ken_b asked about my power numbers in another Foo thread - [webmasterworld.com
...] - and I gave a partial answer. For anyone who cares, below is a more complete answer.
As you all know I had my car dynotuned last month. I previously had it tuned at the same location January of 2012. I got the run files from January today and took a look. Max numbers were:
2012 2014 690
687 Horsepower 669
Appears that HP number is down slightly and the Torque numnber is up noticeably. A closer look reveals interesting info. First off, maximum HP on the 2012 pull (690.09) came at 6230rpms. At this engine speed the HP on the 2013 pull was 686.05 - off about 3 HP.
However, at 6430rpms the HP on both pulls was virtually identical at 685. So really the HP levels of the 2012 and 2014 pulls seems like a tie. Nope, but I'll get back to that after we look at the torque numbers. (Note: you can skip over the next two paragraphs if numbers make your head spin)
There is a marked increase in torque in the middle of the rpm range on the 2014 pull. As you recall from the above chart, 2014 maximum torque was 688.58 ft/lbs. This came at 4172 rpms. The 2012 pull at the same rpm level registered 668.75 ft/lbs. THe 2012 maximum torque of 669.75 registered at 4542rpms. The 2014 torque at that rpm level was still 16 ft/lbs higher.
You don't have to remember this but in case you want to know, the formula for calculating horsepower is Torque X RPM / 5252 (the horsepower/torque curves will always intersect at 5252 rpms). Assume a torque level of 685 at 4542 rpms, plug it in: 685(ft/lbs of torque) X 4542rpms / 5252 = 592 horsepower. This number is confirmed by my dynojet graph. (OK, you can start reading again)
I guess I said all that to say this: HP and torque are about a wash between the pulls at higher rpms. But in the mid range
, I'm running as much as 20 ft/lbs of torque more on the 2014 pull vs the 2012 pull, and almost 18 horsepower more in the 2014 pull than the 2012 pull.
The take away is this - just looking at the maximum numbers posted on the graph doesn't tell the whole story. For those of you interested ONLY IN HORSEPOWER NUMBERS, it is NOT a tie as we figured above; I'm actually up nearly 18 HP.
Differences between the two pulls - 72 lb injectors on the 2012 pull and 80 lb injectors on the 2014 pull. I also installed Magnaflow resonators (straight through pipes) before the rear axle between the two pulls.
Are there any questions?
[edited by: lawman at 5:01 am (utc) on Apr 12, 2014]