Request for data on air temps :)

[jlitman]

Moderators, please do not move this thread -- I have a very good reason for posting this in the FI section!!

Hey guys,

I'm trying to compile some data on air temps read at the MAF under various conditions, and I know most of us with FI also have methods for logging this data.

This is an open request for the following data:

1. Engine coolant temp range (ideally, fully warmed up, but you can start recording when car is completely cold)

2. Ambient temp (and humidity if possible).

3. Air temps at idle

4-5. Air temps at various speeds, which means engine speed should be recorded (for example, temps at a fairly steady speed of 40 and 60 mph, which are normal road speeds).


I'd like to have this data for a CAI, an unshielded SRI, and also if possible for the stock airbox (I may be able to get that myself, and I will have data for a shielded SRI).

If you record data for even 15 minutes after being fully warmed up, that would be great! Reporting a range (low to high) will be sufficient -- no need to provide a full data file (though, if you can compile the data easily enough, feel free to email them to me at jlitman@shell.cas.usf.edu as either a text or excel file).

To give you an idea of what I'd like to receive, here are some fictitious data as an example:

CAI
1. Engine temp range = 181-185
2. Ambient Temp = 30 F
3. Air temp range at idle (3 minutes at stoplight) = 35 - 41 F
4. Air temp range at 40 mph = 32 - 35 F
5. Air temp range at at 60 mpf = 31 - 33 F

If you have any questions, post here or PM me -- thanks in advance! :)

~Jordan

[Jesse IL]

http://www.newcelica.org/forums/showthread.php?t=233154

[jlitman]

http://www.newcelica.org/forums/showthread.php?t=233154

Cool -- that's a great start for SRI data, thanks! All ambient and MAFS temp measurements are C, right? Also, can you give me an estimate of the time that elapsed during idle intake air temp measurements?

EDIT: NM -- I see where you have that noted.

Now I just need some measurements at road speed :eatpop:

[jlitman]

Quick comment -- been doing some data logging, and Jesse's method for logging temps at idle with an SRI didn't work out quite the same for me... just sitting still with the hood up, the intake air went up 10 F above ambient after 5 minutes! However, once warmed up, with the hood down, it didn't get as hot as it did on Jesse's test either :shrugs:

I'll share a buch of results soon.

Anyone else have any data for me yet? Preferably from a CAI or stock airbox? :)

[Jesse IL]

I started with a hot car, then shut it off and let it sit with the hood open for a good 15 minutes. This allowed the engine bay to cool off and the coolant to drop only slightly.

I read intake temps well above ambient as well. I just converted this and it certainly wasn't 60 F on the day I was doing this test. I remember it being in the 40's. The thing is, the air temperature always logs above ambient. I just checked some logs from a day I know for a fact was around 0 or less, and the car was only logging -4 C air temps.

Also, keep in mind that I idled a car for 15+ minutes on a day that was on the 40's, much of it with the hood closed.

[jlitman]

I started with a hot car, then shut it off and let it sit with the hood open for a good 15 minutes. This allowed the engine bay to cool off and the coolant to drop only slightly.

I read intake temps well above ambient as well. I just converted this and it certainly wasn't 60 F on the day I was doing this test. I remember it being in the 40's. The thing is, the air temperature always logs above ambient. I just checked some logs from a day I know for a fact was around 0 or less, and the car was only logging -4 C air temps.

Also, keep in mind that I idled a car for 15+ minutes on a day that was on the 40's, much of it with the hood closed.

Ah, okay -- thanks for clarifying. I'm just trying to get a clearer idea of just how much difference there is in actual airtemps for various intake set-ups and driving conditions.

[Jesse IL]

The guy whose car I'm working on is going to be getting an Injen CAI. I guess I'll have a better idea then if it lowers the intake temps. With the short ram setup, since its pulling underhood air, there is always some radiant heat at work, so you should always see higher than ambient temperatires. Heat soak into the metal pipes would most likely also play a role.

With my turbo, I will see intake temps at cruising right at ambient, and even on short pulls through the gears will see little to no fluctuation. The extremely large intercooler is acting as a huge heat sink and regulating temperatures. With low heat load on the engine (cruising), the intercooler will be at the ambient temperature, so I'll log intake temps right at ambient.

[jlitman]

The guy whose car I'm working on is going to be getting an Injen CAI. I guess I'll have a better idea then if it lowers the intake temps. With the short ram setup, since its pulling underhood air, there is always some radiant heat at work, so you should always see higher than ambient temperatires. Heat soak into the metal pipes would most likely also play a role.

With my turbo, I will see intake temps at cruising right at ambient, and even on short pulls through the gears will see little to no fluctuation. The extremely large intercooler is acting as a huge heat sink and regulating temperatures. With low heat load on the engine (cruising), the intercooler will be at the ambient temperature, so I'll log intake temps right at ambient.

