I have never had a turbo before and am trying to understand how the turbo works. I have read on the forums about Peak @ 21psi, holding 18psi. How does it work and when does it happen? Is peak boost when the turbo first spools up and you get that initial kick? When it drops from ‘peak’ to ‘hold’ should you be able to feel it? Why can it not peak and hold the same pressure?

Is there anything that can effect the holding pressure? Leaky dump valve? Weak actuator

Any info would be great.

 

as you said really, the peak is usually the kick and boost noramlly tails off towars th top end of the revs (if the turbo cant flow enough air - like on smaller turbo cars) or the chip has been programmed to do this from a safety point to help protect the engine.

and yes. air leaks including from the DV would affect this aswell as old, sticky weak actuators.

 

Thanks

Stu

 

Weak actuators are a bugger. My first Saph Cos used to peak at 20psi and hold 12psi!!!!!! a brand new -31 soon sorted that.

 

yep, mine boosted at 10psi, and held at 6psi. And that was after the boost controller top fell off, with it on, it boosted at 6psi and held at 4. HAHA. Aswell, a -31 sorted that