Boattail on a Prius

[Cd]

So... project dead ?
It was looking good for a while there.

[aerohead]

I like where you're going but I agree with others that you'd achieve attached flow and wake reduction with less length using proper curvature rather than constant angles.---- You're very likely to graze other vehicles,objects and bystanders with the huge cantilever.I also suspect that on some steep driveways and ramps that you'll experience a ground strike.--------In a rear end collision a cyclist or motorist could be impaled on the aluminum spars as there is no provision for crush.------ Another safety aspect to consider is that people won't expect a tail.It has such little visual "mass," that motorists approaching from behind may strike it before they even realize it's there.----------- These are some of the issues I chewed on before arriving at the trailer idea.The articulation allows cornering without colliding.Cropping the tail such that it maintains some degree of "visibility" from behind lessons the likelihood of a rear-ender.A tail fin with light adds to visibility and at night and dusk,reflectors and high-conspicuouity tape add extra "mass."Your long tail would preclude the use of a fin unless expertly designed,as it would create an enormous weathervane and yawing moment in a crosswind gust.--------- Low drag is best when safe! ------- And yes,I am kinda beating up on you 'cause I want you to survive your adventures.-- Look hard at basjoos Civic.At Cd 0.17 it's a great target to shoot for and safety proven.

[ENERGYprof]

Sorry no posts for a while-- wife had a baby (girl), school started,... its been crazy. :-)

I switched over to Goodyear Assurance Fuelmax tires, which can handle 51 psi, and have them maxed.

Als I swapped out the factory springs for some Japanese aftermarket racing springs that lowered it about 2". (I 'helped' lower it by cutting the front set a little before installing them.)

I'm averaging just over 61 mpg as of this week @55 mph hwy. I've been doing a little bit better on my driving technique, but don't really think the tires did much improvement over my old bald tires. I also don't think the springs help my highway mpg, but man it corners now like a mo-fo.

I'm going to cut the boattail down a little as advised, and get rid of the straight lines. Will try to get some pics up tomorrow!

With the new low ride, I scrape my driveway every time I come in, and have enough clearance built into the tail that the addition will not, however, be joining the rest of the car in leaving scrape marks on the ground. I'll probably have to add some LEDs to the tail once its complete to make sure it is highly visible, lest I whack some unsuspecting pedestrians and bikes!

[Cd]

Great to see the project is alive !
If possible, can we see a profile shot of the car with the tail ? ( Once you get around to reinstalling it .)

[gascort]

Car is looking good! I would try to reduce length if at all possible at this point, as basjoos said. 1 meter or a bit more past the bumper and your car will still fit in a regular parking spot.
Those wheel skirts you linked to look nice, but holy moly! $375 + $90 to paint them? At a 1.5 mpg (very generous) increase per tank, those save you about 0.2 cents per mile with $3.00/gallon gas. (assumed stock prius @ 45 mpg)
$465/$.002$/mile = 230,000 miles to pay off.

[RobertSmalls]

Sounds like it's time to ecomod your driveway.

[tf4624]

this boat tail project dead? or wife made you kill the idea?

[ryannoe]

I think it looks good. Just got my own Prius and love it. I'd say a constant curve would not provide attached flow, but may be safer. I've been watching the dew on my rear window and it looks like the flow has detached before it even reaches it. Anyone looked at vortex generators instead of boat tails on a Prius?

[tf4624]

Like to get parts that you used.. to make this.. is it easy removable so when you go shopping you can access the back?

[Xist]

This thread seems dead, but I wanted to make the images more accessible just in case: