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Discussion Starter · #1 · (Edited)
I've seen several people (Jim V, MJChip) allude to '03's running richer when adding long tubes.

Popular wisdom is that they should, with the same tune, run leaner, But that doesn't seem to be true.

I have a theory. As can be seen in my other posts, I am concerned about the efficiency, or lack thereof, of the Eaton at high boost and high RPM.

One of the drawbacks of a roots blower, is that no compression of the air takes place in the blower. Because of this, the pressure in the blower is less than the pressure at the blower outlet, which causes a "boost stackup" and reversion back into the blower.

When you add long tubes, you make the engine which is really just a bigger air pump than the blower more efficient. Now with the scavaging effect of the long tubes, the engine will accept more air that you are trying to cram into it with less resistance. Boost may drop compared to pre long tubes. With lower pressure at the outlet, the blower is more efficient. Since the blower is consuming big power (150+ hp), even a slight increase in blower efficiency would allow more net HP to the wheels with engine actually needing less fuel.

What do you think?

JT
 

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sounds pretty reasonable to me! I think our blowers is what's truely going to be the limiting factor on our cars! I hope they put the lysholm on the next cobra! and that it will swap over to our cars? The K/B is just a little to pricey for me! good info JT!
Leon
 

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John , Your on the ball, You and I will tune the maf On my car.
Keep thinking, , I posted my car went richer with long tubes, weeks ago, Boost lost, blower eff. boost coming on so soon,
But when you tune to it :) :D
 
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