Aeromod my van:Where to start?

[Goldenfrog]

I have already adjusted my driving habits and removed all the extra weight from my car, including the jack and spare tire. Now I want to do a bit of modding and need a worthwhile starting point. Most of my driving is under 35mph city travel with maybe 15% freeway at a max of 60-65(trying not to get run-over). I know I need to make a belly pan but I'm not sure that's where to start. I was thinking 1. front spoiler 2. belly pan 3. rear wheel skirts.

I want to start with something that might help with my low speed trips, considering that's the majority of my travel.

Frontend with lots of air openings.


You can see that my front and rear wheels stick out in the airstream and that someone has thrown trash under my van.


Look at this huge wheelwell.

[azraelswrd]

I'd focus on the tires before aero then because you're not driving very fast. If you already did that (and forgot to mention it) then I would start with the easiest aero mods and that would be to clean up the front or initial point of fluid contact. Anything "unsmooth" will need to be smoothed out or over.

I think your plan of aero mods are sound -- clean up the underarea then address the rear-wheel area. Search the forum for how others have done it but before you go nuts and start spending $$$ I suggest testing and a monitoring device/system because driving habits can ALWAYS be improved upon and this is the best/easiest way to jump the MPG hurdle.

[Goldenfrog]

It's a 93 so a Scanguage is out. I replaced all my vacuum hoses last month and put in an extra t-connector for a vac gauge. I put off buying a gauge when I had to fork over $450 to get the old lady's car fixed(timing chain jumped some teeth and tore up all the gears). I had all the tires inflated to max sidewall with nitrogen already.

I have AC but I removed the belt to reduce drag and so I won't be tempted to turn it on. I'm still carrying the compressor around though. I don't want to lose the option of having AC for long trip.

[MetroMPG]

An MPGuino would be a good option for MPG instrumentation in your van.

As for where to start - I'd start with a partial grille block. That's the lowest hanging fruit & easiest to do.

[Goldenfrog]

Start with the grill or closing off the bumper and lower openings? Maybe make a front airdamn that covers the bumper, lower air holes and sticks out past the front tires. Would a thick piece of coroplast with bracing work for this?

[SuperTrooper]

If you have a roof rack with crossbars you can start by removing the crossbars. Then you could think about the rack itself.

OMG!! That stand up hood ornament must be killing your MPG!

[aerohead]

Already much good advice.The urban driving is most challenging.If your highway mpg is around 24 mpg,your in-town mileage would be on the order of 29.25-mpg,if not for all the traffic,stoplights,and stop signs,etc.At low speeds,the van could be really "un-aerodynamic" and your challenge would be one of conservation of momentum.The hyper-milers have been perfecting tips which can help compensate for urban "challenges" and you'd be ahead to look at that forum.------------------- If you can warm-up the van as you drive,combine all your trips into one big loop,minimize cold-starts,try to anticipate traffic lights,avoid stops as much as you can,you'll preserve the motion you dearly pay for.Anything you can do to maintain momentum will reflect at the gas pump.Don't do drive-ins of any kind.Don't idle for more than 30-seconds.Hundreds of techniques.Really! Check out the hyper-miling.Be safe!The aero mods will help at higher speeds,but right now,stop signs and traffic lights and traffic are your big challenge.

[aerohead]

P.S.,I saw a minivan like yours at lunch.The front and rear wheels are not shielded at all from the airstream.The front airdam could be widened to just conceal the tires,and rocker panels could be extended at least 4-5 inches ( 100-125mm) to clean up flow along sides of the van( including behind rear wheels ).There may be kits available,don't know.Or make your own.