Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - White Lightning (Nissan Leaf) Build Thread

Flakbadger · 02-03-2021, 07:52 PM

Hello everyone. Been a hot minute since I've done anything productive on the Leaf; but seeing my numbers drop precipitously from my summer highs has motivated me once again.

So looking at the Leaf overall, I think there's a lot of room for improvement if I included front/rear wheel boattailing. As with a lot of us, I'm looking to Volkswagen who did their homework on the XL-1 to inspire a lot of my work.

The VW XL-1.

I noticed something. They seem to focus more on the leading edges of the wheels than the trailing. Don't get me wrong, there's boattails behind the trailing edges too, but the front ones are much larger.

If you look at the front splitter, it clearly covers the aerodynamically dirty area of the suspension components. But if you look at the leading-edge splitter for the rear wheel, it's MUCH larger than the trailing-edge rear wheel boattail.

I also recognized that the giant wings underneath Semi trucks seem to focus on the leading edges of the tires/axles, and ignore the trailing edges of the front wheels.
This tells me that the leading edges and that flat face must cause the vast majority of the drag.

Notice that the leading edges of the wings are "inboard" of the front tires, and the trailing edges are even with the faces of the rear tires.

The Leaf, stock, already has flexible rubber deflector-thingies underneath, and just like the Volkswagen, they appear to be much wider than the tire's width.

Here's a high-tech mockup to let you see what I'm talking about. Reminds me of a 'cards against humanity' card.

I was also realizing, while messing about with a nice teardrop-shaped trailing edge design, that I would have to account for the jacking point, if I ever want to work on the car again---which I most certainly do.

Even with a truncated boattail, it'd still be close to where it gets jacked up at. Also, wash your damn car, my dude.

So now I'm just thinking of focusing on the leading edge of the front tires first, and following up with the leading edges of the rear tires next.

Here's my first attempt at a shape, it's just a little wider than the tire. The outer face is even with the outer face of the tire, the inner edge extends ~1 inch inboard of the tire.

The profile of the front-tire splitter.

I bought me one of them fancy hot-wire foam cutters recently. I've got a well-ventilated garage, a NIOSH respirator, and a whole sheet of pink foam just sitting there waiting.

This cardboard design follows the natural curvature of the bumper, so it would be pretty unobtrusive, and should streamline the front face of the tire. I think I'm gonna start with this and see where it takes me. What are your thoughts?

02-03-2021, 07:52 PM	#99 (permalink)
Flakbadger Always Too Busy Join Date: Apr 2012 Location: Oregon Posts: 566 White Lightning - '17 Nissan Leaf SV Team Leaf 90 day: 159.47 mpg (US) Thanks: 405 Thanked 190 Times in 134 Posts	Throwing stuff at the wall to see what sticks w/ respect to tire boattails. Hello everyone. Been a hot minute since I've done anything productive on the Leaf; but seeing my numbers drop precipitously from my summer highs has motivated me once again. So looking at the Leaf overall, I think there's a lot of room for improvement if I included front/rear wheel boattailing. As with a lot of us, I'm looking to Volkswagen who did their homework on the XL-1 to inspire a lot of my work. The VW XL-1. I noticed something. They seem to focus more on the leading edges of the wheels than the trailing. Don't get me wrong, there's boattails behind the trailing edges too, but the front ones are much larger. If you look at the front splitter, it clearly covers the aerodynamically dirty area of the suspension components. But if you look at the leading-edge splitter for the rear wheel, it's MUCH larger than the trailing-edge rear wheel boattail. I also recognized that the giant wings underneath Semi trucks seem to focus on the leading edges of the tires/axles, and ignore the trailing edges of the front wheels. This tells me that the leading edges and that flat face must cause the vast majority of the drag. Notice that the leading edges of the wings are "inboard" of the front tires, and the trailing edges are even with the faces of the rear tires. The Leaf, stock, already has flexible rubber deflector-thingies underneath, and just like the Volkswagen, they appear to be much wider than the tire's width. Here's a high-tech mockup to let you see what I'm talking about. Reminds me of a 'cards against humanity' card. I was also realizing, while messing about with a nice teardrop-shaped trailing edge design, that I would have to account for the jacking point, if I ever want to work on the car again---which I most certainly do. Even with a truncated boattail, it'd still be close to where it gets jacked up at. Also, wash your damn car, my dude. So now I'm just thinking of focusing on the leading edge of the front tires first, and following up with the leading edges of the rear tires next. Here's my first attempt at a shape, it's just a little wider than the tire. The outer face is even with the outer face of the tire, the inner edge extends ~1 inch inboard of the tire. The profile of the front-tire splitter. I bought me one of them fancy hot-wire foam cutters recently. I've got a well-ventilated garage, a NIOSH respirator, and a whole sheet of pink foam just sitting there waiting. This cardboard design follows the natural curvature of the bumper, so it would be pretty unobtrusive, and should streamline the front face of the tire. I think I'm gonna start with this and see where it takes me. What are your thoughts? __________________ Nissan Leaf driver? Join me in Team Leaf and feel smugly superior about our MPGe Current Car: White Lightning ---------------------------------------------- Retired Car: Betty White Last edited by Flakbadger; 02-03-2021 at 08:41 PM..