Stock, I could not get over 35-36mpg even with an empty car on the highway. Around town, driving aggressively, I've gotten as low as 20mpg.

A few days ago I put on my home made $40 short ram.

I was on the road today for 8 hours heading down here to Gulf Shores from Memphis. At one point with some slowing and speeding (and a burst to 100mph to pass a couple trucks) but setting cruise at 75mph, I got 40.5 mpg with about 500lbs total baggage and people. AMAZING!! I never got over 36mpg before this.

Then after that, on a more stable portion about 150 miles long, set at 75mph, I got 43.8mpg!!!!!! I am shocked and amazed.

Here is the thread about my SRI:
https://www.fitfreak.net/forums/fit-...am-intake.html

 

So if I read this right, you measured close to a 22% increase in the miles/gal by just changing the OEM air filter design to an "under the hood element " that no longer pulls in outside cool air but I'm assuming is less restrictive.

Did you measure that increase using a scan gauge or tank fill up and miles gone?

I'd be interested to see more of a A-B-A test as 22% from a change like this seems way higher than anything I have ever seen on any car.

 

Did you have any trouble with the ECU after changing the filter setup?

-piper

 

I was getting about 26-29mpg with the stock intake and after switching it to the Last Station Short Ram Intake (chamber intake) i notice that it was less restrictive, smoother shifts, and better consistent mileage, id say about 30-32mpg.

(i measure by the total mileage divided by the amount of gas i put in)

 

Sid,

Did you hook up the IAT sensor? I think you mentioned it in the other thread.
Sensing warmer air would cause your ECU to lean back your fuel mixture and make your engine use less gas. In general the SRI may intake warmer air under the hood tricking the ECU into a different fuel map.

 

is that good or bad? if it is bad then i guess i should reinstall my stock intake then.

 

i think it's bad, you'd be running lean all the time when the sensor is just hanging out in the engine bay somewhere. this would show an increase in gas mileage but it's not good for your car at all. (correct me if i'm wrong).

 

i hope you are wrong i dont want to have wasted money on the intake but if you are right then alot of people have wasted money in SRI not only me.

 

Deja vu.........yes/no?

 

I mounted the IAT over next to the battery. I will be mounting it in the bend when I get back home.

No ECU problems I can see.

I divided miles by gallons when I filled topped off the tank.

 

oh i was referring to people making their own intakes who didn't mount the sensors, and just left it out somewhere. that would mean their engine is actually intaking air that was at a different temperature than that read by the sensor.

 

I'm not stupid. I am planning on mounting it correctly, I just did not have time before leaving town.

 

How could the IATsensor cause a lean condition?? If anything it seems it would be on the rich side. How could the air in the intake be cooler than the air a foot away?

Please explain your logic.

 

Am I the only one going huuu on the 22% increase? with an air filter change?

 

well i don't know...rich, lean, or no difference at all...that's why i said "correct me if i'm wrong." i just guessed it was running lean because he was getting such a large increase in fuel economy. and i assumed the temperature in the intake pipe would be different from that of the sensor because who knows where the sensor is sitting?

yea me too haha

 

doctordoom is right...

The car is running LEAN. That's because the IAT is detecting hotter temperatures(lower resistance). It's measuring the engine bay temperature as opposed to ambient air temperature (if the sensor was plugged into the stock airbox).

The results, the engine will retard your ignition timing in addition to lowering the lean-out limits.

 

The IAT wire is very short (maybe 2"). It was never at any point "hanging somewhere by the manifold".

For the sake of argument, why is running a little leaner a bad thing? It's bad for a forced induction motor, right? Yeah. You want to run fat with a turbo, close to an 11-11.5:1 a/f. When I was tuning my AEM EMS on my 1991 Eagle Talon AWD, I was shooting for an 11.5:1 a/f on my AEM WB-O2. At 20psi on my GT30R and 20 degrees total advance, on 93 octane, I made 470whp. I would have made a few more horses with more timing, or leaning it out, but I would have reached the limit of my Precision 750hp intercooller and started knocking. So I played it safe.

But in an all motor setup, a lot of guys I've seen tune for 13-13.5:1 a/f. Running lean is not a horrible thing.
And regardless IF, IF the car was running a little leaner than before, this motor is a 1.5 liter, low compression, naturally aspirated motor making 85whp. Running 93 octane gas. I couldn't get knock if I hit it with a 10lb sledge!

And IF, IF I traded 5 whp, for 7 more mpg, WGAF? I'll trade 5whp on the highway for 7 more mpg anyday!

The sensor was reading air temps up near the top of the throttle body, under the hood. The SRI has a 90 degree bent tube with a total length of 6", sucking in UNDER-THE-HOOD AIR. I seriously doubt there was much of a difference in the temps at the IAT and the TB.

But, I mounted my IAT in the SRI today using a 5/8" hole saw bit and the factory rubber grommet, so we will now see if that helps/hurts.

 

haha for those worried about how much this is leaning out, factory settings on a motor are EXTREMELY rich because a rich motor never killed anyone.this isnt going to hurt anything. i am in no way condoning just letting it sit there in the engine bay dangling tho lol, just as soon as possible un-rig ur contraption and do it right. at least drill a tight hole in the boot and shove that sensor in there!! if ur going to do something right, do it the first time so there are no issues.

 

Already done.

And I simply did not have the time before we headed out of town to mount it in the bend.

I would recommend to anyone, do it the right way the first time.

 

And here is where the sensor was sitting before I installed it into the bend. It was wedged in between another couple of wires, so it wasn't dangling around.

Not really anywhere near the exhaust manifold.