Redliner100, is this what you are looking for.
The draw from the pump will create negative pressure and will actually "help" the pistons rotate downward and in turn help seal the rings and prevent flutter at higher speeds.
CLARIFICATION - There will always be this confusion attached to the PAIR VALVE; there are two options available!
There is is only one 'Pair Valve' MOD!
There is only one 'Pair Valve' BLOCK-OFF!
They are not the same. They are both truly modification's, however, THE 'MOD' is a modification and re-routing of lines increasing the efficiency of the pump in reverse order and the 'Block-Off' is merely a removal of the whole system. If you install and "aftermarket" exhaust and do not block off and remap,, you will develop improper back pressure and most likely blow flames on throttle down decelerations.
1) Pair Valve Removal and Block Off (which is NOT the mod. It is simply a removal and blockage) Removal of known horsepower.
Step one; Remove all of the 'Pair Valve' system and block the four ports into the head and block the intake lead into the airbox. Done! Remap and you are set.
2) Pair Valve Crankcase Sucker ('PCS MOD')
Step one; Remove the larger line that is coming FROM the 'pair valve' that goes to the bottom of the air box (recirculating spent gasses back INTO the air/fuel system)
Step Two; Connect a male-to-male joint from the larger line from PV to a none-collapsible hose that you will then
Step Three; connect to the Crankcase vent where single hose was to bottom of air box.
Step Four; block with plugs/cap the inlet on the bottom of the airbox that the crankcase went too!
Actually, re-mapping is not imperative for this MOD! Although, if you are like me, always staying on top of the curve is best,, so re-map away, but again and some may disagree, but not absolutely necessary.
http://www.suzukihayabusa.org/forum/index.php?topic=44582.0
QUOTE
Pair "mod" will pull about 4 to 7 inches of vac. Nothing like the pumps but enough to make a difference. Several people have done the dyno test and most say anywhere from 1 to 5 HP. I'm sure it helps with the ring sealing and cuts the "pumping loss" somewhat.
I have seen the before and after dyno sheets on a 1397cc Hayabusa a few years back that showed increases of 5-6hp from hooking up the PCS MOD.
Back in early 2001 my friend Mark Feuerborn (Buster @ NorthWestDragBike ) while checking base numbers after a 1397 build had made his base run, ran the first set of numbers. While trying different maps, then thought it would be a good time to try routing the hoses from the 'Pair Valve' and to the Crankcase. While the dyno technician was out on a break,,, the tech returned and made another measured run, he was astounded and asked, "What did you do, Mark?!",,, "the numbers are notably higher!" Of course Mark showed him. He was totally surprised that the mere re-routing of hoses could yield suck increases!
After telling me this story, he helped me connect the lines up the way he had them to my,, then stock Hayabusa, and I could not believe the difference in performance. The front wheel came up with ease and the acceleration was much more crisp!
This is an 'Old Time Racer's' trick that has been around a long time, guys. No real science here. SchnitzRacing, for a while, sold a pump for about $235.00 that you can upgrade too and increase your hp gains. For whatever reason, they discontinued the sales.
Hmm, maybe people realized that they were selling what people already had on their bikes,,, for FREE!
Keep in mind - There is controversy associated with this MOD. Usually, those that choose to run with the PCS MOD usually keep to themselves and don't broadcast the fact that they DO run with it. The others,,, clearly do not.
I will be spending time on the dyno this Spring and plan to run base runs before the PCS hook up and after to have on paper showing the positive gains.
I will post the readings then for those who wish to see.
In the beginning of the Hayabusa when everyone was tweaking and going through the first discoveries this topic was exhausted on multiple boards. Time evolves, topics change, information gets lost.
The naysayers can say what they will, but the proof is there and has always been there. Throw away horsepower if you will. I refuse to give an edge away based off of fear!
I can walk anyone through the proper connections.
Expect 2-3 hp increase with stock - no matter what mods
Expect 4-6 hp increase with big-block