Long overdue cam upgrade on the silver bullet - while yes, this is a 290 degree cam, the *actual* duration is a lot less. What I mean by that is, although this cam is 286/290 degrees at 0.010" lift, the more important number is at 0.050" lift, when it actually starts to let the valve flow some air which is 225/229 degrees. So it's not a wild race cam but has a nice lumpy overlap to sit and listen to on the grid!
Unfortunately, due to NZ being in lockdown, we can't get the car onto the dyno just yet to see how much gain we'll make with this cam but that will come!
The aim with this is not to necessarily to increase torque, but to widen the curve as much as possible. While the factory cam works well, the profile is extremely mild to provide a smooth idle and relatively responsive low-end but uses rather aggressive cam timing to retain some high-end power. This makes for quite a peaky torque curve and sluggish to come on boost.
The new setup uses a profile with more duration designed to the 5000 to 8000rpm range we typically use on the race track which, coupled with adjustable cam gears to correct timing, should give us a nice broad torque band over this rev range... plus the idle isn't half bad either!
0 Comments