power valve control solenoid

[locknload]

After reading some of the posts here on the forums I decided to plug the power valve hose going to the solenoid but someone at the local dealer said that when the power valves are full open the solenoid sends a signal to the ecm to increase ignition timing, does anyone know if there is any truth to this?

 

[R44guy]

After reading some of the posts here on the forums I decided to plug the power valve hose going to the solenoid but someone at the local dealer said that when the power valves are full open the solenoid sends a signal to the ecm to increase ignition timing, does anyone know if there is any truth to this?

Well that sounds like misleading information. The solenoid as long as it is still plugged in has no idea you have plugged the hose. Now if you unplug the solenoid it would send a signal to the ECU.

I would suggest that you change the springs in the ves or power valves to the pink springs if you have not done so yet since these have proven to give the best results with the hose disconnected or plugged off.

 

[Mentzel]

Where are you guys getting this information to plug the hose? That is bad advice!

If you plug the hose the power valves will open! And stay open...

 

[Mentzel]

The power valves use cylinder pressure through a hole in the cylinder wall. This hole provides pressure to the bellows and normally vents to atmosphere. The ecu closes the vent using the solenoid at about 5500 rpm. Once the solenoid closes the bellows inflates and opens the power valves. When throttle closes, RPM drops, ECU opens solenoid and vent. The bellows then deflate and the power valves close.

Problem is Polaris only drilled 1/16 pressure holes in the power valve housing and 5/64" hole in the cylinder. These holes gum up easily since they are using combustion products for pressure. Stupid Polaris design! Skidoo has a way better design as they take clean crankcase pressure to inflate the bellows. The fix for Polaris is to drill the holes out in the power valve mount to 5/64" and 7/64" in the cylinders pulse port. Don't hit the piston and make sure to vacuum out all the chips! Clean all parts well, replace bellows and springs. Oil springs well so they don't rust/break. Polaris should have used SS springs. One of mine rusted in half! Next drill 1/2" hole in spot right above left shock tower behind shock upper mount. Route vent hose to this hole and push through snug hole. Leave it sticking out of tub vertical 2". Make sure it is always puffing. With the increased pressure up to the solenoid the valves will react way faster when the solenoid closes. The sluggish valves are the main reason the sleds stumble in the mid range. This is why some sleds do some don't. The pressure ports simply plug up and are slow to open.

Plugging the vent hose does not fix the problem or add performance in any way! Plugging the vent will simply open power valves and keep the open all the time. Low end power will suffer and run poorly.

At minimum take apart and clean the valves and ports.

Someone please make this a sticky!

 

[R44guy]

The power valves use cylinder pressure through a hole in the cylinder wall. This hole provides pressure to the bellows and normally vents to atmosphere. The ecu closes the vent using the solenoid at about 5500 rpm. Once the solenoid closes the bellows inflates and opens the power valves. When throttle closes, RPM drops, ECU opens solenoid and vent. The bellows then deflate and the power valves close.

Problem is Polaris only drilled 1/16 pressure holes in the power valve housing and 5/64" hole in the cylinder. These holes gum up easily since they are using combustion products for pressure. Stupid Polaris design! Skidoo has a way better design as they take clean crankcase pressure to inflate the bellows. The fix for Polaris is to drill the holes out in the power valve mount to 5/64" and 7/64" in the cylinders pulse port. Don't hit the piston and make sure to vacuum out all the chips! Clean all parts well, replace bellows and springs. Oil springs well so they don't rust/break. Polaris should have used SS springs. One of mine rusted in half! Next drill 1/2" hole in spot right above left shock tower behind shock upper mount. Route vent hose to this hole and push through snug hole. Leave it sticking out of tub vertical 2". Make sure it is always puffing. With the increased pressure up to the solenoid the valves will react way faster when the solenoid closes. The sluggish valves are the main reason the sleds stumble in the mid range. This is why some sleds do some don't. The pressure ports simply plug up and are slow to open.

Plugging the vent hose does not fix the problem or add performance in any way! Plugging the vent will simply open power valves and keep the open all the time. Low end power will suffer and run poorly.

At minimum take apart and clean the valves and ports.

Someone please make this a sticky!

