NO I shut it myself and locked it,anymore question's call Vito's performance,he did my engine and told me to do that.

 

And no they close at a higher rpm not open.Why would you want to restrict the exhaust flow with the valve open?Have you looked at an exhaust valve?They are round with a rectangle opening in the center,so why restrict the exhaust flow with it open at top end??They close at top end.

 

Like i said your powervalve is locked wide open,when you want to go outside do you shut the door or open it...As for powervalves they improve low/mid power they have no influence at all with how your engine will perform at high rpms.I have been playing with powervalved engines for quite a while now weither they were sleds or Banshee engines,you can even see two of my Shee engines on my page in the gallery section, both of them use powervalves...

 

By the way how much you want to bet??I can show you it just make the trip to the state's across the BlueWater Bridge,it's not far from the bridge,my quad that is.

 

I dont need to see it,if your powervalve is locked shut then your engine wont have any top end whatsoever so it is obvious that it is locked wide open.

 

Look Pointdexter,Call Vito's Performance,I know what's done to the engine and so does he.After all,he done all my engine work.I'm not new to racing or working on 2 stroke's.For that matter Mac Dizzy go to that site ask him how they work on the LT engine's.We are'nt talking sled's or shee engine's.

 

My Zilla top's out GREAT,4.53's in 300ft @ 70mph and it still pull's strong,without the nos.and your's does???

 

Well my Shee is set up as a duner so ne time slips for me or anything but with that said,a guy on Planet Sand Jon Lorio is his name ran under 4sec a few times with his 7mm 500cc T-REX engine wich is exactly what my T-REX is.I had the engine built with the idea in mind of turning it into a full drag beast once i have the time and $$$ to build another Shee from the ground up, the Cheetah is used as my spare engine.

By the way there are a few guys in your neck of the woods running stock bore,stock stroke 350cc alky Banshees and hitting in the very low 4sec, 4.1-4.2 to be more precise.Michael Zielinski and Dan Hull just to name a couple, both of them will run 3.8s in 300ft with their 520-540cc monoblocks stroker engines on alky.

Oh and i stopped logging onto MacDizzy's site as soon as it became a pay site,to be honest with you it may be a good site for Zilla owners but for 250r and Banshee owners Planet Sand is light years better.

 

Simplicity and Complexity
While guillotine-style power valves are overwhelmingly popular in today’s high-performance sleds, very different systems are employed to control their opening and closing. Ski-Doo and Polaris use control systems that are similar in principle and are the simplest in execution. The Ski-Doo system uses exhaust-port pressure to actuate its power valves — a small hole in the exhaust port allows port pressure to act on flexible bellows that are connected to the power valve. Under heavy load and high revs, back pressure pulls the valves open quickly. Polaris’s system is also pressure- actuated, but uses cylinder pressure rather than exhaust pressure as the actuating signal, via a small hole in the cylinder liner. Both systems employ a light spring above the guillotine valve to help keep the valve closed at lower revs.
but on the lt500 heres the scoop
SAEC technology can be found on both Suzuki QuadRacer models. A barrel valve located at the base of the cylinder, on the under side of the exhaust duct opens and closes according to a mechanical device that is driven off the crankshaft. This valve allows the exhaust gasses to be exposed to the chamber which is complementary to the shape and volume of the chamber stamped into the exhaust pipe. On the LT500R, from zero to around 5,500rpm the additional exhaust chamber remains open. By having this chamber exposed to the exhaust the gasses, it changes the characteristic of the exhaust system so that it lowers the pipe's effects on the engine's rpm range. Above 5,500rpm the barrel valve is completely closed allowing the pipe to have its usual effect on the LT500R's engine.

 

http://www.offroadhaven.com/powervalve.htm check out this site if you are confused about the functioning of a powervalve as Imback is