Re: peaky? (archive)

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The 3.2L Euro motor has been described as peaky, but it is not nearly as peaky has the Honda VTEC motors. Peaky is a relative term and it's more accurate to say that the Euro motor is more peaky when compared to the US motor but is less peaky than the Honda VTEC's. Above 4500RPM is where the Euro torque really came on, up to redline. I would suspect that they reworked the intake and VANOS along with the increase in displacement to make the curve flatter and higher in the low end. In other words get the higher torque of the Euro merged with the flatness of the US version. Sounds good to me.

: Since everyone is worried about this being a peaky motor (see my previous posts) I actually dug up the dyno data on the VTEC motors from honda. The way those work is the VTEC features (variable valve lift and timing) don't kick in until "stage 2" which is stock defined at ~5500rpm. For example, the S2000 generates ~150ft-lbs at 7300, and that is about as constant as a VANOS motor, but only from 5000 to 8000 or so. The reason honda did this is if you don't flog the car, you never get into the high torque region and you get great gas milage. They do sell controllers that engage the VTEC early, but again, its aftermarket. The torque BEFORE the vtec engages is much less, (like 25-35% less), that is why they feel peaky(like my friends civic Si). You can literally see a spike in the dyno chart when the VTEC turns on. With the vanos motor from BMW the torque curve will be high across the entire rev range (see previous post). One interesting point though. The S2000 gets most of its acceleration performance by having a 4.1 rear end (as compard to the M5's 3.15. With the rev limit of the E46 being as high as it is, BMW could put in a 3.46 and get better accel. (it would also put the shift points a little more reasonable, 42mph for 1-2 and 71mph for 2-3, "crusing" rpm would also be effected, but you would still run ~2300rpm at ~65mph. The reason VTEC people bitch is because if you shift at much below redline, you drop out of the VTEC region of the torque curve and your perf. sucks. With the vanos E46 motor this won't happen, so you will get good pull wether you are flogging the car or not

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