The 2001 F4i
 

I was looking at Motorcycle Consumer News performance index.

They had tested the F4i twice.

This is what it showed for horsepower and torque:

CBR600F4i ’01 96.6 43.6


CBR600F4i ’06 90.1 40.3

I asked MCN - by email - what the difference in hp/tq. for 2001 and 2006 might be attributable to.

He said:

1. Tests may have been run on two difference dynos.
2. Might have had environmental variance not corrected by SAE (usually within 5% variance).
3. One bike may have been in a better state of tune or manufacture (pretty common).
4. Honda may have changed fueling or equipment for emissions regulations (I suspect this).
6. A combination of any or all of the above.

That was around the time when fuel injection on motorcycles was relatively new and required emissions equipment caused manufacturers all sorts of performance headaches. Many bikes received reduced performance "upgrades" thanks to the EPA. OEMs have gotten much better at working around emissions restrictions in the last 2 decades..


Is there any common knowledge around that the 2001s were higher tuned, more hp, than later models?

Nope. They are all the same.

I don't doubt you but how can you be so sure? They had different issues with EPA compliance in those years. The Hayabusa that came out in 1999 was definately stronger than the 2000.

Look at the tests at this link: http://www.mcnews.com/mcn/articles/2015_01PerfIndex.pdf



They show a 6 p difference. It could be other things, but how do you know for sure they're the same?

Was it the same dyno in the same weather conditions? Were the bikes engines broken in the same? Did they both have the stock exhaust and map? Was the test done in the same gear? Was the gearing on the bikes the same? There are numerous variables that can lead to a 7% difference and no two dynos will read the same.

How would I know? Everybody knows that those factors affect the result of a dyno test. I called attention to those issues in the original post.

It doesn't answer the question.

I getting the sense that this forum is one of the more hostile ones where the old timers just rag on and on and they don't really want any new participation.

I think I'll replace my F3 with a 636 instead.

Hostile?
Ragging on and on?

You got 2 opinions in answer to your questions. Take em or leave em....

The only hostile one here seems to be you.

The same way we know the answers you seek.......
Because the bikes have been out for almost 2 decades. There is a F4i facts sticky on the top of this page. There are thousands of dyno's of F4i's all in the 90-98whp range for all the years. And to top it off we know how dyno's vary the HP they say you are making. We've all stated nothing but well known facts. You wanna get pissy about it, then you deserve a 636 ahahahahaha