Dragstrip Test Data
Stock jetting for the 950 Holley HP is 78 jets in all four corners with a 6.5 power valve in both the primary and secondary sides. There are 0.031-inch accelerator pump squirters on both ends of the carb. To learn more about the effects of density altitude on e.t. and mph, see "Horsepower in the Air" (June '05).
| Run | Density
Altitude | E.T. | Speed | 60-Foot | Description |
| Previous Best |
| 1 | N/A | 12.10 | 112.23 | N/A | Before pump upgrade |
| Day 1 |
| 1 | 4,374 | 11.53 | 115.26 | 1.573 | Pri. 79, Sec. 83 |
| 2 | 4,528 | 11.92 | 112.62 | 1.710 | Pri. 77, Sec. 81 |
| 3 | 4,897 | 11.87 | 112.17 | 1.650 | Pri. 80, Sec. 84 |
| 4 | 4,833 | 11.71 | 115.47 | 1.636 | Pri. 79, Sec. 83 |
| Day 2 |
| 1 | 3,234 | 11.42 | 117.47 | 1.579 | K&N filter, best air* |
| 2 | 3,608 | 11.70 | 115.80 | 1.630 | Lean high-speed bleed |
| 3 | 3,725 | 11.63 | 116.48 | 1.640 | 79 to 80 primary jet |
| 4 | 3,995 | Trans broke | | | 81 primary jet |
All runs are listed as observed at LACR's 2,800-foot elevation.
All jet sizes are listed as Holley jet numbers.
*Best Run
Corrected to sea-level pressure: 11.05/121.42 using NHRA correction factor for altitude
This is a graph data-logged using Innovate's Logworks program. The two data points are air/fuel ratio and engine rpm. Arrow one points to the slack rpm curve with each of the three peaks indicating the peak rpm point of 6,500 rpm. The lower purple graph (arrow two) shows the engine's air/fuel (A/F) ratio. Even after reducing the original air-filter restriction, the A/F slopes richer as the car runs down the track. The near-vertical spike (arrow A) is a lean-rich spike the engine exhibited on every pass. This spike consistently jumps between 10.0:1 and 15.8:1 in the span of 0.08 second. Clearly, we still have work to do. The beauty of data-logging each pass is that the engine tuner has an opportunity to carefully study the data, which gives him more information from which to make intelligent tuning decisions.
| Parts List |
| Description | PN | Source | Price |
| Holley 950 HP carb | 0-80496-1 | Summit Racing | 679.88 |
| MaxJet pair of jets | MJxx-2* | Summit Racing | 4.69 pr. |
| nnovate O2 Meter | ILM-1 | Summit Racing | 349.95 |
| Innovate rpm converter | 3726 | Summit Racing | 99.95 |
| Holley air-bleeds | 126-xx-10* | Summit Racing | 27.39 |
| K&N 14x4-inch filter | E-3730 | Summit Racing | 41.69 |
| K&N Flow Control kit | 66-3200 | Summit Racing | 134.69 |
| Wilson 4-hole, 1-inch spacer | 004110 | Wilson Manifolds | 120.58 |
*Note: Substitute the jet size required in the individual part number. For example MJ88-2 equals a pair of 88 jets or 126-55-10 will get you 10 number 55 air-bleeds-odd sizes only.