24-01-2013, 11:34 AM
I don't know any that run a charge air temp sensor unfortunately.
It's obviously logged in development vs IAT, and for a standardised intercooler or non-intercooled system is probably just sits in a trend line with engine coolant temp or oil temp etc.
Generally you have enough control in other maps to compensate for the higher charge air temps. Ie, at high injection amounts at high rpm, you can assume it must be on boost to make the high injections, and so you can tune in the knowledge that IAT is always within a certain range at that point. If it varies it probably only does at that point due to coolant temp or oil temp etc.
It's not ideal, but it was probably deemed acceptable. It's not ideal for tuning a car because all these basic mappings are kinda built into many tens or hundreds of look up tables.
When you delve deeper and deeper it's surprising how much tuning is done in so many little maps all over the place. They are fine left alone most of the time but as you change too many things then they can become important.
Ie, the mappings all expect that IAT is around 0 - 5 deg above ambient, and it's right in assuming that until you change it.
Who knows what the impact of changing that are... but I'd say anything that increases IAT is just bad full stop. It's de-tuning and there is no other way to sell it.
Dave
It's obviously logged in development vs IAT, and for a standardised intercooler or non-intercooled system is probably just sits in a trend line with engine coolant temp or oil temp etc.
Generally you have enough control in other maps to compensate for the higher charge air temps. Ie, at high injection amounts at high rpm, you can assume it must be on boost to make the high injections, and so you can tune in the knowledge that IAT is always within a certain range at that point. If it varies it probably only does at that point due to coolant temp or oil temp etc.
It's not ideal, but it was probably deemed acceptable. It's not ideal for tuning a car because all these basic mappings are kinda built into many tens or hundreds of look up tables.
When you delve deeper and deeper it's surprising how much tuning is done in so many little maps all over the place. They are fine left alone most of the time but as you change too many things then they can become important.
Ie, the mappings all expect that IAT is around 0 - 5 deg above ambient, and it's right in assuming that until you change it.
Who knows what the impact of changing that are... but I'd say anything that increases IAT is just bad full stop. It's de-tuning and there is no other way to sell it.
Dave