RS6-4dr911
January 16th, 2010, 23:01
A cold rainy day, decided to pass the time crunching numbers and making pretty graphs.
Anyone know what to log to find the effectiveness of the intercoolers? I could only find ambient air temp and intake air temp. I don't know where the intake air sensor is located however, so I'm not sure if I'm measuring before or after the intercoolers. I suspect it's after as the temperatures are in the range of mid 30's to mid 40's. This is in the range of some of the "after" readings of the Wagner graphs. What makes me wonder is that the intake temps actually decrease with RPM, not increase as shown on the "before" curve of their graph. Those curves were supposedly done with a tuned engine running more boost and I'm still stock. In thinking about, it could make sense that the temp would decrease since the air velocity is increasing, reducing the residency time in the turbo, soaking intercooler and actual intake. Which makes you wonder about the Wagner graph, as many have done already.
When I plot the somewhat spotty data, the trendline after several runs of before and after, nearly identical ambient temps, show the Apikols dropped the intake temp several degrees (C). Ideally, it would have been nice to have had a sensor just before and just after the actual intercooler but in the absence of that, intake temp seems to be a good proxy, especially with identical ambient temp's.
Not unexpectedly, maximum boost gained maybe 30-50 mBar over the leaky OEM units. That is the only explanation I can find for the intake temp curves starting to cross at the upper RPM range since boost is higher "after" than "before".
MAF's readings are still off at part throttle but at full throttle they are now within 10% or less, enough for me to leave them alone for now. So the lesson in this is, if you're getting MAF error reading codes, and large differences between them, look first to leaky intercoolers, not the MAF's themselves.
Anyone know what to log to find the effectiveness of the intercoolers? I could only find ambient air temp and intake air temp. I don't know where the intake air sensor is located however, so I'm not sure if I'm measuring before or after the intercoolers. I suspect it's after as the temperatures are in the range of mid 30's to mid 40's. This is in the range of some of the "after" readings of the Wagner graphs. What makes me wonder is that the intake temps actually decrease with RPM, not increase as shown on the "before" curve of their graph. Those curves were supposedly done with a tuned engine running more boost and I'm still stock. In thinking about, it could make sense that the temp would decrease since the air velocity is increasing, reducing the residency time in the turbo, soaking intercooler and actual intake. Which makes you wonder about the Wagner graph, as many have done already.
When I plot the somewhat spotty data, the trendline after several runs of before and after, nearly identical ambient temps, show the Apikols dropped the intake temp several degrees (C). Ideally, it would have been nice to have had a sensor just before and just after the actual intercooler but in the absence of that, intake temp seems to be a good proxy, especially with identical ambient temp's.
Not unexpectedly, maximum boost gained maybe 30-50 mBar over the leaky OEM units. That is the only explanation I can find for the intake temp curves starting to cross at the upper RPM range since boost is higher "after" than "before".
MAF's readings are still off at part throttle but at full throttle they are now within 10% or less, enough for me to leave them alone for now. So the lesson in this is, if you're getting MAF error reading codes, and large differences between them, look first to leaky intercoolers, not the MAF's themselves.