Raising stall points tav 30 converter

delray

Well-Known Member
#22
Worked great with the green springs and adjusting the driven pully as mentioned. But the belt just can't hold the power. I jump way out in front and then get left 200 ft out or so by the quick guys. Was hoping I could adapt the cheap 40 series or 20 series driver and use my driven pulley. The driven pulley has the bevel on both sides.
you said the driven was bevel in both sides. that would be a 20 series and your driver was a 30 series and you wondering why you have belt problems?
 

delray

Well-Known Member
#23
Think it’s an old harbor freight doodle bug clone? What I was told anyway. HF orange under the black spray paint anyway.

Non-hemi 212, mod2 cam, 160 head, .010HG, flywheel, header, jetted stock carb, wheelie bar, slick with a 75t. 12t on converter. I was worried about PTV with the 1.3 rocker and 160x head, Should I not be? Id like to run 1.3 rockers… actually have a set. Also seems to run better without the muffler. It’s a large scooter muffler 1.5” straight through design. Not sure why it seems to slow it down. Sounds great.

I honestly don’t think it’s a power issue. We are all pretty similar power wise. I believe it’s slipping. If I clean the sheaves well with alcohol it doesn’t slip near as much the first pass or 2. As the day goes on it gets worse. TONS of belt dust. Believe they are only rated for 7hp or so?

I ordered the comet clone 40 series driver pulley and dual sided belt to try. I’m just curious if it will work. I have a ¾ to 1” shaft adapter as pictured above as well. It the belt didn’t slip up top I think I’d be too far out front to catch by 300ft as it sits now. trying to keep it reasonable part wise are the polar units similar to the cheetah?

I have a new cheetah dual disc clutch sitting here. I just feel the torque converter has the advantage off the line assuming it didn’t slip up top. I know you give up some power but for a 300ft race I think it’s worth the extra off the line performance.

Thank you for the interest!
I see your engine nowhere near like my engine. I have ton more mods done. might be the same cam but that's it. also see your still running a stock carb with just a jet kit. that's like running a restrictor plate and that big ass muffler got to go and you need a good three stage header pipe. 1.3 rockers will work all day on that low lift cam,but you will need the correct guide plates and a good set of moly push rods too and valve springs ….etc... your engine setup is definitely lacking top end performance. engine setup could be a whole nother subject so I will leave it at that.
40 series is not going to fix your problem. if anything it will create a big problem when you try to spin it at 6000-7000 rpm's. if you are running billet aluminum flywheel with that Big steel stamp unbalance driver unit on the end of you crankshaft it will create a unwanted vibration.
before you start to spending a ton of money just try that cheetah clutch with a 3600 stall first and gear the bike to go 6000+
if you don't have enough gear on the bike and you need to go with a jackshaft? just use the comet backing plate from the torque converter. you will use least amount of power to turn that type of jackshaft and back to your rear sprocket. if your really interested in trying to make good power up to 7000+ you can always pm me and then you can look into gearing it some more so it pulls 7000+and maybe change the stall speed too.
 
#24
Appreciate the input! I have the "TAV" cheap 30 series china converter on it now. Has a bevel on one side. They are only rated to 7-8hp I believe. I was wanting to upgrade to the 1" bore "40 series" unit that has the bevel on both sides. Should hold roughly twice the power that way I'm told with the two sides of the belt gripping the sheaves vs only 1 side? Running the PLV cast alum flywheel. believe they are only at 28* adv as well.

I do have 22lb valve springs in it. Was just playing with the idea of mixing the 40 series parts on a 30 series unit. The 40 series china driver was $34 plus a belt and shaft adapter. Not alot invested. Mainly curious.

The cheetah is installed now. waiting on a chain guard and need to make a tensioner of some sort. I'll look into a carb. Spoke to some guys at GO POWERSPORTS racing and they have a 22mm china clone that they claim is already dialed with the correct jetting and all the "tricks" for $100. (not the flat slide). Was debating on that VS just buying my own for $58 and figuring it out. suggestions?
 
#27
They are about 53 in ebay shipped. But the ones at gopower sports have the adapter, throttle cable, and filter. And claim to come jetted and "tweaked" to perfection. lol. I'm torn.... farting around with jetting and guessing at plug readings for hours may be worth the extra 20-30$. then again... may end up doing that anyway it its not "perfect".
 
#28
Well i picked up power no doubt with the 24mm carb... 31* of timing and 27" straight pipe. but this cheetah clutch has gotta go! NOTHING like the converter. Tried 3k to 5k stall points. Its a total turd off the line. Once it locks its a beast. But the 300ft race is half done by then. Need a converter that holds some power!

The 40 series driver showed up. But it weighs more than my flywheel. Prob wont work. Noticed go powersports sells a 30 series 3/4 driver called juaggernaut now. They claim it holds more power. Whats my best bet for 3/4 converter that will hold 12-15 hp?
 
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