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Two Sphinx PV cylinders on banshee bottom


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The concept of pv work the same no matter the application. How they work will vary on the design. Some use exhaust pressure, some use electric motor, and other. Some work better than others.

The reason I ask was because with a manual transmission the revs would raise and fall alot more frequently than on a CVT. The rotax PV seem to be the favorite because they are activated by exhaust pressure and seem to work well on other applications. My question would be with the difference in times the PV would be activated would that play a role in the reliability of them? If so we would be back to square 1 right where Trinity left off.

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But that can be same for diff cyl and set up with pipes, carbs, gearing etc. so I'm asking why are PV good?

The reason I ask was because with a manual transmission the revs would raise and fall alot more frequently than on a CVT. The rotax PV seem to be the favorite because they are activated by exhaust pressure and seem to work well on other applications. My question would be with the difference in times the PV would be activated would that play a role in the reliability of them? If so we would be back to square 1 right where Trinity left off.

Ya CVT makes a diff on how powa is put to ground. But when I stated how a diff cyl set up wid pipes, carbs, gearing to put powa down no one balee dat
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Ya CVT makes a diff on how powa is put to ground. But when I stated how a diff cyl set up wid pipes, carbs, gearing to put powa down no one balee dat

I get what you're saying JT. I don't think we are talking about the same thing though. Yes you can set a quad up for tight technical trails. You can also set it up for open fire roads. You can set it up for drags and for hill climbs. What I and I believe most of the people who are interested in PV setups are wanting is a motor that can do all of that well. How many times have we seen the noob come into this site with a motor question " I want more power. I ride woods and drag race my friends what motor should I get" if we had good working PV setups we would actually have a motor perfect for them. Sorry about the windycityjohn length post.

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True, so you wouldn't need a pv that moved quickly. The pv seems to work great in sled and dirt bikes, just not on a banshee.

Hell. Just have a PV locked at 192 duration. Then a manual lever to put it at 196. No need to guess what it needs in the middle. We know the same pipes and carbs will work with both of those. Serval when you want it, then a Cub when you want it. No in between.
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The reason I ask was because with a manual transmission the revs would raise and fall alot more frequently than on a CVT. The rotax PV seem to be the favorite because they are activated by exhaust pressure and seem to work well on other applications. My question would be with the difference in times the PV would be activated would that play a role in the reliability of them? If so we would be back to square 1 right where Trinity left off.

Trinity valves work very similar to the Rotax Rave valves. However, they use a keihin jet to bleed off pressure from the bellow. Smaller jet bleeds less, so you get a slower operation of the valve. Larger jet bleeds off pressure and makes the valve react vaster. It's not a bad set up. I fiddled with a 421 cheetah and it was actually pretty easy to get the valves dialed in for a buddy. I've got a 535 on the way now, so I'll see how it goes a second time around.
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Trinity valves work very similar to the Rotax Rave valves. However, they use a keihin jet to bleed off pressure, kinda like a waste gate on a turbo set up. Smaller jet bleeds less, so you get a faster operation of the valve. Larger jet bleeds off pressure and makes the valve react slower. It's not a bad set up. I fiddled with a 421 cheetah and it was actually pretty easy to get the valves dialed in for a buddy. I've got a 535 on the way now, so I'll see how it goes a second time around.

Where do you find these? Trinity stopped making them correct?

 

Sent from my BIG BLACK COCK using Tapatalk.

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Hell. Just have a PV locked at 192 duration. Then a manual lever to put it at 196. No need to guess what it needs in the middle. We know the same pipes and carbs will work with both of those. Serval when you want it, then a Cub when you want it. No in between.

Lotta boats in the smaller classes with snowmo engines doing this.
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Aight I'm gona step in here and keep it 100. Peeps talkin PV fo tight slow shit etc...can only go so quick so fast in dirt...ain't gona be able to put down "cub" powa to ground and prob can't go faster due to trail or track etc anyways

For me, it is perfect on the ice. I've tested with plenty of sleds in oval and it works. The 535 I have coming is going in my current bike and it'll see trails to. Our trails go from twisty stuff in trees to open power lines and fire roads. So it'll be nice to lug the bike in tight stuff and then be able to get it wide open with out it feeling like it's hitting a wall on the top end.

 

There is no question that a properly designed PV set up can benefit any motor that sees a variation of RPM. It's getting it to work in a particular application that makes it worth it or not.

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Where do you find these? Trinity stopped making them correct?

 

Sent from my BIG BLACK COCK using Tapatalk.

You can still get all the cheetah stuff new. Harry McDermott sold Trinity to Dasa I believe, but he is now working under his own name at McDermott Motorsports. He kept the rights to a few Trinity products after the sale though. The cheetah is the main product he held on to.
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Aight I'm gona step in here and keep it 100. Peeps talkin PV fo tight slow shit etc...can only go so quick so fast in dirt...ain't gona be able to put down "cub" powa to ground and prob can't go faster due to trail or track etc anyways

You are right. My next engine will be about 100hp and it's retard power to drive in trail and get my beer pack...

 

But it's fun ;-)

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Hell. Just have a PV locked at 192 duration. Then a manual lever to put it at 196. No need to guess what it needs in the middle. We know the same pipes and carbs will work with both of those. Serval when you want it, then a Cub when you want it. No in between.

192-196 is not nearly a wide enough range. 180-190 would probly be better. manually operating it would never work well on a atv. manual sliding pipes like boats use wouldnt work well either. theres no way you could pull a bunch of levers back and forth, at the right time, while operating the throttle and clutch, while trying yo turn and jump

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