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https://www.slantsix.org/forum/viewtopic.php?t=20034		 Page 2 of 3
Author:  Joshie225 [ Sat Oct 07, 2006 6:09 pm ]
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Sandy,

The grill must stay open. The decorative trim can come off, but all the body panels must be unmodified and mounted in their oriignal relationship to one another. No spoilers, air dams, etc. This is a stock body class and they mean it.
Author:  sandy in BC [ Sat Oct 07, 2006 6:21 pm ]
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How are they with things like plexi glass behind the grille and lower valance openings? or cool paint...?

http://www.artcars.com/artcarweekend/ac ... /vicky.jpg
Author:  Joshie225 [ Sun Oct 08, 2006 8:50 am ]
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Looking in my old Direct Connection chassis book I find just over one page on aerodynamics. They only list the CD times frontal area for a few vehicles. The Duster comes in at 11.4, Challenger 11.2, Volare 11.0, Mirada 10.4 and Arrow 7.7. Also given is a formula for aerodynamic horsepower. To go 160 MPH the Mirada would require 290hp, the Volare 307hp and a Duster 319hp. The Arrow would only require 215hp to overcome 160 MPH aerodynamic drag, but an Arrow doesn't work in Classic Production. I thought the required horsepower difference between the cars would be greater. I still need drag data for early A bodies before a decision can be made.
Author:  sandy in BC [ Sun Oct 08, 2006 9:37 am ]
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The frontal area is fairly easy to figure . Take a digital photo of the front of the car from straight on....having a yardstick taped to the front bumper is good....print photo on graph paper....

Using Brents coastdown method VS frontal area....

Image


Just for fun: My GFs Talon AWD TSI cd x frontal area = 5.92


Josh: if you think its useful I will do some math on the Valaint (coastdown and frontal area)
Author:  slantvaliant [ Sun Oct 08, 2006 11:00 am ]
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From "Automotive Math Handbood" by Forbes Aird:

F drag = Cd * A * V^2 / 400

F drag = aerodynamic drag, lb
Cd = drag coeeficient (no units)
A = frontal area, sq ft
V = velocity, mph


Drag hp = Cd * A * V^3 / (15 * 10^4)

Drag hp = aerodynamic drag, horsepower
Cd = drag coefficient (no units)
A = frontal area, sq ft
V = velocity, mph

... and, of course, F = ma
Author:  drrw [ Sun Oct 08, 2006 1:53 pm ]
Post subject: 
Anybody know if Wilford Day is available for input?

"Bonneville racer Wilford Day set records there five times in F- and G-production classes. This Mopar slant-six (300 hp!) from the late '60s once produced 152.8 mph ........"

Here's an interesting little article:

http://www.geocities.com/frankraso2000/ ... Record.jpg
Author:  Joshie225 [ Sun Oct 08, 2006 5:46 pm ]
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Sandy,
Author:  drrw [ Sun Oct 08, 2006 6:27 pm ]
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I have a question regarding the records. I was on the SCTA (Southern California Timing Association) site and they list "Bonneville records". This shows a Production coupe and sedan F engine record (held by a 280Z 2+2) at 167 mph. http://www.scta-bni.org/Bonneville/reco ... _cat_f.htm Are these different, and why, from the records at Landracing.com.

How fast are you aiming for?

Re: Wilford Day - I could have sworn I read somewhere that he started out using an AFB on a hyper pak, was eclipsed by a Ford, came back the next day with triple webers and went faster. I can't find that anywhere, though. I know he used the hyper pak exhaust.
Author:  Joshie225 [ Sun Oct 08, 2006 7:08 pm ]
Post subject: 
Drrw,

Most 2+2s are not allowed in Production (they really should be in GT or sports) and that Datsun has been a sore point for many people. If any 2+2 were allowed in Production Sedan I could run my '87 RX-7 with a peripheral port 13B and get close to that Datsun's record. My RX-7 was going to be a V8 track car and it already has a full cage.

I expect (hope) to run 140-150 MPH. The 170 will need to spin 7000 RPM+. So far I have Venolia pistons, Clifford intake, a selection of carbs, a whole 225 for parts, extra head, etc. The cam is easy, the headers will probably be fabricated. I need to get a buildable 170 core and figure out what I want to do for connecting rods. I'm leaning towards welding the sides of the rod journals to narrow them to run a light Chevy 5.700" rod. I could even offset grind the crank a little to get right on the 3.00 liter limit.
Author:  sandy in BC [ Sun Oct 08, 2006 7:09 pm ]
Post subject: 
Ill work on some numbers on the Valaint.

Im looking for a rust free Cuda body....might be interested in part of the package....I have all the driveline...just need a rust free body.
Author:  drrw [ Sun Oct 08, 2006 8:15 pm ]
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I wish I could magically teleport the 170 paperweight sitting on my garage floor to you.
Author:  slantvaliant [ Mon Oct 09, 2006 1:19 pm ]
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I'm glad my wife doesn't have the capability to teleport things out of my garage just yet ... :shock:
Author:  GTS225 [ Mon Oct 09, 2006 3:51 pm ]
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You guys have got me to thinking. :shock: I wonder where my Mitsu Challenger would fit into, and how fast I'd have to go to be close.

'81 Mitsu Challenger, 225/auto, 2440# empty. (Probably some "hot rod" class.)

Roger
Author:  Joshie225 [ Fri Oct 13, 2006 10:23 am ]
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Forging ahead with the engine planning and building I dropped off a spare head to have the chambers welded up. The math shows I'll need to get the chambers down to about 36cc to get a 12:1 compression ratio. I'm keeping my fingers crossed.

I spoke with Pauter Machine about connecting rods and a custom set is $1200. Ouch! Anyone make a good custom rod cheaper?

Welding up the cheeks of the rod journals and turning them down to 2.100" so I can use $310 Chevy H-beam rods is sounding better all the time. I have a call in to Crankshaft City in Portland to see what they want for that job.

I may end up working with stock rods. Between polishing, shot peening, cryo treating and good rod bolts they would probably be ok for a while.

I also called All American Classics about a 170 core. They have several. About $300 for a '64-'67 engine or $400 for the '69 model year. Now I'm really kicking myself for scrapping two of these around 2001.

Ok, Wildcat just called me back. $150 for a 170 core or $350 for a good runner if it's still there. $150 beats $300 most days.
Author:  slantzilla [ Fri Oct 13, 2006 10:37 am ]
Post subject: 
Quote:
I spoke with Pauter Machine about connecting rods and a custom set is $1200. Ouch! Anyone make a good custom rod cheaper?

Unfortunately, no. :shock:
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