for just a slip-on, you really dont need a power commander. If you run full exhaust, then you will have to.

the valve, believe or not, is more for noise emissions than it is for performance. You wont notice any ill effects from not having it. No worries about rough idle or hesitation.

If you want more performance,(which it sounds like you really dont) then go full system, air filter, power commander. If its only sound your after, a slip on will be just what your looking for.

 

I run 87 is my cbr1000rr had no problems, my brother ran 87 in all his bikes also.

 

Why? A full tank of gas only cost about 8$ max? Are you that poor? If so then sell the bike and get a geo.

 

The ignition system is designed to run off 87, running anything else would be the same as retarding your ignition, because it takes longer for the fuel to burn and start pushing down on the piston top, the results would be less power, you probably would notice the powerloss, but why even waste the extra $1 when you dont have too?

 

Your probably right, but Honda spent months designing the exhaust manifold, the only real restriction is in the muffler, Im sure you gain minor hp and tq from the aftermarket exhaust manifold, but if you want the best bang for your buck go with just a slip on and a power commander, the stock air filters flow just as good as aftermarket only positive is you can clean and reuse the aftermarket air filter. Im not saying your wrong, I'm not saying im right, I'm just throwing in my 2 cents.

 

Who told you it was designed for 87 octane? If your bike has a knock sensor then the effect on ignition timing is likely opposite of what you stated. This is especially true in high compression engines. What's the difference in flame front propagation with 87 vs. 91 octane fuel?

 

I was told it was 87, not sure if its true, does anybody have the owners manual to verify? The only thing a knock sensor does is tell the computer when it hears engine knock, and then the computer switches to a different map which basiclly retards the ignition, this is called limp home mode, it will also throw a check engine, the knock sensor does not "tune" the ignition timing. The difference in propagation is that 87 burns quicker then 91, I dont feel like ripping out the books too give you the equations.

 

I know you were told 87, but by whom? The owner's manual does not say the ignition (or the engine) is designed for 87 octane.

Limp home mode is for a serious problems like a sensor failure, not spark knock. The ECU does in fact use the knock sensor to tune the ignition timing. Billions of ECUs hear spark knock everyday and don't throw codes.

You have books that give equations for flame speed propagation based on octane number? I don't think so...

 

Whoever would run anything less than 91-94 octane on an engine with 12.0:1 + compression is lost...

 

hmm i have been wondering what to use in my 07 cbr 1000...so i went on a long trip...i filled up with 89,,,,,,cool responsive throttle,,,,,,then i went to 87 octane,,,,same response no problems ,,,,,then finally went with 91 premium,,,,,,OMG,,,,wtf,,,,,waht happened to my power,,,,{am i back on a 600rr?..wtf..where is my power,,,the throttle was slugglish,,,,lots of lag,,,the quickness of the throttle respoinse was in SLOOOOWWWW MOTION,,,,,no way,,,i am not using premium,,,,,,hell no,,,,im back to 89,,,,OH YEAH,,,,that answers my quest..thank u very much.