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Well, if people are really getting better mileage because of doing this, I'll try it.

It bumped our MPGs up on both of our Sparks. Its a little louder for sure, but if louder squeezes more MPGs out, im alllll about it. Our lt averages 39.1 at the pump; LS averages 37. She drives the ls and apparently has a heavier foot than me :0

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OK after driving around with the 90 on the air box to pull in cooler air from under the car I can say it definitely helps. Its worth the little effort it take to remove the tube between the air box an

I'm 99% sure I'm going to eliminate the resonator box and route hoses to both dummy fog light holes. Cut out the fog light holes and have a dual feed "ram air". Kills two birds with one stone. I ha

If you make the extra effort to go under the fender guard to remove the resonator box, the tube can be left in place to draw cooler air from underneath by the wheel well. Same effect as a cold air i

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Heck, for me the goal is mpg. I don't care about noise, power, none of that. So, I'm going to just pop out the pipe that goes between the two air boxes and run it like that and see what my mpg does. I don't see a need for a snorkel. Heck, if anything, picking up air right at the box is beneficial, as it will be warmer air and warmer air is more efficient. Plus, I can test this modification and undo it in under 30 seconds too.

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Report your MPGs please. As it cools off, sucking in hot air (which you will be doing sort of) helps fuel effiiciency..... if you want MAX mpgs the best bet is to lose the "ram snorkel" that goes up to the grill........ leave the tube attached to the box in the fender, and ditch the front snorkel.

Edited by tommyspark
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I drove 105 miles today, 50% highway and got 42.3 mpg avg, based on the Spark dash.

My previous best was 40.9 for a similar distance, which would have also been more highway.

My only modification was the NOMAD foglight modification and removing the pipe that goes from the airbox to the resonator.

I'm SHOCKED at the mpg difference. I'll need to really prove it with Fuelly and not just rely on the car dash. It just seems too good to be true. I'm thinking maybe the computer is calculating the mpg wrong or not having the resonator is messing with the MAF or MAP sensors. It just doesn't make sense that GM engineers would lower the mpg by 2 just to make the car a little quieter.

Edited by Chris Bemis
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I have to say that as it cools off, in the early morning or late night after class, I can actually FEEL the power difference. Obviously the Spark does NOT put out a lot of power, but out of the 4 GMs i've owned, the Spark hands down benefits the most from a CAI type of intake. I've never had a car benefit as much power wise behind the pedal as the Spark. Obviously though this comes with a price; which is much lower MPGs.......

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I did some preliminary testing.

I was doing a road trip on lightly traveled highway, so I could do long stretches at 70 mph without hitting the brakes or drafting. The road was also pretty flat too. I would reset the average mpg when I was up to speed and had hit the cruise control. I did 4, 7 mile runs with the parameters detailed below. I also did 4, 8 mile runs as well, then averaged the numbers. I changed up parameters between tests, meaning I didn't do a 7 mile and then a 8 mile with the same parameter back to back. As I feel that the numbers were inconclusive, I am now doing "real world" full tank testing.

Here's what I came up with on the preliminary testing:

Grille intake opening open and the resonator pipe pulled off, so both open: 39 mpg

Grille intake opening open and the resonator opening taped over: 40.7 mpg

Grille intake opening taped over and the resonator pipe pulled off: 38.6 mpg

Stock: 39.6

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Nice testing. The highest numbers confirm.warmer air=better gas mileage. That opening is close to the exhaust manifold. Me and greg were discussing coming up with.a way to maximize the warm air volume to the airbox. Id simply run a snorkel to the manifold, but it may melt.... thanks for the tests!

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I'm thinking stainless tubing bolted to the heat shield and then some kind flexible coupling to the airbox and maybe back up to the hood snorkel. Only thing stopping me is I'm not sure if the tubing will get warm enough with the cooling air blowing across it and the air gap between header of shield, plus the small contact area with the heat shield, etc. In other words I'm still thinking about it for the winter to try and improve my mileage in the cold.

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I remember some of my older cars had a heat tube that went from a heat shield on the manifold to the air filter box. It was a metal accordion. Something like that would work.

What I envision, is keeping the grille snorkel stock, but connecting from the resonator connection over to the manifold.

I'll have to experiment with that though.

Another thought, is a similar metal tube to replace the grille snorkel, but make it extra long and have it lay right on the engine / manifold to soak up heat.

We also have to remember that GM engineers aren't stupid. If they could pick up mpg, with this easy of stuff, they would have.

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We also have to remember that GM engineers aren't stupid. If they could pick up mpg, with this easy of stuff, they would have.

However in todays market NVH plays a HUGE deal in consumer perception! The 5spd with the intake mod has a NOTICEABLE "groan/drone/flutter' at or around 3k/4k RPM. Guess where I spend most of the time on the highway? I like it, gives the impression the car has some sack (impression...)

But I can see my grandmother asking why is the car so loud or why does it sound like it does.

Remember in the 70s almost nothing had dual exhaust even though it was/is proven to boost power and MPGs. Emissions devices and the cost of cat converters trumped the MPG benefit.

If you guys are that concerned, go full tilt - Remove the box, stick a cone on the end of the tube for winter months (aka, a 'warm air intake') and in summer months put the snorkel/box back.

Edited by psquare75
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Another thing to remember though is that GM went out of their way to seal the incoming air intake. That rubber around the intake, ensures that the air coming into the air box is fresh air from the grille. If they wanted a warm air intake, they would have built one, right?

That being said, right now, I'm trying something out. I've got a section of flexible exhaust pipe that I am bending and cutting to go over the existing air intake snorkel. It should hang on the existing tube and nearly touch the exhaust manifold heat shield, so it will definitely absorb heat and heat up the incoming air. I just hope it doesn't melt the snorkel.

Remember though too, that my test numbers above had by far the worst numbers when I taped off the grille intake snorkel and opened up the resonator tube.

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