Manual vs CVT Clutch

[Zorph]

I currently have a GX390 with a TAV2 on my mini bike. I was considering upgrading to Vegas Carts 460 25hp engine. I am a larger guy around 250lbs so torque is important, plus I am not really racing just having fun. I will probably go to the strip and run 1/8th mile runs.

I was considering going with a comet 94c or the new Motorsports 3D 1" manual clutch if/when it comes out. I would also look at less expensive jr dragster clutches, but they all seem to expensive for this project. I am also concerned with the installing a jackshaft to get it to work. I currently have everything on the left side and working prety good.

I understand that the CVT clutch if tuned properly should keep it in the power band longer, but I will also lose more power because of friction/weight of the components.

I assume the manual clutch would allow me to launch a little better after getting use to it. With the manual clutch I only have 1 gear so not sure how that would work. I know some higher reving engines it is fine, but this one won't rev high. I would love to hear the advantages and disadvantage for these options. If there is another option I am all ears.

 

[bob58o]

Clutches tend to burn up faster when you are cruising a lower speeds and they are not fully locked up.

A drag mini bike may be set up to do 70mph at 6000 RPM.

If you are trying to drive around at 25mph (2150 RPM) they clutch may get hot and burn up, because it is not fully locked up at this low of RPM.

I think Joe - Rep'n the 405 - would be a good guy to ask. He bought a manual clutch for his minibike then returned it before using it. He went with a TC I believe.

 

[Jfive]

Bob he's talking about a full locked clutch not a centrifugal clutch.

 

[DeathMachine]

Just go direct drive like E J Potter.

http://www.macsmotorcitygarage.com/2013/04/30/remembering-ej-potter/

 

[itsid]

both will work..
a 94c duster is much more expensive (but comes with a huuuge benefit when NOT racing)
sure you'll loose transfer efficiency, but you'll gain low end torque and that makes a nice take off or hill climb.
and you still hit good speeds.

A manual clutch is great for insane ratios that would otherwise burn out cent clutches or TC belts in minutes.
But you can have either good torque OR nice topspeed.. not both (since it's a true single gear setup)

on the 1/8" mile.. I'd almost say the clutch outperforms the TC (both ideally setup for the track)
on the average day having fun.. the TC is the way to go IYAM.
climbing hills, cruising or speeding all in one box w/o changing the gear setup.
Things you might need to do to get the same performance with just a single gear ratio (no matter if cent clutch or the manual clutch)

'sid

PS I'd say get a series 40 clone off ebay.. much cheaper than a duster 94c.. about the same performance .. just less adjustable

PPS that is if you don't push your GX390 to above 28hp (which in itself is quite a task really )

 

[Zorph]

Just go direct drive like E J Potter.

http://www.macsmotorcitygarage.com/2013/04/30/remembering-ej-potter/

That is way more than I could handle Very interesting read.

---------- Post added at 03:40 PM ---------- Previous post was at 03:30 PM ----------

both will work..
a 94c duster is much more expensive (but comes with a huuuge benefit when NOT racing)
sure you'll loose transfer efficiency, but you'll gain low end torque and that makes a nice take off or hill climb.
and you still hit good speeds.

A manual clutch is great for insane ratios that would otherwise burn out cent clutches or TC belts in minutes.
But you can have either good torque OR nice topspeed.. not both (since it's a true single gear setup)

on the 1/8" mile.. I'd almost say the clutch outperforms the TC (both ideally setup for the track)
on the average day having fun.. the TC is the way to go IYAM.
climbing hills, cruising or speeding all in one box w/o changing the gear setup.
Things you might need to do to get the same performance with just a single gear ratio (no matter if cent clutch or the manual clutch)

'sid

PS I'd say get a series 40 clone off ebay.. much cheaper than a duster 94c.. about the same performance .. just less adjustable

PPS that is if you don't push your GX390 to above 28hp (which in itself is quite a task really )

I just want to make sure the 40 series would be strong enough. I currently have a 1" TAV2. Could I mount this up to it?

http://www.ebay.com/itm/40-Series-1...ash=item54302c49f2:g:4vgAAOSwnNBXVdzA&vxp=mtr

If so that would be super convenient and cheap if I decided to upgrade later. I assume that is a china knockoff. But this one looks like it is very close but twice the price. http://www.ebay.com/itm/40-Series-T...757260?hash=item5b2077f88c:g:xa4AAOSwll1Ww29F

I am a person who would rather spend a little extra instead of having to buy 2 or 3 times. Not saying I want to throw money away either of course.

Thanks for the advice.

 

[bob58o]

I currently have a 1" TAV2. Could I mount this up to it?

I too have wondered if a 30 series backplate can be made to bolt on to a big block.

And then a 5/8" 40 series driven on the 30 series jackshaft?

Not sure the spacing would be right?
Not sure size what belt you'd use?
Not sure if the single bearing and 5/8" shaft would handle the Torque?

 

[itsid]

I just want to make sure the 40 series would be strong enough. I currently have a 1" TAV2. Could I mount this up to it?

You can.. if you're willing to maybe cut some of your engine block..
BUT it won't be reliable at all.. the belt just isn't made to transfer the torque, thus the driver will just chew it up and spit it out on a more or less daily basis.

If you're willing to try, supermanotorious posted how he fitted a tav2 kit on a predator 420 some years ago

http://www.ebay.com/itm/40-Series-1...ash=item54302c49f2:g:4vgAAOSwnNBXVdzA&vxp=mtr

If so that would be super convenient and cheap if I decided to upgrade later. I assume that is a china knockoff. But this one looks like it is very close but twice the price. http://www.ebay.com/itm/40-Series-T...757260?hash=item5b2077f88c:g:xa4AAOSwll1Ww29F

Same thing.. both chinese knockoffs.. likely made by the same company.. just a different retailer .. (and of course one belt )
the cheaper one will do just fine.. and if it doe NOT hold up for one reason or another..
an ORIGINAL COMET is the only option for you to step up (more like 350-400 bucks)

'sid

 

[Zorph]

The minibike has the TAV2 installed on it now with GX390. It seems to fit, but not sure how much he needed to mod the TAV2 mounting plate.

Thank you very much for you help.