On the matter of dyno's and such...
As mentioned previously, it's all about run "A" vs run "B" with the two representing either SAME setup and the two (or more) runs netting consistent numbers when one is concerned with the ability of the dyno (whatever brand it may be) to MEASURE a given value of performance repeatably. That's always hurdle number 1.
...when talking about relative IMPROVEMENT in performance from run "A" vs "B" then the dyno MUST first be capable of the above... THEN the two runs with varied setups will provide the INCREMENTAL improvement from one run to the next. THAT'S what every testimonial in the earlier post is praising. Good deal. Sounds like the dyno you are on is in and of itself "capable" of accurate, repeatable results.
Now the STICKY part...
When we begin to compare ABSOLUTE NUMBERS between different cars on DIFFERENT DYNO'S, the entire discussion takes a major dive. Issue here is, each dyno may be capable and repeatable, but NOT necessarily CALIBRATED (nor designed) to READ (or MEASURE) the same values inherent to it's function of ascertaining performance. The solution is two fold:
1) Get a BASELINE value on whatever dyno you are running with a STOCK setup (with "known" values relative "known" or "proven" dyno models) and then provide subsequent data from runs AFTER modification...
OR
2) Get comparable numbers off the SAME dyno for the cars being compared. (Preferably under consistent conditions... climate, elevation, etc...)
Of course, the ultimate objective of any dyno (used correctly or OTHER than for out-n-out dyno-shootout purposes) is to aid in the TUNING PROCESS, or otherwise provide a relative performance number for approximate comparison purposes, especially when different dyno's or conditions are involved.
Everyone should also understand that dyno's can be "set up" to read differing values relative their calibration or initial parameters which can often be "off-set" to compensate for temperature and elevation, etc... or even reflect "crank" HP as opposed to WHP with pre-assumed parasitic loss values entered into them.
Finally, I have had MANY MANY runs on dyno's with motorcycles, and in year over year runs on the SAME DYNO in similar conditions with the same bike, had BOTH perfectly consistent (within ONE HP of each other) results AND seen upwards of 5~10% in other instances. Also, running on "steady-state" dyno on true eddy current -vs- basic power "sweep" runs on a drum, I've seen better than 20% variance with the same bike with nearly same tune. One bike I had ran low 150's repeatedly until I was at a "stunt-show" with a DYNO-CONTEST and it ran 178WHP on that one. I don't think so.
An additional consideration (especially with a "drum-sweep" run), you have to realize that the PEAK horsepower value is often a "momentary BLIP" in the chart or reading, and NOT representative of your power under the curve in the meat of where you actually DRIVE and USE it. (Generally at the TOP of the RPM band, and noted as a "spike" in the curve) Keep in mind that TORQUE is what accelerates you... and the earlier and more abruptly it comes on... along with HOW QUICKLY the motor can SPOOL through it has a big bearing on how HARD your vehicle pulls and strong it really is in real world driving. I've had bikes that "only" read lower 150's in absolute HP at the rear wheel, but absolutely WALKED all over bikes that could hit upper 160's and even lower 170's on the same dyno!
LASTLY, NONE of this is to take any credit, credibility, nor recognition away from anyone's numbers!

The near 300 numbers posted in here by several are fantastic for these cars any way you slice it, and definitely show that there is some substantial modification and tuning going on out there... much to the credit of those who take the time and effort (AND CASH!) to achieve them! KUDOS!
...now... just as soon as I get my Supra back out of the shop... I'll get some baseline runs with the current setup WITHOUT the meth/water injection I need to REALLY turn up the wick... and we'll see how far into the 400's I can get at a modest 17~18psi on pump gas.
-crisp
