Meet Grumpy the Rally Van

[s1120]

So how has the project worked out? Have you done any mods to it yet??

[JV-Tuga]

So, the way I undertand it from what I have been readin the boat tail works by extending the length of the vehicle and allowing the air to stick to the body longer. Now, if the concept still works when drafting, that means that there can be a gap and the concept still works. In this case, it might be worth it to invest in modding a trailer instead, since you want access to your back doors.

Has anyone considered putting the boat tail on a trailer or at least on a trailer hitch mount? That means it is detachable and you can still reap the rewards.

I'm just thinking out loud and apologize in advance if I said something dumb.

[GasSavers_RoadWarrior]

That could work, but you'd gain a minimum of a couple of hundred pounds of extra weight to lug around and the extra rolling resistance of two more wheels. So on long highway hauls it would probably show benefits, but less so on shorter hauls and probably would lose MPG in mixed driving.

[JV-Tuga]

Originally Posted by RoadWarrior

That could work, but you'd gain a minimum of a couple of hundred pounds of extra weight to lug around and the extra rolling resistance of two more wheels. So on long highway hauls it would probably show benefits, but less so on shorter hauls and probably would lose MPG in mixed driving.

Right. The enemy is weight but if all you have is the wheels and the frame and you're not carrying any load, other than a massive Styrofoam structure (you do need some weight or this thing may go flying. ) then it might pay off. Of course the payoff would come in longer stretches of steady, moderate speed, possibly drafting a much larger vehicle.

It would look something like...

[fumesucker]

Originally Posted by JV-Tuga

Has anyone considered putting the boat tail on a trailer or at least on a trailer hitch mount? That means it is detachable and you can still reap the rewards.

Make it so it plugs in to a trailer hitch receiver. Make it a tapered box, or even a box somewhat smaller than the rest of the van but not tapered.

If you made it from foam sheets and covered it with some kind of skin it could be both light and strong.

[ihatemybike]

Grumpy has sat on the side for a few weeks. Last weekend it started for the first time with the new $30 fuel pump. I decided to withdraw from the BA/BE Rally this year, due to lack of team members and paying for my Husky's heart worm treatment. 2009 currently looks good, so I have a long time to prep. In the meantime, I'll use Grumpy in various local events and hand out fliers to find team members. I'm going to finish bringing the mechanicals up to par before I really try work on any aero stuff, but the boat tail plates from the semi trailer post look promising.

[JV-Tuga]

Originally Posted by fumesucker

Make it so it plugs in to a trailer hitch receiver.

Thanks for translating from english to english. I think you're talking about the square thingamajiggy that the actual trailer hitch attaches to. If so, that's what I meant to say.

English as a third language can be a problem once in a while.

Actually, if it turns out to be as effective as I think it may be, this trailer hitch or small trailer aero extension is something that probably can be marketed for the boxier vehicles. A couple of steps short of the full body aero additions proposed on another thread, but probably more practical and less expensive.