npr looks way too small
02-23-04, 04:52 PM
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npr looks way too small
I was sizing the NPR intercooler, and it looks like it's WAY too small to have low-restriction in the intercooler. At only 6 lbs boost at 7000 RPM the engine needs about 380 CFM (if it's running 85% VE).
Now 380 CFM requires about 42 sq-in of area for the Charge Air to flow through in order for it to flow enough to not cause major restriciton. (it's 42 because about 45% of the width times thickness is available for charge air to go through, because ambient air tubes take up at least half of the space, and then you also have the thin walls and turbulators also).
So, that leaves us with a 2" intercooler core (which the NPR is 2" thick) needing to be 21" thick at LEAST in order to run at only SIX pounds of boost. The NPR is 19.5". If we went up to 10 lbs boost we require 460+ CFM at 85% VE, and there's no WAY the NPR could flow that without being restrictive.
Any thoughts on this?
Now 380 CFM requires about 42 sq-in of area for the Charge Air to flow through in order for it to flow enough to not cause major restriciton. (it's 42 because about 45% of the width times thickness is available for charge air to go through, because ambient air tubes take up at least half of the space, and then you also have the thin walls and turbulators also).
So, that leaves us with a 2" intercooler core (which the NPR is 2" thick) needing to be 21" thick at LEAST in order to run at only SIX pounds of boost. The NPR is 19.5". If we went up to 10 lbs boost we require 460+ CFM at 85% VE, and there's no WAY the NPR could flow that without being restrictive.
Any thoughts on this?
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