im getting a ctr/itr cam combo.... i got a ls/vtec motor.. not sure which valvetrain to go with... not planning to rev past 8k... would the stock gsr valvetrain be fine???

 

I'd use ITR springs because of the increased lift of the CTR/ITR cams and just as a preventive measure. You shouldn't have a problem finding a set at a reasonable price. I'm sure some people have used GSR or B16 springs with this setup and haven't had a problem yet, but even with an 8000 redline, I'd rather be safe than sorry.

 

as long as you do not have a lot of miles on your car the stock setup is fine at 8k but if you are worried buy ITR intake springs and move the GSR intake to the exhuast.

k

 

would portflow valve sprngs be too stiff for the CTR cam?

also, at what rpm does the CTR cam stop making power?

 

What if you do have a lot of miles on your engine? What's the recommendation then? tia

 

The recommendation would then be ITR intake valve springs as mentioned above.

 

Just use the portflow inner springs and you will be fine.

When going to bigger cams the GSR intake manifold becomes a restriction around 8000rpm. If you want to effectively rev the engine higher then this you should switch to the Skunk2 manifold. The CTR/ITR makes good power till about mid 8k if you what to go past that then toda/JUN etc.. are required

But that being said i know someone who made 195whp using the stock manifold (ported) but peak power was around 8000rpm and then fell off from there.

k