reading lower intake temps (1 Viewer)

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Sumotoy,

My point was that when talking about air density you can't ignore dew point.

I have no desire to be a internet prof. I am not one for teaching. BTW, I was not taking people through the Ideal gas law earlier. When did mixed gases with contained vapor become an Ideal gas? Your examples and calculations are far to over simplified if someone was looking for that last 3% of engine performance due to air density.

Sumotoy "An airbox measured temp of 155 (vs 104 ambient) is 12% decrease in density or equivelent to 4000ft.
And an airbox measured temp of 176 (vs 104 ambient) is a 15% decrease in density or equvelent to 5000ft."

I asked a question, how did you take the external air box temp and relate it to the IAT then move that to air density. I don't currently agree with your interpretation of the data.

Take this off line and lets not highjack this thread with banter.
 
Thats pretty interesting Kevin. I was thinking of temp removing the front turn signals because they are redundant with the signals on the ARB to see what that did.
 
landtank said:
Right now I'm just trying to base line some differences between idling and driving, hood no hood and maybe insulated filter can and not.

This is the data I want to see. idle vs driving. Our clutches are about the same in setup.

landtank said:
During this phase is where removing the fan shroud would come in as it would either decrease the need for venting or increase it.


Are you considering removing the fan shroud and then taking the IAT and coolant data during idle and driving?

Thanks for the data collection. Hope the house is coming along.
 
Kevin, Any thought about trying a little duct tape from the arb to the inside of the turn signal? I wonder if that might direct air into the fender?
 
Cattledog said:
Kevin, Any thought about trying a little duct tape from the arb to the inside of the turn signal? I wonder if that might direct air into the fender?

I am sure that it would help or possibly make for good airflow, but a scoop wasn't part of my plan, so I didn't test it. Only posted the failed test for a data point. Bill (Photoman)? slotted one of his corner lights converting it to a vent, but I don't think he has ever driven, tested it?
 
Correct never tested and on the left side. I also included a louver in the back of the fender for flow. What goes in must come out. In addition I installed a small fan (see white object behind lens) for slow speed because I put an oil cooler in there. There is a hardware cloth screen that I made and powder coated in the lens. This is to keep the bugs, leaves etc. from going in. It pops out for cleaning. Just my way of doing it. Sorry for the hijack Rick. Good luck on your project.


Bill
Turn-Signal-Lens-and-Louver.jpg
 
Tools R Us said:
...
The area along the fender well is normally one of the coolest spots under the hood on my truck, to get fan temp air over to the air intake that cool airflow must no longer be there? Anyway not a good place for a vent, if you were willing to make an air scoop it may work, but that is not what I had in mind. It wasn't a total loss, learned something and reinforced the need for careful testing when making airflow changes.:cheers:

Kevin:
Interesting stuff there, screwdriver in hand... I'd suggest trying to block off the 2 holes at the rear quarters of the engine bay and trying this again. The one next to the fuel pump resistor pack on the DS and the power antenna on the PS.

My bet is you have a lot of fan pressure offsetting that scoop. IOW, the air flows around it because there is less pressure on the curve of the fender. The fan is putting pressure into those rear quarter panel holes causing high pressuer in the panels. So, either the holes need to be blocked off, or the holes vented out the quarter like Photoman did.

I will note that porsche 911 uses a finger scoop in that area for cooling the oil cooler (that sits in the fender just forward of the front wheel) with some pretty impressive results.

IDoug brought up the idea of using the LR sport quarter panel vents, which would look pretty sharp just aft of the front wheel well on the 80. I suspect it would also be a good alternative to hood vents, tho not for the swimmers....

When I called my LR buddy to get a quote on those jewels, he informed me that those are fresh air inlet areas on the LR's. I suspect that still indicates a low pressure zone however.

ST
 
Cattledog said:
Sumotoy,

My point was that when talking about air density you can't ignore dew point.

Take this off line and lets not highjack this thread with banter.
PM sent. Current 'Standard Temperature and Pressure" results haven't universally adopted dew point. ISO does, and maybe 2-3 more of the top 12, but the automotive field especially (SAE, EPA, etc), do not consider dew point in STP baselines.

