Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Aero Crosstour- Squeezing blood from a stone

Chonk_Master · 04-07-2020, 10:45 PM

Howdy, all. I'm setting up a build thread for my aero Honda Crosstour project. This post will be a data dump of everything so far and then I'll use it as my primary build log.

Specs, goals, and completed projects will be updated on this first post. All other journal entries will be new posts.

2011 Honda Crosstour Specs:

Currently, MPG is roughly 21 MPG. Regularly updated MPG log is here: https://docs.google.com/spreadsheets...it?usp=sharing

Crosstour curb weight is 3852 lbs. With me and 16.5 gallons of gas weight is calculated to be 4142 lbs.

The Crosstour has Honda's Variable Cylinder Management (VCM) and a Tire Pressure Monitoring System (TPMS).

Goals:

Goal is an average of 25 MPG (16% increase in MPG)
I expect to have to do more than current prosposed projects to meet this goal. Recommendations welcome.

Proposed projects:

Wheel covers
Lower radiator blocker plate
Foglight covers
Low profile side mirrors

Completed Projects:

Lol

Resources:

Scrum board: Kerika
Image analysis for front surface area cross section:
ImageJ
EcoModders aerodynamics stencil:

This is the image that inspired a possible rear spoiler.

Journal:

So, first phase is just tooling up and ordering parts to complete the project.

I installed a Harbor Freight drill guide on my old IKEA desk for drilling the lugnuts. To install the guide, I drilled holes slightly smaller than M5-.08 nuts and epoxied them (SteelStik) into the desk for a semi permanent installation and to improve stability. I used a thread tap to clean the still-wet epoxy out while leaving the max amount of epoxy still in place.

Ya'll like Patrick Nagel?

I also designed and 3D printed a simple centering jig for the lugnuts. It's the black thing holding the nut beneath the drill bit. If I let gravity center the bit, it gets pretty darn close to perfect. I'll verify with measurements before drilling.

Side note: I'm considering using steel zip ties vice drilled lugnuts. I'll have to see how centered I can make everything and go from there.

Other than that, I printed some organization tools for the shop and built a scrum sheet for the build using Kerika: https://kerika.com/app/BQBC4/board/BQBDh
Also printed a drill bit sharpener for a Dremel so everything goes smooth when the time comes.

I'm also planning on fabricating a vacuum molder but I don't have photos for that. This will be how the foglight covers are made from clear Lexan.

First project tackled was wheel covers, since the pizza trays came in first. I wanted to passivate them, as they're pretty cheap and I don't trust the aluminum any more than I can throw it (which is probably pretty far, actually).

Technique was, well....bathtub. I used what was left of the Barkeeper's Friend under the sink and the minimum amount of water needed to cover them.

They soaked for a little over an hour with hot water.
It will be hard to tell how well it worked but I'll definitely be monitoring for corrosion and taking notes.

I'm leaning heavily towards steel ties vs. threaded lugnuts. Utility, ease of install/modification both seem better. Aesthetics won't be any better or worse.

Next big project is the side mirrors. I wanted to do a full elimination with a printed vanity cover but the Crosstour's enormous blind spot makes it a non-starter.

I'll be using ImageJ to try and get an approximation for how much the new mirrors take from the front cross section. I jumped into this project head first and the passenger mirror has already been removed, so I'll cut and paste the driver's side mirror into the image to get a closer estimate.

Here's a side by side to show how much reduction there will be. Not amazing but it's something.

ImageJ will hopefully give some hard numbers on how good it was but, of course, final MPG is king.

Speaking of which, I'm going to intentionally pace project implementation such that I can get a couple of tanks of gas after each mod. maaaaaaybe do A-B-A.

I'll also have to build a plate to cover the old recess that the side mirror was integral to. New side mirrors bolt onto an adapter plate (which is for much older Hondas) and the adapter plate bolts to the car. I'll have to fab an adapter plate from this:

Which really shouldn't be too hard. It's a triangle with no major curvature. Measurements are easy to take with a caliper. The three bolts are what penetrate the unibody to mount the mirror. The plate will be 3D printed and those bolts will be replaced with heat set threaded inserts. I'll threaded a bolt into them from inside the vehicle.
Image of inserts:

Image of the scheme for the mirror mounting hardware:

Next minor project is replacing the front emblem. This is more of an aesthetic thing but it'll hopefully help with some aerodynamic smoothing, since the Honda emblem is pretty big and cavernous.

I work as an intern at an aerospace firm and they throw away A LOT of carbon fiber. This benefits me immensely.

This is the CAD mock up of the emblem. Pretty easy. I also own a crock pot.

It turns out, the rivets holding in the factory emblem were either missing or sitting in cracked, ineffective housings. So, it popped right out. Anything will be an upgrade after that, I suppose.

And that's it for now. Hopefully, I'll have an image for ImageJ before the end of the week and can have an adapter plate for the mirrors fabbed up in CAD (real CAD, not the cardboard kind. Okay, it'll be TinkerCAD but still). I also want coast down times but the friend who was trying to help is having bad allergies and I may forgo it or do it myself by filming the speedometer.

Let me know what you think. All suggestions are welcome and appreciated!

