Ideal HAI question

[99metro]

I have an insulated box around my exhaust manifold, then run a vacuum hose to the intake. I have found (no A-B-A) that around 90-110*F I get the best economy. It gets "funky" above 125 degrees, and fuel economy drops below 80 degrees. On hot days/afternoons I leave the hose disconnected. In the mornings I have it connected. I have about $2.50 invested in the system. It would be nice to have a push/pull cable to connect/disconnect, or get something more thermostatically controlled.

[cfg83]

Floordford -

Originally Posted by Floordford

I was daydreaming, as im sure alot of people here do, and I was thinking of the benefits of ram air intakes. Then I thought of hot air intakes Then I thought of hot ram air intake. Like some how trapping air that has passed through the radiator and route it to the intake. But then I thought that there must be an ideal hot temperature for engine efficiency before it looses too much power or causes problems.

What kinds of HAI temps are beneficial?

By the way im not following through on some odd hot ram air intake. Its just the thought that led me to the question.

There was a member named lovemysan that ran his HAI up to 190 degrees F. At that temperature he said his Saturn S-Series 1.9 liter 4-banger started to have driving problems.

I don't think I've gotten higher than 160 degrees F, but I am not positive.

More details from lovemysan :

Originally Posted by lovemysan

...

1a) Your bellypan will cause cooling issues. A few notes on the saturn: A panel can be added underneath the radiator to force air through it. A sealed grill block with passages to the radiator would be best. The HAI will reduce underhood temps. Limit IAT temps to not more than 190, you will loose power and mileage. Do not exceed 200f coolant temp, again you will loose power and mileage. I found IAT 150-180 and coolant at 190-195 to be most efficient.

...

Originally Posted by lovemysan

I find HAI to work best on map sensor based cars. Works on the saturn and works well. We tested it multple times and fiddled with the IAT on nissan and it did NOT work at all. The only result was a serious power loss.

CarloSW2

[California98Civic]

Originally Posted by Floordford

So yesterday I tried an idea. I got aluminum rain gutter parts and tried to make a 90 degree air channel that would come from the lower radiator area and aim it at my air filter. But it didnt work out like I wanted. I have my ABS block, upper radiator hose and A/C lines that get in the way.

I did however block off a big fender hole that lets in cool outside air and I took of the K&N provided shield that insulates the filter from hot air. So now its an open filter that will suck under hood heat. Plus I sealed the gaps around the passenger headlight so that the hood doesnt scoop cool air onto the filter.

The testing grounds is a 158mile down and back from Nashville to the Alabama state line. All highway and close to 2.5 hours of driving. I got 32mpg Friday when I made the trip so if these mods are worth anything ill hope to see it Monday when I make the same trip.

BTW, my intake temp Friday when making that trip was 75 degrees with 185 coolant temps. Ill note the modified intake temp.

Oh, I also took my passenger mirror off. So Mondays testing will have to consider that too.

I hope your testing went well. If it didn't yield satisfactory results, consider that everything from temps to humidity to barometric pressure and the density of traffic all have been shown to have possibly significant impacts on test results. How was it?

[SentraSE-R]

I performed some fairly thorough tests of a WAI setup on my Scion xB's MAF system. My testing found no significant difference between the WAI and control setups. See my WAI test writeup here.

[suspectnumber961]

Warm air intake on a Focus....

Warm air intake on a Focus....

Am seeing what I think are some definite mpg gains from using a warm air intake with a Focus....after seeing a low 40s mpg trip on a 15 mile run under the conditions mentioned below....and this run involved a few stops and slowdowns for curves, etc.

This is after the car is warmed up and when ambient temps are above 80F.

My simple warm air intake results in IAT temps ~ 30F above ambient in these conditions (car warmed up/ambient above 80F) ...meaning IAT of around 110F to 120F.

So I'm thinking that if there was a way to maintain the 110F-120F intake temps or above under a wider range of conditions...mpg could be increased meaningfully.

Thinking of removing the heat shield from the exhaust manifold....and fabricating an outlet from sheet metal to allow attaching the intake tube for increased heat intake.

Not sure of the effect of removing too much heat from the exhaust tubes as far as efficiency is concerned though. Also might be an issue of too much heat for the plastic air box?

Interested in results or comments from anyone else using heated air on a Focus or other car. The Focus uses a MAF...not the MAP...which is supposed to be more effective with warm air.

I'd like to get to the point where I have warmer air SOONER and under cooler ambient conditions....60-70F.

I think people with MAF intakes should TRY warm air...you never know?

[California98Civic]

Originally Posted by suspectnumber961

I think people with MAF intakes should TRY warm air...you never know?

I really recommend you read Sentra_SE-R's test results. He posted the link just above this post by you. But here it is again: Running a WAI through the wringer - GasSavers.org - Helping You Save at the Pump Hypermiling and Fuel Efficiency Forum

[suspectnumber961]

Interesting read.

A guy on a Focus forum claimed a 4 mpg gain from just removing the intake hose from under the air box so he was pulling warm engine compartment air in instead of ambient...and had as a result....less air resistance also.

Different car makes and years have different fuel management systems...resulting in differing results?

I'd have to do some dreaded A-B-A testing to prove anything though.

[California98Civic]

Originally Posted by suspectnumber961

Interesting read.

A guy on a Focus forum claimed a 4 mpg gain from just removing the intake hose from under the air box so he was pulling warm engine compartment air in instead of ambient...and had as a result....less air resistance also.

Different car makes and years have different fuel management systems...resulting in differing results?

I'd have to do some dreaded A-B-A testing to prove anything though.

It would be interesting to see if you had different results than Sentra-SE-R, if you indeed have the MAF too. You might avoid an ABA test if you look closely at the systems in his car and compare them to yours... maybe there is enough similarity to convince you that his results will likely apply to you too--and so no testing needed. Also, one guy was suggesting I try a Cold Air Intake, which the ricers and racers love to buy to boost horsepower, but which might also boost FE if different driving techniques are applied. I have attempted several tests now and the results nearly always surprise me. And yup, I fully dread the time needed to test anything just now. So I am doing relatively uncontroverisal and not so creative mods at the moment: airdam, rear undertray, and wheel skirts.