yeah that makes sense, sorry bout that, dont know where my brain was there. Too much yard work, lack of oxygen to the brain I reckon....lol I believe I was confusing "backpressure" with headpressure.... opps, of course there would be less restriction using larger diameter pipe, if anything, the excessively oversized pipe would increase the head foot limit of your pump, as the pump curves and stated head limit are based on backpressure which decreases with larger diameter pipe. only problem you could run in to with dramatically oversized pipe is that you would be operating your pump at its peak running capacity, you would want to create a little extra backpressure at the discharge with a ballvalve so as not to burn out your pump prematurely...
But I do think that the sweeping elbows make a big enough difference in my books, and wallet.

"Now to remove my foot from my mouth...."gota get off the crack....