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EA82T Inlet Temp Test Data


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Hey guys, thought some of you might be interested in what I found. I set up a couple of thermocouples on my ’87 RX (bone stock) to get some base line numbers to work from. I’m hoping to start on some mods soon (after new rings, bearings and a reseal) and its always good to know where you started so you can gauge how much you’ve gained.

 

 

Anyway here’s the set up:

 

 

’87 EA82T, 252,000 miles, all stock systems intact and functional (weak compression on #1 cyl).

 

Point #1 (T1) located just behind the MAF mounted at “duct B” (appendix like chamber), thermocouple in airflow about ¾” off the intake boot wall.

 

Point #2 (T2) located just before the TB mounted through the connecting hose, thermocouple in airflow about ½” off the tube wall.

 

Readings taken with a Fluke digital thermometer.

 

 

Data as of this mornings ride to work:

 

Ambient air temp about (T1) = 45 F (would rise some at idle, steady at road speeds)

 

Max boost temp (T2) = 155 F (full and part throttle pulls in all gears show similar temps)

 

Max deferential (T2-T1) = 110 F

 

Cruse boost temp (T2) = 100 F (70 – 75 MPH, 5th gear, just below 0 psi manifold pressure)

 

 

Note: temps under sustained full throttle seem to be slightly less than at part throttle, by about 10 F. I suspect that even though the boost level is the same, the less restricted intake path and higher flow move the compressor into a more efficient region. Or perhaps the higher flow reduces the transferred heating effects.

 

Given this data it appears that even the stock system could benefit from an intercooler as the temps are high enough above ambient to see some cooling from an air-to-air IC.

 

Its suppose to be near 80 F by this afternoon so the ride home should be good to show the effects of ambient temp changes, I’ll post those numbers soon.

 

Gary

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This is EXCELLENT info. I never knew that the temps after the turbo would be 110F more than before. Whoa! Looks like I'm going to have to save all the info I gather for future purposes. Please keep us posted.

 

 

BTW: I'm always reading about thermocouples and people testing air temps and stuff but never took the time out to see how to set something like that up. Any tips on how to go about it? I know it's supposed to be simple but just pretend I'm a complete idiot. :)

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Russ, yeah I’m using the standard open thermocouples. And yes, the idea will be to add more boost with an IC and achieve the same or lower intake temps. Or just use the IC to lower intake temps to use cheaper fuel or more advanced timing. Either way low temps can mean more power.

 

 

Myxalpyx, the set up pretty straight forward, just put the leads through the joint so that the thermocouple is in the air flow and clamp it down. I’ll try to take some pics when I get home.

 

MorganM, Whatcha got and how much? :)

 

Gary

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O.K. here’s the data from the ride home:

 

 

Ambient temp (T1) = 85 F (it was a beautiful day in the northwest)

 

Max boost temp (T2) = 208 F

 

Max differential (T2-T1) = 123 F (happened at sustained part throttle pull in 5th gear, up Snoqualmie pass)

 

Cruse boost temp (T2) = 145 F

 

 

Again noticed the higher boost temp at part throttle, max differential noted on full throttle pull was about 110 F.

 

The accuracy of the thermometer is about +/- 4 F, this should at least offer a good basis for comparison.

 

 

Here are some pics of the setup.

post-367-136027592547_thumb.jpg

post-367-136027592552_thumb.jpg

post-367-136027592556_thumb.jpg

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Good info! I'm loving this! :drunk: Where can I pick up some thermocouples? What did you attach the electrical end of the thermocouple too? I'm not familiar with these things except for folks saying they put it in an intake to get temps. I'd like to do some testing myself. Good info and I like the idea that you are testing before intercooler/mod temps for a baseline so you can achieve these or similar temps after mods/raising boost, etc.

 

This is the same thing I try to do on my cars except I always test the EGTs (Exhaust Gas Temperature) stock and then try to keep the same or similar EGTs after mods.

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the one in question is made by fluke for flukes . really easy to use just slip it inbetween the hose and run it. I have one as well I have used it in cooling system aplications but not in the intake yet. I will give some input when I find time to test stuff.

Alltalk are you running multiple point at the same time?

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Kevin, an EGT gauge uses a thermocouple (most likely “K” type), thermocouples are made up of two different metal wires that meet at one point, they produce a small voltage (mV) that varies with temperature. The thermometer or EGT gauge is really a very sensitive voltmeter. EGT is one of the variables I plan to measure, it can be used to get an idea of fuel mixture. The simple bead type thermocouples I’m running now have Teflon insulation that’s only good to 500 F, I’ll need to get a proper high temp type before I stick it in the exhaust stream, I guess I could steal one off my snowmobile EGT.

 

Russ, my thermometer (fluke 52 http://www.ie2000.com/fluke52.html ) has two channels (T1 and T2) so I can monitor two points and get delta T in real time (well 1.7 sec sample rate in delta mode, 1 sec in straight reading), I can also record MIN and MAX on any one channel or the delta. Back when I was in school I had use of a Fluke data logger call a Hydra, it would monitor 8 inputs of all most any type at high sample rates, store the data and download to a PC spreadsheet for analysis and graphing, I wish I had one now.

