Here's a good explanation of DCR:

http://www.empirenet.com/pkelley2/DynamicCR.html

And a calculator that will give you your DCR and your Boost CR:

http://www.rbracing-rsr.com/comprAdvHD.htm

 

wow i would have thought better #'s for that motor. i bet there is somethign not right though. that thing should have some torque to at least get you in the 13's imo.

 

Wow, something isn't right, I think that's been established. My 408, even with stock iron heads, truck intake, a 2800 converter and 4.10's ran 7.8X's 1/8th mile naturally aspirated, which is around a 12.20 or so 1/4 you've got to have more in it. Granted i'm a rcsb 2wd but ****, 14.89 isn't right, I hope you get it figured out.

 

Well I'm pretty sure that my low DCR is to blame. I read the article posted above, and my DCR is actually about 7.02 according to that calculator. The article says that ideal is between 7.5 and 8.5. Knowing that makes me feel a lot better. A turbo should really wake this motor up.

I put the numbers into the other calculator linked above and got 6.77:1 DCR, corrected for altitude (1200 ft) and rod length. My dynamic stroke length is 2.83", so I'm losing a TON of the stroke length (and a TON of torque) due to timing events.

Putting 15 psi into the calculator gives me a DCR of 13.7:1, 20 psi gives me 16:1.

The good news is that I think I'll be able to run somewhere between 15 and 20 psi every day on pump gas. The bad news is that I am impatient.