Re: intake manifolds
You can see an operating line depending on the sc-map and the assosiated engine suction lines.
In stock you have a more then 3 psi (0.2 bar) higher pressure then nessessary because of the Y construction no pressure equalisation and way to small dimensioned (15 cm² - one feed). With the crossovers you always feed from 2 sides steadily (50 cm²). (
so the dynamic pressure drops the same as the operating pressure.)
The 3 psi pressure drop on max rpm on a stock car gives you 10 kW (
less supercharger loss) and additionally maybe 1% more volume flow. The pressure drop on lower rpms is far less because the pressure drop depends mathematically on the square of the volume flow.
Look on the map 10 kW gain on max rpm; less then 5 kW at 5000 rpm you cant find appreciable gains below according the sc map.
So back to my question many of you tell about the gain on low rpms. How does that work together - the facts: With the crossover you feed far more constant. When with stock imf an inlet valve opens you have a higher initial pressure which drops fast (change from 1 to 2 feed) maybe you have in stock version more oscillating air that matters most properly you loose some fresh air to the exhaust? What do you think?