Under tray

My truck would be my spirit animal too but I have yet to turn it into an animal...

Here is an update on more flow simulations. I like design #2 and design #8. However, both generate a bit of lift. I am thinking some little vortex generators right above my windshield will fix that...

I need to go through these and compare with more metrics. I also need to determine what type of vortex generators to use. If you have suggestions lmk. I am a ME but new to aero stuff so idk what I am doing tbh.

Overall, I have decided to go with the general design of #8. I will work on refinement.

 

1. You’re on the right track with smoothing the undercarriage.
2. Cold air intakes actually hinder efficiency quests. It’s warm air that you’re after if you want to burn less gas. More O2 means more gas.
3. I haven’t seen one for Tacos, but this aero cap is kind of a holy grail for ecopickups. This would be a great project too.


4. Loads and loads of info to be found at www.ecomodder.com where lots of people have done all of these experiments and more.

 

OP: gotta ask......how old are you??? Just curious is all - early 20's??

 

Drewskie: (I like the look of that truck) I will have an undercarriage card board cutout by the end of today. I will use this as a template once I select my material and design.

As for the cold air intake, you are only partly correct. For my setup, I have oversized injectors in prep. for future mods. The cold air helps balance my engines ability to dump fuel in. Additionally, I have it tuned for the combination so it remains stoichiometric. So overall it should be the same efficiency from a chemistry perspective but realistically my setup allows me to accelerate faster if I want to. My specific cold air intake is designed for this truck and has a box that resonates with engine vibration and ever so slightly compresses the air as it flows into the engine via sound. This makes my setup more efficient than without it if I baby the throttle. If I stomp on the throttle it becomes less efficient than without it because it also has an extra injector before even getting to the intake valves which helps mixing to minimize preignition. I am fine with this since it has noticeably more power and less engine resistance. Also, I just like the hum it gives off. I need the cold air intake since I will be modifying my engine to have a turbo kit in proximity to the intake. This will drastically increase under the hood temps so I am making small mods as of right now in preparation for that.

Thank you for sharing that link.

PacoDevo: Yes, I am 25 atm.

 

You're starting to understand now why I said what I said about the undercarriage.. Though it's understandable; my descriptions were probably hard to visualize

 

For the record, slightly leaner than stoich is better for fuel economy. Stoich is best for emissions.



Cold air = higher density. Higher density = higher mass. Mass airflow is what your engine measures to inject the appropriate fuel. So yes, warmer air is what you want.

No idea what you're trying to say about resonance and sound compressing air. Sounds like you're regurgitating what a snake oil salesman told you.

 

I would rather have clean emissions running it at stoichiometric ratio. This also gives more power. My truck project is to transform it into a sleeper. When I say I want to make it as efficient as possible I mean as reasonably possible with the intention of later making it as powerful as reasonably possible without having it destroy itself as I drive it.

I am not going to compromise performance for efficiency but I will make it more aero efficient so I can have a more effective machine.

Good clarification in the thread though for people that do not know

 

Understood. You're basically mentally where I was 5-6 years ago, so I'd like to share my insights/collected knowledge as much as possible.

 

treyus30, I appreciate that. I will start a conversation directly with you

 

Ok, that's all well and good, but not how you started out the thread:

When you announce your primary intention as "save gas money," it doesn't really imply future turbos etc. So yes in that case, warmer (less dense) air is more helpful on a quest to save gas money. And where did you find an intake that "compresses the air as it flows into the engine via sound?" I've seen some spurious claims for alleged power boosters, but that's a first. In my experience, opening up the air intake does little more than increase the sound in the cabin unless you're moving considerable volumes of air, and it really doesn't help save gas money.

So it seems more like your main goal is to improve the top end speed ability of this pickup truck. In that case, of course improving the aerodynamics (e.g., smoothing the undercarriage airflow) will help. Any gas money saved will be incidental, if any is realized. Skinnier tires, lighter wheels, smooth wheel covers, lowered suspension, and grill blocks are other relatively easy ways to make vehicles more slippery. You can certainly make relative improvements to the aerodynamics of this truck but again those are relative. You've picked a challenging base for creating a high speed sleeper. Good luck.

 

I am making a sleeper so yeah I am going for aero improvements that will save gas money and help with performance. I put a link in for the vortex cold air intake somewhere earlier in the thread... You will have to search around more to find info about the fuel savings though. Its been years since I bought it so idk where my original sources were...

 

Its taken longer to get supplies for the undertray than anticipated but now that I have some of what I need I can start prototyping.

As for the aero shell I have been working hard on simulations and have come up with a viable and easy to make solution. This is prototype 12 in my results summary. It still needs a lot of refinement and will probably take at least 8+ more iterations till I have something will actually make. Regardless, my current prototype performs on par with a typical camper shell with about 1/10 th the weight. This makes it a viable solution for city drivers as well since it so light. Aero 12 has about a 3% improvement in overall pressure differential across the vehicle compared to no aero shell. Since drag coefficient is proportional to this pressure differential we can approximate the drag coefficient as 3% improved. Lets say our drag coefficient is .55 to begin with. Then our new drag coefficient is now .5335. This seems rather insignificant. However, the drag force scales with the drag coefficient multiplied by 1/2*V^2* fluid density*Frontal Area so you could imagine that the gains will scale exponentially with speed. I could imagine that this mod could be worthwhile if you do a lot of highway driving, especially if you live where their is a lot of rain (since this will simulate scaling fluid density).

On the scale of the tacoma at highway speeds (specifically 60 mph at sea level without rain) the aero shell provides 7 pounds of force less resistance. While this may not sound impressive, this is before refining this design.

According to this site: https://www.nextbigfuture.com/2009/03/reducing-drag-on-cars-and-trucks-by-15.html a .01 Cd improvement equates to .1 MPG improvement.
This mean that a 30-40 pound product can equate to ~.2 MPG improvement.
I am hoping I can drastically increase the performance of this idea.