thrashmetal15

Hello! This seemed like a pretty decent forum, so I decided to join.

Anyway, on to the subject at hand. I just recently bought a 95 Del Sol Si, 5-speed, 86K, with no visible modifications. One of my buddies gave me a short (Not CAI) after-market intake (no brand on it or anything) that had come on one of the cars he bought. Said it was for my Engine (D16Z6 I think) and to give it a try and see if I liked it. Well it went on with no problems, but it SEEMED to kill my power and my gas mileage. The car just didn't feel as peppy with it on.

It sounded really different and made sort of a honky drone when I was heavy on the throttle...I didn't particularly care for the sound. I suppose it's possible that it only sounded odd from inside the car.

When I installed the intake my gas needle was exactly at 1/2, and I had 180 miles to the tank so far. Between 1/2 and Empty I only got 100 miles. The MPG I calculated on refilling was 31.6 which, from what I've heard, is below average for this car. I've since put the stock intake back on and will be checking the mpg again.

I'm just basically wondering if it's even possible for an intake change to hurt gas mileage this much. Perhaps the filter was no good and was reducing my air flow?

I apologize in advance for any noobie mistakes I may make...I've only been learning (or caring really) about cars for about 2 weeks, since I got my Sol.

Thanks!

Nbboy7

iTrader: (5)

you may be sucking in heat that will cause bad gas mileage and loss of accretion. I had an aem CAI and it worked wonderfully i got to 38 to 39 miles to the gallon.

xwhitchx

all so if the filter is bad (dirty) it will do that to you car, i have a aem long arm intake and i hit some mud it my car all most die it seemed like.

madu

A cheapo shortram intake does no good, just increases intake sounds but other than that is most likely a lot worse than the stock airbox. I've got an AEM Hybrid B16EK-intake on my car and I don't know, it might help a little with mileage or it might not, not a very huge difference anyways. Nice intake sounds anyways, no clue about performance, makes the engine bay look a little nicer since it removes a lot of the ugly stock plastic.

instructor74

Guessing how much fuel is in your tank to get accurate mpg is not going to work just because your gauge is at 1/2 tank doesn't mean you have used exactly 5 gal of your 10 gal supply. The only way you are going to know for sure is to run several tanks full with the intake on and calculate mpg for each full tank say 5 tanks add all 5 tanks mpg and devide by 5 to give you average mpg over the 5 tanks. Then change your intake, run the same number of tanks and then look at your average for the 2 test. this will give you much better idea of what is going on

thrashmetal15

Excellent point. I really wished I had tracked my MPG with the stock intake before I changed them. Oh well, live and learn.

You guys basically just reaffirmed everything I feared. lol, not much point to leaving the cheapo intake on.

I'll have to see how my mpg's look over the next week or so with the stock intake.

Thanks a bunch!

SHO-NUFF

In actuality, a warm air intake will increase your MPG a tiny bit. You are reducing the amount of oxygen getting into the engine because air is less oxygen dense when warmer.

That being said, I doubt the intake is doing much harm to your MPG. You are probably adjusting your DRIVING style to better suit what the intake has done to your powerband. Let me explain a bit. Normally when you add performance parts to your car, it shifts the powerband a bit. By adding an intake, you can potentially increase power in your upper RPM's, but at the same time reduce power in your lower/mid range. As for most typical intake designs, they will produce power in the upper RPM range with a sacrifice to lower and mid RPM power. Car makers will usually design their airbox's for maximum power to the midrange and for noise reduction.

Like I said, you are proably more of a lead foot which can also lead to a loss in MPG.

thrashmetal15

You know...that could be it... It felt like it lost power in the low/mid range. I never really tore it up with the intake on...so this could explain why it seemed to be losing power since most of my driving is done in the scooped zone. That being said I rarely (to the tune of ALMOST never) get the car above 4000 RPM's ...can you still be "driving hard" while keeping RPM's low?

rhennin

As an engineer, I can say that it'll be fairly difficult to get a completely accurate and exact answer. In general, intakes tend to reduce the required work (really pressure difference) for the motor to pull in air. Yes, it could be warm air, but this generally is only applicable when your talking about higher ambient temps. I just usually fill up every time I get gas and calculate the mpg. It's not necessarily accurate cuz I'm not 100% confident that the gas nozzle cuts off at the exact fill for every gas station. However, it's likely that it's close enough to say it's fairly negligible and therefore the mpg is generally close. I just use the mpg as a reference to see if the car is running fine and also to adjust my driving depending. Sorry, kinda used big words, but from an engr. stand point. there's tons of variables and the only thing you really can do is determine which ones can be considered negligible and which are the significant ones. Either way, it shouldn't effect it much unless the filter has gigantic restrictions on the flow. What kind is it anyways? I know there have been flow tests comparing plenty of these aftermarket filters. Google....

