Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

EcoModder.com (https://ecomodder.com/forum/)

- Aerodynamics (https://ecomodder.com/forum/aerodynamics.html)

- - Dodge Dart Aero mods (https://ecomodder.com/forum/showthread.php/dodge-dart-aero-mods-28895.html)

Dodge Dart Aero mods

I had a fun time eco modding my Nissan Versa, gained about 5.5% over factory numbers, but now that she's dead (car accident in December) I've upgraded to a Dart. However, the "low hanging fruit" has already been plucked by the Dart's designers, thus I'm scratching my head as to where to go with it. I always balance my mods as time spent vs cost vs potential gain and my only ideas are venturing into the "expensive" categories. I'm so desperate to do something that I executed one of the most pointless mods ever; I created a lower partial grill blocker the other day even though I have active grill shutters, just to feel like I've done something (I justified it this way; the grill shutters close at somewhere around 50 mph, or so I understand, thus my grill blockers are for the speed regime up to 50 mph).

I'm curious if there are any Dart owners out there that have done anything?

I found this technical drawing of a Dart
http://www.autotribute.com/wp-conten...t-Drawings.png
There's not a lot of aft-body for the car and plan taper starts rather late,leading to a relatively large wake.
Thule makes a 1-inch receiver hitch type bicycle rack system which could be modified to create a slip on bustle/boat tail extension for elongating the car.
Something like this would help recover pressure,raise the base pressure,cutting pressure drag which Hucho says is the entire premise of streamlining.
Front skirts,rear skirts,and tail should show significant savings.An inspection of the car's underside might reveal some wiggle-room for belly pan sections.
AeroCivic would be an outstanding benchmark to model after.

Quote:

Originally Posted by aerohead (Post 423530)

I found this technical drawing of a Dart
http://www.autotribute.com/wp-conten...t-Drawings.png
There's not a lot of aft-body for the car and plan taper starts rather late,leading to a relatively large wake.
Thule makes a 1-inch receiver hitch type bicycle rack system which could be modified to create a slip on bustle/boat tail extension for elongating the car.
Something like this would help recover pressure,raise the base pressure,cutting pressure drag which Hucho says is the entire premise of streamlining.
Front skirts,rear skirts,and tail should show significant savings.AeroCivic would be an outstanding benchmark to model after.

Weird drawing; Dodge doesn't make a hatchback version that I'm aware of...unless it's in the pipeline.

Edit: ahh...no "hatchback" perse but yes, that's an accurate drawing of what the shape is.

I don't own one, I'm just a parts guy.

Quote:

23 - Body/Exterior/GRILLE, Active Shutter/Operation

OPERATION

The AGS system is controlled by the powertrain control module (PCM) over a dedicated network LIN bus. When the ambient air and engine coolant temperatures are below a specified threshold, airflow across the radiator is not required. When airflow across the radiator is not required and vehicle speeds reach a calibrated threshold, the PCM will command the shutter vanes to close.

It'd be interesting to see if any tuners can recalibrate the speed threshold, but simpler to just rig an override switch.

Quote:

Originally Posted by Fat Charlie (Post 423534)

I don't own one, I'm just a parts guy.

It'd be interesting to see if any tuners can recalibrate the speed threshold, but simpler to just rig an override switch.

And what is that speed threshold? Edit: right, so ambient plus engine coolant temps will determine what that speed threshold is for the given temps...

I don't know the speed threshold. It isn't something the tech would deal with- Chrysler dictates it in the PCM software. What it ought to be is closed until coolant temp rises to a set threshold- who cares what the grille is doing if you don't need cooling yet, and if you do need cooling you need it regardless of your speed.

Clever would be hacking the PCM. Effective would be an override that keeps it shut until the temp passes a threshold, then allows the PCM to do its thing. Of course, it might take a lot of clever to do that without getting the computers mad:

Quote:

To aid with diagnosis, the grill shutter vanes can be commanded to the open or closed positions with a scan tool. The active grill shutters perform an initialization each time the vehicle is started. The initialization can be used as a quick way to validate the operation of the AGS. To perform the AGS validation, start the engine and observe the grill shutters, the shutters will cycle to the fully open position and then to the fully closed positions to initialize and learn the hard stops on the grill shutter frame for that key cycle.

If the AGS smart module detects the grill shutters are jammed, it will attempt to free them by cycling the shutters from the open to close positions 3 times. If this condition is detected when the ambient air temperature is greater than 4.4° C (40° F) the MIL will illuminate and a diagnostic trouble code (DTC) will set. If the ambient air temperature is below 4.4° C (40° F) and a jammed condition is detected, the smart module will assume the shutters are frozen and will not illuminate the MIL or set a DTC.

The active grill shutter assembly contains an integral smart module, the module receives a command position signal from the PCM to properly position the shutter vanes. The AGS module reports the position to the PCM on the LIN bus. The AGS module four-pin connector also contains a battery voltage, ignition voltage, and a ground circuit.

It would be good to allow it to do its diagnostic hokey-pokey, and might be difficult to override the system without throwing a CEL.

Smooth wheel covers, mirror delete/fold, antenna removal, wiper delete, upper grill block...are some things on top of what it comes with factory.

Just to clarify: you actually have the "Aero" (eco) version of the Dart?

Quote:

Originally Posted by MetroMPG (Post 423558)

Just to clarify: you actually have the "Aero" (eco) version of the Dart?

Yes. Just looking to gain even more. The wheel covers on are on the list and I've been poking around the underfloor and noted a couple of areas for improvement. Not keen on mirror deletes and the Dart designers noted the windshield wiper is "out of play" aerodynamically. The antenna delete is of interest for sure.

So I have the turbo and the car has a single exhaust on the right hand side of the car, however, on the left hand side is a open space where the twin exhaust would go on the cars with that option. On my car that area is open and leads to a parachute rear bumper. In this shot you're looking up at the rear bumper (top of image) and you can see the gaping hole that leads to a small section of parachute bumper:http://www.mulsannescorner.com/Ecomo...08_163357.jpeg

Initially I stuck a piece of corplast, angled to meet the bottom of the car and to close the opening in the leading edge of the bumper. So here we're looking rewards, the bumper is now at the bottom of the image. Ran in this configuration for a couple of weeks:
http://www.mulsannescorner.com/Ecomo...08_163641.jpeg

But that was always just an interim idea. The angle of the panel was relatively abrupt and probably not ideal (not BAD, just not necessarily ideal, I extended the panel as far forward as I reasonably could). But I envisioned a infill panel with a rounded leading edge to slid into the slot, so I ended up shaping one out of foam sheet insulation (the blue kind you can buy at Lowes for $14 for a 4' x 8' sheet) and then laying up (in this case) carbon fiber over it. When everything was cured I ate out the foam insulation with acetone, not a particularly green process I'll admit to that, giving me a hollow box with the requisite shape:
http://www.mulsannescorner.com/Ecomo..._144443-1.jpeg

I noticed on the exhaust side the bumper is open there too so I filled that in with the same angled panel concept I used on the opposite side (there's not room to really put anything in more extensive, plus I'm sure the airflow there is such that this one isn't doing much), just reversed.