427w back from rebuild with dyno results

[eschaider]

A couple more thoughts on correction factors for inquisitive minds:

The primary reason a correction factor is employed is to compare testing performed under different atmospheric conditions, high altitude (Denver?) vs low altitude (Coastal Cities) including ambient air temps less the impact of humidity. The correction factor will contain a temperature, barometric pressure and an efficiency percentage that is used to bring all test results to a level playing field.

There are two different correction factors that Detroit has used for 'normalizing' dyno results. One is the SAE J607 correction factor that corrects to 60˚F and 29.92 inches of mercury. The second SAE correction factor is J1349 which corrects to 77˚F and 29.31 inches of mercury.

In both cases wet bulb readings are used to calculate a saturated, current and corrected vapor pressure. The corrected vapor pressure is then subtracted from the observed barometric pressure because this pressure in the ambient air is attributable to water vapor and not air (remember the 10 lbs per minute per 100 HP metric) This methodology will yield corrected barometric pressure.

The corrected barometric pressure is used to calculate the correction factor for each standard. Once the correction factor has been determined the observed dyno power is multiplied by the correction factor to get the corrected power output.

Now for those inquiring minds the actual correction factors are calculated as follows:

J607 Correction Factor Calculation

........CF= [(29.92/Corr Baro)^(1.2)*{(Inlet Air Temp+460)/(520)}^0.6]


J1349 Correction Factor Calculation

........CF= 1.18*[(29.31/corr Baro)*{(Inlet Air Temp+460)/(537)} ^0.5]-0.18

The easiest thing to remember is cooler air and higher barometers produce more power and hotter air and lower barometers produce less power. This is why legit shops use correction factors to normalize measured power irrespective of atmospheric conditions at the time of the test.


Ed

[tortuga]

Mc cleod
Anyone care to xplain how the heck this works?

[Gaz64]

That is a dry twin disc clutch. Works with the same principle as multiplate wet clutches in Automatics or motorcycles. The "Steels" are the driving member, the "Frictions" are the driven member.
The more plates you have, the more torque capacity the clutch has. Automatics have 6 or more plates per stack, since they need to get the torque capacity in a small package.

[Tommy]

Originally Posted by Gaz64

That is a dry twin disc clutch. Works with the same principle as multiplate wet clutches in Automatics or motorcycles. The "Steels" are the driving member, the "Frictions" are the driven member.
The more plates you have, the more torque capacity the clutch has. Automatics have 6 or more plates per stack, since they need to get the torque capacity in a small package.

Let me be sure I've got this. The black ring attaches to the flywheel and the metal disc between the two friction discs so those three metal parts turn as one. When the clutch is engaged, the forward friction disc presses against the flywheel and the aft friction disc presses against the metal disc. Is that correct?

[tortuga]

Here it is...

[hauss]

Originally Posted by tortuga

Here it is...

I love your clutch but you may want to take a closer look at your ring gear.Not sure if it is the picture but bottom right side looks like worn teeth.

[tortuga]

Originally Posted by hauss

I love your clutch but you may want to take a closer look at your ring gear.Not sure if it is the picture but bottom right side looks like worn teeth.

I think that is an optical illusion.

[Gaz64]

Originally Posted by Tommy

Let me be sure I've got this. The black ring attaches to the flywheel and the metal disc between the two friction discs so those three metal parts turn as one. When the clutch is engaged, the forward friction disc presses against the flywheel and the aft friction disc presses against the metal disc. Is that correct?

Effectively, yes.

We now have 4 friction faces (2 clutch plates), so all 4 faces will start to slip at the same rate as the pedal is depressed. The opposite in reverse as the pedal is released.
The steel plate in the middle is a floater, just like any "steel" in an Automatic.

[tortuga]

getting excited