Mentzel, This is a different explanation or theory on how I have previously been explained about how they operate. I appreciate your information and will look into this today to see what I can confirm but several other sources who have explained this differently are not back yard guys who claim to know it has all came from reliable sources like certified Polaris tech's, dealers, performance dealers, and etc. I would sure like to know the straight scoop and suspect if you are correct maybe all of this other information may of been based on the old style ves motors with out the soleniod? I am always open to be reeducated and now I want to make sure I was not given bad information so I can understand this correctly.

Guy

 

[chumbilly1]

I have never had any sort of blockage in the ports at all. Maybe in an untuned sled being ran on $hit oil. I blocked my hoses 2 years ago and my sled runs great. The pv's are not open all the time. I am pretty sure the solenoid is only there to keep valves shut during the lean midrange so poo can pass the emissions test.BS

 

[PAT2]

power valves

When I was at Dyno Tech I wanted to try plugging my hoses and I also brought a couple different sets of springs to try. I was told not to wast my dyno money. I was told that Factory Polaris race techs and others have tried all of that with out any better results. The Polaris snow cross guys spent a whole day playing with that stuff and didn't find anything that worked better than factory setup! Just repeating what I was told. They also said that the solenoid needs to communicate with ecu correctly and it wont when blocked off.

 

[PAT2]

I have never had any sort of blockage in the ports at all. Maybe in an untuned sled being ran on $hit oil. I blocked my hoses 2 years ago and my sled runs great. The pv's are not open all the time. I am pretty sure the solenoid is only there to keep valves shut during the lean midrange so poo can pass the emissions test.BS

Pretty sure Polaris has been running solenoids on exhaust valves on there snow cross sleds since 2001. They didn't need to pass emissions??

 

[mngoat]

The power valves use cylinder pressure through a hole in the cylinder wall. This hole provides pressure to the bellows and normally vents to atmosphere. The ecu closes the vent using the solenoid at about 5500 rpm. Once the solenoid closes the bellows inflates and opens the power valves. When throttle closes, RPM drops, ECU opens solenoid and vent. The bellows then deflate and the power valves close.

Problem is Polaris only drilled 1/16 pressure holes in the power valve housing and 5/64" hole in the cylinder. These holes gum up easily since they are using combustion products for pressure. Stupid Polaris design! Skidoo has a way better design as they take clean crankcase pressure to inflate the bellows. The fix for Polaris is to drill the holes out in the power valve mount to 5/64" and 7/64" in the cylinders pulse port. Don't hit the piston and make sure to vacuum out all the chips! Clean all parts well, replace bellows and springs. Oil springs well so they don't rust/break. Polaris should have used SS springs. One of mine rusted in half! Next drill 1/2" hole in spot right above left shock tower behind shock upper mount. Route vent hose to this hole and push through snug hole. Leave it sticking out of tub vertical 2". Make sure it is always puffing. With the increased pressure up to the solenoid the valves will react way faster when the solenoid closes. The sluggish valves are the main reason the sleds stumble in the mid range. This is why some sleds do some don't. The pressure ports simply plug up and are slow to open.

Plugging the vent hose does not fix the problem or add performance in any way! Plugging the vent will simply open power valves and keep the open all the time. Low end power will suffer and run poorly.

At minimum take apart and clean the valves and ports.

Someone please make this a sticky!

This explanation is correct.....pulling lines and capping nipple at the housing will cause your valves to open base solely only on cylinder pressure and stiffness of you exhaust vavle springs that the pressure has to overcome. . No place for the pressure to go except push up against the bellows opening your valves. Remember the engine side of the bellows is being vented not the cap side. This is why you get the gunk coming out.

 

[R44guy]

Ok I got some feed back from 2 of 3 sources and the 3rd is going to post something in this thread in regards to the theory of operation in relationship to the solenoid and ves correct operation later today or tomorrow.

From what I was told again today as I have been previously been told was how the power valves work is the same as they always did before the solenoid. The solenoid just holds the valves shut longer to help the cfi4 pass emissions and then about half way into the power range the solenoid opens.

So if you block of the solenoid and change the springs it is doing the same job with out the solenoid that is controlled by the ECU when it is commanded open and or shut depending on your engine rpm's at any given time.

I have also been told that this will not make more or less power but will change the engine cut out you feel at mid engine rpm's when the solenoid opens or closes where it is much less noticeable with the hoses blocked off or plugged. There are plenty of owners and testers that think or believe the throttle response at the lower range is better or more crisp with these plugged.

As we all know with the factory piston excessive tolerance issue can cause more oil to blow into the ves and potientially cause a stuck exhaust valve easier then with the oil being displaced thru the hose to the solenoid that drains the excess out into your belly pan.