04-07-2020, 10:45 PM	#1 (permalink)
Chonk_Master EcoModding Lurker Join Date: Mar 2020 Location: Austin, TX Posts: 63 Crosstour - '11 Honda Crosstour EX Thanks: 48 Thanked 29 Times in 25 Posts	Aero Crosstour- Squeezing blood from a stone Howdy, all. I'm setting up a build thread for my aero Honda Crosstour project. This post will be a data dump of everything so far and then I'll use it as my primary build log. Specs, goals, and completed projects will be updated on this first post. All other journal entries will be new posts. 2011 Honda Crosstour Specs: Currently, MPG is roughly 21 MPG. Regularly updated MPG log is here: https://docs.google.com/spreadsheets...it?usp=sharing Crosstour curb weight is 3852 lbs. With me and 16.5 gallons of gas weight is calculated to be 4142 lbs. The Crosstour has Honda's Variable Cylinder Management (VCM) and a Tire Pressure Monitoring System (TPMS). Goals: Goal is an average of 25 MPG (16% increase in MPG) I expect to have to do more than current prosposed projects to meet this goal. Recommendations welcome. Proposed projects: Wheel covers Lower radiator blocker plate Foglight covers Low profile side mirrors Completed Projects: Lol Resources: Scrum board: Kerika Image analysis for front surface area cross section: ImageJ EcoModders aerodynamics stencil: This is the image that inspired a possible rear spoiler. Journal: So, first phase is just tooling up and ordering parts to complete the project. I installed a Harbor Freight drill guide on my old IKEA desk for drilling the lugnuts. To install the guide, I drilled holes slightly smaller than M5-.08 nuts and epoxied them (SteelStik) into the desk for a semi permanent installation and to improve stability. I used a thread tap to clean the still-wet epoxy out while leaving the max amount of epoxy still in place. Ya'll like Patrick Nagel? I also designed and 3D printed a simple centering jig for the lugnuts. It's the black thing holding the nut beneath the drill bit. If I let gravity center the bit, it gets pretty darn close to perfect. I'll verify with measurements before drilling. Side note: I'm considering using steel zip ties vice drilled lugnuts. I'll have to see how centered I can make everything and go from there. Other than that, I printed some organization tools for the shop and built a scrum sheet for the build using Kerika: https://kerika.com/app/BQBC4/board/BQBDh Also printed a drill bit sharpener for a Dremel so everything goes smooth when the time comes. I'm also planning on fabricating a vacuum molder but I don't have photos for that. This will be how the foglight covers are made from clear Lexan. First project tackled was wheel covers, since the pizza trays came in first. I wanted to passivate them, as they're pretty cheap and I don't trust the aluminum any more than I can throw it (which is probably pretty far, actually). Technique was, well....bathtub. I used what was left of the Barkeeper's Friend under the sink and the minimum amount of water needed to cover them. They soaked for a little over an hour with hot water. It will be hard to tell how well it worked but I'll definitely be monitoring for corrosion and taking notes. I'm leaning heavily towards steel ties vs. threaded lugnuts. Utility, ease of install/modification both seem better. Aesthetics won't be any better or worse. Next big project is the side mirrors. I wanted to do a full elimination with a printed vanity cover but the Crosstour's enormous blind spot makes it a non-starter. I'll be using ImageJ to try and get an approximation for how much the new mirrors take from the front cross section. I jumped into this project head first and the passenger mirror has already been removed, so I'll cut and paste the driver's side mirror into the image to get a closer estimate. Here's a side by side to show how much reduction there will be. Not amazing but it's something. ImageJ will hopefully give some hard numbers on how good it was but, of course, final MPG is king. Speaking of which, I'm going to intentionally pace project implementation such that I can get a couple of tanks of gas after each mod. maaaaaaybe do A-B-A. I'll also have to build a plate to cover the old recess that the side mirror was integral to. New side mirrors bolt onto an adapter plate (which is for much older Hondas) and the adapter plate bolts to the car. I'll have to fab an adapter plate from this: Which really shouldn't be too hard. It's a triangle with no major curvature. Measurements are easy to take with a caliper. The three bolts are what penetrate the unibody to mount the mirror. The plate will be 3D printed and those bolts will be replaced with heat set threaded inserts. I'll threaded a bolt into them from inside the vehicle. Image of inserts: Image of the scheme for the mirror mounting hardware: Next minor project is replacing the front emblem. This is more of an aesthetic thing but it'll hopefully help with some aerodynamic smoothing, since the Honda emblem is pretty big and cavernous. I work as an intern at an aerospace firm and they throw away A LOT of carbon fiber. This benefits me immensely. This is the CAD mock up of the emblem. Pretty easy. I also own a crock pot. It turns out, the rivets holding in the factory emblem were either missing or sitting in cracked, ineffective housings. So, it popped right out. Anything will be an upgrade after that, I suppose. And that's it for now. Hopefully, I'll have an image for ImageJ before the end of the week and can have an adapter plate for the mirrors fabbed up in CAD (real CAD, not the cardboard kind. Okay, it'll be TinkerCAD but still). I also want coast down times but the friend who was trying to help is having bad allergies and I may forgo it or do it myself by filming the speedometer. Let me know what you think. All suggestions are welcome and appreciated! Last edited by Chonk_Master; 04-08-2020 at 01:24 AM..