ZR-1 Net Registry Forums - View Single Post

Aurora40 · 07-18-2009

Hey Jim,

What I meant is, look at the MAP at low RPM at WOT. What is the highest the MAP reading goes up to? That is potentially the atmospheric pressure at that time. It's better if the RPM is really low, but at the dragstrip you probably aren't driving that way.

If the max pressure is that 100.1kPa, and in the snapshot it is 96.7kPa, then you are getting about a 3.5kPa pressure drop. That seems a little bit high, though not a lot. I think I usually have closer to a 2kPa drop as the revs climb. Possibly it gets lower as the RPMs go up from there? That snapshot is at 6,300.

Intake pressure directly affects power. Though here we're talking maybe 2% at the max, which on a 400hp motor would be like 8hp. Certainly that's not nothing but hardly huge. How "off" were your runs?

07-18-2009	#7
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,704	Re: Need help understanding scan data Hey Jim, What I meant is, look at the MAP at low RPM at WOT. What is the highest the MAP reading goes up to? That is potentially the atmospheric pressure at that time. It's better if the RPM is really low, but at the dragstrip you probably aren't driving that way. If the max pressure is that 100.1kPa, and in the snapshot it is 96.7kPa, then you are getting about a 3.5kPa pressure drop. That seems a little bit high, though not a lot. I think I usually have closer to a 2kPa drop as the revs climb. Possibly it gets lower as the RPMs go up from there? That snapshot is at 6,300. Intake pressure directly affects power. Though here we're talking maybe 2% at the max, which on a 400hp motor would be like 8hp. Certainly that's not nothing but hardly huge. How "off" were your runs?