Will running a stiff valve spring (such as Web Cam) result in power loss with stock ITR cams?

 

Yes it will. As for how much maybe 5whp. Do you plan on getting some bigger cams?

-Alan

 

Yeah, I'm going to be putting in the Skunk2's (in a GSR) and knew they had just a little bit more lift than ITR cams (much more duration though) and am basically in valve spring hell right now. I posted the question of which spring and all different answers. I need a valve spring and retainer combo that can handle being revved to 9k, but won't cause a loss of power since the Skunk2's don't have big lift. (This was my roundabout way of asking if I even had to worry about power loss.)

 

Get the Mugen springs then.

 

Big Phat R, very good call. Do the Mugens require titanium retainers, or just a spring swap? I notice King doesn't have a listing on their website for retainers.

 

stock retainers are fine

 

What about power loss with the Mugen valve springs?

 

Any opinion of Portflow inners & retainers w/ ITR outers for this application? It would be a cheaper combo than $460 for Mugen valve springs, however, I don't want to sacrifice reliability.