Smooth -


Lumpy -


I don't know enough about Dynapacs to be able to tell from the above whether the 'scaling' is the same or not?

Edit - just read Clint's post re: hp increments.

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MY09 Evo X - 1.6bar@3500rpm - got lag?
Barbagallo - 56.03 (S); 1:08.09 (L)
Collie - 50.77
Possibly the most under-driven Evo X in the world??

That is much nicer. Very smooth.

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RS Liberty - Because WRX's are only good for parts...

Way to miss the point

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MY93 Impreza GX 1.8L, 0hp, 0nm

The scaling looks to be the same. So what is your point?

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RS Liberty - Because WRX's are only good for parts...

ones in 10hp increments the other in 20.
same same but different

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MY93 Impreza GX 1.8L, 0hp, 0nm

However the 10 hp increments are spaced half as far apart. You can see the similarities in the grid spacing. They both have the same scaling.

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RS Liberty - Because WRX's are only good for parts...

This is my graph and its 3" all the way from the dump. Obviously mines not twin scroll though.

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[COLOR="Red"]I have the right foot of Subaru death![/COLOR]

[SIGPIC][/SIGPIC]
365hp and 515nm

New Beast to arrive April 2015 - 365hp, 450nm, 0-100 in 4.4sec. AMG Goodness!

I think the jury is still out on the 'advantages' of a 2.5" rear section of an exhaust. Until I see hard evidence in the form of a comparison dyno i'm taking those kind of recmomendations with a serious grain of salt.

As for the explanation of why the 2.5" is better because it "maintains the gas velocity as it cools" is total shit. You can't disobey the laws of energy conservation and get something for nothing. Increasing the velocity of a fluid in a pipe by reducing the diameter comes at the cost of pressure loss, which creates back pressure (in other words a resistance to flow) and back pressure is the enemy of the turbine (in regards to operating efficiency).

What it would come down to is optimising the design of the engine, because maximum torque and where it occurs is a result of the inlet, valves and cylinder designs and how fast you can achieve that optimum AFR. Thing is though an engine will eventually choke at high rpm as the physical size of the inlet and valves etc become a bottleneck (a turbo helps here to shove that air in!) as well as mechanical inefficiency and we see that characteristic torque die-off.

Taking a stab in the dark, i'd say that backpressure from the exhaust side helps to keep some remaining unburnt air in the cylinder or something like that... We do know that it has an effect on torque if there is too little though, especially in NA cars.

For a turbo car though, the biggest form of backpressure is from the turbine housing, not the main exhaust. Plus, earlier and smoother turbine spooling comes from reducing the backpressure in the dump as low as possible and an earlier and more efficient spooling turbo = more air flow to the engine inlet = more power. A lot of factors at play here.

So yeah, I want some hard evidence

The grid spacing may be the same distance apart, but the fact that one graph has half the data points of the other graph, means it will be 'smoother' due to the interpolation that the machine must do.

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[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]

as john has said,

half the data points produces a smoother graph.

inject more data points and you will see a lumpier curve.