I can see he's done a major rewrite of the sound engine, so why can't you. The implementation of that rewrite might not be perfect yet, but the rewite has occured nevertheless.
Has it occured to you that the sound system might not be constrained by the sound system anymore, but by some other aspect of LFS, one that perhaps might need an incompatible patch to fix? Has it not occured to you that the new system is already vastly more powerful than the old one, albeit in it's early stages of use? Look at the air intake noise, the turbo whine, the gear change clonk, the starter sound. I wouldn't be surprised if there is room in the system for brake noise as well (when brake temps get modelled). The engines might sound too alike AT THE MOMENT, but that doesn't mean they always will...
Just because YOU don't like the current sounds doesn't mean the underlying system isn't any better. I appreciate that we all have different tastes, different ears, and different requirements for LFS, but trolling for the sake of trolling (as a number of you are, in my opinion) isn't getting any of us anywhere.
If you want LFS to sound better, suggest some stuff (as some of you have), and give it time to be coded/implemented. Scawen DOES read our suggestions, and the ones he thinks have merit will likely get looked at. We can't ask for any more than that, and I don't beleive we get any less than that either.