Riva Bypass Upgrade Kit $94.95

Thursday, April 19th, 2007
Well I don’t need to tell ya how to install this easy one so lets get into the whole idea of this mod.

This is one of those modifications that does nothing more then deliver what the consumer wanted. You get what you ask for. Neat looking filters that go onto your BOV and Relief valve. Performance gain is minimal if that. So lets take Riva description and clarify it.
Easy to install Bypass Upgrade Kit contains all parts necessary to redirect hot air from the engine’s bypass valves and crankcase vent; eliminating power-robbing engine emissions from entering your air intake system. Kit includes fitted K&N filters for bypass & blow-off valves and crankcase vent. Designed to work with both RIVA Pro-Series & Performance Power Filter Kits for Ultra 250X.
Lets start with Crank Case Vent. It’s referring to the top hose coming off the oil catch can. The oil catch can is used to retain oil when ventilating the crank case. The motor vents from case to valve cover then out into the catch can.

This filter add on looks cool when seat is off but ugly if you ever overfill your oil. I chose to vent my crank case vent into my Riva Pro Intake, that way if oil every does over flow the catch, it will be routed into my engine intake and hopefully burned off. To much oil could pool in the inter-cooler so oil level is crucial. The “engine emissions” is referring to the oil vapor from the catch can. If your maintaining optimal oil levels then the level of oil vapor is so minimal that little to no performance loss is evident.
Bypass and Blow Off are the units below in Blue and Pink.

Not sure as to why they are saying that the air from the BOV and Relief Valve is HOT. This over sized inter-cooler does a great job of reducing the hot air from the supercharger down to ambient temps. Since the inter-cooler uses water from the pump, I have often seen cooler temps from the water being colder then air temps.
Some have claimed that not redirecting the air back into the intake will cause lag due to the escaping of stacked air. This is completely wrong in this application. First let me say that the air is only compressed down with 11lbs of force. As soon as it is released it is instantly uncompressed. So returning it to the air box in hopes that the supercharger will labor less because the redirected blow off is already compressed is completely wrong.
Another theory about this system is that the air is measured using a Mass Air Sensor and redirecting it will again cause engine lag from mapped air escaping causing the ECU to run the engine rich. Its not at all. Cars use this to measure the amount of air entering the intake manifold so that ECU can control the amount of fuel to help maintain an optimal AFR.
So redirecting the air that escapes the inter-cooler through the BOV or Relief Valve has no true disadvantage or gain. What it does do is give a really cool sound that warns off those grudge seekers. It also looks pretty sweet and chicks dig it.
I will say that redirecting mine has done nothing for RPM gains or performance as of now. The choice is yours. This upgrade is defiantly an eye catcher but if your expecting noticeable performance gains then I’m afraid you will be disappointed.
Personally, I bought it because it looks and sounds killer.