Discussion and questions related to the course How to Degree a Cam
My VCT gear has died and i´m not keeping it, because they are way too expensive and prone to fail and later i plan to install Tomei or Kelford Cams since i already have upgraded valve springs and retainers, so:
1) i´d like to know if i can replace it for an adjustable cam gear
2) Should i make adjustments (retard or advance) the cam or leave the ajustment to 0* ?
3) Should i buy S13 SR20DET Cams (non VCT) or S14 cams since they have different centerlines, IVO and IVC timings ?
I might not be able to answer your question fully but here's my 2 cents.
Personally I'm not overly familiar with the SR20 NVCS - it may well be possible to fit non NVCS cams or pulleys, block up the oil feed and disable the function in the ECU but if you'd like to ditch the VTC system consider fitting a non-NVCS cylinder head complete with cams, the NCVS heads a pretty sought after and can command a premium.
Adjustable vernier pulleys are available for for the SR20 and should fit both the non and NVCS cams however leaving them at 0 negates the point having adjustable cams. If you have the option to, perform a timing swing test on a dyno - one pull with the cams fully retarded and 1 full advanced. you should see peak power and torque move around the rev range giving you enough information to make a decision on what would suit your uses better more power at the top end or more in the mid range etc. its worth pointing out that NVCS will give you the best of both worlds.
Regarding S13/14 cams having different profiles (IVO/IVC points, centerline etc.) it again comes down to what suits your requirements as this will also effect the torque profile to either give better mid or upper range performance, try plotting the cams position on a graph as this will allow you to visualise the cam profile a little better. There should be plenty of information out there from people that have gone through a similar process to you to better inform your decisions.
I'm sure someone with a bit more recent SR20 experience will be along soon.