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hobieboy hobieboy is offline
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Join Date: May 2002
Location: Up North
Posts: 1,446
Originally Posted by DW SD View Post

Doesn't (V)olume stay constant between the turbo pressure side and the combustion chamber at a given moment in time?

The examples about the tires and straws are good, but I think in this case, the volume is fixed in time.
Doug, yes... that is why my original question: how does bigger turbo generate more hp. And we are talking 25-30% more so a simple 30degF drop in air temp won't cut it

But, if I understand it correctly now... pressure builds when the fixed volume is completely filled. For an engine, it can be: a) while the valves are open (then turbo fills air in chamber then the rest of the intake track), b) when valves are closed (then just the intake track).

I suspect a small turbo will not fill the chamber as well as big ones BEFORE the valves closed. Hence, the peak boost reading really comes AFTER the valves closed.

If not, I am back to asking: how?

BTW - I am certain my IAT sensor is working properly to a good degree & reacting fast enough. For reference - even coming off the track, the output side of my intercooler is stone cold. So, for temp to be stable at 15-20degF higher throughout the run is believable IMHO.
87 930 K27HFS/B&B/Twin-Plug... Megasquirted
Old 07-17-2008, 06:40 AM
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