Quote:
Originally Posted by taibanl
Now that you mention it isn't it the big turbo from low RPM and a small turbo at high rpm?
|
No, it's quite the opposite.
Small turbo requires less exhaust gasses to run up, but runs out of puff, i.e. reaches max capacity early on. Large turbo is able to feed the engine with more high pressure air to develop more power, but takes longer to spool up (lag). Hence the need for both - small turbo delivers shove at low revs where there is not much coming from the exhaust, then large turbo takes over to give the big power figures once the revs have built up sufficiently.