Size doesn't always matter; this inch-long device allows shifting at wide open throttle with no clutch and also delivers a cool "pop" out of the pipe with each gear grabbed.
The full exhaust (stainless...
The full exhaust (stainless with carbon fiber can) weighed in at 8.92 pounds, lightening the load significantly from the porky stock pipe's 18.1
An aftermarket exhaust is always high on the wish list, but with so many options out there it feels like a crapshoot sometimes when trying to make a purchase. Internet forums are packed with “experts” who claim a particular brand is superior to all others, but do you really want to take a stranger’s advice when it comes to shelling out major cash?
There are some safe bets however, and that’s why a Leo Vince full exhaust found its way onto the CBR this time around. Over the years we’ve always had positive results from Leo Vince pipes; the company’s full systems and slip-ons always add power, drop weight and sound great, and this pipe did all of the above.
Despite the Leo Vince claim that the exhaust systems don’t require an aftermarket fuel management system we always go ahead and order one anyways, figuring that the air/fuel ratio (AFR) can be tweaked to perfection. But again we were wrong. The AFR holds firmly in the upper 12 to lower 13-range, meaning it’s operating within the safe zone so it’s not really worth spending hours of dyno tuning searching for an elusive single horsepower. Since ridability is excellent without any bogs or dips (except on the extreme low end, which fueling won’t fix anyways) there was no reason to tweak the fueling. The dyno operator loaded an aftermarket fuel map specifically for the full Leo Vince system, but it showed no power gains or advantages. The conclusion was that we wasted money on a Power Commander V because the exhaust performed exactly as claimed—it added power throughout the rev range without any fuel adjustments.
We realized that the low-end...
We realized that the low-end dip can only be solved with the stock pipe's flapper valve, but the added power everywhere else in the rev range and the amazing exhaust tone make up for this one glitch. The stock baseline of 143 has been improved to just over 153, and it sounds sensational getting there.
All was not lost on the Power Commander V purchase, however, as it also is responsible for handling quickshifter duties. After installing the Power Commander unit, the quickshifter is simply plugged in (after inserting it into the shift rod) and activated. From that point forward the throttle can be held open and the next gear tapped in. Typically this mod is used for racebikes to eliminate the need for closing the throttle for shifts, but it works great on the street as well because it softens the lever pressure so shifts are buttery smooth. Missed shifts are all but eliminated in the process because there is no load on the engine when the fuel is cut. And perhaps best of all is the wicked little burp that pops out of the exhaust after every shift due to the unburnt fuel from the brief delivery interruption during the shift. Kill times can be adjusted, but we’ve found that the factory preset of .065 milliseconds works pretty well. A cool feature of the quickshifter is that the kill times can be adjusted with a laptop in a matter of seconds, then tested on the nearest road and tuned accordingly—you’ll feel like both the crew chief and racer wrapped into one. SSB
Next Month: A few glam mods.