The Dyno Dip

[Matt Davis]

I am looking for general information from people who know something about
the engines characteristics. What i am looking for is the reason why on a
Dyno graph that all sr20's Seem to have a SURGE of power @ 3600 Rpms.

For example i just Dyno'd my b15  SE @ 143 and 137 WIth I/H/E...

For 2000 rpms the dyno seems steady on the 120Tq Mark then  It SURGES to
136-37 respectively until 5500 Rpms.

I was Looking at the a/f maps and it seems that A/f was 14 up until 3600
then it starts getting Richer. Could this Surge be From the Timing ? Is it
likely that the Lower rpm power is being Killed by the Lean Fuel tuning
(thus lower knock resistance)?

Thanks for hearing me out.. I am really intrested in making the Sr smooth
as a babys But:D

thanks
Matt Davis
Sr20dee at b15sentra.net