ratio to the fnr...I agree hard on the trans....
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I'm home on fxxking dialup! I think fine! LOL!!!
No.... It was a joke on some Karate movie.
You must think like a flower..... You must become the flower....
It's a meditation thing. I wasn't insulting....
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Oh I thought you were saying I was as slow thinking as (a)bug! 3: :m
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Hehehe,sorry bug.I couldn't resist that one.
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harder on everything, compared to the belt I believe is the point...Need a cush drive, but hell thats another can yet to open... ;D
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