Front end shapes for Streamliners

[Chris Horoho]

I have been researching for a while and am still somewhat undecided
I have seen a few different designs and none are really the same
I was curious to your all's input to what you think the best would be for a streamliner (motorcycle and car both)
I know the saying its not how you enter the air but how you leave it but im still torn between a few different ideas

Thank you for any and all input

[Moxnix]

If you look in the archives for the 2010 Shoot Out thread, there are photos of vehicles, both 4 and 2 wheeled, that were timed over 400 mph during the course of their runs.

[maguromic]

The front end has a a lot to do with it, but I would worry more about rear end and how you closed the hole you just punched in the air.  Tony

[Stan Back]

We can see your focus is on rear ends.

[Chris Horoho]

lol
yes tony i did plan on a very well taken care of rear of the vehicle but im torn on the front as ive seen a few different designs

[debgeo]

Not only is his focus on rear ends- he is great at picking them

[Anvil*]

A basic bulb or rounded front end. I would move the center just down a bit since the flat playing surface changes the distribution a bit and you want the overall angle of attack slightly down to neutral. That said, rounded nose to rounded-boxy transitions are only a bit more drag and the frame and sides much simpler to build. You'll notice most exchange a few horsepower to getting something built and on the salt much sooner.

As many have said the tail is more important and the windscreen area and wheel areas are also worth a close look.

[Rex Schimmer]

If your plans for a streamliner are other than a slab sided or flat bottom shape I would suggest looking at the NACA 66000 series profiles in revolution. These profiles were designed to provide long runs of laminar flow which is the lowest possible drag regime. Of course you still need to have a good rear end shape, not like Tony's avatar!, to make it all work. Look at the build thread for Rob's NACA 6600 stream liner for some ideas.

Rex

[Dr Goggles]

sure , it's  lakester but I think there's a lot to be said about where the hot exhaust goes....up or out sideways is really going to upset all the hardwork you put into trying to make the pesky air travel uninterupted along the bodywork to where to you are trying to put it "back togther"......

Now , before I get subaru-stormed by people pointing out all the really fast cars that have exhaust coming out the sides I'd like you to consider all the low-powered( 300hp and less) jobs that have achieved respectable speeds that have made the effort to get it out the back

[Chris Horoho]

A basic bulb or rounded front end. I would move the center just down a bit since the flat playing surface changes the distribution a bit and you want the overall angle of attack slightly down to neutral. That said, rounded nose to rounded-boxy transitions are only a bit more drag and the frame and sides much simpler to build. You'll notice most exchange a few horsepower to getting something built and on the salt much sooner.

As many have said the tail is more important and the windscreen area and wheel areas are also worth a close look.

i do understand your reasoning but why is it that the treit streamliner (target 550) is using a different front end
and i was also thinking of a front ram to feed all air in the motor bay as well as a small feed to the cockpit

[interested bystander]

Looking through a list of geometric shapes it looks like a flattened ovid bolus would be pretty close for a front end shape.

[John Burk]

Ack Attack is the fastest two wheeler and the nose is nearly hemispherical .

[Bville701]

All I can say is that the Goldenrod set a record of 409 MPH with engine trouble in the 60's...   

[Dynoroom]

All but one ran over 400 mph. And I'm sure the diesel powered 'liner can go just as fast as the others.......

[Dynoroom]

A couple more. Motoin I never got the chance to run over 4 but did run in the 350 mph range.