13hp Clone + 250 lb Kart = Torque Converter?

[doesgo]

Is a torque converter pretty much a necessity with a 13hp engine in a heavy kart? I'm estimating 300lb with engine.

Anyone ever use this one? Any opinions on it? http://www.bulletlines.com/GTC-TC2-1-Bore-Torque-Converter-p/54.htm

 

[Doc Sprocket]

The short, sweet answer? Yes.

I can't comment on that particular CVT, I've never used that brand.

The longer answer- I have to assume you refer to an offroad kart, and the associated terrain demands. My offroad kart weighs just north of 300, and I'm using an 11hp Honda with a Comet 40 CVT. My tires are 18" turfs and for what I do with that kart, a standard centrifugal clutch would go out Bin Laden-style in a hurry...

The CVT you linked to says it's good to 13hp, but I am skeptical about that. IMHO, you're far better off sourcing Comet 40 components. They're a bit hard to find, but surely you can come up with something with some patience. From everything I have seen and heard, the Comet 40 is a lot more bulletproof than the TAV2 (and related imitations). You wouldn't believe the abuse my Comet 40 will take, and I have never had even a hint of a problem with it...

 

[B man]

should work fine.

 

[redsox985]

^^^ NO! Stop with this crap. I don't want to see him blow $200, devour belts, and come back here unhappy saying why did you guys (putting the blame on all of us) say it would work? It doesn't. It's an exact clone of a piece that was rated for 8HP.

Now, your options are very limited when it comes to a CVT. You will need a Comet 40/44 series TC as ToyStory said. I think that there are also clones of the 40/44 series out there now. You can go the more expensive route and get a CVTech TC. I believe that you can request a Comet one be made as their production has been taken over by someone else. Check here. http://www.hoffco.org/

 

[B man]

8 hp is not all it can handel.it could handel 13hp fine. have you ever tried it? engine still governed to 3600rpm. as long as its all setup right should work fine. can you explain why it wouldnt?

 

[B man]

i just read it and it says 8-13hp. shouldnt it say 2-8hp though?

 

[doesgo]

Thanks for the info, guys. The description of the GTC TC2 says it's a replacement for the Comet TAV2 Torq-A-Verter which, according to the Hoffman site, is good for up to 8hp.

Crap.

$215 was hard to swallow but I could accept it. Going upwards from there for a Comet 40-series....ouch.

*edit*
GoKartParts.com has the 40-series and 44-series Comets, sold in components as redsox985 said. Looks like about $350 for a drive, driven, and belt. I'd still need a jackshaft setup, too.

 

[B man]

but they had different TC2's. one said 2-7 the other said 8-13. why is that? do you know redsox?

 

[doesgo]

Yeah, the GTC website does claim up to 13hp with the #1004 setups. Might be worth the extra $150 for a 40-series though, just in case. Don't let my wife hear me say that, though. "It's for the kids, honey!"

METALTHRASHINMAN sure had a poor experience with a GTC TC, with only a 9hp engine. Okay, time to research jackshaft setups...

 

[redsox985]

i just read it and it says 8-13hp. shouldnt it say 2-8hp though?

Because they are a shady Chinese company that cares about your money and not your satisfaction. They are lying. Comet was in business for a very long time and made products which are very valuable due to their quality and reliable performance. They knew what was up and rated their products to 8HP because they cared about being right, not taking your money.

but they had different TC2's. one said 2-7 the other said 8-13. why is that? do you know redsox?

Those are the 1" bore models in both chain sizes. It's an exact clone of the Comet TAV2 but in the 1" bore. It uses an asymmetrical 3/4" belt and has the exact same driven on all four on that page. The drivers and JS sprockets are the only difference. Again, they want your cash. 8+ HP engines almost always have a 1" PTO, if not larger. Those rated to 13 HP are the exact same thing with a larger hole in the center. They're just trying to sell to a larger market. It's all about $$$.

Why yes, I do know B man.

 

[doesgo]

Thanks redsox985. This $400 upgrade to a Comet 40-series is painful! Last-ditch effort....might a Hilliard Extreme Duty centrifugal rated for 13hp (http://www.mfgsupply.com/m/c/H1P37.html) survive a while or are the demands of an off-road kart such that I'm just asking for trouble?

BTW, Northern Tool is listing the Comet 40-series TCs now, $300 for the drive/driven combo.

 

[Doc Sprocket]

Naw, just shop for a Comet 40- even if you have to save your money awhile longer or shop harder. Not only is the 40's durability legendary, there's a big performance difference, too. The c-clutch offers only a fixed gear ratio, so in order to keep it from burning up and to have any kind of low-end grunt, you'll have to gear fairly low. The CVT offers superior performance in that because it offers a variable gear ratio, you can get away with gearing somewhat higher, and yet be able to accelerate from a standstill with some authority AND enjoy a potentially higher top speed.

