Hey,
I have a question about boost. Many people say boost is not RPM dependent, it is exhaust flow dependent. Now what I dont understand is wide open throttle? What exactly is it? How does that relate to boost? Do I have to be at WOT to produce any boost? Thank you.

 

The wastegate controls boost.

 

Where to start?....

I'll try to explain it as simply as possible...

Exhaust gasses cause the turbo to spin, the faster it spins, the more air it pumps into the intake manifold and the more boost it produces. That said, it is somewhat RPM dependant because at higher RPMs exhaust gasses are coming out faster and spinning the turbo faster, thus creating more boost.

Did that make sense? I'm sure someone else can explain it better but I thought I'd give it a try!

 

i was thinking boost was more load dependent.

 

boost is load dependant.. if you apply enough throttle, you will start building boost, and you don't need to be at wot.. ho soon your turbo spools will depend on turbo specs (compressor and turbine size), so i till take longer for larger turbo to spool while smaller turbo can spool much earlier...


besides engine and turbo.. manifold, type of wastegate, intercooler and piping will play a role in how your car responds with boost..


maybe this will help too: http://auto.howstuffworks.com/turbo.htm

 

when desired boost is reached.. the wastegate bleeds off the exhaust so the turbo keeps a constant boost.

every other part indirectly affects boost.. but the wastegate controls it