Russ

Not the GTech, but my Tazzo...you bet. I trust it more than any dyno run
when it comes to measuring intake modifications. OK UL, we've gone over this subject before and you're not going to convince me otherwise. You can atmospherically (is that a word?) break the conditions down anyway you want but if I take my car and make five runs on the same day within 10 minutes of each other and follow that up by removing the air box and making five more runs in the same direction on the same road within minutes of the first series, and show a consistent drop in time from 30-70mph in 3rd gear, it ain't because the wind picked up 3mph, the temp rose 1-degree, the barometric pressure inched forward immeasurably or the increased tire wear resulted in a higher final gear. Unless I'm using it during a hurricane (IOW, the eye), the weather conditions of my runs remain consistent enough in a 10-15 minute time period, even in Vermont, as crazy as that sounds (was 80F yesterday, 30F today) to provide me with enough information to make a valid judgement on what happens when I take 15 seconds to remove an air box cover.
No accelerometer is immune to changes in one's testing environment (weather-wise) but I dare say an accelerometer is a better measuring device for testing intake mods than a stationary car on rollers with a fan blowing near it.



I suppose if I wanted to clog up the plumbing with more bends and twists in the pipe I could input perhaps a dozen or more atmospheric numbers into some convoluted formula but in the end, I'm not looking for thousanths of a second accuracy. Until I do this for podium points, a decimal point and change is fine for now.
http://tazzo.com/tazzo/dual.HTM

Greg888

removing the airbox cover is bad. no questions. i have never seen any reputable info that hp is increased, but have seen people suck dust through the filter. the paper material can tear very easily, and then you have dust in your engine.

Russ

Greg, no offense but before writing "no questions" you probably should spend more time in the archives considering your s2ki.com age, especially since you claim you haven't seen "reputable info," though I suppose a case can be made that 1-3hp differences could be dyno noise. There have been threads in the past showing minute increases with the airbox OFF (however small). I've also read threads which show small DECREASES. Go figure. Such is the case with comparing dyno plots in different states. Sucking dust in the filter? I'm not sure what that has to do with this guy's decision to remove his S2K airbox but those people you claim to have seen who have sucked in dust through their filters...were they S2000 owners? I'm not sure what that added to the discussion since a defective filter in the S2000 would suck in dust with or without the cover off but more important, an exposed filter in the engine bay is surely less susceptible to dust particles than the AEM types sitting just above the road surface. Take a look at these type of filters six months into ownership. They're usually filthy.
Personally speaking, I have a problem with all encompassing answers regarding intake questions. "No questions" indicates you feel quite certain removing the air box cover under no conditions will create horsepower. A suggestion. Come to Vermont anytime between late October and early April. I guarantee your S2000 with its airbox cover off will be making more horsepower than with it on. Exposing the filter to air temps in the negative degrees does wonders for your F20C...trust me.

I probably wouldn't do it myself though outside of the above scenario because as I've stated in the past, most of us spend more time in "heat soak" land than sustained 80mph + speeds which is the point in which having the cover off helps with increased air flow.
This is essentially my point. In all but the most aggressive mph scenarios, the air box cover removal is begging for heat soak conditions but at high speeds, having it off does no such harm. Engine temps at idle are obviously not the same as they are when the car is moving along at 80mph which should in turn, mean the affects of those engine temps on the filter are lessened as well.
This explains why short-ram intakes CAN make hp increases despite their exposed filter location. They require speed to do it.

ultimate lurker

Sigh, Russ, its clear you missed the point. I don't care if your measuring device is accurate and repeatable to 99.99999% (and it probably isn't unless you spent huge $$$$). You've got uncontrolled conditions and you're trying to assess a 1% differential. Someone tells me they see a 2 hp gain on the dyno and I generally file that under "interesting, but non-conclusive".

Some conditions that must be considered - coolant temp, intake temp (yes, it may change with the airbox cover off, but heatsoaking the manifold will affect results), oil temp, tranny temp, differential temp, wind conditions (yes, a 5 mph gust will make a difference), steering input (are you on the crown of the road or not), etc. Heck, were the cooling fans on or off? All these things make a difference and you can control some of them, but not all of them. And that doesn't even get into measurement error, or whether or not there was an A-B-A test structure.

UL

[QUOTE]Originally posted by Russ
[B]

Not the GTech, but my Tazzo...you bet.

Russ

Agreed, but as I pointed out it is my determination after four years of doing this that a series of runs with results consistently showing improvement reveals...improvement. I'm not so much concerned about the degree of numbers as I am in the determination of their direction (IOW, gain or losses). In many respects, once a modification is in place, I'm not going to remove it if it shows ANY gain. I use these devices to verify gains first, amount of gains a distant second. In this case, I removed the airbox and subsequently performed five consecutive runs with each run showing a reduction in time when compared to the pre-air box removal tests performed minutes before . My point wasn't to debate the accuracy of the tests, rather to point out that it makes no sense to discard five runs showing consistent gains because I didn't have a host of monitoring devices to chart conditions over a 15-minute time span. In fact, taking into consideration the parameters you pointed out regarding various engine temps, if anything, my repeated runs (which no doubt INCREASED engine and fluid temps...especially since no cooling down period was performed) should have DECREASED performance with each consecutive run but again, it did not. I showed the same margin of gains over OEM each time (within a few one-hundreths of a second).
If I can use another thread as an example. The 4.10 vs. 4.44 posting. Is there any doubt after using his GTech that the latter gearing makes for a quicker car than the former? Because the times are so close to each other, I don't believe any fluid and/or engine temp variances encountered during these runs were substantial enough to throw the results.
Either the car is quicker or it isn't.

srehmann

Hi guys,

how do you like the idea to cut a NACA type inlet into the hood to get cool outside air directly into the covered stock airfilter-box?

Regards from Germany, Soeren

WRS2K

man russ... offsets and now this?

ultimate lurker

It's about magnitude Russ. You're talking about changes on the order of 10%. Even with measurement error and changes in conditions, it's hard to eliminate all that. But the improvements could be half of what they are.

In the case of the 3hp gain though, your measurement tool is only accurate to +/-1hp. And small changes in various conditions can account for variances of several % in either direction. Even if we see average gains in a controlled dyno test, we also look at standard deviation. I recently did a test for an oil manufacturer. Two oils showed almost the same gain, but on one the standard deviation was larger than the average gain, so we had to say that we had no conclusive evidence that the oil freed up more power.

In summary, anytime you're going to look at very, very small changes, you've got to have controlled conditions and statistically significant measurements or the information you have is pretty useless.

UL

p.s. - I've seen instances of cars picking up hp after a few basic runs with no changes, so don't be so sure. As I said, there are many, many factors to take into account.

Yellow Streak

[QUOTE]Originally posted by ultimate lurker
[B]<snip>
p.s. - I've seen instances of cars picking up hp after a few basic runs with no changes, so don't be so sure.

jackson1628

how about the K&N aircharger? it looks similar to the stock without the cover. would that suck in hot air too in low speed?