lee101315

I was in the same situation, and got the same result.

mark kibort

if the cams are the same, why is the turbo fitted with stronger springs then? is the RPM higher with the turbo? valves are the same size to, right? as i understand it, the only differences are a slight difference in cam profile (not lift) and sodium filled ex valves.

eman930

Valve springs are stronger because of boost

lee101315

+1.

My personal experience is that the time investment/cost to power gain ratio sucks.

chrenan

I put an 09R (late N/A) cam in when I did my head gasket a few years ago. Feels like a little more pep up high in the rev range. If you're in there doing other work already you might as well put one in, I'm not sure I'd pull things apart for no other reason though.

Thom

Late NA cam in turbo won't make a big difference when using a KKK hotside as the back pressure will prevent most of the gains in flow that normally go with a higher amount of valve overlap.
Increasing boost will increase back pressure and the parachute effect felt from the driver's seat will increase.

It would be interesting to know the amount of back pressure on a fully stock engine running its ~10psi of stock boost. If back pressure is barely higher than boost, then I would think that (new) NA valve springs would work just fine considering the turbo cam is (slightly) "softer" than the late NA cam.

boost feen

If anything a later 09 or 10 (2.7 cam) is just a lower mileage newer cam with less wear and with the added bonus of getting a slight HP bump after 3K rpms