Yes, it is a physical fact and I never said dec IAT did not increase power. However, a decreased IAT could also further lean the mixture in the instance where a MAF is not functioning properly.

 

I doubt you'll need a flame suit, but yours is an interesting take on things. Not sure if I altogether agree with it however, but nontheless another point of view which surely causes one to think.

So your argument is that the power comes from leaning the mixture as opposed to cooler air, and you later state that the cool air may even contribute to a more lean condition?

I am new to this tuning thing and there is talk of "LTFT (VE)" tuning, where guys disconnect the MAF to tune the car, on the road in actual driving conditions, and then sometimes leave it disconnected. Speed Density, its called.

It would be interesting to see what type gains they get with cold air intakes.

 

Well, my argument about these "wonder boxes" is this:

INC AVAIL AIRFLOW + DEC TEMPS = MORE POWER? The increased avail airflow part is really not recognized correctly by the PCM, so the power MUST be coming from COOLER AIR (~68F in my case) AND LEANER CONDITIONS (maf not reporting as much air/cooler air). I'm only suggesting that IAT is not the only factor to justify these wonder boxes. Maybe some don't care, I do. I'm sure there is much more to it than I'm stating too, but I know these facts as I have really measured them and tuned around them using various scaling of the injectors as an offset.

IDLE AIRFLOW should be the same from any airbox. But, on my 03, it was decreased when adding the airboxes above. This tells me the MAF is expecting a certain flow characteristic to work correct. Hit and miss from box to box??? Now, this is minor at idle, but what about when accessing spark tables and the load data is offset from the maf being incorrect?

WOT o2 sensor voltages should be rougly the same as stock? I mean, afterall, if the MAF is measuring incoming air, the computer still calculates fuel demand the same way. Well, its changed too and less air is reported at WOT, though cooler. I had a wideband installed in my car and I used it and the 02 sensors to tune it, so I also know this is true. Also, consider what RPM LTFT are adj for? Hmm, I think up to 2200???


I'm for the airbox, I just wish one of the MFGs that make them would design it so the MAF would work right with it. The HP gain would be probably much higher. If you install an airbox and the car feels like it falls flat on its face, you are probably lean because more available, cooler, unmetere air is there.

 

And by the way, didn't want to hi-jack your thread. I like the Haltech products. Had one on my last car.

 

Still need to get around to doing this mod, Dave68 your write up (cold air mod) and review are great, thanks for your help!

 

Hey, if it helps, I'm happy! It does seem to go faster when a helper is there. I assisted a forum member in doing this mod and it took us no more than a few hours. The hardest part was getting his C5's front mask snaps off (held in by those screws under the front fascia). Most C5 owners don't have to worry about the snaps, two of which took a little bit of patience to remove, but they did come out.
You will notice the results - more power during stop & go and low speed driving, as well as during high speed runs.

 

Hey Dave, I read your artical in the Halltech tech site last year, it was one of the first mods I did to my 04 Z06 last July, works great.
Just as an note, I did the whole thing from the top side of engine. Just raised the hood, cut the hole in the shroud with an exacto knife, used double washers and rivets to make the attachments, it took me about an hour & half just taking my time, measuring twice, cuttin once.
Great mod!!! info was much appreciated.

 

Dave... great post!
Don`t let the skeptics get to you, the rest of us greatly appreciate your time and effort to provide us with this data.

Cheers, Rick
"long live the SCMR!"

 

RoHo,

That's great - ingenuity at its finest! I wanted to make sure I liquid-gasketed the "scoop" from the underside and that would've been a bit tricky from the top. I'm glad it worked out well for you.

Thanks, Rick! I figure if I can do it, anybody can!

 

Good info Dave. Also, as I see it, another big advantage to this mod is that it does not involve big bucks at all. If someone's not happy with it, or needs to return a car to stock for example, it is easily (and cheaply) done.
Robert

 

How did I ever miss this one? You guys have got this so screwed up even I can't begin to straighten this one out.

Happy to see I was missed though.

Well, I do have one comment. No such thing as cold air unless you run it through a fridgedaire. Ambient air is as good as it's gonna get.

OK, one more comment. No such thing as ram air unless your Vette does about 700 MPH.

 

To the king of dumb comments and the biggest hypocrite of them all, I salute you Korreck.

He runs a blackwing with a cut fan shroud........ no cold air huh?

 

It just wouln't be the same without him.

 

Sorry man,

But you don’t know what you’re talking about.

Force of drag equation states:

Force=1/2*(density*coefficient of drag*velocity^2*frontal area)

Plugging in some round about numbers of:

Coefficient of drag: 0.30
Density of air at sea level: 1.25kg/m^3
Velocity at speed: 70mph or 31.3 m/s
Frontal area of a vehicle: 2.2m^2

Will give you a drag force of 410 Newtons, or about 92 pounds force. These are not the numbers for the Corvette, but if you like, you can do the math.

Any time you reduce the effective frontal area of a car, say, by adding air scoops (Vararam for instance), you not only reduce the drag caused by frontal area, you create a ram air effect with the previous area that was causing drag. Let’s say the scoops on my V-ram are 4” high by 10” wide. This provides an area of 40 inches squared, or 0.026 meters squared. The force reduction on 92 pounds would be about 1 pound reduction. So not only are you reducing the frontal drag force, but you are converting that force into a ram air scenario.

Small as it may seem, it does have a noticeable effect, and that effect is affectionately referred to as “ram-air”.

 

I have a suggestion. If you went to school, ask for a refund. Let me make this simple for you and basic to what you just posted. You have not decreased the frontal area. You have increased drag, not reduced it. And then you convert this to ram air.

 

 

You guys want more? Chew on this.

It has nothing to do with the area of the car, there is virtually no ram air effect period. Air is essentially incompressible at subsonic speeds.
It's great to think that the forward velocity of a car is being converted into free supercharge, the actual air pressure gain is extremely small at automotive speeds. For example, at 150 mph, the pressure gain when air is efficiently brought to rest is 2.75 percent. Because this is a dynamic effect, it is proportional to the square of the air velocity. At a more realizable automotive speed of 75 mph, the effect (again with 100 percent efficient conversion of velocity into pressure) will be only one-quarter as great — that is, just under seven-tenths of one percent. In fact, velocity energy is not converted into pressure at 100 percent efficiency. A figure of 75 percent efficiency is usual, which reduces our notional ram-air gain at 75 mph to one-half of one percent.
So all the claims of the ram air crowd is MARKETING!! The best you can hope for is an UNOBSTRUCTED supply of ambient air.

I know for a fact 2000BSME is a little confused.


That's what I have with my Big Mouth Air Damn and Blackwing.

 

Confused? Doubtful. Regardless of the compressibility of air, frontal area is key in determining the Force of Drag, as well as the other variables that I outlined. Ram air is just what it is advertised as. Put your hand out of your car window at speed. See if there isn't a VERY positive pressure of air trying to push it back. Heck, let's just open up some holes in the front of the car and use that effect for air intake.

It works, and I'm sorry that you have to get upset, confused and make a personal attack at my education, based on your lack of ability to comprehend basic physics.

 

I see people going from other intakes to Vararam and getting better performance results.












.......But I never see anyone going from the Vararam to another intake and getting better performance results. Especially the Blackwing.





Has ANYONE HERE gone from the Vararam to the Blackwing and gotten better performance results than they got with the Vararam?

 

I'm not upset. You don't know the difference between dynamic and static. I'm amazed you would print what you did on a forum. Positive pressure. What kind of sense does that make? You don't have a clue do you.