5500 is too soon to shift. I shifted the stock 6.0 at 5900 or 6000 depending on gear.

 

Yep, with my HPP3 I was shifting at 5900 or 6000 also and it was still pulling up there. Problem was the springs with boost. That problem will be gone when I pick it up tonight. 2 more lbs of boost, higher rpm shift points, and hopefully a nice gain in power!

 

how does boost effect valve float?

anyone?

 

anyone?

 

boost will try and push the valve open so it effictivly reduces spring presure.

 

got any further info on that? maybe a link I could read up on?
I was always under the impression it was mainly an rpm thing, I guess I learned something new today.

 

VALVE FLOAT

Definition: A high-rpm engine condition in which the valve lifters lose contact with the cam lobes because the valve springs are not strong enough to overcome the momentum of the various valve train components. The onset of valve float prevents higher-rpm operation. Extended periods of valve float will damage the valve train.

 

here's a good read, harmonics might be a factor as well:

http://www.hotrod.com/techarticles/1...am/index1.html

I still can't find anything on boost induced valve float......

 

In a boosted engine, you have pressure (boost) pushing against the intake valves at all times. The more boost, the harder it is to close the valve. Imagine how much volume of air is being "forced" into the cylinder through that intake valve, it doesn't let up, then imagine the valve trying to close with that air passing through. Just gets harder at higher rpm.
Under NA, the engine just sucks air, under boost its being forced.
My turbo VW bug had valve float at just 6 psi with stock springs. Felt like it was hitting a rev limiter. Changed the springs, and turned it up to 14 psi no ploblem.

 

sounds good to me, I've just never heard of that before and can't find any professional talk of it either