 

[redsox985]

Yoohoooooo!? B Man??

And yes, I agree with ToyStory.

 

[B man]

yeah?

 

[amcjavelin]

bmi go karts you get a 40 series driven for $115.00 and small engine ware house get a comet 44c clutch for 174.00 and bmi carts for a belt for 29.00

 

[redsox985]

yeah?

Just wanted to say hi.

 

[B man]

Just wanted to say hi.

oh. hello. lol

 

[anderkart]

Is a torque converter pretty much a necessity with a 13hp engine in a heavy kart? I'm estimating 300lb with engine.

No, its not always necessary or the best choice.

My kart weighs 410lbs with me in it, and has 20+hp. I would absolutely prefer to have my centrifugal clutch over any torque converter system in my kart.

While I totally agree that torque converter systems can offer some major advantages along with their drawbacks, there's lots of very high quality 1"-bore centrifugal clutch models that would hold up and work just fine for years on a heavy/13-hp kart that was used when riding on mostly all flat/hard riding surfaces, and when top speed was more important to you than improved low-speed torque/acceleration/off-road ability.

Try to post a pic of your kart and tell us how much the riders (and passengers?) will weigh, and also tell us what type of terrain you'll be riding this kart on. (like maybe only on large parking lots/streets, or if you'll be attempting serious off-road/hill climbing type riding)

Maybe simply installing a $150 centrifugal clutch would be a much better choice for you too. (or maybe not...)

 

[Doc Sprocket]

Interesting thoughts, Anderkart! Can you give us a clearer picture of why you would prefer a clutch with your setup, I'm always open to ideas and information...

My own opinion (as stated above) is based on my own experiences. My kart weighs about 320 (haven't weighed it since I suspended the frontend) plus my own weight of 140lbs. It is driven exclusively on dirt/gravel/hard pack with some hilly terrain. I used to do a bit of pavement riding but I don't take it there anymore.

The OP didn't state "off road", I assumed it.

I also assume that the primary use isn't "pin it to the floor and keep it there", I'm imagining a lot of throttle/road speed variation. Due to my own circumstances, I perform a lot of part throttle/low speed driving over horrible terrain. I canot imagine a clutch being too happy with this- Not with 18" tires and 4.8:1 gearing...

 

[anderkart]

Interesting thoughts, Anderkart! Can you give us a clearer picture of why you would prefer a clutch with your setup, I'm always open to ideas and information...

My own opinion (as stated above) is based on my own experiences. My kart weighs about 320 (haven't weighed it since I suspended the frontend) plus my own weight of 140lbs. It is driven exclusively on dirt/gravel/hard pack with some hilly terrain. I used to do a bit of pavement riding but I don't take it there anymore.

The OP didn't state "off road", I assumed it.

I also assume that the primary use isn't "pin it to the floor and keep it there", I'm imagining a lot of throttle/road speed variation. Due to my own circumstances, I perform a lot of part throttle/low speed driving over horrible terrain. I canot imagine a clutch being too happy with this- Not with 18" tires and 4.8:1 gearing...

I agree your kart absolutely needs a T/C.

You guys all very have good points about the advantages of T/C's that I totally agree with. But I just dont think they're always the absolute best choice.

You know I race karts both on the track and also on large-open parking lots with my buddies. I can tell you for a fact that you'll never see anyone using a torque converter system on a competitively raced kart whether it be a paved road-racing type track, or a dirt (or paved) oval type racekart track.

(but you will always see T/C's used on off-road Stadium-racekarts where low speed torque/acceleration is way more important than top speeds)

The go kart that holds the current (non-shifter) top-speed world record at Bonneville (144.832mph) did not use a T/C.

I absolutely enjoy posting and hanging out here on DIY the most, but I've also done countless hours of research/posting at several other kart racing forums. The subject of utilising the advantages of T/C's has been raised several times on those racer forums.

The guys in any form of racing always seriously explore any possibility of even gaining a slight advantage over their competitors. Lots of top kart racers have tried to use the best T/C's money can buy to gain an advantage during the low-speed starts of the race.

And with using T/C's they did in fact get better starts. But... after all the karts were up to full racing speeds, they all discovered the karts with centrifugal or disk-type clutches (or even direct-drive) took off and left the T/C-equipped karts in their dust.

I cant explain exactly why T/C's are sometimes at a disadvantage when it comes to higher powered engines and top speeds, but I've always assumed that the tension the belt always has to be under, plus the need for a jackshaft and secondary-drive chain causes a bit more resistance (waisting some of the available h/p to friction) than just using 1 simple drive chain alone like a centrifugal clutch does.

But again, I totally "get it" that T/C's are indeed a much better choice for many karts. But just not always...

That's why I'm one of the few guys here that realises high-quality centrifugal clutches can sometimes be a better choice, and worth at least considering. (especially with higher h/p engines like the op's 13hp here...)