Magazine Dyno Results for 427 Side Oiler???

Oh, BILLIE!!! I HISS AT THEE, and summon thee forth

Bill S. has actual experience with everything you speak of. Bill can speak about what he's seen and built.

Just don't listen to 180out or Patrick (NoOp5L). All they do is regurgitate public information you've already seen. And as such, they are worth no more than the piles of puke they produce.

I don't think you'll find what you're looking for. But my two cents is to take the as-tested weight from any given 427 Cobra magazine story, and the trap speed in the quarter mile, and use the trap speed horsepower formula to get rearwheel horsepower, i.e., rwhp = (trap speed/234)^3 * weight. Then divide by 0.80 to account for a 20% drivetrain loss. That will give you a ballpark figure, although without any of the corrections for altitude, barometric pressure, etc., that a dyno cell would use.

As far as Pound Pup's comments, he's a strange guy who drinks and smokes too much and is given to these bipolar outbursts. You can take my advice or leave it, likewise as to Bill S., as you wish. It's sad that one of the few on-topic threads in months comes along and from the gun Pound Pup wants to turn it into a flame fest.

180 Out

Oopsie... I was just melting away in the hot tub, (the air actually heated the water today) and Usenet percolated forth among other random thoughts, like "I'm glad I don't have the disease where your skin falls off".

I forgot about my truce with 180 with this post. I guess just I reverted to olden times. I don't even actually know if anyone's listening, but the group suddenly took the tone of "someone farted in here".

If you guys were listening, and are righteously pissed, I retract my statment. It just seemed this place needed a roust, and I know who to poke in the ribs, that's all. No harm was intended. Pat and Bill aren't worthless piles of puke. Continuez donc.

I'm a bit grouchy. All this sobriety makes me damned irritable. And, it's

1000 degrees outside.

Better late than never................ Disclaimer:All HP and TQ figures based on actual rear wheel results +18% for drivetrain losses

Stock, 24,400 mile original 1970 428CJ Mach I (actual dyno numbers as performed 6/06/05)

367hp 394ft/lbs of torque

Stock 3,672 mile 427 "street" cobra w/1-4V (actual dyno numbers as performed 6/06/05)

399hp 467ft/lbs of torque

Stock 22,200 mile original 1967 427 Corvette 1-4V (actual dyno numbers as performed 6/06/05)

401hp 422ft/lbs of torque

Stock 2,400 mile original Hemi Cuda (actual dyno numbers as performed 6/06/05)

418hp 451ft/lbs of torque

Look for the write up in a "unmentioned" (due to contractual obligations) Muscle car magazine some time in January 06

TS#15

Wound Up wrote:

Does that mean that we should make the conversion to fwhp, or that you already did?

My guess is you already did, or else we would be looking at 448 fwhp for the CJ, 487 for the Cobra, 489 hp for the Vette, and 510 hp for the Cuda. Using the equation that trap speed = cube root of ((rwhp/weight) * 234), a 3000 lb car with 500 fwhp (410 rwhp) would trap at 121 mph. A 3500 lb car would do 115. A 3800 lb car would do

111. I don't think anyone has ever claimed those kinds of numbers for a stock muscle car. 367 hp sounds exactly like the number everyone has always suspected of the "335 horse" Cobra Jet.

Those numbers are interesting. You wouldn't expect the extremely oversquare 427 to be so skewed in favor of torque. I'm guessing this Cobra was not running anywhere near the 6500 rpm that the 427 in G Girard's Edelbrock link was pulling. 399 hp at 6500 rpm would require only 322 lb-ft of torque, which would be a huge falloff from that 467 lb-ft peak.

There were only two 4-bbl 427's available in a '67 Vette. One was the

390 hp grocery-getter version. A friend of mine had one of these back in '73, with 4-spd and 4.11's, and it was not very quick. The other was the very rare (20 units total?) L-88, advertised as 430 hp but usually guesstimated at 550.

Wow, 2,400 actual miles on a 35 year old car?! I would love to see that car. And it only put out 17 more hp than the grocery-getter Vette.

Initials "HMM"? I will definitely be on the lookout.

180 Out

Since HP figures were originally taken at the rear wheels, the figures I posted are with the 18% added for estimating the actual "flywheel" HP as would have been how the magazines and manufacturers would have posted them back in the 60's and 70's..

TS#15

snipped-for-privacy@hotmail.com wrote:

To convert rwhp to fwhp you divide by the percentage of what's left after drivetrain loss. If x = fwhp, y = drivetrain loss (expressed as a fraction), and z = rwhp, then:

x - xy = z x(1 - y) = z x = z/(1 - y)

So 350 rwhp with an 18% (18/100ths) drivetrain loss is 350/.82 = 427.

On the other hand, to do the conversion by adding 18% of the measured rwhp would give you 350 + (350 * .18) = 413.

Not a big deal, I guess, but still.

Bill, would you know what type of chassis dyno the testing was done on? I've heard that the DynoJet units will show higher numbers than a Mustang dyno.

-- Ed Nicholson TS # 27

Super Coupe Club of Ontario :

SCCoA message boards : Great Lakes Cougar Club : Greater Toronto Area Mustang Club :

This one gives us the correct answer.

This one gives us the wrong answer

How to check answer * .82 = listed rwhp Stan

Ed,

This would be on an 05 Dynoject with all of the bells and whistles. Two of the cars had their own printouts from a Mustang unit, and both were compared......Less than a 2% difference, one that I chalk up to different temp and humidity (and altitude) from the days we made our pulls.............

TS#15

fast Ed wrote:

If the dyno prints out corrected HP and Torque then barometer, temperature and humidity would be taken care of. Stan

"Bill S." wrote:

Given the limitations of guessing, both figures are well within range, so neither can be called absolutely "correct" nor "incorrect". I've seen drive train losses anywhere from 10-25%.

BW

Stan Weiss wrote: