Regression analysis of 1/8 mile vs 1/4 mile trap speed

Using data collected at dragtimes.com, a regression analysis of 1/8 mile vs 1/4 mile trap speed was performed. Chosen vehicles were Mitsubishi Lancer Evolution and Subaru Impreza WRX and STIs as they are AWD, have forced-induction, are about the same size and weight and present similar frontal areas.

Based on 100 observations, significance F is 2.3*10^-114. P-value was less than 0.05 thus we are forced to reject the null hypothesis.

y = 1.32024246643736 * x - 5.40977006570778; where y is predicted 1/4 mile trap speed and x is observed 1/8 mile trap speed.

Detailed graphs found here.

Building upon the LRT formulas as put forth by Jeff Lucius, we can estimate horsepower given the equation:

hp = (mph / 215.39)^3.3135 x weight (lbs)

Torque values

Why is it so difficult to get high torque values out of a 4 cylinder engine? Can't we keep increasing the boost assuming that fuel quality is not a problem?

A piston's acceleration does not follow a sinusoidal waveform. Plotting instantaneous torque with mean torque vs crank angle rotation, a 4 stroke, 4 cylinder engine would typically experience almost 4 times more than mean torque values at peak and almost 2 times below of mean torque through each cycle of rotation. On a dyno this is averaged out. On the other hand an even-fire V8 or V12 would go through lower extremes through its own cycle.

This is why I believe it will not be easy to get "torque monsters" out of 4 stroke, 4 cylinder engines as compared to V8s and V12s with similar swept displacements. It ultimately comes down to engine design and materials.

Apple price gouging

Using current spot exchange rates of SGD 1.43 to USD 1, the MacBook Air 1.6 GHz at USD 1799 should be priced at SGD 2573. Yet it is going for SGD 2988 here, a USD 290 premium. That's 16% of the retail price! If that's not ridiculous enough, the 1.8 GHz model is USD 3098, but in Singapore it goes for SGD 5088 or USD 3558, a mind-blowing USD 460 difference!

Moral of the story: buy your Apple products elsewhere.

0 to 160 km/h test

0 to 160 km/h test
Originally uploaded by crufty

Bought a RaceLogic PerformanceBox recently and have been having some fun with it. It measures vehicle performance using GPS. Overall the hardware is pretty decent, although the software is a little clunky and could be better. For instance, the main icons and menus take up 1/5th of the screen real estate.

Anyway here are some tests done on an full-weight Evo 8. Figures include gear shift times:

130-160 km/h: 2.17s
120-150 km/h: 2.10s
110-140 km/h: 2.3s
100-130 km/h: 2.15s
90-120 km/h: 2.08s
80-110 km/h: 1.92s
70-100 km/h: 1.85s
60-90 km/h: 1.79s
50-80 km/h: 1.80s
40-70 km/h: 1.72s
30-60 km/h: 1.38s
20-50 km/h: 1.33s
10-40 km/h: 1.30s

4th gear:
140-169 km/h: 2.31s
130-160 km/h: 2.15s
120-150 km/h: 2.07s
110-140 km/h: 1.98s
100-130 km/h: 1.96s
90-120 km/h: 2.06s
80-110 km/h: 2.58s

GT35R, no alcohol/nitrous/race gas/water injection, 1.7 bar boost, street tires.

Spam Sieve statistics

Sick of spam? If you're a Mac user, you might want to check out SpamSieve. Have been using it for years, and it's one piece of software I would gladly pay good money for. The author regularly updates the software too. Below are some statistics accumulated since my last reset in 2005.

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Filtered Mail
2,351 Good Messages
23,698 Spam Messages (91%)
31 Spam Messages Per Day

SpamSieve Accuracy
15 False Positives
202 False Negatives (93%)
99.2% Correct

Corpus
571 Good Messages
1,307 Spam Messages (70%)
91,175 Total Words

Rules
676 Blocklist Rules
982 Whitelist Rules

Showing Statistics Since
11/22/05 18:47