Exhaust Manifold Absolute Pressure Sensor (EMAP)

[Hags86]

Any of you blokes out there running one? Got any feedback on their usefulness as a tuning aid or installation pics to share?

[gtengr]

No experience with them, but seems like it'd be useful for fine tuning the exhaust cam timing and overlap.

[Irace86.2.0]

Originally Posted by Hags86

Any of you blokes out there running one? Got any feedback on their usefulness as a tuning aid or installation pics to share?

I think EGT sensors are more popular as a tuning tool. Pressure is dependent on temperature and pressure changes will change temperature too, so I could imagine a pressure sensor being usful to validate temperature data, but I have no idea if it is a useful thing for tuners to have or if tuners are even knowledgeable about how to interpret the data.

[Hags86]

I have 1x EGT measured directly before the turbo I use as a safety for the anti-lag. "Collector' exhaust gas temp is not particularly useful in tuning though as it is an average across the 4 cylinders and then has a little time to cool.

I also have 4 extra bungs - one in each exhaust manifold directly after the head exhaust port - which get 4x EGT installed when it's being tuned on the dyno but get removed when done. You are correct in saying individual cylinder exhaust temperatures are a useful tuning aid. During the initial tuning we had one port injector not firing. The overall AFR appeared lean but with 7 of the injectors firing it was hard to know for sure, but with one exhaust gas temperature wildly different to the other three it was easy to find.

I've currently got a smaller turbo installed (GTX2863) which is running out of puff for the power I want to make. I'd like to use data rather than opinion to help select my next turbo and thought the EMAP might help with turbo/housing selection.

[Irace86.2.0]

Originally Posted by Hags86

I have 1x EGT measured directly before the turbo I use as a safety for the anti-lag. "Collector' exhaust gas temp is not particularly useful in tuning though as it is an average across the 4 cylinders and then has a little time to cool.

I also have 4 extra bungs - one in each exhaust manifold directly after the head exhaust port - which get 4x EGT installed when it's being tuned on the dyno but get removed when done. You are correct in saying individual cylinder exhaust temperatures are a useful tuning aid. During the initial tuning we had one port injector not firing. The overall AFR appeared lean but with 7 of the injectors firing it was hard to know for sure, but with one exhaust gas temperature wildly different to the other three it was easy to find.

I've currently got a smaller turbo installed (GTX2863) which is running out of puff for the power I want to make. I'd like to use data rather than opinion to help select my next turbo and thought the EMAP might help with turbo/housing selection.

Isn’t the data already supplied by the manufacturer—enough data? That is what the turbo compressor map is all about, right? While direct measurements might be better, and it sounds like you are a fan of going that route, shouldn’t the compressor mapping allow you to size the turbo for your application?