Good Day, American Pilsner uses 66% pilsner malt and 33% Rice. "Minute Rice" can be added directly to the mash, since it has been pre-cooked.
Normal rice needs to be "cereal mashed" cooked with a lot of water near boiling for 20 minutes.

Another formula is 60% pilsner, 20% rice, 20% corn meal. The corn meal need to be "cereal mashed" also.
This was the formuls for Hamm's, and Olympia beer back in the 70's

You can "cereal mash" the adjunts with half the Mash water, in the bag, in the kettle. Then add cold water the kettle to get the infusion temperature, then add the pilsner, and mash as you want.

Have fun, BeachBum made beer like this as "American Malt Liquor" (low hops) http://www.biabrewer.info/viewtopic.php ... alt+liquor

Good Day Again, If you understand "points per pound per gallon" (an Old system for recipes)
the 60/20/20 formula has 54.5 points/pound. (60% of 32pts for pilner/20% of 39pts rice/20%of 38pts for corn)
the 66/33 formula has 34 points/pound. (66% os 32pts for pilsner/33% of 39 pts for rice)

If you want 5 galllons of 1.040 O.G. Am. Pilsner, that would be 40pts times 5 Gallon or 200 points.

the 60/20/20 would need 200/54.5 or 3.7 pounds.
the 66/33 would need 200/34 or 5.9 pounds.

My experience with using adjuncts with BIAB is that maize in particular seems to produce a freer running mash that squeezes out to a smaller weight of dryer residue, with great efficiency.
Apart from the Evil Malt Liquor I've made a few rice and maize beers such as Cream Ales. My favourite adjunct is ordinary supermarket Polenta, used at the ratio of 80% malt to 20% dry weight of Polenta, which is then boiled to a mush in a stockpot. I nearly always do a cereal mash as follows:

I generally let the mush cool down to around 50 degrees, add about half a kilo of the dry base malt that I've stolen from the main grain bill, then raise it gradually to boiling again, stirring well. When you hit around 70 degrees the base malt zaps the starch in the mash within a couple of minutes, it's amazing when it happens. Then I pour the whole pan of "cooker mash" into the main mash. There are online "mixing" calculators that allow you to hit mash temp spot on.

Half a kilo of base malt seems to do the trick, that Alpha Amylase must be the Pit Bull of all enzymes