Clutch and Torque converter please help!

[Alngoose]

Hello this is my first post on here. All of the ones I have read have been very helpful throughout this process!

I have a 2 seater go kart frame that I have put a predator 13hp motor in that I purchased at Harbor Freight. I bought a hillard heavy duty clutch that was rated for 13hp. That clearly isn't going to work for the engine. It will move slightly on the pavement but stops completely once you hit the grass.

I took it to a mechanic friend of mine, and asked if it would possibly need a torque converter. He said that he has never put a torque converter on any of the go karts he has built. He suggested a different clutch that was rated for higher rpms. He suggested the enforcer clutch that I can order from heeters:

http://heeters.com/kartclutches.shtml

He also stated that I would probably only get 40mph out of the motor. Is this correct? Would the different clutch solve my problem? Also, beings that the clutch is almost the same cost as a torque converter would I be better off keeping my current clutch and adding the torque converter?

Thank you in advance!!

 

[Denny]

Find a new mechanic friend quick! A cvt will most certainly help. you will need to use a 40 series drive and driven. I cant recommend a gear ratio without knowing your rear tire size. It would also be helpful to know how many teeth are on your axle sprocket and what size chain you are using.

Denny

 

[Alngoose]

Hi Denny! Thank you so much! My tires size is 8 inches. (18x9.50-8) and the teeth on the axle sprocket are 60 and the chain is a 41.

Thank you!

 

[landuse]

I would also suggest a 40 series TC. Do NOT even think of looking at the 30 series ones. The won't work well for you at all. Post the sprocket tooth counts and tyre diameter like denny asked and we can help you further

Edit: Oops...we posted at the same time. You could get the 40 series with a 10T jackshaft sprocket. That should work for you

 

[Denny]

10 tooth right on the money!

 

[OzFab]

Currently, you have a clutch with around 14 teeth, correct? Which means your gear ratio is around 4.3:1; even on 10" tyres, that's not healthy; on 18s, it spells disaster...

Without a jackshaft, there's no way of achieving the ratio you need; take the advice of the guys above, get a 40 series CVT with a 10t J/S sprocket & you should be golden...

FYI: According to our speed calculator, you sould get 32 mph@3600rpm with a 6:1 ratio but, remmeber, a CVT has a 10% overdrive which should give you around 35mph...

By removing the governor (if you choose to do so), valve float will kick in at around 5000rpm, which raises your top speed to around 48mph...

 

[Half-breeder]

Hello this is my first post on here. All of the ones I have read have been very helpful throughout this process!

I have a 2 seater go kart frame that I have put a predator 13hp motor in that I purchased at Harbor Freight. I bought a hillard heavy duty clutch that was rated for 13hp. That clearly isn't going to work for the engine. It will move slightly on the pavement but stops completely once you hit the grass.

I took it to a mechanic friend of mine, and asked if it would possibly need a torque converter. He said that he has never put a torque converter on any of the go karts he has built. He suggested a different clutch that was rated for higher rpms. He suggested the enforcer clutch that I can order from heeters:

http://heeters.com/kartclutches.shtml

He also stated that I would probably only get 40mph out of the motor. Is this correct? Would the different clutch solve my problem? Also, beings that the clutch is almost the same cost as a torque converter would I be better off keeping my current clutch and adding the torque converter?

Thank you in advance!!

Yea... may wanna think of going to someone that knows what their talking bout... like someone that has worked on more than 1~2 go karts/TC's

W/ 13hp 60T #41 on 18"s you have a pretty good starting setup for a pretty wide variety of riding if you get a 40 series TC/CVT. You'll need to getta jackshaft fashioned up for the driven (if you dont already have one), but that's small change, IMO. A Cent Clutch(the clutch you posted link to) will not really do you anygood w/ that tire size, unless geared WAY towards the torque end... and IMO anything less than 20mph, as an adult, is quite boring after about the first 20ft.

Depending the TOTAL weight of the kart driving, Id say you could easily top out at 40mph (5:1 gearing... 12T~>60T #41) if said total weight is less than 350-400lbs.
*Top speed is not governed/calculated by the engine hp, but by the engines RPM's (3600 w/ governor) and by the gearing.
*Gearing is governed by the amount of torque that is produced off of the clutch and the amount of drag on the axle (tire size/weight/traction).

CentClutches take the torque produced by the engine and transfers it directly to the applied gearing(chain) upon FULL engagement... where as TC/CVT's take the torque off the engine and creates a much higher initial (starting) torque amount before sending the power to the applied gearing. The amount of drag on said gearing effects the amount of time the clutch and engine will be 'topped' out.

... its 2am... I 'think' I got that right.

I personally run 50mph w/ a modded 6.5hp(~10hp), 5k RPM, 30 series (5:1 ratio), on 16"s right at 300lbs. But unless your frame is made for 'speed' Id probably try to keep it no more than 40mph tops, due to a high CoG and possible lack of control at high speeds. I have replaced/installed/worked on SEVERAL TC's, mostly 30 series but have done acouple 40's, on a range of 5hp all the way up to 10hp... so yea, Im pretty sure youll have lil issue if you go w/ the 40 series TC vs the CClutch.

 

[Alngoose]

Thank you everyone for your help. I got the 40 series torque converter. I am having some issues getting it to fit now which with a little welding hopefully it works. The question that came about today is can the chain be eliminated? Can the TC be used to drive the go kart by itself?

Thanks!

Jenna

 

[itsid]

Nope!

you need the additional gear reduction from the chain (or different sized sprockets to be precise)
to make your kart go.. 18" wheels are large; two seaters are technically closer to a buggy than a kart (especially weight-wise)
So you need a good reduction to move... and the series 40 alone can't provide that.

'sid

PS in theory, a kart lighter than 50kg(incl passenger) on wheels smaller than 11" with an engine bigger than 50hp... that could work.. but I guess none of that fits.. so that's still a no

 

[OzFab]

I am having some issues getting it to fit now which with a little welding hopefully it works.

Hold up; what are you welding?

 

[landuse]

Hold up; what are you welding?

I agree. Post some pics of what you are doing before you go further

 

[Alngoose]

I have attached a few photos here. It appears that to hook up the TC correctly I will need more length as the the belt is longer. (is this the correct belt?) Our plan was to weld a plate on that goes further back to support the TC. Or somehow attach something to stabilize the TC. Where I have the sprocket now can someone please advise on how to hook up the chain correctly and will if it will work in it's current position? Or should it be moved?

Let me know if any additional pictures or information would help!

Thank you!

 

[landuse]

Have a look at the table near the bottom of this page. You can see what belts you can get for whatever distance you decide to go with between the centers of the driven and driver. You have a belt that requires quite a large distance between the two. You could maybe get a belt that doesn't require the two to be so far from each other

Have a look at this thread for some nice pics

http://www.diygokarts.com/vb/showthread.php?t=11692

 

[OzFab]

Your belt number doesn't even appear on this chart which tells me it's huge! There's absolutely no reason you need a belt that large; buy a much smaller belt, based on the minimum centre to centre distance possible, which should solve all your problems...

 

[landuse]

Your belt number doesn't even appear on this chart which tells me it's huge! There's absolutely no reason you need a belt that large; buy a much smaller belt, based on the minimum centre to centre distance possible, which should solve all your problems...

Sorry to dissagree with you Tony, but the belt is on the chart. It is the 4th from the bottom on the list for 40 series belts. You could probably get a belt at least 4 inches shorter