Hondaworkshop - project log

[larrydag]

What did you do for the WAI? I would love to try that mod on my Honda. Did you do it yourself?

[hondaworkshop]

March 22, 2008 - Added a Warm Air Intake

I wanted to wait until I was happy with this WAI before posting pics etc. so this is a belated post. Let's get straight to the pics:



The inlet is a $5.29 flexible steel exhaust tube from an auto-parts store. Its is approx 2-1/4 in diameter. I tucked it just under the exhaust manifold shroud, but I was careful to make sure it was not actually touching anything. It is zip tied firmly onto one of the fan shrouds. I also slightly rearranged the O2 sensor wire so it was not touching the inlet.



The coupling is a 2" plumbing coupler from Home Depot. This costs around $2.99. Be sure to get one that is safe to use with hot water, so it will withstand higher temps.



The filter box for my particular engine (D16Y7) is uncommon for Hondas. The filter is inside a box with a downward facing throttle body... kinda like a carb intake that was converted to fuel-injected. I have asked around, and it has been agreed this was designed for fuel efficiency, better emissions, and low end torque improvement. In any case, this particular manifold is well-suited for conversion to a WAI. I simply sawed it off short, removed the sound-dampennig box, and put my flexible inlet on.



This mod has been the biggest improvement I've seen outside of changing my driving habits. I'd say its around a 10% FE improvement, and with my driving style changed, I haven't noticed the accompanying loss in horsepower at all.

With intake air temps averaging 140°F I'm still wondering what this will do to my spark plugs and sensors. I'm also getting an itch to pre-warm my fuel...any thoughts?

[Harpo]

I blocked off some cold air entry points thereby raising the IATs accross the board. With a slight change in weather (Temps up 8-10° and RH down to 25-40%) and this mod, it looks like I have about 5% savings on same weekly trip cycle. Judged by ScanGuage and Fill Data, both in perfect agreement.

My IATs are nowhere near 140° however. Maybe consider backing the IATs off by moving your intake a few inches back of the manifold at a time.

I'd think on startup/early ops, the 140° may be very beneficial, but as FWT get normalized around 185°, I'd say a few degrees less WAI will still provide same FE increases.

I found a spot in my parking garage, that if I back in to, the sun will only shine on my hood for about 2-3 hours prior to the afternoon drive home. I'm anxious to see if the additional underhood heat load will help on getting the FWT and IAT up earlier on the trip home.

[hondaworkshop]

Well, it turns out my gauge got wonky somehow, so I only got about 37mpg on the last tank... still good, but not the 40 I was hoping for.

I'm going to take your advice and try to pull the tube away from the manifold to get somewhere around 110°F on average. Stay tuned.

[MetroMPG]

You know you can adjust the SG to correct for differences at fill time.

[hondaworkshop]

Originally Posted by MetroMPG

You know you can adjust the SG to correct for differences at fill time.

Yeah, I've been doing that and getting some wild swings in useage readings vs. fillup readings. I'm using the same pump at the same station, but I think maybe the variations in temps threw it off a bit, because I did a morning fillup once then an afternoon fillup later on, and the temps were different by maybe 40°F.

I dont know what else it could be, but when I fillup, I'm adjusting my useage by more than a half gallon every time. Maybe I should try using a different station/pump, or not worry about it now that temps are more consistent.

[PaleMelanesian]

I've just kept a running log of Scangauge gallons (uncorrected) vs real gallons. After a year, it's pretty consistent, so I just use the average offset now. That's +8% fuel in my case.

[Harpo]

Originally Posted by hondaworkshop

I'm going to take your advice and try to pull the tube away from the manifold to get somewhere around 110°F on average. Stay tuned.

Mine seems to start making FE progress at around 90°, and seem to be really good at 105°-110°. I think you'll see a difference. I added another baffle over the weekend, and my return trip averaged ~ 105° IAT today, previously 95°ish.

I went to synthetic oil this weekend. The previous owner (first 36K) used dino oil from bulk drum at dealer. The FWT was 5-8° cooler than similar trip conditions last week. Result - return trip was 46.8mpg (up 3mpg) after those two mods. Daily trip average was busted by an errand I had to run this AM at 8:30 down the busiest road we have. Even with that diversion, I was up 0.7mpg for the day.

My ScanGuiage adjustment stays at -1.6% the last three fills. Dead on.

[hondaworkshop]

Today I commuted with the intake about 4 inches away from the exhaust manifold. AVG temps were 125° and FE increased by a little bit. I'm going to try to get to 105° tomorrow. Thanks everyone for the tips.

[ECONORAM]

Originally Posted by Harpo

Mine seems to start making FE progress at around 90°, and seem to be really good at 105°-110°. I think you'll see a difference. I added another baffle over the weekend, and my return trip averaged ~ 105° IAT today, previously 95°ish.

I went to synthetic oil this weekend. The previous owner (first 36K) used dino oil from bulk drum at dealer. The FWT was 5-8° cooler than similar trip conditions last week. Result - return trip was 46.8mpg (up 3mpg) after those two mods. Daily trip average was busted by an errand I had to run this AM at 8:30 down the busiest road we have. Even with that diversion, I was up 0.7mpg for the day.

My ScanGauge adjustment stays at -1.6% the last three fills. Dead on.

I realize this is a Honda inspired thread, but I've noticed similar results on my Dodge RAM. When the OAT is about 90*, I see a slight mpg improvement driving back from work. I have tried a WAI from the eng bay side of the radiator to the airbox, but that only gave a 5-7* temp rise. Not enough when it's 30*F outside.

Originally Posted by Hondaworkshop

Today I commuted with the intake about 4 inches away from the exhaust manifold. AVG temps were 125° and FE increased by a little bit. I'm going to try to get to 105° tomorrow. Thanks everyone for the tips.

This makes me think I need to remove the insulation I wrapped around my manifolds. I don't think I gain anything from it, other than slightly cooler eng bay temps...might have to start a thread like this one to catalog the journey.

I highly recommend synthetic oils. My truck has seen synthetic since its 1,500 mile mark. If you like to worry (like I do), you can get a filter-mag for your oil filter. It's a curved magnet that sticks to the filter. It traps all the ferrous stuff inside. Remove and stick on the new filter at your oil change....