Acceleration:
Today Chad performed a total of five acceleration runs (actually six, but one was an abort due to monster wheelspin.) The uncorrected results ranged between 14.8 seconds @ 98 mph run to his best at 14.3 seconds @ 98 mph. The highest trap speed from his runs was 100mph. The first run was the slowest, due to some crazy automatic shifting. As far as I can tell, in auto mode the Monte simply creates a single new gear from second and third! If someone else can explain this please give me a call. I'm starting to see UFOs...
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Once again the Monte was traction-limited, meaning if Chad didn't roll very slowly onto the throttle the right rear tire unloaded and disappeared into smoke. For whatever reason, this time around the Monte spun its right tire far harder (compare the previous attempt to this one) and that slowed down his quarter mile times as well as his 0-60 acceleration -- this time out his best was 6.3 seconds (from 6.1 previously.)
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Power:
There are several differences between this run and the previous ones from the equipment and calculation side. The first is the beta G-Tech firmware I'm using now seems to have fixed all previous RPM detection problems, so our power readings should be spot-on. The second is that I'm now using slightly different figures to "reverse" calculate the crank horsepower (which may need to be tweaked -- we'll see), and finally I'm now correcting for atmospheric factors and aerodynamic drag.
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The best raw (uncorrected) output from today's runs was 197bhp @ 4600rpm. That squares well overall with the 190-195bhp we've recorded in previous Monte runs. The 4600rpm power peak also indicates that the RPM calibration problem from the 4.01 G-Tech firmware has been corrected in my beta 4.1 firmware. My best corrected figures with a revised spreadsheet calculate the output to be about 260bhp @ 4600rpm, and 305 lb-ft of torque @ 3700rpm. These are slightly lower due to my revised spreadsheet -- more detail on that in the Corrections section.
Technique:
Not that comes as a great surprise, but the Monte Missile's main limiting factor is traction. Throughout the runs Chad had to roll very slowly onto the throttle so he didn't vaporize his tires. As you can see in this launch comparison, with just a bit too much throttle Chad can easily provoke a gear or two (or three?) of wheelspin. Sheesh!
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Unfortunately, there's not much from the technique standpoint that Chad can do to improve the situation. He was already rolling quite slowly onto the throttle to keep the tires connected. If he's interested in some wrenching there are a couple changes Chad could make to really allow the Monte to hook up:
- Put on better, wider tires in the rear, or use narrower wheels, or some combination of both. The Monte simply needs more traction and the tires are the limiting factor.
- Put in a limited-slip (positraction, for you old-style gearheads) differential to let BOTH tires put power down.
- Replace the Monte's 3-spd auto with a 4- or 5-spd manual. Not only will this greatly increase its quarter-mile acceleration (the current top gear is horribly tall, but still leaves the Monte nearly at redline at the end of the quarter!), but it will also allow better control of the launches.
Finally, as I recommended in the last test Chad really let his motor wind out. Even though his power is starting to drop off by about 4800-4900rpm, Chad shot for 5000-5100rpm shifts (shifting as high as 5450rpm!) since his tranny's three gears got progressively taller very quickly. Quite simply, each succeeding gear was so much taller that we avoided it as long as possible.
How well did that work? You can see the differences very clearly in a couple ways. The first acceleration run Chad chose shift points about 5000rpm, and the best run (the third) he let it run to nearly 5500rpm. When comparing the two runs even though the latter run has a faster ET by only .05 seconds, the trap speed is nearly two mph higher! You can also see this in a comparison of Gs throughout second gear. The higher shift point gave another half-second of acceleration that the successive, taller gear sacrificed.
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Corrections and Other Factors:
As I said this is the first Monte run with fully corrected data. Although it was hobbled by the excessive right-tire wheelspin it overall ran about as fast as last time, especially given that the previous run was a month later and therefore would have boosted power with the more dense air. Here is the data from his best run in original and corrected form:
| Recorded Data | Corrected Data | |
|---|---|---|
| Best Run | 0-1/4 mile in 14.3 secs @ 98mph | 0-1/4 mile in 14.0 secs @ 100mph |