From what I've read on this forum through the years, Honda has been tweaking the fuel ratios and ignition timing for each year model. If I'm getting it right, the originals power band dropped off significantly after peak power at 8300 rpm because the ECU richened up the mixture. This was allegedly done to protect the engine. Later models tended to do a little better because Honda programmed the system to maintain a more power efficient fuel mix between peak power rpms and redline. The MY04's + are simply a continuation of that evolution.

Just a thought......

Drive Safe,
Steve R.

 

The 02 was bone stock.

No, you're actually incorrect about the shifting the lines, too. Look at the post VTEC power, not only does the 04 make more power, but it is more accessible. first gear goes by too quick but I'd expect that if we lined up these cars in second that the 04 would pull away pretty hard.

 

OK, I found an interesting article about piston speed for 04
according to this article
http://www.caranddriver.com/article.asp?se...article_id=7274

03's piston speed = 4906 feet per minute @ 8900 rpm
04's piston speed = 4761 feet per minute @ 8000 rpm

so in calculation
04 piston speed @ 9000 = ~5356 feet per minute
04 will have same piston speed as 03 when rpm is ~8244 rpm
04 @ 8500 rpm = ~5059 feet per minute

in conclusion 04 piston speed actually increased rather than decrease.
i dont think 04 engine w/ 9k redline will be so safe.

btw how's the project going?

 

interesting posts!

 

Thanks for the info on the '02. The dyno curve at the link earlier in the thread shows a much weaker mid range for the pre-'04, which is why I wondered if there was a difference.

Regarding the lines, I did say "except at the very top", right? The '05 at 7200 is about 200 horsepower on that graph, about the same as the '02 at 8000 rpm; in both cases that's about 10% below red line. It's only in that last 10% that the '05 makes more power while the '02's power flattens out then falls.

 

^ that would be relevant if the cars were geared to redline at the same speed. In fact, the 04/05 reaches the power earlier due to shorter gearing, which means it'll accelerate a lot quicker.

 

Car is running well stay tuned fellas

 

Can't wait to see what the outcome is.

 

If USDM 04-05 rev to 8K how can JDM 04-05 rev to 9K, I don't understand.

Asghar.

 

Hmmm,

I am very interested in seeing how this pans out. UL posted about buying a 2.2l short block for under 3k. That could be a sweet project, a 2.2l with an F20C head.

But I wouldn't do it if the redline dropped from 9k rpm.