Has anyone tried a front splitter in a Gen 2 for lower drag?

[Radek Uchytil]

Weekend trip 400 km, energy consumption 14.4 kWh/100 km. Ordinary tires category C rim 17". Height profile in the picture.

 

[Radek Uchytil]

It's 4.34 miles/kWh.. 1/3 highway Speed 65 miles.

 

[archuser]

It's 4.34 miles/kWh.. 1/3 highway Speed 65 miles.

How does that compare to your usual run on that route? My usual routes went from 4.3 to 4.6. I've built the rear air dams & will be installing them today or tomorrow.

 

[Radek Uchytil]

Unfortunately, I don't keep consumption statistics. But I consider the fact that I completed a 120 km highway drive with a balance of 15% SOC a decent result.. I have a 30 kWh battery with 83% SOH.

 

[archuser]

I finished building & installing the rear air deflectors today. Now to test them.................

 

[Radek Uchytil]

It looks better on a square threshold than on a round one.

 

[archuser]

Unfortunately, I don't keep consumption statistics. But I consider the fact that I completed a 120 km highway drive with a balance of 15% SOC a decent result.. I have a 30 kWh battery with 83% SOH.

Sounds good!!! I'm seeing about .2~.3 increase with just the front mods...will have more info soon about adding the rears. Agreed about the square vs rounded....in my case it was really trying for a "air dam" sort of appearance....and yes, it is more in "style" with the 2018 forwards body...............

 

[Radek Uchytil]

It looks like the rears will have a flatter shape over time. I grind on the asphalt with a loaded suitcase on bumps.

 

[archuser]

Judging by what I am seeing....you might want to make them longer (wider??). It "looks" like I have gained another .1 by adding the rears. They are just over 10 in long (25 cm) & angled at about the same as the front. Judging by what I am seeing, a skirt between the front & rear wheel arch areas might net some nice positive gains, Need to think about designing them so not to have a problem when using the jacking points on the car.

 

[archuser]

Just to update the long-term totals......the display keeps bouncing between 4.7 & 4.6 now....so the increase is real & measurable. it "looks" like there is a .1 or so increase with the rear deflectors...not big....but not unwelcome either. I will be looking at side shirts next...I think that I have enough material to go the length between the wheel wells on both sides...need to go to a metal supply to get 1/2 in by .125 thick by about 5 ft aluminum strips for the upper support for the skirts....may do that tomorrow (Saturday).....if I get them, I'll start the mod that day or Sunday......

 

[archuser]

Well---I need to order more rubber from Amazon, so it will be a while before this mod.

 

[archuser]

Yesterday I had an altercation with a thrown retread from a Semi & the air deflectors on the driver's side lost the battle........ I pulled the car into my shop this morning & repaired the damage. The front deflector suffered only a bent bracket & was easily repairable.................but the rear was a total loss. It was not even there & left 1 of the mounting brackets behind as it left the car. So, as I was not really pleased with how they were mounted, I decided to redesign them to utilize the pinch weld area to reinforce them. I have not had time to retest, but I "believe" that with the straight-line addition to them---they might be more effective. Time will tell. The positive spin on this is that they will integrate better with the planned side skirts.

 

[countryleaf]

Have you noticed any efficiency gains with the rears?

 

[archuser]

With the first set I was getting about .1 increase...I have not extensively tested the second mod, but my first run today aligned with prior data. (mostly 45~55 on the highway & 35ish in town -- total of 40 miles saw 4.6 at the top of my hill turning into the driveway (I saw a high of 5.5 midway through my drive while in town) -- I reset the guess-o-meter this morning before the run).

As I indicated before...the best increase is with the front mod.....I think that the air is disturbed enough that the rears only help a small amount....I'm hoping with the short inline section on the new parts will help smooth airflow before deflecting it around the rear tires. Judging by the bug splatter on all deflectors I am sure flow is being moved in the right direction....O to have a windtunnel to really test.........I would really like to see the Cx values with & without.

To add sizing to the photos....vertical is 4" length is 11" the straight section is 4.5" & the angle was bent to end with the fenderwell, so about 30 degrees or so.....there is about a 1" step between the pinch seam & the lower fender. A small "L" bracket was made to stabilize the outer edge & a Large sheetmetal screw was used there....the inner bolts were 10/24 with matching washers & nyloc nuts. The aluminum was .125 thick.

Depending on how they survive, I might goto the 4" rubber & cut the aluminum back to 3"--- it all depends on if I integrate the future side shirts into the design.

 

[archuser]

OK---First real Freeway (67 to 72 mph) runs. 2 different days about 40 miles of the run were at 35~45 mph...the rest at 67~72 under cruise control. Hilly terrain between Eagle Point & Merlin Oregon...with several good ascents/descents. Tires inflated to 39PSI with nitrogen. This is with the Second mods for the front & rear.
( I am redesigning the rears this weekend, and I'll update you when that is done.)

About 220 miles total---Guess-o-meter shows 4.1 miles/kWh

 

[archuser]

OK---this is about my final update on this mod....long term usage: 4.3 Kwh with average speed 34mph. I did redesign the rears a bit, ran the same rubber on them as the fronts. If anyone wants photos of the final version....just ask.

All-in-all.....well worth the time & cost involved...I believe that the increase is around .1~.2 increase.