you want reliability? Get a geo metro :beer: :drag: :stupid: :beerchug:
KGB Supra said:NewZ,
Wow, answering each of your questions in detail would lead to one seriously long post!!
Thought I would take a brief stab at answering some of your questions at a high level:
1. Price: Cars in decent to good condition typically run anywhere between 20K to mid 30Ks on average depending on year, mileage, transmission preference. Rare colors (such as Royal Sapphire Pearl and Quicksilver) also demand a higher premium.
2. Which year better for responding to mods: Basically, the cars have remained the same from 93-98 with the exception of the introduction of OBD2 in 96. Since modding OBD2 cars usually leads to more issues of warning lights, ect....being generated, some people prefer to work/mod the OBD1 cars. Not that big of a deal, either way, though.
3. Tranny: The auto tranny is pretty tough, and capable of supporting close to 500rwhp before needing to be beefed up. The 6-speeds are considerably tougher. However, while not overly common, the synchros in the 6-speed trannys have been known to fail (particularly in higher mileage units). Until recently, the 6-speed tranny (Getrag unit) was a replacement only item and pretty expensive at that (@5K new or 1.5-2 for a used unit). Recently, some shops have developed replacement parts for the 6-speed units, but I do not know how successful efforts to rebuild the Getrag tranny have been.
4. Clutch: Unfortunately, this has proven to be the first weak link in the Supra drivetrain. Typically, the stock clutch will handle BPU power levels (350-400rwhp or so) for a while before finally giving up the ghost. There has been a recent increase in the number of newly developed clutch choices, though. Some of the more popular clutch choices for higher HP applications (400-700rwhp+) are (in no particular order):
O.S. Giken twin and triple disc
TRD twin disc
RPS Stage III
Arizona Single disc from Wide Open Motorsports
5. Reliability: Obviously, this will be somewhat dependent upon what level of modification you intend to take the car and more importantly, the competency of whoever actually tunes it. However, this is one of the Supra's greatest attributes. Toyota has earned is reputation for building quality, reliable cars and the Supra was it's performance flagship. Virtually every component of the driveline was seriously overbuilt.
6. Order of mods: Seems you already have this one right. First mods recommended are a boost cut defensor (like the Greddy BCC), Downpipe, exhaust, and boost controller. These mods (and an aftermarket intake) constitute BPU (Basic Performance Upgrades) and will typically net you 375-400rwhp.
Commonly recommended power mods after BPU would include:
Lightened Underdrive pulley (some controversy over this mod)
Front Mount Intercooler
Obviously, there are more options available, but these are the most common choices.
7. Targa: Not typically known to be problematic for leaking. However, sometimes the rubber strip/lining might get worn and need replacing. Think there is a write-up on doing this on the FAQ at MKIV.com. Never had a problem with leaking targa tops on either of my MKIVs (owned a 93 NA before picking up my current 93 TT).
Also, the targa is held in place by several bolts. I know I have seen several threads on this board where the bolts have stripped. YMMV.
8. Exhausts: Selection here is largely a matter of personal preference. The Tanabe G-Power Medallion is a high quality unit that looks pretty stock. Also happens to be one of the quietests Aftermarket units available (if that is your thing). Me, I am running the Tanabe Racing Medallion (pretty much the most obnoxiously loud one of the bunch).
Lots of different aftermarket options to choose from, though. To each his own.
9. Electrical gremlins: Again, you will find that this car is extremely well-built. No common issues that I can remember.
All in all, the MKIV is a great car. However, be forewarned that you will end up sacrificing a good bit of that low-end V8 grunt when switching to a FI 3.0 litre I6.
Looks like I ended up writing a book, anyway. lol. Hope this has been somewhat helpful.
Good luck in your search!!