24v pyro gage

[NorthWoodsDuce]

Check out hewittindustries.com. Contact Van Sorrels (van@hewittindustries.com), he has sold many pyro and boost gauges to people w/ 2.5tonners and 5tonners. Has a lot of good info and good prices. I got his info from another SS member couple years ago.

 

[m16ty]

Travis, I'm not saying you're wrong but all the info I could find says 200-300deg difference. I did find some info that said it could get as much as 500deg under light loads but that's not where you're going to have to worry about EGT anyway. These figures are from the "top end" gauge manufacturers. Why would they give blatantly fase info on how to install the probe? Wouldn't they want their product to work as advertised?

I have two Frieghtlinners and a KW that came straight from the factory with a post-turbo pyro. I'll be interested to see what Jatonka's results are.

With all that being said, I'll more than likely tap the manifold. I think I'm going to pull the turbo though because I'm not convinced from what I've read ( the grease method, and the drill and tap while running method) that no shavings will enter the turbo.

 

[mudguppy]

m16' - i understand that's what the vendors say, 200° - 300°. but then they also say it could be as much as 500°. that doesn't seem like a large margin of error?

the point is that there are a tremendous amount of variables that alter accurate indication, way more than pre-turbo. the deviation is not constant (linear).

no need to patronize John - you, too, also know that the 'just add 100° and you'll be fine' advice that was given is not correct. i'd love to install a 2nd gauge to note variances. but to map the actual deviation you also need to record rpm, boost, and drive pressures in addition to both temperatures. however, i also don't want to that much trouble. so, for all intents and purposes, i'm wrong. and that's ok.

however, if you would still like to do it, i'd love to see your observations. exhaust manifold, near the turbo flange, at the collector, rear bank please.

 

[mudguppy]

some related non-scientific data from another forum. a few minutes on google finds a lot of discussion and several similar threads posting observations ranging from 200° - 600° temperature variations with a bazillion variables. your choice.

 

[Stalwart]

Remember Travis when doing those calculations you must use absolute temperature and therefore use Kelvin or Rankine scales NOT Celsius or Fahrenheit. A few remaining tibits I remember from aerodynamics and aircraft performance while at Embry Riddle Aeronautical University.

 

[ida34]

I really have to wonder why just about every thread on pyro gauges degenerates into a back and forth about where to mount the thermocouple. I put my pre-turbo and have had not problems so if we are taking sides I go pre turbo. I offer no supporting evidence because I don't have to.

Don't take me to seriously I am kidding. Except for the pre turbo bit. I also got a K thermocouple and swapped my light bulb out to a 24 volt. Works great.

 

[steelandcanvas]

i hate to be so sarcastic, but i don't like seeing blatantly erroneous advice thrown around. so, do some reading and do it right.

I just didn't pull this figure out of my butt, this is what the Hewitt folks told me when I bought my gauges and fittings. Sorry you think it is so "blatantly erroneous". I thought it was a pretty good source for the information, I guess you're the expert though.

 

[mudguppy]

Remember Travis when doing those calculations you must use absolute temperature and therefore use Kelvin or Rankine scales NOT Celsius or Fahrenheit. A few remaining tibits I remember from aerodynamics and aircraft performance while at Embry Riddle Aeronautical University.

good point.

ERAU, eh? Florida Tech grad, here. ERAU was definitely our rival in every way!!!


and, back to the topic - cool, just add 100° like Hewitt says. or, add 200° like Autometer says. or add 300° like Isspro says. or add 500° if it's a light load. or, add 200° if it's been more than 30 seconds at a constant load and rpm. if you guys can't recognize a huge deficiency in these 'expert guidance' (from a vendor that wants your money), cool. then, i'm flat-out wrong, i guess.

i never said i was an expert on this, i have read a lot on the subject many times and try to apply logical thinking. and when i see so many massive variations posted by other enthusiasts (including 150° - 200° swings from a difference of 3" between mounting locaitons in the down pipe), i have to believe that these 'rule of thumb' instructions just don't hold up.

every truck i have is tapped at the manifold. it takes 20 minutes and no turbo removal. good luck, guys.

 

[ccequipment]

Wow, Why drill a hole when all you have to do is unscrew a 1/4 npt plug and install the thermocouple in the exhaust manifold, maybey its to quick and easy. No number adding to mess with, and 20 minutes later your done.

 

[FMJ]

Wow, Why drill a hole when all you have to do is unscrew a 1/4 npt plug and install the thermocouple in the exhaust manifold, maybey its to quick and easy. No number adding to mess with, and 20 minutes later your done.

Sometimes, (most times for me) That handy dandy 1/4" plug won't budge. . .

Plus, I like having the probe seeing 3 cylinder temps, versus 1.

http://www.steelsoldiers.com/deuce/45917-55mph-detonation-post-mortum-3.html

 

[ida34]

Wow, Why drill a hole when all you have to do is unscrew a 1/4 npt plug and install the thermocouple in the exhaust manifold, maybey its to quick and easy. No number adding to mess with, and 20 minutes later your done.

You really want to see the temp near the turbo to see if you are frying it. The plug is the farthest from the turbo you can get and still be in the manifold and like already stated, you are basically getting just that one cylinder. Ideally, you would put in two thermocouples on either side of the turbo to be as accurate as possible. Some have done this.

I am surprised this side of the debate has not surfaced but a lot of folks campaigning for post turbo say they do it to keep the thermocouple from going through the turbo if there is a failure. Then the debate because centered around if they really fail like that or not.

 

[Trudge]

thx guys i def got my answers .......as soon as i replace my head gaskets ill put a pyro on.........

 

[Beerslayer]

I really have to wonder why just about every thread on pyro gauges degenerates into a back and forth about where to mount the thermocouple.

Because in general we are degenerates?

There are plenty of guys who are OCD about the smallest details of things. It gives them an outlet for that

 

[wdbtchr]

thx guys i def got my answers .......as soon as i replace my head gaskets ill put a pyro on.........

I'm sure glad you figured it out, I'm still confused. That's why I still haven't installed a meter on mine. It still boils down to a questionable reading after the turbo, or a questionable reading on one cylinder before the turbo.

 

[steelandcanvas]

I'm sure glad you figured it out, I'm still confused. That's why I still haven't installed a meter on mine. It still boils down to a questionable reading after the turbo, or a questionable reading on one cylinder before the turbo.

Search through the turbo threads and look at some photos, it will be clear. You have these choices: Threaded port in exhaust manifold, pre-turbo, in the turbo itself, and post turbo. I put mine in the elbow, post-turbo. Some people don't like this, I don't care. It was the easiest place for me to install it at the time. Get all the information you can and make your decision. Good Luck!