That's great info -- please keep it coming!

My shielded SRI is close (2-7 degrees F) to ambient as well when moving but heat soak is considerable at idle (12 - 20 F!) and seems to pick up about 2 F every minute (sorry, will have better summarized results shortly)!

I want to see how much of a difference there really is for these different set ups -- I have a feeling that a series of heat shields for the underhood piping on a CAI is probably the ideal set up, but I want to see actual data on temps first.

What little I've been able to find suggests that heatsoak is nearly as bad for a CAI as for a SRI, contrary to consensus view. It suggests that whether you use a CAI or SRI, extensive heat shielding is a must to maintain optimal intake temps -- but again, I want to see just how great the difference really is.

I'm also wondering whether some filter mediums are better or worse conductors of heat (i.e., dryflow meduim vs. oiled cotton).

[Jesse IL]

On the SRI car, literally as soon as you stop, intake temps start to go up. They are steady at when you're moving, and they drop very quickly back to steady state once the car is moving again.

Other than temperatires, you need to also take into effect the length of the intake pie, which will dramatically affect performance potential.

[jlitman]

On the SRI car, literally as soon as you stop, intake temps start to go up. They are steady at when you're moving, and they drop very quickly back to steady state once the car is moving again.

Other than temperatires, you need to also take into effect the length of the intake pie, which will dramatically affect performance potential.

That's a good point. Right now I have a straight path from the filter to the MAFS, with only a single bend to the throttle body and throttle response is much better than it had been on my previous set up, which included an additional bend.

Kind of makes me want to develop a little "cold air box" with peltier cooling plates, an idea I'd been toying with for some time. Hard to make it work effectively, tho'.

[jlitman]

Some initial findings for my heat shielded SRI

(Sorry, should put this into a table, but I can't upload word docs or excel files, so this seems to be the easiest way for now...)

All measurements taken from MAFS using OBD II scantool

Engine Temp = 181-187 for all

Idle torture test, closed hood

Note: With open hood, intake temp rose to 93 F (!) at idle while allowing the car to reach normal operating temp.

Ambient Temp = 73 F

Elapsed time, intake temp
0 min = 93 F
2 min = 102 F
4 min = 106 F
6 min = 108 F
8 min = 109 F
10 min = 109 F
12 min = 113 F

Conclusion: The intake temps climb several degrees F every minute at idle!

**********************************************
Cool down test from initial intake temp of 113 F

Ambient Temp = 73 F

Engine speed 5 - 15 mph
After 30 sec driving = 99 F

Engine speed 30 to 40 mph
After 30 sec driving = 84 F

At stoplight, idling
After 30 sec stationary = Climbs from 84 to 105, but returns to 84 F after driving 35-45 mph for 20 sec.

Conclusion: The intake temps cool down quickly, even at slow road speeds. However, it may climb 20+ degrees idling at a stoplight!

**********************************************
Cool down test 2

Ambient Temp = 71 F, Initial Intake temp = 88 F

Engine speed = 25-30 mph

After 30 sec driving = 79-77 F
After 1 min driving = 73 F

At constant speed of 35 mph, intake temp holds at 73 F

Conclusion: Provided you don't sit idling for 10+ min, the SRI will hover close to ambient temps while driving, even at relatively slow speeds.

**********************************************
Intake Temp at Highway Speed Test

Ambient Temp = 61 F

Speed held @ 45 - 50 mph
Intake temp = 64-66 F

Speed held @ 65-70 mph
Intake temp = 64-63 F

No change in intake temp at 75 - 90 mph.

Conclusion: After speeds of 65 mph, there is little additional cooling, but that's okay, given that the intake temps are now within a few degrees of ambient!

[deltaB]

Two emails sent. Make sure you got the first one, I got an error when I hit the send button. I could do an idle torture test (it looks easy).
dB

[jlitman]

Two emails sent. Make sure you got the first one, I got an error when I hit the send button. I could do an idle torture test (it looks easy).
dB

Got it -- thanks man!

Maybe I'll compile all the info into a table once I have comparable data for unshielded SRI, CAI, and OEM. I can make the table into a jpg file and upload it that way :)

Can you give me an idea of where and when this data was compiled -- approximately what would have been the ambient temp?

[jlitman]

***Data on OEM airbox***

All measurements taken from MAFS using OBD II scantool


From deltaB

Ambient Temp = unknown, but see below...


Intake Temps from cold engine to fully warm (181 F)

53-63 F -- that's a range of only 10 degrees!


Driving Test -- spped ranges from 0 to 60 mph

Engine Coolant Temp = 179 - 181

59-61 F at all speeds... Wow -- temps are incredibly stable!


