Helpful link on turbos

That is what turbos do! Glad you are starting to educate yourself on FI from your last thread.

That's a reasonably good collection of information for a starting point, but there are a few mistakes and untrue statements. Here is the first one that jumped out at me:

Turbo lag is caused by the turbo having to spool up after venting out all it's compressed air when the throttle plate closes.

Click to expand...

Not really... turbo lag is the result of two factors: insufficient airflow to spin the turbo fast enough, and inertia of the rotating parts of the turbo. When you first spool up the turbo, at low rpms there isn't enough exhaust flow to get the turbo spinning fast enough to make boost. That is the traditional concept of turbo lag. As the author mentioned, you can also have lag between shifts. When you close the throttle plate, you cut off all the exhaust flow to the turbo, and the compressor slows down significantly to stop making boost. When you get back on the throttle after the shift, then you have to get the turbo spinning fast again, and it takes a moment to overcome the inertia of the turbo (change the speed from maybe 40,000 rpm to 100,000 rpm) and build up the airflow.

Turbos are great fun though! If you select the correct size, they can make huge torque in the mid range and efficient top end power. Compared to a centrifugal blower, a properly matched turbo can make more power everywhere for the given boost level, because it has a much higher efficiency. Compared to a positive displacement blower, the blower will always make more low end torque until the turbo gets spooled up, and then the turbo is more efficient.

Good link