GEARSPLIT program under Win XP

[desotoman]

Dave, if you made a coastdown program I know I would use it for my cars. Thanks, Tom Gerardi

[robin dripps]

Dave, the new program would be very welcome.  And if this, as well as the original Gearsplit program, were able to also run on a mac platform this would be fantastic. I know this is asking alot.

[ddahlgren]

I have no plans to do anything for a MAC platform if there is a windoze emulator for the MAC that would be your best bet. For right now that is my stand in the future if any complilers and linkers come out that will do both windoze and MAC it might change but until then i see little hope for any MAC stuff.

[John Burk]

Keith - If you are interested these are the coast down formulas . Speeds are in Ft/Sec (mph x 1.47)

If you're timing the seconds to coast from speed (A) to speed (B):
  (A) minus (B) divided by coast down seconds divided by 32 x car wt. = drag in Lb.

If you're seeing how much speed you loose while coasting for a given distance:
 
  Speed lost x 2 divided by coast down Ft x car wt. = drag in Lb.

 Lb drag includes aero and rolling friction and is for the average speed . The greater the change in speed the more the drag curve affects the accuracy . The accuracy is as good as the speedometer and the observers eye & thumb .

[ddahlgren]

aero and rolling have to be separated to get any meaningful answer.
Dave

[deadbolt]

This GearSplit sounds very interesting, where would I find a copy of it?

[landracing]

http://www.landracing.com/miva/merchant.mv?Screen=PROD&Store_Code=L&Product_Code=GSLP&Category_Code=OSM

[Rex Schimmer]

Headshot, I read were you think that the Cd on you Dodge pickup to be around .5. NOT EVEN CLOSE! Your truck is not a brick, it's two bricks! A short one setting on top of a long one. The Cd for the bottom may be some place below 1.0 because of its length but the cab, being so short probably has a Cd above 1 and combined  you have a brick! It is not the shape of the front of the car it is the shape of the back that counts most.

Paul Van Valkenburgh has a good discription of finding the Cd via the cost down method in his book "Race Car Engineering and Mechnics".

Rex

[Sumner]

Headshot, I read were you think that the Cd on you Dodge pickup to be around .5. NOT EVEN CLOSE! Your truck is not a brick, it's two bricks! A short one setting on top of a long one. The Cd for the bottom may be some place below 1.0 because of its length but the cab, being so short probably has a Cd above 1 and combined  you have a brick! It is not the shape of the front of the car it is the shape of the back that counts most.

Paul Van Valkenburgh has a good discription of finding the Cd via the cost down method in his book "Race Car Engineering and Mechnics".

Rex

Saw a recent Myth Busters where they drove two identical pickups down the highway until they ran dry with one following the other.  It was a long ways on a full tank, over 300 miles if I remember right.

Anyway the test was to see if the tailgate was down if you got better mileage.  Well the one with the tailgate up went quite a bit further.  

They said, I don't know if it is true or not, that the newer pickups are designed so that with the tailgate up it makes a bubble of air circulate back forward to the cab and up the back of the cab which then tumbles in a circular motion that stops the air going over the top of the cab from getting sucked in behind the cab thus streamlining the air flow (Some of the F1 cars use diverted air to help with the airflow around the open wheels and I've considered experiment with that later on my lakester if it ever actually runs.).  

Hope you understand what I was trying to explain .  I think they even put Styrofoam balls or something in the back to see how the air really was circulating and it followed the above statement.

Disclaimer:  All of the above could be true or a myth since I saw the show a couple weeks ago and at least 1/2 of those memory cells are no longer with me .

c ya, Sum

[WOODY@DDLLC]

You can run XP programs virtual in WIN7! There is a demo at the link on the jpg! 

[WOODY@DDLLC]

Does this mean that this CFD Subaru might actually work!?! OMG?!? 

http://www.symscape.com/blog/tailgate-up-or-down

http://www.stanford.edu/group/uq/pdfs/conferences/SAE-2005-419.pdf