new thought about comet torque converter tuning

joshua. c.

Well-Known Member
When it comes to comet 30 series torque converters mounted on a heavily modified engine, as most know, in stock form they limit the engines rpms. There are several well known ways to make comet torque converters run better but so far there is no magic part that can make one engage at 3000 rpms and pull to 8000s. as far as tuning there are different springs for the driver clutch to change with engagement changing when the shift starts and stops and you can get a stronger yellow spring for the driven to slow down and stretch the shift a little allowing the engine to rev higher. I have herd from many people saying the yellow driven spring isn't strong enough to hit the rpms they want but changing springs isn't the only way to slow down the shift in a driven. this driven clutch is nearly identical to a snowmobile clutch and works on the same principles. and most snowmobile clutch tuning company's prefer to change the ramp angles on the clutch helix before messing with the springs. the comet driven clutch has a helix so why has no one tried messing with the angles on it yet? I would think making a custom helix the same size with longer shallower ramps combined with the stronger yellow spring should slow down the shift a lot more. also a lot of people complain that the overdrive a comet 30 series asymmetrical clutch reaches is to high of a gear ratio and drags down the engines rpms. from what iv read the 20 series symmetrical clutch doesn't reach an overdrive ratio so wouldn't that be a better choice when searching for every last rpm?

joshua. c.

Well-Known Member
hear is another crazy idea. I think you could potentially get more rpms out of a rupp roadster 2 type torque converter driver. it uses centrifugal force to push against a coil spring instead of pulling against a tension spring like a comet 30 series dose. this could allow you to use a dual rate spring engaging quickly then slowing the shift more and more as it upshifts having the same results as increasing the engagement of 30 series without compromising the drivability the way a higher engagement dose.
A lot of custom parts and tuning may make chicken salad from chicken $h!t, but it still won't be GOOD chicken salad.
Jr Dragster bits are light-years ahead on this stuff.
And, the scooter-type CVT setups contain peaky high-power builds, have tuning ease.
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Active Member
im confused as to how a TAV can limit engine RPMS. if the engine has the power to turn the wheels at the gearing of full TAV engagement, what is physically limiting the engine from continuing in RPMs if the governor is removed?
im confused as to how a TAV can limit engine RPMS. if the engine has the power to turn the wheels at the gearing of full TAV engagement, what is physically limiting the engine from continuing in RPMs if the governor is removed?
From my understanding it doesn't limit the rpms like it sounds (like a governor does). Once it's shifted out that just all that is gonna happen. The engine might be able to spin faster but the rest is just out of gear to use.

My understanding is limited because I don't race these things and haven't researched much into them.
Comet used to sell an aluminum driver weight. I have one its weighs a few oz. this would also have an affect you speak of with yellow would easily hold the driver out to 3k

Sent from my Fischer price Speak and Spell


Well-Known Member
Look how far we've came since this post. Now we have Super Drivers like the Juggernaut and Torkzilla
I don't know what these guys are talking about here but it's easy to get higher than 3K engagement if that's what you want. My China TAV engages at 2700 RPM. If I wanted higher than that it's just a matter of getting heavier springs and or lighter weights into the driver. The yellow spring in the tightest hole gets the latest belt shift under full throttle. Again, easy enough.

But yeah a lot of guys love those new drivers. I'll never get one. Don't need it.
I just finished tuning my 30 series torque converter and I got excellent results.

I use the die cast aluminum driver weights with the light blue springs. This gets you 3300rpm engagement. The aluminum weights weigh 146 grams and the zinc ones weigh 320 grams. Because the aluminum weights are about half the mass of the zinc weights, it take a longer time (more rpm build) for the aluminum weights to be fully deployed in the driver. I also made up a brass driver spacer so the driver wont fully deploy and place the TC in the .9:1 overdrive ratio. My bike pops wheelies on command and revs out to 8k without issue.

I also feel that making a driver spacer limits how much tension and stress is placed on the belt and backing plate assembly when in high range.