for data logging so we couldn't capture all the variables we'd have liked to, so we captured what we felt was most important. That was speed, MAF, rpm and IAT, throttle position was also logged. The main goal was to try and get some comparitive data, and to do that we tried to ensure the conditions were similar for each intercooler. Michael did some seperate logs with the IPP intercoolers where we captured boost, but he'd already taken the stock IC's out so a comparison wasn't an option with them. I don't think there is any solid conclusion to be drawn from the FATS in terms of affect on HP, the TC was happening too soon.

Here's something to consider on that point though. If the ECU is able to make requested and actual boost match, any HP gains should only be a result of lower intake temperatures, not pressure drop, though those two are tied together. There were some fairly impressive HP gains noted when the IPP IC's were dyno'd a while back by Bruno_S4. He made the following remark about boost levels on his car: "Used to see 17 peak 14/15 hold. Now after IPP IC's see 19 peak 16/17 hold" That type of boost increase should lead to a substantial HP improvement. But in the case of LI-S4's APR code, once the boost exceeded what the ECU was requesting it started to TC.

My observation of data that has been made available is that with software that doesn't TC when actual boost is greater than requested, if you can reduce the pressure drop through the IC, that improvement can translate directly into more boost - thus more power. Perhaps the AMS software Bruno_S4 used was requesting 16/17 psi, but boost had been limited to 14/15 psi due to the stock intercoolers, a log of that car might answer the question. On Michael's 3- car with APR K03 code, the turbos could easily meet requested boost and then some. The ECU would TC with the excess boost. As I mentioned in the write up, TC happened on both the stock and IPP IC's, but more often with the IPP IC's. I interpreted that to mean the IPP IC's caused less of a pressure drop than the stock IC's.

The bottom line is, I think if the turbos can meet the boost requested, the only way the IC is going to help make more power is if the intake air temperature is lower. On the road tests we performed we did not find any conclusive gains in temperature drop of the IPP intercoolers over the stock ICs.

National Motorists Association