Just for the record, I've also had some surprisingly lousy results with TMY and think it's a highly overrated film. While its sharpness/resolving power is indeed a bit higher, its grain isn't really any better than good old Tri-X, and I much prefer the look of Tri-X's grain (not to mention its more managable contrast).(posted 9069 days ago)If you want near-grainless 11x14s from 35mm, you're going to have to bite the bullet and use a slower film. Old 100-speed standbys like Plus-X, APX 100, and FP4+ will certainly do it. T-Max 100 is even better, but it's more exacting both in terms of exposure latitude and developing precision. (The Delta 100 story is similar. Many folks find it easier to use than TMX, but I've always had better luck with TMX.)
And for TMX, less-active development in diluted D-76 or Xtol will also help. And whatever film you use, you may also want to try agitating less than recommended and slightly increasing the development time to compensate; vigorous agitation tends to promote visible grain. (Another advantage of the old-tech films is that, requiring less chemically active development, they will develop evenly with less agitation. This technique can also be done with TMX, but more additional dev time is needed. If one extra minute is enough for PX or APX 100, TMX will require two or three minutes.)
There's just no getting around that "small" 35mm negative - in my experience, 400-speed films just won't go to 11x14 without significant grain...