I'm not really wanting to get into a big to-do about this, and perhaps it's been addressed in another thread already? I like the guys that make the part, I don't have, nor do I want to or intend to make a competing part. But the part is flawed and that flaw is a big issue to IPS cars and S cars particular, IMO (and Lotus’s).
The problem is that there was a general lack of understanding about MAF based systems when the part was designed. The strategy used broke a few fundamental rules that should be respected with a MAF based EMS.
1) The ID of the MAF tube was *changed* from OE specification. Any change in the ID of this portion of the intake (where the MAF is located) will have a significant impact on the calculated airflow. When the airflow is miscalculated, the calculated engine load becomes incorrect or different from what the ECU expects, and that can impact a whole host of things--- like the fuel and spark introduced to the motor.... and the shifting on an IPS car. We know that the ECU is miscalculating load in this particular application as a result to the intake.
2) There was no air straightener incorporated to the CAI intake system like there is on the stock system and the MAF sensor is in proximity to a curve. Without a straightener, airflow metering becomes unstable and will change erratically based on air speed in the tube. This lack of air straightener contributes to more of the problems as explained above.
3) The filter used is an offset design. We've seen firsthand in the data that the orientation of the filter will impact, greatly, the metered airflow which is certainly a problem working in concert with the lack of an air straightener.
After looking at a lot of data from cars with the CAI intake system, the power it "makes" is not primarily due to airflow or availability of air to the motor. Rather it's due to manipulating the measured airflow the EMS "sees" that results in a significant leaning of the AFR and greater spark timing due to “tricking” the ECU into miscalculating the load. Consequently, the IPS cars will tend to not shift correctly and possibly fail. As for manual trannys, the issue isn’t the tranny, but rather one car may run differently than the next, and “differently” is outside of what the Lotus or otherwise engine tuner had in mind. IMO, the S cars should tread very lightly when considering changing the intake as well since they’re more susceptible to engine failure from ECU load manipulation.
For those of us who have been around the lotus scene for a while, a similar learning curve took place on the 111 platform circa 2006ish… (Good-gawd, time flies, it's ~2013!!