However... there is also this report from an old thread by Bagadoosh for air temps measured with the OEM airbox

Ambient = 27 F

idle (2 min, stoplight) = 64 F

cruise (40 mph?) = 46 F

Bagadoosh reports the following for a CAI on the same night:

Ambient = 27 F

idle = 43 F

cruise (40 mph?) = 30 F

Conclusions: Although Bagadoosh's results suggest that heatsoak is a problem with the OEM airbox as well, the data from deltaB are compelling, and suggest that building some sort of "cold air box" for a CAI or modifying the OEM airbox to accept a cone filter for an SRI may be a worthwhile mod.

This would enable you to have both less restriction than a panel filter as well as the heat shiedling of the stock airbox. With either clever ducting for a SRI or a using a CAI, you have a source of cooler air as well.

Of course, we need more data -- anyone?

[Jesse IL]

Moderators, please do not move this thread -- I have a very good reason for posting this in the FI section!!
OK and what reason is that?
Of course, we need more data -- anyone?

What point are you trying to prove?

[jlitman]

...I know most of us with FI also have methods for logging this data.
Most N/A folks don't have datloggers. :shrugs: If this gets moved to another forum, I'm less likely to get any useful data...

I guess the "ultimate" reason is to develop a perfectly shielded intake (SRI or CAI) that is safe from both heatsoak and hydrolock in all driving conditions.

The factory airbox does a seemingly good job of this, but restricts air flow -- thus, I'd like to see something that is the best of both worlds, but there really isn't anything out there.

Moreover, none of this data on air intake temps is well known, so even if something were developed, there's really no basis for comparison. Even if you just look at dynos, they can be misleading, as they will not necessarily reflect normal driving conditions.

If I develop plans for one (or two) designs, I could have a buddy of mine fabricate it for me and others, as well as simply share the plans if someone wants to build it themselves. Besides, unlike most companies, I'll actually test it and collect and share the findings of the tests.

Also to satisfy my own curiosity :)

[Gtsjeg04]

I will post up when i get home and convert my temps from C to F. On second thought I might have to take not of the outside temp and do some new logg files. I will have to see what is all listed in the log file. Info by Friday.

[jlitman]

I will post up when i get home and convert my temps from C to F. On second thought I might have to take not of the outside temp and do some new logg files. I will have to see what is all listed in the log file. Info by Friday.
Cool, thanks! :D

[Entranced]

Back from the dead! =O but are you still wanting info jlit? I can get some data from my AEM CAI if you want.

[jlitman]

Back from the dead! =O but are you still wanting info jlit? I can get some data from my AEM CAI if you want.
Sure, that would be great! Same summary format as above, please for easy comparo :D

[Gtsjeg04]

I am seeing engine temps form 231f to 246f. I am going to have to take my car down to titan motorsports for some dyno time. However I logged air temps at 77F at 65mph to 87.8F at idle at stop. I didnt make note of the outside temp bc I was going to do some logging today but my drivers side wheel bearing is FOOKED and makes my car pull to the right. It should be fixed by monday evening at the latest. Will see about a new thermostat and temp sender to see if that engine temp is correct.

[jlitman]

I am seeing engine temps form 231f to 246f. I am going to have to take my car down to titan motorsports for some dyno time. However I logged air temps at 77F at 65mph to 87.8F at idle at stop. I didnt make note of the outside temp bc I was going to do some logging today but my drivers side wheel bearing is FOOKED and makes my car pull to the right. It should be fixed by monday evening at the latest. Will see about a new thermostat and temp sender to see if that engine temp is correct.
Whoa -- yeah, the engine temps, if accurate are way high :AF:

Any evidence of overheating? Consuming coolant? Hopefully just a misread...

At that speed it's gonna be ambient for the shielded SRI too. After you get the problem sorted, see if you can get more data like I did above -- for example, take note of the rise in temp at prolonged idle, the rate at which it rises, and the rate at which it cools down once you get moving.

You definitely need to know the ambient temp to make sense of the data. Taking note of humidity would be helpful as well -- probably cools down a bit slower the higher the humidity.

[hombredelassrta]

holy hell son. hope those temps are not accurate

[Gtsjeg04]

those are what the conversions from C to F are. whats funny is that its only a 10 degree shift from hot to cold so I am pretty sure they arent correct but the temp guage on the dash works just fine.

[Boosted2.0]

weird. But ditto on those temps being way too high.

[Jesse IL]

Sounds like a stuck closed thermostat to me.

[Boosted2.0]

Sounds like a stuck closed thermostat to me.

He said gauge works normally and indicated temps only change a total of 10C - thats not a stuck thermostat if its reading close to full warm when its actually dead cold. Thats electrical.

[Gtsjeg04]

i am going to change the temp sensor and see what happens. I think i might change the thermostat too.

[jlitman]

i am going to change the temp sensor and see what happens. I think i might change the thermostat too.
You sure your conversions are correct? What are the temps you're logging in C? (e.g., 230 F is 110 C)

[Gtsjeg04]

Pm me your email and i will send you the whole file. Its in excel format.