Chevelle updates

[VintageMusclecar]

Here's some interesting math for those who care to know;

You can calculate your (near) optimal elapsed time by dividing 1320 (length in feet of a 1/4 mile) by the observed trap MPH.

For example--

1320/105 mph should result in an optimal e.t. of 12.57.

1320/110 mph should result in an optimal e.t. of 12.00.

1320/115 mph should result in an optimal e.t. of 11.47.

Note that my last pass ran 115+ mph, but the e.t. was only 12.25, which is .78 off the pace--and that's with severe clutch slip through most of the run. The car has the potential to trap at least 118-120+ MPH without the clutch slipping.

Using the Wallace racing calculator with the following (estimated--do not have actual data on hand for the day) weather parameters:

ET (1/4): <span style="font-weight: bold">11.47</span> (which is the theoretical optimal e.t for my trap mph)
MPH (1/4): <span style="font-weight: bold">115</span>
Weight : (in pounds) <span style="font-weight: bold">4050</span> (had the gas tank almost full this time)
Elevation : (in feet) <span style="font-weight: bold">1000'</span>
Temperature (F): (in Degrees) <span style="font-weight: bold">75°</span>
Relative Humidity (%): <span style="font-weight: bold">80%</span>
Actual Barometer (in/Hg): <span style="font-weight: bold">29.8</span>

We get the following data:

Your HP is 523.06 from your ET
Your HP is 523.78 from your MPH
Your HP Correction Factor is 1.09
Your Grains of water is 108.29
Your DA (Density Altitude) is 1,474 feet
Your DA (Density Altitude) is 449 meters

As you can see that's about 90 HP shy of what the engine actually made on the dyno, but two things have to be taken into consideration:

1) That was not an optimal pass--more on that in a moment.

2) The Wallace calculator shows observed HP while the dyno figures show corrected figures based on SAE weather standards.

SO--let's *assume* (I hate that word) that the car can trap 118 MPH on an optimal pass.

Re-calculating the figures using an 11.18 e.t. @ 118 mph (1320/118 = 11.18), we come up with the following;

Your HP is 554.55 from your ET
Your HP is 565.85 from your MPH
Your HP Correction Factor is 1.09
Your Grains of water is 108.29
Your DA (Density Altitude) is 1,474 feet
Your DA (Density Altitude) is 449 meters

These figures are much closer to the actual <span style="font-weight: bold"><span style="text-decoration: underline">observed</span></span> power figures on the dyno.

Making the HP is relatively easy. Putting it all to optimal use is the *%*@$@^# hard--AND expensive part...esp. when you're trying to do it with a stick in a two ton plus tank. [img]<<GRAEMLIN_URL>>/smirk.gif[/img]

FWIW, if it wasn't for the fact that I would have to buy ANOTHER high-$$ driveshaft to make it work, I'd have a 400 Turbo in the car this week (I have a good core stashed under my workbench).