Before I put the GM CAI (SLP type) in, my MAF readings with the Ligenfelter intake was around 12 grams per second. Now with the GM intake, at idle, fell down to 6gps. Not really sure if I have a leak between the MAF and CAI, I had to use electrical tape as a fast fix because it's going to paint the shop tomorrow.

But if all is accurate, the Ligenfelter flows relatively better than GM/SLP. Atleast 6gps better

I'll get some more #s when I get the car back.

 

You can't use the MAF readings as a measurement method for restriction. The problem with the SLP design (GMPP) is that you have two converging air streams just before the MAF sensor. This can cause air turbulence at the worst spot possible (just before the sensor). If I were to guess, I'd bet you don't have the screen on your sensor anymore. The screen will help stabilize the air and give you a more accurate reading. Even so you might be better off with a different CAI (see below)

Another problem with the SLP style intake is the filters are very small and the pleat height is about the shortest in the market. These limitations produce a filter that doesn't have very good loading characteristics and produces more restriction at high flow rates. Each filter will flow about 300 CFM but at a higher restriction. In an engine, CFM is what you are after and restriction is the enemy. Hope this makes sense to you.

Scott

 

well I have an SLP and it flows at 6 grams/sec on idle. but then again my car has it's issues.

 

My MAF screen is still in place. Wouldn't this data show that one flows better than the other? I don't understand why it wouldn't. I just thought it was a pretty big drop from Ligenfelter.

 

Your data merely shows that something is affecting your MAF readings. Either the change in the CAI was enough to upset the MAF calibration (the calibration table is in part determined by the configuration of the air inlet track), or you have the air entering the engine by some other means.

Your engine takes a certain amount of air and fuel to idle. That "amount" doesn't change based on what your air inlet system looks like. If you put on a super efficient CAI, and there was less pressure drop in the air inlet system, the "mass" (pounds) of air entering the engine would increase by a very TINY amount, due to the fact the intake manifold pressure (MAP) would be higher, causing the cylinder fill to be denser. But, since you engine doesn't need that extra air mass to idle, the IAC would close down slightly to bring actual mass air flow right back to the exact amount your engine needs to hold the specified idle speed.

Do you really think that the air flow through the CAI dropped by 1/2 because it is somehow "better"? Doesn't work that way.

 

Measure MAF g/s @ WOT (wow..that's alot of acronyms ). More g/s @ WOT = less restrictive.

Can you back that up Fred?
Ryan

 

Well Put Injuneer Fred!!

To make another suggestion, make sure you plugged the vacume line in for your OPTI (if you have a vented style). Check to ensure your intake elbow isn't folded over under the TB and allowing air to enter from behind the MAF sensor. I had this happen once and never noticed it until I took it off months later (no SES light or anything). Let us know what you find.

 

Yes... at WOT, a lower pressure drop in the intake system makes a difference. Maybe your MAP was running 95kPA at WOT with the old CAI, and the reduced pressure drop has increased MAP to 98kPa. That means the intake charge is denser, and the air in the cylinder is denser = more mass in the cylinders = add more fuel to that mass = make more power. The gps shown by the MAF should increase to reflect that small improvement in density/volumetric efficiency. But, that's still only going to be about +6 gps on a stock engine, with the MAP numbers I used for the example.