Reason with me before I destroy a classic - Page 5 - Fuelly Forums

Click here to see important news regarding the aCar App

Thread Tools Display Modes
Old 08-06-2007, 12:37 PM   #41
Registered Member
Join Date: Jul 2007
Posts: 73
Country: United States
I'm back.

I need a reality check from the collective here.

Im neither mathematician nor aerodynamicist but it seemed counterituitive that the Spit would be less aero than the Geo. (Incidently, my garage CD calculations indicate that the Spit's overall number is about .39, rather than the published numbers which vary from .38 to .42). Based on CD alone, the Geo wins.

Admittedly I was looking for support for my thinking, but when I searched for it I actually found some info which was quite profound.

A lot of aerodynamicist types downplay he CD aspect unless it is compared against frontal area. The equation can be pretty complex, but in simplest form you can just multiply the drag coefficient by the frontal area, and that constitutes a more realistic view of a car's aerodynamic potential.

Once again, in stock form the Geo wins, but only by a slight margin. I used the published numbers for each:

Geo: 19.2 sq. ft. X .32 CD= 6.144

Spit: 15.2 " " X .42 " = 6.384

If we begin with stock vehicles, then reduce the overall CD it starts to get more interesting. Let's say we reduce the overall CD of the Spit to something like .36, which seems doable with some pretty basic aero mods, maybe by simply replacing the 5 mph bumpers:

15.2 X .36= 5.47

We have already beaten the Geo (at .32) in the real world, yet the Spit still has a higher CD of .36.

If this is correct, The Geo will never catch up to the Spit, mod-for-mod. In fact things will only improve exponentially against the Geo, and if all other factors are the same, he car that begins with the least frontal area will always win the aero game.

Anyone care to shoot holes in this? I got no dog in this fight, either. Just stuff from the 'net.

Everyone wants to live inTheory. Because everything works THERE.
mustngr is offline   Reply With Quote
Old 01-28-2008, 04:13 PM   #42
Registered Member
Join Date: Jul 2007
Posts: 73
Country: United States
Talking Finally got all the parts.

Assembled most of the basic parts to convert the Triumph, so tonight I broke out the scales.

Geozuki 1.0 w/manifolds,alternator, fuel injection, Samurai flywheel, pressure plate, less starter: 145.5 lbs.

Samurai transmission: 54.5 lbs.

TOTAL 200.0 lbs. even.

Published engine weight for Spit 1500 from various sources on the 'net, LESS smog equipment and manifolds: 275.5 lbs.

Spit trans.: 92.5 lbs.

TOTAL 368.0 lbs.

We're talkin good 'ol British cast iron here.

I once put a small bock Chevy and a Muncie in place of an Austin Healy straight 6. Afterward the front end sat over an inch higher. As I recall 302 Z28 motor weighed over 100 pounds LESS than the 3.0 six. (That car ran like stink, BTW)

Decided to redo both cars (Spit first). Still need a donor 5 speed car for the ECM, fuel pump, wiring harness, etc. etc., and also to provide the bones for converting the Geo to 5 spd.

Every danged car I call about turns out to be an automatic.

I'll start a separate thread if anyone's interested. This week I'll just focus on getting it mounted up.

Everyone wants to live inTheory. Because everything works THERE.
mustngr is offline   Reply With Quote
Old 01-29-2008, 02:04 AM   #43
Senior Member
101mpg's Avatar
Join Date: Dec 2007
Posts: 736
Country: United States
Thumbs up

Hooray! Mod the Spitfire. (Late vote since you're starting but I wasn't on the forum last year)

Ever hear of the expression, "I don't know how to define _____, but I can sure tell it when I see it!"? (I believe originally defined as porn by a Federal judge in a pornography case.)

The Spitfire looks like it can be aero modded better mod for mod, because it wasn't designed as aero in the first place.

There is DEFINITELY something to be said for coolness factors - if it just looks and feels better, that is worth a bit of your money and effort in this short life. The Spitfire should be a whole lot more fun than the Geozuki *to you* - it sounds like you'll have a lot of fun with this project, and isn't life all about everything BUT money?

ENJOY. Keep us posted. I'd love to see the results and the fun in getting there.

Looking to trade for an early 1988 Honda CRX HF (Pillar mounted seat belts)
101mpg is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
New vehicle make request, how long to add. ScorpioTurbo Fuelly Web Support and Community News 2 07-19-2011 06:45 AM
NOS Honda N600 Grille Block on eBay GasSavers_DaX Aerodynamics 4 01-03-2007 07:50 AM

» Fuelly iOS Apps
No Threads to Display.
Powered by vBadvanced CMPS v3.2.3

All times are GMT -8. The time now is 08:59 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.