New Baseline -- Rebuilt Engine

Background: In September I had my Northstar Engine rebuilt to correct an excessive oil usage problem.   The cylinders were bored out, and new oversize pistons and rings were installed.  After the engine rebuild I conducted a careful 500 mile break-in.  The engine did not use any oil in the first 500 miles.  At 500 miles, I changed the oil and filter, using Mobil 1 synthetic oil and an AC-Delco oil filter.  

Expectation: My 96 STS has fairly consistently run from 0-60 mph in 6 seconds plus the temperature in degrees F.  In other words, at 90F it runs 6.9's; at 45F it ran a best ever 6.37s.   My hope for the tests today, with the temp at 69F, was for the car to run under 6.6s 0-60 mph.

Test: Here are the results of acceleration tests -- note these runs benefit from 'good' conditions with the temperature in the 60's compared with my summer runs in the 80's.   These runs and the historical runs were executed at the same test location, using the Race Technology Ap-22 performance meter.   

For the first test, I ran almost out of fuel, since that is what I happened to have on board when the car was ready.  Noting this, before the second run I filled up with 93 octane from Sam's Club (at $1.28/gallon, a good deal I think), so that run is with a full tank.

 My test location is around 600 ft elevation; other atmospheric details are as noted: 

Oct 07, 2001
First tests after rebuild; 

Low on fuel - 4,022 lbs
** Note: Weight not reset on AP-22, so hp figures are high for this test.**
Temp 69F Humidity 37%
Barometer 30.15 Alt 600 ft
Start Speed 0.0mph
mph    s    g   ft  hp 
10.0 0.92 0.52   6  58
20.0 1.80 0.47  25 107
30.0 2.73 0.50  59 171
40.0 3.69 0.44 109 204
50.0 4.87 0.43 187 250
60.0 6.32 0.30 304 222
70.0 7.88 0.27 453 240

Pk Power: 50.1mph 4.89s 188ft 250hp
Peak G: 17.0mph 1.51s 18ft 0.54g
----------------------------------------
Full Tank of Fuel - 4,125 lbs
* Note: full fuel tank for this run.
** Note: Weight properly set into AP-22 configuration**
Temp 69F Humidity 37%
Barometer 30.15 Altitude 600 ft
Start Speed 0.0mph
 mph   s    g   ft  hp 
10.0 0.88 0.53   6  59
20.0 1.78 0.45  26 102
30.0 2.74 0.49  61 167
40.0 3.72 0.42 112 198
50.0 4.96 0.39 194 229
60.0 6.48 0.29 316 215
70.0 8.09 0.26 470 234

Pk Power: 74.2mph 8.85s 551ft 238hp
Peak G: 15.6mph 1.35s 15ft 0.54g

Now, for comparison please refer to these results from when I had just put in new AC-Delco spark plugs, but with similar temperature, albeit much worse humidity.  Note that the test weight for this one was low on fuel as well:

Baseline with new Spark Plugs
Weight: 4,095 lbs
Temp: 65 F
Humidity: 97%
Barometer: 29.91s Altitude: 600 ft

Start Speed 0.0mph
  mph   s   g    ft  hp 
10.0 0.91 0.51   6  56
20.0 1.84 0.43  27  98
30.0 2.85 0.47  64 160
40.0 3.89 0.40 117 184
50.0 5.21 0.39 205 230
60.0 6.75 0.28 329 206
70.0 8.43 0.25 490 217

Pk Power: 50.5mph 5.26s 208ft 234hp
Peak G: 16.4mph 1.47s 17ft 0.52g

So this appears to be a 0.2-0.4+ sec improvement from 0-60 mph under roughly similar conditions (6.32s to 6.75s), and I think my new baseline, then is 0-60 mph in 6.5s at around 60F.

Also interesting to note that as I filled up with 17 gallons at 6 lbs/gallon or 102 lbs of fuel, I added roughly 0.16 seconds to my 0-60 mph time, or around .01 second per gallon.

Information on the AP-22 and details on other test runs can be found at http://www.caddyinfo.com/ap22review.htm