Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
- Messages
- 9,644
Well, I am no where experienced as Nick or some of you guys (No pun intended) but my own perverted logic tell me this;
If you build a stock HA motor, and plan on stock boost levels on straight 93, you want the stock HG.
If you change the VE, through better flowing heads, intake, TB, Turbo etc, you can get away with a bigger cam, to get the same or higher BMEP
If you have a stock set-up, you can get higher BMEP through boost or compression, provided, you can get away with it through octane.
In my mind, if you raise the CR at a given boost level, on straight 93 only;
- On a IC'd car, you can add a bigger intercooler to reduce KR tendency, and that "may" work. (Or reduce timing, etc)
- On a HA, (Which we all know is much more sensitive to KR), there is not much you can do, if you run straight 93.
I am making some very gross ass-u-m-ptions here . . . . . .
One other thing we need to remember is the dynamic CR.
In general terms, the folks that run the larger cams have high CR's combined with sufficient octane to gain the BMEP's at the lower range.
Bottom line is:
Many of these decision come down to the purpose, the philosophy of the builder, and the calcs.
Don't focus on static CR only. :wink:
If you build a stock HA motor, and plan on stock boost levels on straight 93, you want the stock HG.
If you change the VE, through better flowing heads, intake, TB, Turbo etc, you can get away with a bigger cam, to get the same or higher BMEP
If you have a stock set-up, you can get higher BMEP through boost or compression, provided, you can get away with it through octane.
In my mind, if you raise the CR at a given boost level, on straight 93 only;
- On a IC'd car, you can add a bigger intercooler to reduce KR tendency, and that "may" work. (Or reduce timing, etc)
- On a HA, (Which we all know is much more sensitive to KR), there is not much you can do, if you run straight 93.
I am making some very gross ass-u-m-ptions here . . . . . .
One other thing we need to remember is the dynamic CR.
In general terms, the folks that run the larger cams have high CR's combined with sufficient octane to gain the BMEP's at the lower range.
Bottom line is:
Many of these decision come down to the purpose, the philosophy of the builder, and the calcs.
Don't focus on static CR only. :wink: