Here is the deal with intakes for the 2.0T FSI.....
The 2.0T FSI has a very uniquely shaped maf housing. The shape and diameter of the housing as well as the flow straightener integrated into the housing has a very direct and precise influence on the calibration of the maf sensor and how accurately the maf sensor reads.
In the past and on other VAG engines, the maf housings are not that unique and and the maf sensors themselves are not as affected by small differences in the housing.
All intake manufacturers followed their normal design and manufacturing procedures of recreating a similarly sized maf housing for their product which to insert the maf sensor. During initial prototyping, most intake manufacturers use a more precisely manufactured housing than when they go into production.
Almost all intakes currently available to this day that include a new mounting point for the maf sensor are manufactured with methods that do not allow for precise enough tolerances regarding the diameter of housing around the sensor and can be too large and too small to a point that creates improper maf readings. They can also be spot on.
Some intakes currently available to this day also include mistakes in the design regarding the specificity of the shape, flow straightener and placement of the maf sensor, which was not as important on previous VAG engines.
APR and Carbonio have tried nearly every method of cost effective manufacturing to repeat the tolerances required to ensure that every intake we would sell would be sized properly for the maf sensor's calibration. APR and Carbonio have tested batches, usually 3-5, of nearly every available intake for the 2.0T FSI.
We have found that sometimes you can get a perfect maf sensor reading and sometimes you can't. The manufacturing processes used simply don't allow for precise enough results. We have tested intakes made from bent tubing of various metals, plastic injection molding, rotoformed tubing, plastic cast tubing and carbon tubing.
The most cost effective method available to ensure the repeatability of the maf housing area in the intake is cnc machining a metal, most specifically aluminum.
There are no intakes available (other than our Stage III maf tube) that are made with a cnc maf housing. ITG uses a metal tubing that has fantastic tolerances but they are as expensive as cnc machined housing whereas the waste during quality control when measuring the internal diameter of the maf sensor location is very high. ITG has recently changed manufacturers of the metal tubing to find a way to reduce costs but that resulted in random tolerances like all other intakes face and they are about to release a machined insert for their intakes that fixes the issue.
That being said, the problems you guys "feel" with different intakes and the different results people experience with the same intake are all due to wide variances in the size or diameter of the maf sensor placement. Some other intakes have some inherent design flaws as mentioned above that exacerbate this problem even further but most people know which ones those are and generally stay away from them.
Scientifically and completely without doubt, a properly designed and manufactured intake for a 2.0T FSI with k03 or k04 turbo will result in faster spool, better throttle response, more top end power, better fuel economy and overall increases in the efficiency of the engine's operation. Any results that you guys have experienced that differ from this are due to the maf sensor placement, manufacturing repeatability or a design mistake.
APR and Carbonio tried to bring a design similar to our 2.0 TSI Stage 2 intake pipe to market that would also use our 2.0 TSI Stage 1 intake like pictured at the beginning of this thread. We tested 10 of an initial run and all was well. However, we then ordered an initial production run of 200 and found that random sampling resulted in random results and never released the product as we've searched for a better solution.
ITG makes the intakes for VWR and APR and Carbonio tested those intakes to find that the repeatability was very good and the best we had tested. Therefore, APR and Carbonio abandoned the Stage 2 intake project and we recommend the VWR intake to 2.0T FSI clients that want more than our current Carbonio intake, which consists of a new front scoop and panel filter for the standard airbox. The caveat as mentioned above is that ITG switched tubing vendors and had to develop the insert to correct the issue presented by the new tubing vendor.
The standard airbox cares about a lot more than response, fuel economy, power output and efficiency. NVH, which stands for noise, vibration and harmonics, is a separate engineering discipline that is accomplished after the initial engine design and is a science of restriction regarding intake systems. Much like exhaust systems, the only way to reduce NVH in an intake system is to add restriction. This means that there are almost always gains to be had when replacing the standard airbox simply by undoing the design characteristics dictated by a desire to reduce NVH in standard cars. Also, OEM's are almost always looking to reduce costs and the filters used are very restrictive as well because to get high filtration and low cost, the filter has to be restrictive, no way around it. To maintain the level of filtration but get a better flow you have to move to a cotton gauze or foam filter and the costs are much higher for these kinds of filters.
If you feel your intake is not doing its job, there are simple testing procedures you can do....
A. Replace the intake with standard airbox and see if things are better
B. Use VCDS to determine your long term fuel trims and ensure they are within +/- 0-5%
