Does the ECU really limit boost when cold? at what temp?
Hey guys, this is purely for my own interest, as it's something I've been wondering for a while.
It's commonly said on here that the ECU limits boost when the engine is cold, I've even said it to others myself before, but I do not know the exact details of how it does this.
Does the ECU definately limit boost (obviously via the N75) when the temp sensor senses cold water in the system, and if so, how much does it limit it by, and what is the cut off temperature at which it allows full boost? it it a stepped limit of Low boost then full boost above a given temp, or is it incremental?
The reason I ask is this:
my stat is stuck open, I know this, and it takes AGES to warm up.
Today, I left work, and the car heated up to 90 whilst stood in traffic, I floored it comming onto the A31, and it flew, boosting 19psi
After 5 mins cruising along the A31, due to the VERY cold winter air and an open stat, the car had cooled to 61 degrees (climate49 viewing). obviously the block and oil were warm after 25 mins driving, but the coolant not so.
Comming off a roundabout onto the A331 I floored it again, and it felt a little sluggish, and only boosted to around 14psi, instead of the typical 19-20.
then, at the end of my journey, in slow moving traffic in town, it warmed back up to around 85, and the boost was back in full.
Sorry for the randomness of this post, I know I need to change my stat, I'm just intereted to know the exact details of how much it's limited, and at what temperature this limit is lifted.
Thanks for reading my epic long post