I have a couple hundred dyno tests, many of them SAE corrected for altitude and temp (per SAE - non dew point STP), that appear to correct pretty accurately for altitude and temp on the same intercooled turbo cars (where dew point should have it's greatest effect) at 5000ft and 300ft. I will agree it's *an* effect, but it doesn't appear to be a significant one. Maybe you can run an example of air density un/corrected for dew point to help us better understand your point.

:cheers:

Scott Justusson
 
SUMOTOY said:
PM sent. Current 'Standard Temperature and Pressure" results haven't universally adopted dew point. ISO does, and maybe 2-3 more of the top 12, but the automotive field especially (SAE, EPA, etc), do not consider dew point in STP baselines.

I have a couple hundred dyno tests, many of them SAE corrected for altitude and temp (per SAE - non dew point STP), that appear to correct pretty accurately for altitude and temp on the same intercooled turbo cars (where dew point should have it's greatest effect) at 5000ft and 300ft. I will agree it's *an* effect, but it doesn't appear to be a significant one. Maybe you can run an example of air density un/corrected for dew point to help us better understand your point.

:cheers:

Scott Justusson


You already emailed me, If you take this offline keep it offline and quit highjacking the thread. Or If you would like I can post my respones to your email here.

Here is a link that does consider dew point...

http://wahiduddin.net/calc/calc_hp_dp_metric.htm
 
SUMOTOY said:
Rick:
It would appear several are having some shakes over goals and targets, which IME on another thread, are better presented as nulls and hypothesis. They do have some value, and can identify differences and/or correlation problems.

Exactly what are you using 'nulls' to mean? You're using it as a noun, and the only def. as a noun is an instrument reading of zero.

Earlier you used it as an adjative 'null hypothesis' indicating that the hypothesis is "without value, effect, consequence, or significance"
 
landtank said:
It wasn't until I thought I had found a way to take some readings without any additional expense that got me to start to evaluate the system. I wasn't about to buy an IR gun based on what I had read in the ABC threads. Strange thing is that I already had the stuff laying around.

Thought I would just map out what I have in mind for some input.

Landtank -

You already know, but excelent work. Before and after temps, of the actual thing your trying to learn about (intake air temp), on the same day, same ambient. You can actually make conclusions from data like that!

Heath
 
Walking Eagle said:
Exactly what are you using 'nulls' to mean? You're using it as a noun, and the only def. as a noun is an instrument reading of zero.

Earlier you used it as an adjative 'null hypothesis' indicating that the hypothesis is "without value, effect, consequence, or significance"

I appreciate the fact you are unclear as to what a Null refers to.
It indicates that you might not have much experience in presenting research papers with a null or nulls. It is quite accepted in the researche community to use "Null" or "Nulls" to mean "Null Hypothesis" (singular and plural respectively). There can be more than 1 Null hypothesis, which the data variable can create. For instance, my Null ([sic] Null Hypothesis) in Part III was: Aux Fan has no affect on A/C vent temps. I found that wasn't supported. What I also found was another Null ([sic] Null Hypothesis) using the same data variable (Aux Fan on vs Aux Fan off): The Aux Fan has no effect on engine bay temperatures. I found that Null wasn't supported, and caused me to move on to Part IV. Based on my conclusion of the data.

" In simplest terms, the null hypothesis states that the results observed in a study are no different from what might have occurred as a result of the play of chance. "

Kind of what I've learned to consider Dew Point affects on air density actually.

I prefer to have a Null in a data collection exercise. This allows the worst case scenario to be addressed. IME/O if it's too broad, or has too many variables, it doesn't address any Null. IMO II, I consider Rick's Null to be too broad, or just not defined, so I disagree with you that he will be able to draw conclusions. That's at the end of the paper, and it should address the Null first.

I say Rick collects data that addresses a Null, or a couple of them. I also say, it's premature to draw any conclusions without Null, method, data, interpretation. I'm happy to skip review of relevent literature in an effort to motivate collection of any data.

I'm sure many of us would consider and welcome any relevent *data* you chose to put forth on this forum Heath.

HTH and my .02

Scott Justusson
 
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Ah.... I looked it up myself and see why I'm not familiar with it. Engineer's generally try to prove things by proving them, not by trying to prove the opposite false. Also explains why in Six Sigma Black Belt training they teach us not to try to become statisticians.

