Quote:
Originally Posted by spooled240
I dont quite agree with this because you're assuming all wastegates are the same design. Yes, in theory this makes sense, but the whole point of a wastegate is to take some of the exhaust flow away from the turbine wheel and theres strong evidence that suggest different wastegates do this more effectively based on positioning. Take a look at the v1 Xcessive manifolds and their spiking issues. They remedied the problem with their v2 by angling the wg valve more toward the collector against the direction of exhaust flow. There are other variables at play here such as manifold runner design, valve size, EGT, etc. but angle this 90 degrees or even in the opposite direction and it just doesnt work as effectively, plain and simple.
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What you are describing is a constant, not a variable.
Wastegate 1 has an efficiency rating of 55%
Wastegate 2 has an efficiency rating of 75%
Due to their designs, 2 is more effective than 1, always, consistently, constantly.
Lets say we port #1 and make it more effective than 2,
the result will also be constant.
Constants never change and when we take the differential of volume flow rate or change in pressure over time they drop out completely as additive variables, not part of our solution. When taking an integral function they factor out and when we try to integrate a variable they appear as a + constant on the end of an equation which describes an infinite series of possible constants we might plug in, but the overall shape of the curve remains unchanged.
More constants makes the math easier to look at, easier to deal with.
In all of my above examples the effectiveness of the gate or efficiency of the gate, due to angles, design, shapes etc.... is not needed because whatever it is or was at the start of our testing never changes, it remains a constant, so it can be neglected. In other words, in a real world application the gate is set at the beginning of the test, and its the same at the end of the test. All we changed is the dowpipe. So whether the gate was 25% or 75% effective due to it's design will not be a factor during our testing, that is we don't need to worry about the gate becoming MORE or LESS effective because it won't magically port itself while we are running our test.
It seems like, in your head, you are changing both the downpipe diameter AND the gate design between tests. When really, the gate never changed, the design or angle or shape, nothing changed when we altered the downpipe and ran the second test with the larger upgrade exhaust diameter, e.g. we didn't upgrade the downpipe AND the gate at the same time, we just changed the DOWNPIPE ONLY and left the same wastegate intact.