Brewingaround,
Your recipe calls for 17lbs 14 oz of Pilsner. Using Lazy Larry's conversion that would be 13.125 pounds of LME. That seems like a ton more than I remember using in the past. It is way more than the BYO recipe too. I know you are all grain but does that seem correct?
My measured mash efficiency for this years recipe was 71.5%. It's not going to be a direct conversion. You do not have to be concerned with mash efficiency.
We need to do a little math.
Using Briess Pilsen Light DME with 1.043 PPG. Assuming a 6 gallon batch, which is what I brew. We need to get to 1.070 for the pre-boil gravity.
1.043 (PPG) x 6 (gallons) = 6.258 LBS DME.
1.070 (target) - 1.043 (current) = .027 (additional needed)
(.027 (additional) x 6 (gallons)) / .043 (PPG) = 3.767 LBS DME
6.258 + 3.767 = 10.025 Total DME needed.
Working that the other way to make sure I did that right.
10.025 * 43 = 431.075 / 6 (gallons) = (71.84 / 1000) + 1 = 1.071 (pre-boil gravity.)
/***** EDIT *****/
Briess Pilsen Light LME only has a potential of 1.036.
That result is 11.8827 LBS LME needed.
/***** END EDIT *****/
That was the long way around to get to that answer. I checked it in BeerSmith just to be sure.
When you add the honey at the end you have to make an additional adjustment. Depending on the potential of the honey, you may need to add more. I used 3.5 pounds of honey this year. The two previous years I only used 2.5 pounds.
Your target original gravity should be around 1.100.
Hope that helps.