This is what I have learned and what I understand from some of the people in the business that I know and trust.

 

[Hawkster]

I plugged them and changed to the pink springs fixing one of it's multiple stumbles ( noticed the differance without even engaging the clutch , it was that noticeable ) theoretically speaking lower compression heads would be more prone to the stumble . The goofy solenoid is an emmisions after thought as far as my 2 cents are concerned . They buildt the engine and than asked the question how do we make it pass emmissions ? A joke , a cheap arse half baked fix that if anything retains exhaust gases that can't be doing any justice when your trying to make an engine perform .

 

[PAT2]

Another issue is the hole in the gasket for the pressure hole is to small. I use a spent 22 shell or right size gasket hole punch to get it to the right size.

 

[Mentzel]

The reason plugging your vent hose may help is because your pulse port s are probably plugged. If so you are not building pressure in the bellows very quickly if at all. If you do plug the vent hose and your valves don't open you have yet another problem. If your sled feels like it has "turbo lag" this could be the issue.

Take them apart and see how they work. They are pretty simple. Notice all the goo in your bellows when you take them apart. Stupid design... Skidoo has it figured out. Coming from Polaris guy.

I increased the pressure ports size to increase the responsiveness of the power valves. No more lazy valves and super snappy now.

A 1/16" pressure port hole in any exhaust system is going to plug I don't care how tuned the engine is, or what oil you use...

The valves must open/close consistently in order to tune your air/fuel ratios when mapping the ECU. This is one reason identical sleds need a different fuel map. Inconsistent power valve operation!

On another note I am considering going to a skidoo/seadoo solenoid with a crankcase pressure line and check valve. This would allow plugging of the pressure ports in the cylinders and power valve base. Basically crankcase pressure would inflate the bellows through a one way check valve on call from the ECU. No dirty combustion products to clog up holes and perform inconsistently. The skidoo solenoid is about half the size and has a deflate vent built in.. HMMM

 

[Mentzel]

Another issue is the hole in the gasket for the pressure hole is to small. I use a spent 22 shell or right size gasket hole punch to get it to the right size.

Agreed

But also look close at the power valve base mount. Only one 1/16" hole actually inflates the bellows. The other goes no where on the cylinder. The cylinder port is 7/64" at the top and 1/8" into the combustion chamber. Stupid...

 

[Kraven]

When I was at Dyno Tech I wanted to try plugging my hoses and I also brought a couple different sets of springs to try. I was told not to wast my dyno money. I was told that Factory Polaris race techs and others have tried all of that with out any better results. The Polaris snow cross guys spent a whole day playing with that stuff and didn't find anything that worked better than factory setup! Just repeating what I was told. They also said that the solenoid needs to communicate with ecu correctly and it wont when blocked off.

FACT: When I asked Casey Mullins (a DYNOTECH frequent returning customer who has dynoed his sled multiple times) about doing a back to back test plugged vs. non-plugged, his response was, "Yeah, mine are plugged, have been for a while, and I leave 'em plugged."

 

[PAT2]

I wish I could get an electric actuator that work with the TPS to work the valves. You can actually see hp drop a little for a couple rpm when the valves open on my dyno sheet. I think electric actuator would be a smother and more precise transition. IMO.
I have seen people drill a hole in the plastic exhaust valve cover (when off) so that you can see the bellow and spring . This allows them to watch the valve open and close to make sure they are working right and not sticking.

 

[PAT2]

FACT: When I asked Casey Mullins (a DYNOTECH frequent returning customer who has dynoed his sled multiple times) about doing a back to back test plugged vs. non-plugged, his response was, "Yeah, mine are plugged, have been for a while, and I leave 'em plugged."

When I was at Dynotech I had a couple different sets of springs and stuff to plug the exhaust valves to see what worked better. Jim told me not to wast my time that it's all been tried there at Dynotech already with no results to speak of and not to wast my money. He also explained why it was bad to plug the hoses! ( I was sleep deprived that day don't remember exact details) I'm sure if you called him and asked he would give his theory/explanation. He actually has a article on his site just about the exhaust valve in the D8's

 

[Fast Rider]

Just something to add..many race teams run a hose from one vent to the other to effectively "T" the valves together, allowing them to open consistantly at the same time (and doing away with the solenoids). Other than that I have heard of ppl changing to the pink spring which was more of a high elevation spring if I remember correctly because of the added responsiveness in the midrange.

