torque convertor vs clutch

#1
Hello everyone I haven't been on here in a while. How has everyone been? I have a question. I Built my bike up can rod and all. I have a tav 2 on it and I'm thinking about switching to a clutch. What would be the advantages and disadvantages if I do so? I need more speed. I'm running 12 - 53 but I will be changing my gearing to. Thanks in advance.
 

joshua. c.

Well-Known Member
#2
you can change springs in a torque converter to get more top end out of it but that only gets you so far. iv done this with excellent results but for what I use the bike for I don't need every last mph and bottom to mid range is more important. torque converters accelerate quicker than clutches but top out faster at a lower rpm. clutches don't take off a quick but they allow the engine to spin more freely and rev higher, meaning slower acceleration but more top end speed.
 

toomanytoys

Well-Known Member
#4
In my experience torque convertors accelerate better and pull harder on the bottom end as gear changes. You gain a slight top end advantage because you get an over drive effect when its maxed out. Now you have to keep in mind torque convertors are limited in rpm. Usually they say 3600 rpm

My super bronc with a torque convertor will climb like a mule. It wouldn't run anything like that with a clutch since its a heavy bike.
 
#5
You can raise your gear ratio at the drive wheel with a smaller sprocket and with a TAV you will still have low end takeoff but way more top end speed. They do sell higher end TAVs that handle high RPMs that were made for JR Dragsters but they are super high rent and I do don't think they engage at low revs so street riding would possibly be a no go.

That said I personally like to get a lot of responses to see what the majority of knowledgeable members have to say on any given subject so let some drag racers chime in too or PM minidragbike (Charles) and ask him what he thinks. The more info and opinions the more you can learn and apply to your situation so you can make an informed decision.
 
#6
Would there be much of an advantage with a torque converter on a bike with 20 hp that made 5 stock? I would think with the added power/torque of a modded engine you wouldn't need a torque converter. You don't see many mini drag bikes with torque converter setups. Maybe the high price of the jr dragster torque converters make them lean towards a centrifugal clutch. Too bad Salsbury doesn't make the 340 anymore.
 
#9
The whole setup is more than $750 after the jackshaft mount and crank support(if needed). More like $1k when all said and done.
Yep. Worth every penny with a $5000 drag engine. :thumbsup: If I were going to build a drag bike, I'd pattern it after the Jr Dragsters like the drag bike builders in So Cal are doing right now.

You said we don't see many drag bikes with torque converters, and I thought, "all of the drag bikes I've seen "have" torque converters" and I was being a smart ass.

Then again, even with $1000 bucks in an engine, why would someone NOT spend an equal amount for a clutch? Or more?
 
#11
Not many drag bikes here in Michigan that I've seen have a torque converter.
Ya know, somewhere on Face Book I saw some very nice mini bikes in Michigan. Cant recall the group name, but there were some high-level bikes in the photos.

The So Cal guys- one of whom is lscustoms who posts here- are hooked up with some of the Jr Dragster guys for engine builds and drives. Just saw the photos, I'm not one of them. I go fast enough with leaky HS40's, and if I need some excitement, I'll just ask my wife to drive. ;)
 
#12
11760096_1001330159911769_1082729838784047841_n.jpg 11826062_1001330186578433_3709994426109749059_n.jpg I have a built Tecumseh H50 makes about 20 on alcohol. I want to run a torque converter setup but don't want to break the bank. Most torque converter the driven is down below the crank pto. This makes it difficult to install in a mini bike without tilting the engine.
 

fistfullabar

Well-Known Member
#18
View attachment 76575 View attachment 76576 I have a built Tecumseh H50 makes about 20 on alcohol. I want to run a torque converter setup but don't want to break the bank. Most torque converter the driven is down below the crank pto. This makes it difficult to install in a mini bike without tilting the engine.
WOW engine looks awesome! Did i miss the build tread on this? Got more pics? What bike???? Stop holding out:drool:
 
#20
Ya know, somewhere on Face Book I saw some very nice mini bikes in Michigan. Cant recall the group name, but there were some high-level bikes in the photos.

The So Cal guys- one of whom is lscustoms who posts here- are hooked up with some of the Jr Dragster guys for engine builds and drives. Just saw the photos, I'm not one of them. I go fast enough with leaky HS40's, and if I need some excitement, I'll just ask my wife to drive. ;)
I'm with you. I like to cruise at a mid range speed take in the sights. My wisps of salt and pepper hair flowing this way and that. People pointing at me saying "now THAT guy looks like a guy who knows how to pary!" Thats enough for me.
 
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