The best all-around single disk clutch I'm aware of, for durability and holding power, and all applications except maybe hard-core drag racing is by South Bend. It's their full-face model with the Kevlar disk. Here's a link:
http://www.dxdracingclutches.com/supra.html
Click "Skip Intro", then "Catalog", then "Toyota", then "Supra"
"
Toyota Supra - Street Series", Part# K922 - TZ Series Stage 2
You might ask why I believe it's the best single disk clutch available for the Mkiv Supra Turbo, for most applications, and my response is that I've seen almost every other single disk clutch break or prematurely wear out in various conditions. In other words, most of the others have serious weak point(s). Note that a common weak point is the ability to stand up to regular old stop-and-go rush hour traffic. For example, it saddens me to say that I personally saw an expensive carbon-carbon clutch reduced to a pricey pile of carbon dust in the bottom of a bellhousing simply because it was daily driven in slow stop-and-go rush hour traffic (slipped as normal when speeds were slower than 1st gear) for a couple of months. I've also seen a carbon-ceramic clutch disk chew up a brand-new oem flywheel with one single drive up onto a steep set of ramps, slipping the clutch for control. Note that an oem clutch would have handled these two situations without any difficulty at all...but of course the oem clutch setup does not handle the power. South Bend's kevlar disk will stand up to all of that (without destroying your flywheel) AND aggressive road course or drag strip driving AND it will hold 520rwhp+ with ease.
Use the South Bend Kevlar clutch (
$565) with an
RPS 'Cyn-R-G' flywheel (2nd item on the page, Part#RP BF-22170) (~$425) (again,
as long as you don't mind the additional tranny noise), with new bearings&snap-rings (from Toyota) and you're set. Do
not re-use the oem flywheel, the existing bearings or the existing snap rings. If you decide not to go with a lightened flywheel, do NOT re-use the old flywheel - get a new one from Toyota (~$400). Your old flywheel will have heat spots and will not work properly because of it. Note that the overall combo is just over $1k+shipping, and is MUCH cheaper than most multi-disk clutches...
Here's a clutch install article, but you have to skip past the outdated&biased 'evaluation' section in the beginning. Start reading with this paragraph:
"
Prior to putting that nice polished looking flywheel and pressure plate in your car, make sure you sand the metal with some 100 grit sand paper to ruff it up. This will help the surfaces mate once installed..."
http://www.mkiv.com/techarticles/clutch/index.html
I'm not sure I offered him any advice...I simply corrected an error in what he was telling his customer(s). I guess my advice to him would be to research and be 100% sure before you pass along critical information...because when you find out your installer has been 'BSing' you, your first thought is that he's trying to rip you off (at least, mine would be). Whether he's actually unscrupulous, or he just made an honest mistake, we may never know. Either way he failed in his responsibility to be MUCH more careful before he passes along inaccurate information like that.