 

Gary

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ok so I got my but in gear and did some testing of my own. differnt conditions than all talk.

 

test one-

temp at intercooler outlet

ambient temp 80 degF

cruise outlet air temp 90 degF

0 to 60 at full boost high temp of 124 degF

 

test two-

temp at intercooler inlet

ambient temp 84 degF

cruise temp 140 degF

0 to 60 at close to full boost( traffic in the way) high of 229 :eek:

 

this is not scientific by any means but it was fairly acurate. and tells me that my IC is droping 100deg under boost conditions. now to really make an accurate assesment of the IC performance I would need to get pressure readings on both sides of the cooler as well. this would give me an accurate assesment of my actual power gain.

 

so once agian I will say that a properly installed intercooler is one of the biggest performance and relyability parts you can install. along with the usual intake and exhaust mods.

 

yes this car does have a 2.5 exhaust and mild intake mods.

 

thanks to all talk for making me actually get out there and do some testing.;)

 

edit: here is an old pic of the IC its a little nicer plumbing now.http://users.adelphia.net/~oddcomp/turboroo.htm

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Russ, I’d say your pre cooler data matches up pretty well with my second set at similar ambient temp, though your peak boost temp is about 20 F more. Still, lets me know that the data is reasonably accurate and that an IC can be of benefit even on a stock system.

 

With your lower ingested temps I bet you could safely run a bit more timing, where do you have it now? I’m running the stock 20deg on 87 Oct fuel with no audible detonation so I’m sure you could run more advance… or more boost.:brow: I can now see the need for the wideband O2 and/or an EGT, so after I install an IC and can sort out high boost fuel supplement.:D

 

Gary

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odd comp thanks for keeping that around for me.

 

all talk I run 25deg timing. thats what my book calls for on the turbo motor in 1987. it says 20deg is the SPFI spec. later years it shows 20 for the turbo. hmm mabey I have some bad info. I have tried 26-27 deg and it was not happy. that was with 91 octane fuel.

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Hmmm, the sticker under my hood and my Chiltons both say 20 deg, maybe their is a early and late spec for the '87?

 

I will make one correction, today leaving work I jumped on it when it was still cold (still on high idle) and got a bit of rattle as it transitioned to full boost, no detonation past that point, maybe the knock sensor did its thing? And still nothing once it warms up, the cold water temp must be leaving more timing in. I know I have to be on the edge running the cheap fuel, I may even have some low level detonation that I’m not hearing, though I’ve always had a very good ear for it. I guess well see later this summer when the temps start to get up there.

 

Gary

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did i mention i run cheap gas and 10-12 psi with no intercooler and almost never get ping .. i think my ignition is 1-2 deg below what the sticker recommends

"but" my tps is worn out so i also suspect i am running a bit rich also

just got one at the junkyard to put on until.... well calebz knows hehe

 

still looking for a intercooler

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  • 6 months later...

Bumpay!

 

I'm on a roll today bumping up old posts. :rolleyes: I thought I'd add something interesting here that I just read (again) at the NASIOC site. The price will seem high to 85% of the people here but I'm thinking of getting it. This is info I'd REALLY like to know.

 

"Intercooler temp gauge. These gauges where in high demand. I sourced them and have 20 instock. These gauges include two Temp probes and fittings and the electronic meter. You install one probe after the turbo outlet pipe and one probe before the throttle body. There is a three position switch. A position for before the intercooler and after. The middle position shows the difference in temp between the probes. Very usefull on finding the best and most effiecient boost setting on your car in the ambient temps you are in. You will also noticed trends in temp rises with TMIC's while at lights ect. I love mine. As I push boost higher and higher I found that past a certain amount of boost air temp out of the turbo shot through the roof.

 

$250 each blow out price"

 

icgauge2.jpg

 

 

From here: http://forums.nasioc.com/forums/showthread.php?p=8161780&posted=1#post8161780

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Bumpay!

 

I'm on a roll today bumping up old posts. :rolleyes: I thought I'd add something interesting here that I just read (again) at the NASIOC site. The price will seem high to 85% of the people here but I'm thinking of getting it.

 

"...$250 each blow out price"

Thanks for the info.

 

Yes, the price seems high. The electronics needed for it are pretty simple, maybe $20-30 in parts max. I know that it is limited market/ limited prduction, but when I can get a 2GHz computer for less its price is a little hard to understand. :-\

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  • 11 months later...
  • 1 year later...
Bump up from the dead... great info though.

 

I need to run the same tests on my T-Leg, I've got a WRX IC for it but I dont want to fit up all the plumbing untell I swap in the TD04... do it all at once.

 

Gary

 

 

Almost 2 years later Gary! :-p I am an old post, info searching whore I guess. Anyways, have you ran these tests on your T-Leg? Anyone else run these tests? I no longer have an RX turbo but hey, I can learn something. I already have all of this samed on my computer at home. Anything new Gary?

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