Originally Posted by
04silverado6.0
212/224 107.5 lsa 106icl
Given the input:.050" Duration: 212/224
LSA: 107.5
ICL: 106
We calculate:ECL: 108.5
Adv: 1
Overlap: 3
Then we calculate the valve events for .050" to be:EVO: 40.5
EVC: 3.5
IVO: -.5
IVC: 32.5
Then we assume the ramp rate for most LS cams to be 25* for opening and closing (50* in total), so we can calculate the .006" duration:.060" Duration: 262/274
Then we calculate the valve events for .006" to be (use the .050" events and add 25* to the opening events and add 25* to the closing events):EVO: 66
EVC: 29
IVO: 25
IVC: 58
Then we find the all important number for end of overlap (don't spray fuel until/after):360 + 29 = 389 Boundary degrees
Assuming you want to zero out the N. ECT table and use use the Boundary table...
1) 580* Boundary Angle works great for most aftermarket performance cams for high RPM areas (starting from say...4000 or 5000 rpm up to 8000). However, you will need to account for the -7* Intake Cam offset and that means your Boundary will be 587*
2) For idle RPM, you will need to add your IPW in degrees to 389* to calculate the Boundary. Assuming your IPW is 2.2 ms, at 800 RPM idle, that comes out to 11* IPW in degrees. 389* + 11* + 7* = 407*
3) For Mid RPMs you will need to blend/interpolate the idle Boundary from 407* to 587*. You will need to experiment here for throttle response, popping, and fuel trims.
Note:
The
7 comes from a hidden table that Verlon found relating to OS's that have a variable cam. When the cam is parked, it pulls 7 degrees out.
If you have an OS that never came with factory variable valve timing, then you can ignore the 7 (assume it is zero).
Tuning:
- This is needed since we are assuming a 25* ramp rate.
- There is also push rod deflection and lifter plunger compression that need to be accounted for.
- Experiment by moving the Boundary lower (sooner SOI) and higher (later SOI)
- CL you want lower fuel trims, no fuel smell, good throttle response for sharp pedal movements, and no popping
- PE you want richer EQ on the wideband and a faster timeslip!
https://www.summitracing.com/newsand...ing-calculator
Here is an example of what I mean. This is a starting point for you and by no means to be considered perfect/done/tuned!