Milwaukee Midget

[fordboy628]

Midget,

Holy Crap!!

I start talking . . . . and BAM, you got 3000 posts to your build diary!!

Guess I need to shut up!!
 
Fordboy

[warspite]

Midget,
I'm curious...how many other cars ran in your class?  Were they any closer to the record?

[Milwaukee Midget]

Midget,

For your permanent records.

5/30/2013 COLD leakdown test of 999cc BMC, post mega-dyno thrash:

Cylinder #           Reading            Leakage %            Source  
    1                             86/90                      4.5%                  rings/cylinders
    2                             84/90                     6.7%                  rings/cylinders
    3                             87/90                      3.4%                  rings/cylinders
    4                             86/90                      4.5%                  rings/cylinders

The consistency of this little engine is starting to amaze me -

Valve clearance is still at spec.

8/20/2013 Hot leak down test - after 10 runs at Bonneville, taken to 180 degrees this evening -

1                                 96/100                       4%
2                                 94/100                       6%
3                                 96/100                       4%
4                               96.5/100                      3.5%

I'm thinking I should just throw the fenders back on, quit my job, and drag it back for WOS . . .

Just don't tell Kate . . . .

[Stainless1]

Sounds like the rings are starting to seat... See you at WoS 

[Milwaukee Midget]

Sounds like the rings are starting to seat... See you at WoS 

LOL. 

Seeing you at WOS would indeed be a treat - not likely, though. 

I remember our brief chat at the Taco stand the night before your accident.  So did Nick - a newbie to the salt, but a professional race team manager for Trek mountain bikes.  The news the next morning is something Nick did not let me know about until later in the day, after sufficient confirmation of your well being was obvious.  I wasn't listening to the radio, and if I had been, I don't know if I would have been able to drive.

I'm glad you're on the mend, Chief!

[Jack Gifford]

Thanks. I'll take the liberty of adding it to my lexicon of "affectionate abuse" terminology...

[Milwaukee Midget]

Thanks. I'll take the liberty of adding it to my lexicon of "affectionate abuse" terminology...

I've sometimes referred to the Midget as "The Pommy Pygmy".

I've always been fond of alliteration.

[fordboy628]

Thanks. I'll take the liberty of adding it to my lexicon of "affectionate abuse" terminology...

You're welcome!   Anytime I can recruit anyone into the ranks of "affectionate abusers", I consider my life a SUCCESS . . . . !!!!    (Really!)
 
Fordboy

[Milwaukee Midget]

Midget,
I'm curious...how many other cars ran in your class?  Were they any closer to the record?

None at this event, but the boys in the SAAB Sonnet are looking to punch out their "J" class 750, and they're already running faster than the "I" record.  I also spoke with a guy who is bringing out a Honda in October - an Insight - I assume stripped of the electronics and hybrid drive.  I don't know what he plans to run for an engine, but that would be one aero 2 seater.

[wisdonm]

Aerodynamics

1969 MG Midget

Drag coefficient (Cd, Cx, Cw)   0.5   Frontal area (A)   1.48 m2 (est.)
Aerodynamic coefficient (Cd×A)   0.74 m2 (est.)   Aerodynamic resistance (Aero horse power) at 100 km/h (62 mph)   18.3 kW (est.) = 24.5 hp




Honda Insight 1999-2006

Drag coefficient (Cd, Cx, Cw)   0.25   Frontal area (A)   1.97 m2 (est.)
Aerodynamic coefficient (Cd×A)   0.49 m2 (est.)   Aerodynamic resistance (Aero horse power) at 100 km/h (62 mph)   12.1 kw (est.) = 16.2 hp


All things being equal the Midget will need 101 hp to go 122 mph while the Insite will need only 68 hp.

[Milwaukee Midget]

Aerodynamics

1969 MG Midget

Drag coefficient (Cd, Cx, Cw)   0.5   Frontal area (A)   1.48 m2 (est.)
Aerodynamic coefficient (Cd×A)   0.74 m2 (est.)   Aerodynamic resistance (Aero horse power) at 100 km/h (62 mph)   18.3 kW (est.) = 24.5 hp




Honda Insight 1999-2006

Drag coefficient (Cd, Cx, Cw)   0.25   Frontal area (A)   1.97 m2 (est.)
Aerodynamic coefficient (Cd×A)   0.49 m2 (est.)   Aerodynamic resistance (Aero horse power) at 100 km/h (62 mph)   12.1 kw (est.) = 16.2 hp

Thanks a lot, pal - dopeslap me with the facts.   

Yeah, if he can put together a legal class combination, that's where I'd be placing my bets.

But at this point, other than some basic aero clean-up, I'm stuck quoting Enzo and repeating it like a mantra -

"Aerodynamics are for people who can't build engines."

[Stan Back]

I guess you could alway put a MC engine in it -- that's what some seem to think is the answer to all the smaller engine classes.  (Don't let the rules bother you.)

[fordboy628]

Aerodynamics

1969 MG Midget

Drag coefficient (Cd, Cx, Cw)   0.5   Frontal area (A)   1.48 m2 (est.)
Aerodynamic coefficient (Cd×A)   0.74 m2 (est.)   Aerodynamic resistance (Aero horse power) at 100 km/h (62 mph)   18.3 kW (est.) = 24.5 hp


Honda Insight 1999-2006

Drag coefficient (Cd, Cx, Cw)   0.25   Frontal area (A)   1.97 m2 (est.)
Aerodynamic coefficient (Cd×A)   0.49 m2 (est.)   Aerodynamic resistance (Aero horse power) at 100 km/h (62 mph)   12.1 kw (est.) = 16.2 hp

Now that we KNOW the speed, bhp available, and can do an accurate calculation of frontal area, we can solve for an accurate range of Drag coefficient.   (+/-)

THAT, coupled with an reasonable estimate of increased bhp, will allow for an accurate calculation/assessment of top speed potential.

I'm expecting the calculated Cd for the Midget to be in the 0.42 range +/- . . . . . . .   (CONFIRMED by an aerodynamicist.)

Total Cd of 0.25 seems to me to be a number more likely for a "lakester" than an Insight.    I know it's a very aerodynamic package, but I'm wondering if it might be more like 0.30/.032 for Cd.    (Previous numbers CONFIRMED by an aerodynamicist.)    Don't forget about the rear width & rear ground clearance.    HUGE differences between road cars, lakesters & streamliners . . . . . . .

OK then, lets run some numbers . . . . . . . .

Midget:   0.42 x 1.48 m2 = 0.62 Aerodynamic coefficient
Insight:   0.30 x 1.97 m2 = 0.59 Aerodynamic coefficient
              0.32 x 1.97 m2 = 0.63 Aerodynamic coefficient

A lot closer than you might have thought . . . . . . .
 
Fordboy

[Seldom Seen Slim]

Bob Wanner has raced his Insight at Maxton and at Bville.  He's got a non-stock engine in it (which brand I don't remember, nor the horsepower), but he might have some information that'd help you come up with a reasonable EWAG for the car's Cd.  He's not a regular on this Forum, but I guess I could ask him for some help - if you really want it.  It's not strictly related to the MM's efforts, but sorta on the boundaries.   Lemme know if I need to get in touch with him for you.

[Interested Observer]

Data in attached document for your consideration:
Cd, weight, and driveline efficiency are estimates.  What are actuals?

Cd for Insight of < 0.30 may be realistic, have seen coast-down test results for production class Firebird at Bonneville of about 0.26.