Exhaust valve's Leave them or not

What do you guys think about the exhaust valves? Should they stay or go on the turbo sleds.

We leave them in. Lost to much mileage and top end with them out or blocked. The new 3D rave valves are controled by soleinoids so they are a very tricky part of a turbo sled. We know that motors run better with them in also and when they are clean and working right. That is why every sled company uses them. Some use a cable some use vaccume some use exhaust gases. so chime in here and let us know your Phlisophy.

Quote from triple7 copied from a different thread

"And thats why there are different kits on the market. Multiple opinions, multiple ways of getting the job done.

Like it or not, the Rave valves on a doo do not have any mechanical form of opening or closing. They are done off of pressure. When boost is built, they are "blown" open. So, if you want a laggy turbo kit, that doesnt build boost until you are well into the rpm band, then you could probably see a gain by leaving the valves in. But, if you want a turbo setup that builds boost instantly and doesnt have much or any lag to boost, then you are dealing with a different animal. The Rave valves will be blown open immediatly and you will not see any gain off the bottom by leaving them operational.

Mind you, if your turbo setup builds boost quickly rather than building boost later, you cannot offset the gain of quick boost with a closed rave valve and not having boost built yet.

As Dave said, fuel economy really hasnt been a problem. I would venture to say that fuel economy would not change between leaving the valves operational or deleting them simply because the turbo setup is building boost damn near instantly and the valves would be blown open.

On a Cat things are a bit different because the valves are mechanically controlled I believe.

My .02

Jake"

If the valves are blown open as soon as you come on to boost Then just leave them in there is no difference than having them wired open or taken out. Right. Well the valves on the doo are controled by the ecm and solenoids. They can not open until told to do so. the valves are closed all the way up to 6500 rpms then the ecm tells the solenoids to open controlling the exhaust. If the ecm senses that something is wrong the valves, deto, or above 150 degree water temps the valves also also go wide open to help control the heat in the motor and then you lose all bottom end. The laggy turbo or heat to the turbo for the millisecond is not the problem it is the controling of the ecu that tells the valves when to open or close.

if a bellow is blown off what happens then? the valve cannot work and the motor boggs like no other and will not pick up any rpms. this is because the valve cannot control the pressures inside the motor. The valves are a must for in and out of the throttle riding. For drags now that a different subject. Even with the old 670 and 583 we built a cap that would hold pressure on the top side of the valve to keep them closed longer.

gus the reason that we would not buy the cylinders with out the exhuast valves Is because they work in mountain riding. We out west are always blurbing the throttle and blurping and blurping for our riding so you need the quickness of the bottom end. valves make this work. Skidoo found this out on the 9500 blizzard and have not looked back since.

just my .02 different strokes for different folks.

Sorry about the copy post there jake I just didn't know how to get it intio this thread. Sorry for the confusion. I knew you could fix it being a mod.

I agree some what on the spot on tune. But when the motor has a closed exhaust port the motor can not pull extra air and fuel until it can get rid of the last burned stuff. so with exhaust valves you do not have the slobbering power jet. The bottom end is cleaner and helps control a bit of the air velocites. that is why you have better fuel mileage. the princiable is just like the variable vane turbo or smaller AR. Smaller outlet better bottom end. more heat more air velocity after open. That equals to better top end. as lond as you dont hold the heat to long.