As far as I'm concerned there's no such thing as overkill on the guages. Some are unneccesary for a certain application and they can certainly be installed in some horrible looking ways but I don't think you can ever know too much about what the car is doing.
The more real data you have the less guesswork you need to do when you're fixing a problem. How many times have you read a thread about rough idle problems and you chase all over the TB checking on the ISC and TPS and coolant sensors and whatever when a FP guage would show that you're overrunning the FPR. Or leaning out and knocking under boost (or worse) and people guess everything under the sun when a FP guage might also show that the FP is dropping off on the top end and not staying 1:1 with the boost.
Furthermore, the more you realize how crappy all the stock guages are the more you want something decent. The water temp and oil pressure guages are both junk. My stock guage has two positions, on a good day, my aftermarket one continually moves with rpm and ranges from 10psi to almost 100psi, plus I can tell when my oil is a little low because I can see minor flucuations in the oil pressure. Water temp is the same thing tho I haven't had an aftermarket water temp guage in a dsm yet, but I know from other cars the water temp will move up and down with the thermostat activity, not wait til the car is overheating to let you know. The stock boost guage is obviously ridiculously useless. We don't even have voltmeters and we're notoriously hard on alternators, most of which are also junk, the replacement ones that is. My voltmeter has paid for itself probably 5 times on one tow bill alone.
The speedo, fuel level and tach are the only decent guages and the tach is too slow to keep up with fast cars in the low gears.
WB 02 is awesome for tuning. It's almost a must have right after a real boost guage. An EGT guage is great on a long uphill pull when you're hundreds of miles from home on crappy gas and you know when to back out of it before the smoke starts. Trans temp is very important on a AT car. Lately I've even been finding myself wanting a water pressure guage to figure out if I'm losing some coolant because I'm lifting the head and pushing coolant under boost.
I have no less than 9 aftermarket guages on a shelf waiting to keep an eye on my investment. The trick will be installing them in easy to view places without looking like ass, I've got that figured out tho. Anyways, my rant is over, back to your regularly scheduled thread.
