Originally Posted by Concillian
But the single pull on the HTA68, you have no idea where it lies in the distribution of "good pull" to "bad pull". In only 3 pulls on the 18g, you see over 4% difference. 3% can be considered in the noise until you see more pulls to more accurately pin down the average.
Can you tell that statistical analysis is part of my job?
Full 3" will help some, I guess we have to wait and see to determine just how much of these turbos are magic. I'll be surprised to see identical spool (as these two graphs clearly show) and 25HP peak difference, but we'll see. I'll gladly eat my words if the data shows it. That's the thing about a well thought out objective analysis, you can actually get people to change their minds.
I'm a math teacher, although this of course means that I'm not a "real" mathematician!
There were plenty of other pulls, ranging from 340/370 to 305/350. There were several 325/360 pulls, but the motor started to heat soak and pull timing up top, which Dom said was mainly due to a restrictive exhaust.
He said this was as balanced as he could get on the STi catback. The pull I have showing was a maintainable pull on a heat-soaked engine. So I guess I really need the 3" exhaust (q300 is on order) to have a fully valid comparison with all else equal. I would be quite satisfied with a consistent 340/370!