mt_goat

Getting ready to order an Isspro EGT gauge and I have lots of choices for the thermocouple. Which is best for a 2001 5VZFE with a stock exhaust manifold? I'm assuming the 1.5" probe length would be a better fit than the 2.5" probe?

Here are some of the choices:
http://www.egauges.com/vdo_send.asp?...rmo_1_5&Cart=1
There is adjustable lenght or non-adjustable?
0-1600F or 0-2000F?
Plug style lead or no plug lead?
High temperature Inconel tip or not?
1/4" NPTF or 1/8" NPT slip nut?

CynicX

if your gonna be S/C I would go with 0-2000 temp since without fuel delivery upgrades you'll break past 1600.

I think Inconel tip is gonna be standard on 2000 degree sensors because of the temp. Inconel is a "superalloy" that can resist the high temps and corrision resistent.

Not sure about the plug or not. Depends on how you are hooking it up, I dont think it really matters I guess, if the connection isnt a plug then you can cut it off.

mt_goat

Who said I wasn't going to have fuel upgrades? URD has about $2500 of my hardearned so far.

TomCham

I use Defi 52mm gauge with exhaust temperature sensor by using 1/8NPT fitting

midiwall

Go 1/8NPT, _ADJUSTABLE_ length (I made that mistake once!) and do NOT NOT NOT get a clamp-on. They'll leak (and that was the 2nd mistake I made ).

I use a Westach 712-4D2k:
http://airstuff.com/eshop/10Expand.a...tCode=WS712xxK

CynicX

Oh i didnt mean that you wouldnt. Just saying the potential for the supercharged 3.4 is above 1600 degrees.....

mt_goat

Good point, thanks. I guess it would be better to go with the 0-2000F, especially since the gauge reads to 1800F. But the 0-2000F choices aren't adjustable lenghts, how important is that Mark?

midiwall

imo, VERY. It's important that the tip of the probe be in the center of the pipe. I can move mine 1/8" either way and shift the readings 200* or more.

btw... I don't agree that it's an issue to worry about reading past 1600 degrees. If you hit 1600* and hold it for more than a few seconds, you're in trouble in so many other ways. In fact, most anything above 1450* is gonna start killing power, so...

mt_goat

Wow, that is very sensitive then. Where excactly is your probe , like how far from the port and which port? Did you weld a bung in or can it be drilled and tapped?

midiwall

Frontmost cylinder on the driver's side, I think that's #6, about 5" down from the port.

Weld in a bung... I originally drilled a hole 'cause my first attempt was to use a clamp-on. When that failed, I had a bung welded on.

I wouldn't drill and tap the headers. There's not a lot of metal there to tap into, and if it strips, you're screwed.

Also, remember the pipe itself is going to get VERY hot, and isolating the shaft of the probe and the cabling is a good idea. The bung will help dissipate some of the heat while letting the tip of the probe be right in the midst of it all.

mt_goat

Thanks Mark, that's very helpful info. So your probe only sees the exhaust from one cylinder at 5" from the port? I wonder if it would make the probe lenght less critical if it was subjected to the flow of 2 or 3 cylinders?

midiwall

The general recommendation is that you want to monitor the port that's has the potential to be the leanest, which would be the one that's farthest down the fuel rail. And you want to be somewhere 4-6" away from the exhaust port. The exhaust cools off pretty quickly once it's in the pipe, and you want to get as good of a shot as possible without interrupting the flow or getting into where the pipes start to physically merge.

Monitoring multiple ports is possible, but it's overkill unless you're trying to match injector flow and have someway of doing that (preferably electrically!) on a 1cc basis.

If you're talking about dropping a probe into multiple ports then summing them together and only running one gauge, then that's not as easy as it sounds. You can't just wire them together and expect the resistance to average out - it doesn't work that way. Plus, there will be some access issues trying to drill the #1 & #3 pipes and get a bung in there - it's fun enough getting to #5!


Bottom line.. one probe, adjustable length, front pipe on the driver's side, about 4-6" down the pipe from the port. That distance may shift if you're running the stock exhaust manifold... The key thing is that you want to be in front of the physical merge of the pipes.

mt_goat

Nope, one probe is enough for me. That clears up a lot Mark, thanks.

I did find out from Isspro that the 0-1600F probe is for diesel applications, but they do have adjustable length 0-2000F probes so I'm going to use that.

FattyCBR

Any chance you want to buy a new Westach dual probe gauge? I installed a WB before I installed the EGT and don't need it anymore.

mt_goat

I almost bought Westach gauges (great gauges) but I ordered the Isspro gauges because they had every feature I was looking for. I was looking for full sweep electric gauges with black dial, white numbers, red pointers, green bulb covers, through the dial lighting (matches my 93 factory gauges) and reasonable cost. I also found out yesterday Isspro has great customer service too!