Daily performance Redux

[Mikeyredline]

Let me know if this is a no-no (raising the dead), but I was looking around and came across this artice, and found it interesting as how it relates to temp/humidity and performance. For a newb like me it was vey helpful. figured it woudl post it as such.

Low to mid 60' dry air, in the morning. The thing may as well be 300HP in my book. It is amazing the difference some air pressure/humidity can make. It can be significant, and it is a definite thing with engines that get blown.

Here's an interesting article I cam along... My only comment is you REALLY think Our little LSJ is able to make the calculations he is talking about spot-o?

http://www.racecarbook.com/pdfs/36airdens.pdf

[Paulumbo]

Let me know if this is a no-no (raising the dead), but I was looking around and came across this artice, and found it interesting as how it relates to temp/humidity and performance. For a newb like me it was vey helpful. figured it woudl post it as such.

Low to mid 60' dry air, in the morning. The thing may as well be 300HP in my book. It is amazing the difference some air pressure/humidity can make. It can be significant, and it is a definite thing with engines that get blown.

Here's an interesting article I cam along... My only comment is you REALLY think Our little LSJ is able to make the calculations he is talking about spot-o?

http://www.racecarbook.com/pdfs/36airdens.pdf

Those calcs can easily be made by the PCM-the MAP (manifold absolute pressure) will take that into consideration. Key on, engine off, if you have the ability to look at the MAP reading, it will guve you uncorrected pressure in kPa. I deal with this EVERYDAY in the aviation world-I live and die by density altitude and pressure altitude.
This highlights the reason notes are so critical. If you have HPT, like some do, and you can log data, then it is entirely critical to record ambient temps and uncorrected baro readings. Then once you have a history built with data, then the real tuning can begin. Where tuners take advantage of this is knowing how to tweak the software in order to take advantage of the atmospheric conditions. I know soe people have a summer and winter tune and some even have spring, summer, winter, and fall tunes and some even more than that!
S/C'd engines are way sensitive to temp/pressure changes-your buttmeter will tell you that on a 20 degree day with a high pressure system above. Also one thing to note-look at the baro readings (weather channel or elsewhere)-notice how a "high" pressure system is higher in January than say July/August? As well look at what a "low" pressure system is in Jan then July/August-it's a much higher pressure low. It's because of heat (read Boyles Gas Law for a good base)-humidity effects performance-but it's a neglibible effect unless you're say in Denver and it's 90+ and the humidity is like 90% or more, then you'll notice it.
Your head is in the right place-I like a sceintific tuner that has some real world knowledge to sort thru the BS of theory and reality:werd:

[Mikeyredline]

:rollinglaugh: "Butt-meter"

I agree. You need the science to get to the measurements but commonscence and an understanding of how things work in the real world to be exceptional.

[Paulumbo]

:rollinglaugh: "Butt-meter"

I agree. You need the science to get to the measurements but commonscence and an understanding of how things work in the real world to be exceptional.

Good Engineer=bridges the gap between theory and reality

[Cat Ion]

Good Engineer=bridges the gap between theory and reality

What an oxymoron!!!!! Good engineer?????? You can't mix good and engineer together. I know this. I've worked on our military aircraft. Some ass hat in a seat with a drafting table thought it looked good on paper and forced it into reality. Things fit fine until they break and then they're a bitch to get to and repair. But what does that good engineer care? He got paid for doodling and calling it "science"!

[Paulumbo]

What an oxymoron!!!!! Good engineer?????? You can't mix good and engineer together. I know this. I've worked on our military aircraft. Some ass hat in a seat with a drafting table thought it looked good on paper and forced it into reality. Things fit fine until they break and then they're a bitch to get to and repair. But what does that good engineer care? He got paid for doodling and calling it "science"!
You can use good and engineer in the same sentence....my dad's got a PhD. in mechanical engineering, but he also put himself thru college by working in a stealership, so he's familiar with how things work in the real world too-those people DO exist albeit in small numbers. Besides, if the "engineer" is still using a drafting table, they probably aren't as good an "engineer" as they think they are
:cominatya:

[Cat Ion]

You can use good and engineer in the same sentence....my dad's got a PhD. in mechanical engineering, but he also put himself thru college by working in a stealership, so he's familiar with how things work in the real world too-those people DO exist albeit in small numbers. Besides, if the "engineer" is still using a drafting table, they probably aren't as good an "engineer" as they think they are
:cominatya:

The 'drafting table' reference only applied to the yahoos that designed all the jets I work on. These days I'm sure it's all CAD and sim wind tunnels until they approve the design for production. The newest plane I work on currently was built in 82. The oldest was built in 57.

[mantiskungfu]

Hmmm.... do I see someone with HPT in new england in our future.... :)

[Mikeyredline]

Hmmm.... do I see someone with HPT in new england in our future.... :)


WOAH NO WAY!!! if you do I want to meet:spineyes: him...