5th generation civic hatchback - improving aerodynamics

[JuniorDavis]

Why is the car still at stock ride height?

[engosti]

andrewJ dear.

Your car water pump every engine on bring the power loss engine

Because water pump mechanic driven engine all time stock

Change water pump to electric water pumps?

Get to %5 engine fuel economy high sir

Sory bad for english

Best regards

Mr.Engosti

[Chris D.]

I saw a dyno gain by cutting and filing down every other impeller blade on a water pump.
It was a fraction, but it all counts..

[mrchance]

I will post my post with link after this... (not enough posts yet. lol)

[mrchance]

Originally Posted by AndrewJ

...ABS seems to me to be the ideal material for making fairings and such because of it's malleability under heat and because it can be "welded" with the right equipment...

sorry to threadjack... back in OP, ABS welding was mentioned... We use "weldon 3" in a syringe bottle all the time for ABS. A chemical welding. no heat, miniscule color deviation along seam. kind of a 'squeezed out' look if you apply too much. You can weld other ABS straps, band-aids, or tapping thickness on back too. Apply it sort of like you would superglue... not too much, but enough on both seams. Fully cured, it always holds fine for me...

Careful of an uncapped needle! Excess fluid will cause a melt drip or fingerprints. It evaporates pretty fast too, so I always empty syringe back in can.

Just my $0.02

[steffen707]

Originally Posted by AndrewJ

So, after reading Hondaworkshops thread, I decided today was a pretty good day try out the warm air intake (hereafter referred to as WAI) that I've been scheming about for a few weeks.

Knowing that there is at least part of the intake coming from inside the engine compartment (about 1 foot from the header) I convinced myself that Honda wouldn't have possibly made it that easy to do a WAI.

"Surely," I thought, "there must be another intake point in the resonator somewhere crammed into the front bumper under the passenger headlight."

So, intakes were dissassembled, bumpers were partially pried off, but no other source of intake air was found.

"Surely," I thought, "Honda couldn't have made it that easy. That second intake point must be SOMEWHERE back there where I can't reach it!"

The heavy artillery was called in.

I hooked up the shop-vac to the intake, stuffed all the known holes with rags, then I flipped the switch.

Technically, I was right.

Honda did leave another point for intake air to enter the resonator. And when I say "point" I really mean it. It's a drain-hole in the bottom of the resonator in the bumper, about 1/8" in diameter. Not even worth bothering with.

30 minutes of dirty work all to find out that Honda actually did make it that easy to make a WAI. /


So, what is neccessary for the worlds easiest WAI, you ask?

One 18" length of 3" aluminum vent hose.
One zip tie.
And one ~12" piece of wire.

Slip the vent hose over the intake "port" (or whatever you want to call it), zip tie the vent hose in place.








Stretch the end of the vent hose up in-between your header and catalytic converter, use your piece of wire to hold it in place.






I illicitly "borrowed" my wifes digital probe thermometer from the kitchen and hooked it up to the intake of my car, just above the air filter and ran a little before and after test.

Before the WAI, intake temps varied from 65º to 85º, getting steadily cooler at higher speeds.

After the WAI, intake temps were around 140º in town and varied from 120º to 180º on the highway.

I copied your idea and i'm shocked at the in town results. I've gone from around 50-55mpg for accross town 4 mile trips under 35mph speeds with 4-5 traffic light, or stop sign stops, to now a record high of 69mpg for the same trip. Just to make sure I drove all the way back to Autozone and drove the same path home and got 67.93mpg so I know its not a fluke. I need to isolate the modification for testing because i also did a front grill duct tape block at the same time. I know 12-14mpg is a TON, so I want to be scientific about it and do an A-B-A kind of test to know how "true" these mods are. Also just driving a few tanks with and without the mods would help to compare, but when you get 500miles on a tank, one needs to drive a lot to test results.

What I have noticed though is that at 65mph I am still getting the same MPG that I was before these mods, between 45-52mpg highway. I think that not having a belly pan of any kind is filling the engine bay with cold air and causing the intake to suck more volume of air due to more throttle input. I was going to use a wind block on the right side of the exhaust/CAT to block wind from blowing right behind the CAT and into the pipe without flowing past the manifold to warm it up more.

I need to find something to test the incoming air temp with and without the WAI, and with and without the front grill block. It amazed me how fast the car heats up now too. That will pay off huge in winter (WHY DIDN'T I READ THIS LAST NOVEMBER!)

[steffen707]

Originally Posted by AndrewJ

Don't jinx it!

I've actually got a pretty good feeling about this tank. The odometer seems to confirm it....


Anyway, I just got off the phone with a guy who owns a golf-cart dealership in town. He said that on Thursday he's getting a load of 12 "used" deep cycle batteries from a ZAP electric car, and he'll sell me a few of them for whatever the core price is.

So, looks like I'll be using Darin's battery testing method and looking for a cheap 12v charger.

While I had the ECU pulled out trying to hook up my SuperMID, I also spliced into my "Alternator Control" wire.
And for all you curious folks with civics/integras/preludes, here's an ECU pinout so you can find it too. It's pin 16A (white/green wire)

Here's a nice article about Honda's alternator control circuitry.


Turns out that by grounding the Alt control wire, the alt shuts off. I tested it all out with my DMM and it looks to be true. 14.4v before, and 12.5ish when the alt control wire is grounded, and there's a noticeable difference in the sound of the engine at idle when doing this.

Here's a little list of things I'm trying to collect within the next few weeks:
-two 6v or 12v deep cycle batteries
-small digital voltmeter (to mount on the dash)
-interuptor switch (to ground the alt control wire)
-4awg jumper cables, welding cable or amplifier wiring kit.
-12v battery charger (around 15 amps)

I wonder how quickly the battery will be depleated without the alternator, I also wonder how fast the alternator can charge the battery back up to full power.

My thought was that on a long road trip, you could disable the alternator for an hour, and then let it run for an hour.

Sure it wouldn't be as big of a gain as no alternator at all, but if what I read about increasing MPG by 10% with alternator delete is true, then perhaps 50% alternator use would gain 5%? Might be worth it without as much hassle as the deep cycle battery and having to charge the car up every night.

[steffen707]

Originally Posted by AndrewJ

Oh, and for now I'll be monitoring pack voltage with a DMM that'll be hastily velcroed to the dash in some fashion. I ordered a little standalone digital voltmeter from ebay, but it hasn't got here yet. Apparently it takes a while to get here from China...

Curious if those are all hooked up to the electrical system in the car, when you go to check the voltage of the pack, you just have to flip the switch to turn the alternator off, and that will give you the voltage of just the batteries right? Will that voltage be a lot lower with the engine running and drawing power from the batteries, or does that not have a large "immediate" change in voltage?

[bhut2180]

That hot air thing cant be true, though I am a newb to this whole thing, I've come from the tuner era of cars and thats the opposite of what a tuner does. Can someone explain why that works?

[steffen707]

Cold air contains more oxygen, hot air has less oxygen.

In the tuner world you want a cold air intake so you can inject more gas with that air to gain more power.

With economy, you would want less air, thus less fuel used, and better economy.

Also there is a plus side in that warmed up engines at "operating temps" get better gas mileage, using hot air in the intake warms the engine up quicker, getting you to those better gas mileage conditions faster.

I'm sure there are better explanations with more specifics, but this is the jyst of it.