Had a tinker with some basic eq-ing and came up with a definitive truth: 8kHz does not exist in Japan. They cannot hear it, so we get bucket loads of it.
Seriously though, I cannot believe how pivotal it is to the sound. Knocking a heap of it out sacrifices a certain amount of "snarl" at idle and very low revs, but the upsides far outweigh. I did a whole lot of balancing in the bottom end and low mids for some nice results, but it was between 4 and 12k where my preferences became extreme - 4k up significantly, 8k down a lot, 12k up a lot (from flat). Would be interested if others mess around, what results they feel they get.
Also got me wondering if PD should consider re-sampling their samples. ie. tune the playback, mic it, record it. I have seen it work wonders with instruments recorded too "transparently". It is so easy to fall in to the trap of recording as clean as possible, to give all the options for after, then realise that colouring before and colouring after are two completely different things. That is one of the "dark arts" of sound production: what comes where in the chain. The extreme version of this is Portishead recording their drum tracks, pressing it on vinyl (no less), kicking the copies around a bit to scratch them just right, then re-recording from the vinyl playback.
Anyway, I'll stop now, but try some eq people.
Interesting, I'll have to have a play with that. The "mids" usually have the most say in the overall character of a sound, as we hear it, but you're tinkering way up the top there. Makes me wonder if there is more to this sample quality issue, i.e. they're over-compressed and so the highs are all messed up.
I've seen this issue with colouration and recorded instruments, especially (obviously) acoustic instruments, and it's potentially controversial. The issue is that for music recording, you're interested in a particular sound for a particular part of the track, and it's the same every time you play it. Now imagine you have to be able to reproduce the sound of, say, an acoustic guitar from any / all listening positions at any time in the playback, according to the whims of the listener. This is more like the situation in a game, which is interactive, and you can't set in stone how a sound is to be heard.
In that instance, you can either pick a subtle colouration (in the recording) that makes it sound like it's located in a space, and not worry about the lack of spatial variation (because it's deliberately subtle). Or you can use several sets of samples from different positions, and hope that you can cover the required range that way (interpolation of position is a huge issue, though, in terms of how to preserve the actual sounds and not accidentally make new ones the instrument never made). Or you can eliminate all colouring from the recording, and add it back in according to what's going on in the dynamic, synthetic scene.
Obviously, it's impossible to get a recording without a colouration to it, because it's a snapshot of the radiation pattern from a given position in the acoustic field that the guitar is producing. This is also a large challenge for fully synthetic instruments, where it is relatively straightforward to make good approximations of the vibrations within the instrument, but not so much how that then translates to the acoustic field it should be producing, at least in terms of real time technologies. Regardless of the approach you use, you still need recordings for some stage of the process, even if it's "only" for validation of your offline (non-real-time), fully physically-modeled, synthetic instrument, so we still need recordists and the associated support and hardware etc.
There's also a separate layer of complication, in exactly the same vein, regarding the actual "playing" of the instrument - in a car game, that's all the physics inputs like throttle, rpm etc.
As for vinyl, that's definitely an intriguing artistic approach. Stripping back the synthesis beyond the recorded sample level opens up some interesting possibilities on that front for engine sounds, but that's perhaps best left to something that isn't trying to sound realistic.