http://picsorban.com/upload/dynodropoff.jpg

 

It's definately mechanical. A/F ratio looks perfect and only takes a slight slip when the HP drops off. What all did you replace when you did the heads/cam and how long have they been in there?

 

I just put in new lifters/rockers/918's,springs/cam, and from what I can tell my installed height is wrong on the springs, but I wanted to get a few second oppinions incase anyone else had a dynograph look like this. The only reason I'm questioning it is I thought valve-float made the dynograph drop off like a cliff, not a 25rwhp dropoff and then hold steady.

 

Are you still running OBDII?

You can do a search of my posts on this topic for more info. I had
the strangest problem that was solved by switching to OBDI.

 

I have a very similar problem....have yet to figure it out. i'm sure its in the valve train tho,

 

Up to 5800 it looks like a normal LE/BRE torque curve. Perhaps more valve bounce than float after that. The package was designed to work with a certain installed height/spring load. Get the installed height correct and redyno it.

 

The micrometer/shims should be here friday, I just wanted to see if anyone else had the same looking dip on the graph.

 

Have you contacted BRE to see if he thinks the 918's are up to the task. IIRC his lobe profiles are a bit on the aggressive side.

 

We already talked about it.... and yes the installed height is off and setting up the springs about 15lbs lighter on the seat than what they need to turn the RPM he is doing. Once that's fixed it should be fine.

Bret