Armycop

Hi all!

Winter has arrived in MI and I'm in the mood for mods! My LS2 conversion has survived it's first HPDE season; very happy with the new power mill! One thing I did experience while on the track was a drop off in the 5500-5700rpm range while on throttle. This also showed up in the final dyno run during the test and tune (see dyno sheet).
I'm running a comp cam XR269HR with .525 intake and .532 exhaust along with the Comp RPM cam kit #54050, springs good to .600 lift. I've been told that the power dip is due to spring harmonics, and that this particular spring set isn't the right one for my cam. If this is true, then what's the right spring set? Could there be another reason for this power loss in this particular rpm range? All answers appreciated!

Supercharged111

You're sure that's no KR? Whatever it is prevents the power from climbing higher than before the dip.

Armycop

Not sure, but why would it show up there as apposed to farther down the rev range? I'm assuming you mean Knock Retard...?