[oldman]

I would caution you on racing dynos, you can't assume what a dynojet would do.

Second, you are approaching a 10% correction factor already i.e. your car is making a whole lot less HP than this dyno shows.

Third, you are on 91 octane, I guess you can get away with this at your attitude, but it is very low. I don't know the effective dynamic compression (download cam doctor), at your altitude you could be like dunno 10.5 or something? i.e. you should have a stage 1 cam.

Fourth, AFAIK all TSP cams can take a cam phaser limiter of 20 degrees, don't know about their big stuff, you can get some of this midrange back by advancing the cam say 6 degrees till 4500 RPM, TSP should be able to give you general guidelines. IMO with fast ramp profiles, the factory phaser is not able to handle (there is dynamic walk).

Fifth, what is a catted X pipe? I also have an M6 and with factory suitcase, there are strange harmonics that lead to all kinds of issues including false knock.

Your header tube size is too small for size of cam.

I would port the heads and mill, you probably need to notch the pistons. Looking for dunno say 12.3 static. thinner head gasket too? Stock head ports flatline above .550 lift and actually flow less at higher lifts, so all that valve lift is just losing HP and torque from flow (as well as dynamic compression).

https://www.enginelabs.com/engine-te...-lt1-di-heads/


Drop the cam size to a stage 2 that works at 2000+ ft.

eliminate the cam phaser

bring tube size to 2"

ported 95mm TB or 103 TB

All of the above assuming you can get 93 octane.

On 91 and 2000 plus feet:
stage 1 cam, ported heads, maybe a slight mill to 11.75 CR.

Full disclosure I live near sea level and 93 octane my whole life.