I've read that if and when using OEM ITR cams and stiffer valve springs such as TODAs, that there will in fact be a loss of power.

Can someone explain this to me in plain English and let me know if there are any dangers to running stiff valve springs with mild cams.

What about using Toda Spec As with the TODA valve springs???

 

The loss of power occurs because of the additional force required to open the valves due to the stiffer springs. The springs are in effect making it more "difficult" for the engine to turn the cams.

There isn't really a reason to run TODA springs with stock cams, as stock springs or stock/portflow combo with titanium retainers can easily handle OEM ITR cams to RPM's that are well above where those cams make power.


[Modified by Spec.R 00-0123, 12:19 AM 4/20/2002]

 

what RPM do Toda A's stop making power?

 

I've seen different numbers on different graphs depending on the setup, but by 9100 RPM (which many people run to on the ITR/Portflow combo) both ITR's and Toda A's should have already peaked.