Sonic_S2k_04

I have an 04. My dyno shows increasing power all the way to the redline after Vtec.

Ive been looking through the Dyno sheets of the Pre-04's and noticed something and wonderd if a few of you would share on it.

At about 8200- the line seems to flatten and drop on most pre-04's ive seen. I Drove a pre-04 and felt the same thing... That after about 8k, the pull seemd to just flatten out. Not Die...but just not as strong.

Is this the case. Does the 9k rev flatten out at around 8.5k... Some times earlier, Sometimes even droping.

Also are there any measures any of you have taken to Give you pull all the way to 9k... i know its only 500-1000 Rpm's were talking about here...

marcucci

A test pipe did it for my '01. Pulled all the way to 9k. Didn't add much power other than extending that curve a little.

As near as I have seen the '04 rev limiter is placed where the motor stops making power. That, I think, is largely because the new design is more "corked" with the '03 and earlier hardware. I think the 2.2L will benefit much more from cams and other NA mods than the 2.2, especially if accompanied by a higher rev limit.

Sonic_S2k_04

So this isnt a case of me being misstaken. The power Flattens out alittle...even drops some?

mikegarrison

Power is just torque times RPM. Once the torque curve peaks and starts going down, it is a race between the lowering torque and the increasing RPM. Most of the time, a NA engine is designed so that the RPM cutoff will be just after the power curve finally starts to drop off.

Since the 04 engine is a modified version of an earlier engine, rather than being designed from the ground up, it is not surprising that it might have a few non-ideal characteristics. In this case, the shape of the power curve indicates that the engine "wants" to be a little bit higher revving (probably 9K) but due to mechanical reasons the RPM has to be limited a little lower.

It's no big deal, just one of those "you don't get anything for free" engineering tradeoffs.

marcucci

Correct.