Wikipedia

"Null hypothesis testing has always been controversial. Many statisticians have pointed out that rejecting the null hypothesis says nothing or very little about the likelihood that the null is true. Under traditional null hypothesis testing, the null is rejected when P(Data | Null) is extremely unlikely, say 0.05. However, researchers are really interested in P(Null | Data) which cannot be inferred from a p-value. In some cases, P(Null | Data) approaches 1 while P(Data | Null) approaches 0, in other words, we can reject the null when it's virtually certain to be true. For this and other reasons, Gerd Gigerenzer has called null hypothesis testing "mindless statistics" while Jacob Cohen describes it as a ritual conducted to convince ourselves that we have the evidence needed to confirm our theories.

Elizabeth Anscombe, a student of Wittgenstein, notes that “Tests of the null hypothesis that there is no difference between certain treatments are often made in the analysis of agricultural or industrial experiments in which alternative methods or processes are compared. Such tests are [...] totally irrelevant. What are needed are estimates of magnitudes of effects, with standard errors."

Bayesian statisticians normally reject the idea of null hypothesis testing. Given a prior probability distribution for one or more parameters, sample evidence can be used to generate an updated posterior distribution. In this framework, but not in the null hypothesis testing framework, it is meaningful to make statements of the general form "the probability that the true value of the parameter is greater than 0 is p". "

Guess since even the statisticians doubt it's usefullness, I don't feel the need to add it to my toolbox.
 
Heath and Scott. Enough of the back and forth banter. I will start deleting posts on both sides if I don't feel they pertain to the thread.

That's not the Null hypothesis, consider it Romer's 8th law of moderation. Don't ask what the first 7 are!
 
It's just a flesh wound!
 
Now that we have all that null hypothesis stuff cleared up...

Given the vent in the marker light not pulling in air as expected, it makes me wonder if removing the hood altogether causes some turbulence that might not allow hot air to escape as easily or efficiently as a properly placed vent would.

Lots of goofy airflow in the rear of a pickup bed, which is totally open. I've seen trash loop around and around like a convection current is rolling it around.
 
C6H12O6 said:
Given the vent in the marker light not pulling in air as expected, it makes me wonder if removing the hood altogether causes some turbulence that might not allow hot air to escape as easily or efficiently as a properly placed vent would.

Lots of goofy airflow in the rear of a pickup bed, which is totally open. I've seen trash loop around and around like a convection current is rolling it around.

The marker light 'scoop' can be a good mod, btdt on other vehicles, and porsche uses a lot of them. The problem is you have to make sure the inside of the fender is a low pressure zone. IMO, it can't be if you leave the two ports at the back of the bay exposed to high pressure radiator fan and/or ram air.

Your pickup truck example is a good one, the redneck test is to see where the beer cans stop moving is the same as trapped heat. That's dead air. Think of the 80 engine bay as an upside down pickup truck bed. You can put a lot of air into the 'bed' but the trapped beers (heat) will not always jump out the bed by blowing on them harder. I've seen lots of 'n' in this experiment.

SJ
 
Here is the Data from today's testing.

I had to make a run to Lowe's and since I forgot my wallet it was a two trip deal and got plenty testing done. Each way was about a 20 minute drive with some highway along the way.

During the entire time the engine temp fluctuated between 185* and 187*. This included idling time as well. The ambient temp was around 67*.

During initial start up the truck's Intake air temp was 66*

First drive out to Lowe's with a winter coat wrapped around the filter canister the Intake Air temps was a stable 82*

Coming back from Lowe's to retrieve my wallet without the coat around the canister the intake air temp was 92*

Second drive out to Lowe's with the coat re-installed: the intake air temps returned to 82*

At this point when I returned home I did an idle test with the coat still installed but with the hood open and then closed. Since I expected the temp to rise I immediately opened the hood first.

Hood open: the intake air temps rose to 91*

Hood closed: the intake air temps remained at 91*

At this point if you intend to positively effect your air intake temps it would seem that insulating the canister is really the only way to do it. Maybe at some speed the louvers might be of some help but I couldn't reliably predict where they would have to go.

Anyone have some ideas of what to use as an insulator? Something in a sheet material with an adhesive backing would be ideal as I can CAD up a pattern and use the equipment I service to cut out the shapes needed to wrap the canister.
 

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