Joshua

Sounds like a great plan, Josh. If you get there, I would like to come and help out. I've never been, but have meant to go for at least 8 years.

Good luck with the project.

Lou

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Home of Slant6-powered fun machines since 1988

Lou

Sounds like a good plan. I would only go much above 1.72" intake if you are going to bore 0.100" or more. Mike does a nice job. You might also consider stroking the crank to get to 3.0L, if that's the class max. I guess an overbore will take you to 2.9L anyway...

The 170 should obey more conventional cam and ignition reasoning since it is oversquare like almost all V8s.

Lou

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Home of Slant6-powered fun machines since 1988

XYZ

PDQ

Several notable Slant Six racers have also used more intake duration (many of the fastest guys) and I will be trying this in the near future.

Too bad about the "spirit of the law" overcoming the letter in this case from SCTA, but it makes some sense.

Lou

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Home of Slant6-powered fun machines since 1988

I'm

I believe its alot more simple to get drag numbers than that. To set up my FX-2 (performance computer) I did a coast down. Flat straight road with at least 60 MPH speed limit, stop watch, working speedometer, and fair weather. The idea is to drive to just above 60 MPH put car in neutral and time exactly the time it takes to coast from 60 -50 MPH. Do this 3 times in both directions and average the measurements. This number you come up with is inputed into a formula which I don't have in front of me. If you what to go this route let me know and I'll dig up the info.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

I like that coast down method....although I think you would need to be above 80-85 MPH to get dramatic info.

I think some poor mans aero research could be done using wind noise at high speeds to locate high turbulence areas.

.....and you can tape bits of wool all over it .

Of course using exact , precise measurements of fuel being consumed plotted against A/F ratio and MPH will tell you HP being used.....

Josh, I can tell you my 65 Valaint HT is far more aero than my 69 Dart HT. ....just based on fuel consumption (same motor....same tune) and wind noise and snow accumulation in winter.

I have also noticed (using snow turbulence patterns) that open mag-type wheels cause far more "swirl" behind the car than smooth wheel covers.

Id vote for an early Cuda with a chin dam , shaved drip rails and domed headlight covers......and Moon discs.

Does a Classic Production car need a cage?

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Yeah....Im the one who destroyed this rare, vintage automobile.....

In college we did some coast-down tests and curve fitting to derive aero numbers. Something like Brent described, but we recorded the start time and time at each 5 MPH increment, and went to a complete stop to get the rolling resistance as well. Throw a little math on it and you could get Cd figures. More importantly, you could get comparisons for various changes.
For data collection, how about using a GPS, placed next to a stopwatch, filmed with a videocam? Refresh rate of the GPS would be an issue, but ... Recording the location coordinates might be more accurate that recording the speed ... Sorry, thinking out loud.
Do the coast-down someplace safe, straight, and flat.
The closer you can get to the speeds you expect to run, the better. Aerodynamics change at higher speeds. The rake will change if the nose rises at high speed, and that changes the airflow.

The splitter on this little beast nearly scraped the pavement at rest. It's doing around 180 MPH here:



www.bborr.com
www.rrorr.net

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

That would be the fastest sheep outside of Falls City, Oregon!


I remember some old historical Photos of Lambourghini checking for 'bad spots' on the Countach's test buck at a track...they had the whole body of the car covered every 6" with a 4-6" streamer of plastic tape.


Good luck on the tests Josh, I'll bet the top cars would be the 63-66 Dart, the 64-66 Barracuda (better choice), followed in line with the 1967-69 Barracuda Fastback.

-D.Idiot

Thanks

Drag is a funny thing. Sometimes something that looks aerodynamic drags like a brick and vice versa. Richard Petty in the late 60's would keep switching off from a Road Runner to a Charger 'cause the Charger looked sleek. Road Runner would place but not so much the charger Mopar started testing and now we know better.

I would argue that although no serious changes are allowed to the body there are subtle changes that can alter the cars drag considerably. The rake or stance can change the flow over and off the car quite a bit. Whether the grille area is blocked or open and where the exhaust dumps can change things. Even body trim has to be looked at.

One of the things I notice from my powder snow studies is that the side of the car where my exhaust dumps (turned down tip on drivers side) collects less snow than the other side.

On an early A a chin dam to replace the lower valance would be a must.

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Yeah....Im the one who destroyed this rare, vintage automobile.....