: Question about the factory air intake...



weister42
03-15-07, 06:18 PM
Concerning the Northstar engine:

The diameter of the throttle body is 75mmm(little less than 3 inch), the plastic air tunnel is about 3.3"(counting the tube is 3.5"), the hole between the air box and the housing underneath is 3.5", and the actual air inlet behind the driverside headlight is a 4.25" x 1.25" rectangle with agressively rounded corners.

The total surface area of the actual air inlet(4.5 x 1.25) is 5.3125 square inches(smaller if you shave off the corners), and the surface area of the hole underneath the air box(3.5" circle, so Pi(3.14) x 1.75^2) is 9.61625 square inches. So, the actual air inlet is quite smaller than the rest of the system, not sure if that actually affects maximum air velocity?

codewize
03-15-07, 06:53 PM
What car are we talking about? Again it's not the velocity we're concerned about it's volume (mass).

weister42
03-15-07, 07:24 PM
I'm talking about the Northstar engine(vin Y) in my car:bouncy: I was just thinking what if the inlet was as big as the rest of the system, would that make a difference?

Ranger
03-15-07, 07:57 PM
Make a run with no filter, box or ducting. Take everything off after the MAF and see if it makes any difference.

eldorado1
03-15-07, 08:50 PM
Make a run with no filter, box or ducting. Take everything off after the MAF and see if it makes any difference.

BTDT GTT-shirt :highfive:

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/100904-few-numbers.html

codewize
03-15-07, 09:05 PM
Oh ok. I saw something about the inlet in the bottom or a hole in the bottom of the airbox? I'm not familiar with that set up. In my DTS the inlet is a HUGE hole going through the panel behind the left headlight.

On the airbox itself there is a horn shaped tube I believe to reduce noise and maximize flow? That's not very large but the hole it penetrates is giant and the hole in my Volant box if even larger.

I was just curious about the differences between the two cars.

weister42
03-15-07, 09:17 PM
Ranger do you mean BEFORE the MAF sensor? Thanks for the info eldo1, so our engine lost a little bit of power through the factory air intake system, he's not sure if it's due to the air filter itself or the entire system though, one more dyno run with the intake system intact WITHOUT the air filter is needed to conclude the beat-to-death subject of "air intake mods."

Ranger
03-15-07, 10:29 PM
Yeah, leave the MAF on and let her breath from there. That should give you a pretty good idea if the intake box/filter/ducting is restrictive or not, on a dyno.

1997BlackETC
03-17-07, 12:36 AM
More than likely will not make much of a difference with stock computer tuning. I wonder if Westers can provide an option for a cold air intake system on the northstars? This might be the ticket to extra hp.

CadillacSTS42005
03-17-07, 03:02 PM
again
without people giving me their vins and service numbers from their computers nothing will develop, everyone keeps sayin cool, no ones getting me the info....

clarkz71
03-17-07, 05:16 PM
This sounds alot like the throttle body deal Eldorado1 went through. Evrybody wanted one until it was time to commit. We'll see how many vin's you get.

AlBundy
03-17-07, 05:47 PM
Mine will be posted tonight. Been very busy with work.

codewize
03-17-07, 09:42 PM
First of all someone JUST recently posted dyno graphs proving that you're wrong. Running the car with no airbox and the MAF in open air increased the engines output by 18HP so anyone that thinks the factory intake isn't restrictive or doesn't matter is dead wrong.

The restrictions are mostly the sound deadening factors in the box and the ducting. More air = more HP period. we've said this a million times. Computer tuning isn't going to do crap. The secret to N* HP is more air in and more air out.

Yes I have suddenly become an expert on this. Why because I listen when I am shown solid proof.

Over the last few days we have been shown that
a) Adjusting the air fuel ration will have no affect at all on a N* due to the fact that the combustion chamber is almost 100% efficient which rules out any possible gain form an aftermarket MAF.

b) We have also learned that a GM drive-train engineer has told us outright that there is only one way to increase the output of the N* and that's more air in and more air out. A free flowing exhaust starting at the engine with a CAI will increase HP.

c) We have also been told several times that a CAT back system is the least of the problem. The bottleneck is the crossover pipe.

So knowing all this info and having hard proof and reliable sources why do we keep asking? The dyno doesn't lie.

I'd be willing to do this ONLY with a money back guarantee. Dyno run before and a dyno run after. Anything less than 30 HP gain I get my $400 back. Knowing what I know I don't think it's going to happen.