93egSLEEPER

all that to really explain what everyone else said in a simpler way. must be fun to be a engineer. and i didnt see to many "big" words anyways. get over the engineer title. on HT it really means nothing.

to the OP in this case it seems like 32 mpg is pretty damn good. recalculate if you feel it is a must but im sure you wont notice much of a difference. if the air temp outside is colder it takes your car a bit longer to warm up thus using a bit more gas in the long run. enjoy the extra throttle responce and "noise" so to say. i know 32mpg would be nice but my boosted gsr just doesnt get that. thats from a normal persons point of view....fyi

fastrxu

an egay short ram will be better than stock because of all the restrictions from the stock intake just check the filter

and yes you can drive your car hard even if you dont take it past 4k it's all about how hard/fast you put it up to 4k

SHO-NUFF

Rhennin, you may want to check out this tool. Quite simple and very accurate.
http://www.scangauge.com/

rhennin

Really? The engr. reference wasn't mean in any other way than to let people know that I do have experience as far as the actual analysis of systems and things that could VERY EASILY apply. I used to hate listening to engineers that sounded like they were over analyzing things, but the reality is that the math proves it and is the only actual proof that you can rely on. When you say, on HT it means nothing, it's interesting, bc even though there are tons of people on here that know a good bit about cars etc... in general it's unlikely that those that aren't engrs. and/or haven't studied engr. could go in depth into the actual math and facts that come out it. I've seen some smart guys on here, but one of the problems is that there are tons of people with an opinion that's general based mostly on opinion and not fact. Fact comes from engineering....

In a d16 del sol, 32 is decent. I'm not sure on the gearing, but it should likely be in the 30-35 mpg range with almost any d16 really. Depends on your driving though. My d16y8 got around 35 highway and 32 city or so.

thrashmetal15

Thanks for the great replies. My driving is half/half highway/city. Another variable, lol. Variables seem to plague every aspect of life.

I'm planning on running a few tanks with the stock intake on, switching, and then running a few tanks with the aftermarket one. All the while trying to maintain a consistent driving style.

I really wish the intake had some markings on it, or something...so I could do research

SOHC_civic_si

I bet my bottom dollar you are NOT an engineer. Seriously. I do not know where you live nor the university you attended for your so called Bachelor of engineering degree, but I call bullshit when I see it. Here at the University of Alberta which I might add is well renowned in North America, it takes 4 years to accomplish that degree. It is my understanding that engineering is usually a 5 year program, but the U of A squishes it into four.

Anyways, what I am essentially saying is someone who has studied full time for at least four years WOULD not waste his or her time on an internet car club forum trying to make themselves sound smarter, or perhaps more important than the regular joe on here. By the way, what kind of engineer are you? You forgot to mention that simple detail. I will make a few decently educated guesses on that. Since you're on an auto forum, my first guess would be mechanical. But then you started blabbering about all these different temperatures, and air intake volumes, blah blah blah, so my next guess was some kind of physics engineer. But I thought about that one and realized there is no way on Earth a physics engineer is on Honda-Tech trying to tell some 14 year old kid off. My last guess would be a mathematical engineer, since you starting talking about how "the math is right". Is that how you put it?

Moving on I would also like the add your spelling and grammar is tremendously poor, and it makes me chuckle the way you flaunt your so called use of "big" words when I would accurately guess them to be of say, grade 12 level?

I also find joy in your statement of "fact comes from engineering". Did one of your engineering professors tell you that? How can you sit here and type such atrocities like, 'I hate it when other engineers over analysis everything' etc. etc. Do you really think we are going to believe that garbage?

To wrap things up here my best guess is you are are trying to create a fake persona of yourself of someone smart, educated, knows exactly what they are talking about, and is and always will be, smarter than the other guy. Who are you trying to fool?

rhennin

How old are you? You in Alberta eh? What degree is it you're persuing?

Look here dick. I'm a mechanical engineering senior at Clemson University. If you knew anything about the curriculum of mechanical engineers, you would know that we have to take classes ranging from basic electrical engineer, statics, dynamics, thermodynamics, fluids, heat transfer..... I could go on. From these classes, we are given a very comprehensive background to draw from when it comes to anything engineering related. Mathematical engineer, and physics engineer? Sure that exits? Your really not helping yourself with statements like that which clearly show your ignorance to anything engineering related. Do you have anything to actually back up your opinion or refute the off hand analysis that I presented? Really, you need to find something better to do and stop making this simple question of a thread into a huge poo flinging contest. Don't start being a dick though, and expect people to not defend themselves.

I'm on car forums, bc I'm into cars and there actually are plenty of engineers that I know that do the same and use it to have discussions on cars and automotive related tech. I already told you I'm not trying to make myself better than anyone else, I'm merely trying to explain that I do have schooling that pertains to analysis which you could use to actually determine the factual answer to the question. Anyone can bullshit, but again actually proving it with numbers is much harder.

My grammar is probably poor, but get this, at the time it was 2am here and I was taking a break from a tiring week of school, so excuse the hell outta me. Again, your making yourself out to be a dick and not proving a damn thing.

As to the engineers, as we all know, sometimes people can over analyze things when they really can just get away with making a decision even if it's not the best "engineered" decision. Make sense?

Either way, stop being a dick and realize i'm not trying to wow anyone or present myself as Einstein. Just trying to help.

LShatchie

wow you guys are reallyyyy lame sitting here arguing on a forum, this should be locked

rhennin

Sorry about that original op and guy above me. Yes, I might have come off on a high horse with my "I'm a mech. engr." speech which came of completely the wrong way than I intended. Just wanted to make sure that people understood that I have done a good bit that applies to doing any kind of actual study of effects of something like this on mpg. Just don't appreciate people being a dick to me is all.

93egSLEEPER

just to clear things up from my previous post I did not post that, my brother did being a ***. I am myself pursuing a mechanical engineering degree and respect what you had to say. my bad on that i wont leave H-T up anymore on my computer when im not around.