 

[Kraven]

When I was at Dynotech I had a couple different sets of springs and stuff to plug the exhaust valves to see what worked better. Jim told me not to wast my time that it's all been tried there at Dynotech already with no results to speak of and not to wast my money. He also explained why it was bad to plug the hoses! ( I was sleep deprived that day don't remember exact details) I'm sure if you called him and asked he would give his theory/explanation. He actually has a article on his site just about the exhaust valve in the D8's

The article that I read from DYNOTECH JIM with plugging the valves was that it would possibly require yet another map for the temperamental 800's due to the INCONSISTENT exhaust valve opening from one sled to the next.

If you'll recall, there were multiple maps for the PC-3/5's and some guys had issues with the DET sensor going off 100' down the trail.

The issue as to whether or not there's a benefit to plugging the exhaust valve hoses can easily be determined by each sledder simply clamping the purge hose with a pair of mini-vice grips on their sled and taking it for a test ride.

And in a lot less time than it takes to read this thread, each individual rider can make their own determination, and disregard all the rest of the B.S.

 

[PAT2]

The article that I read from DYNOTECH JIM with plugging the valves was that it would possibly require yet another map for the temperamental 800's due to the INCONSISTENT exhaust valve opening from one sled to the next.

If you'll recall, there were multiple maps for the PC-3/5's and some guys had issues with the DET sensor going off 100' down the trail.

The issue as to whether or not there's a benefit to plugging the exhaust valve hoses can easily be determined by each sledder simply clamping the purge hose with a pair of mini-vice grips on their sled and taking it for a test ride.

And in a lot less time than it takes to read this thread, each individual rider can make their own determination, and disregard all the rest of the B.S.

Your are correct. There is no replacement for real world results. As a mater of fact, I plugged my hoses when I first got my sled after reading your thread about things to do to make sled run better (very good thread) and had them plugged up until I re did my motor and went to Dynotech. I followed your thread to a T. I always thought that might be why my sled always ran and performed so good! I wanted to do my testing with them unplugged first and get a good map and then plug them and see what happen. I was also testing a SLP programed ECU for another guy while I was there and he also wanted me to plug hoses and test it. He would pay for the time. We were told not to waste time and that the solenoid and ecu need to work together. Also that it would be a bad idea to plug the hoses and strongly recommended NOT to do it. He said Sean Ray and Tim Bender (Polaris Factory snow cross race techs) spent a day on Dyno playing with exhaust valves with out any real gains. Jim is a stand up guy! I don't think he would lie or mislead!
I think the main reasons for multiple PC3-5 maps and why one would work fine for one guy but not the next. I really think the biggest reason was that the fuel pressure on these sleds are all over the place. Mine is 10lbs more than any other sled that was tested at Dynotech, and the other ones that were tested were not all the same either. If a guy who had 10lbs less pressure than me used my map he would have big problem!!! Other problem for multiple maps I think is people not cleaning there exhaust valves regularly and they become lazy and sticky then they don't open when they should. Another contributing factor I think is the TPS not being set right from factory. People like me and you and others fix that stuff our self's. Others don't under stand or don't care or have bad dealer who wont listen, so they just ride sled how they got it(TPS set wrong) and have issues. If you have all those issues and get a map from someone who has fixed those issues that map might not work for you.
If your just going from o-100% throttle all the time, i.e. drag racing you might feel/get more performance from plugged hoses and lighter springs. It's when your cruising half throttle or coasting then giving it 3/4 or more then back down to half or coasting then back on it again like in the woods or tight trails that plugged hoses will give you less bottom end cause exhaust vales are opening way to quick.
The article that Jim from DYNOTECH wrote states right in the bottom paragraph EXACTLY what MENTZEL post earlier here. That one way to fix the slow opening exhaust valves is to make the orifices in the cylinder and valve mechanism bigger!! He never says anything about plugging hoses or needing another map if you plugged hose's!! He does mention a couple other ways but plugging hoses is not one of them!
I'm also pretty sure that me and other people on here don't appreciate are ideas, comments, or theories being called BS. That is what this forum is here for. For people to ask questions or post help, and or advice. We all know everybody has there own opinions and some might be right and some not! I would never post anything on here that I didn't think was right or that I haven't experienced my self. I hope other people don't purposely post wrong or misleading info on here!!