Got a 05 CBR 600 F4i that is completely stock and thinking about putting a slip-on exhaust and K&N air filter in it. K&N has worked great with my truck and car. With all the different exhaust I can't figure which would be the best for the buck. For the money what exhaust is best for power gains and sound quality. Also can you feel an increase in power with the exhaust and K&N filter, if so how much of a gain can you figure? Thanks!

 

Performace will probably go unnoticed with these items without a Power Commander.

I would leave the stock air filter in if you desire your engine to breathe clean air. Those K&N have poor filtration test results.

Go for Akrapovic, Yoshimura, Micron, Hindle, Scorpion etc.....

 

You'll feel the difference, but you won't acutally have MORE overal HP. what you do with a free flow exhaust is free up the midrange. that's where you'll feel it the most. if you dyno before and after the modification, you'll notice you're pulling 6-10 more hp in the mid RPMs, but maybe 1HP at the top. what you feel is more HP faster, and that's all.

if you want more power, change your V-Stacks to shorties, get a good slip-on, a K&N, and a PCIII Custom map.

you'll see the improvement in the midrange like you would get with the K&N+S/O, but becasue you changed the V-Stacks to be shorter, you're improving the top end as well. only thing is that you'll run VERY lean if you don't get a custom map. the V-Stacks on a F4i are all tall whereas on the RR motor, they are a 50/50 mix of short/tall and this modification on a RR make the motor run a little less lean, but lean none the less.

You'll be looking at around a 10HP overall gain with a silky smooth mid.

 

your numbers seem very high mang...very optimistic.

 

not.....really. you'd be surprised.

 

with the stacks yes, but with just a slip on and filter?

 

yeah, 6-10 in the middle. no more up top though. if you're pulling 105 HP @ 13000RPM, you'll still be pulling right around 105 @ 13000 RPM, but down lower, in the 6000-9000 range, you'll notice more HP. lets say stock it pulls ~50HP @ 7000RPM. with a slipon and filter, you'll notice you get ~60HP @ 7000RPM. that's why so many people think it gives them more power, becasue they feel more power on the way up to 13000RPM.

get me?

 

i got you...overall gain maybe 1-2 but if you look at the dyno, you'll see increases in other areas...

you know...you're like the first person to ever put it in this perspective? most say screw the curve, just let me know what i'm at max...

nice and flat...

 

seriously? That's a little troubling... to them, the bike has 105HP and that's that. *sigh* rediculous. those who want power, have no concept of it.

 

hahahah yes it is...HP is not about power but rather a peeing contest.

i only have 92.7 max on my F4i but the mid range power is very flat with an akra f/s and dyno tuning...too bad the lowend got much worse...threw on -1 up front and it was in the money.