Duke

What do you say about this Autometer probe?
Seems a bit cheesy to just drill a hole and strap this thing on...


But then again, it seems so simlpe ;-)

Mike S

I have the autometer gauge on mine and I ended up just going down to the muffler shop and having them weld on a fitting that threaded in. Your gauge should have come with a fitting as well.

toddk911

How do you equate EGT's to air/ fuel ratio??

I take it if your getting high egt's you are lean??

toddk911

How much was it???

Would this be an alternative to a wideband O2???

Mike S

Exactly....if its high you are in general running lean. I have both a wide band and an EGT. I don't use the wideband daily so the EGT is usefull for data while driving.

Temps depend on where you place the sensor. On my car I placed it on the crossover tube directly under the oil pan area near the passenger side before it gets to the cat. My temps are around 1200F-1400F under full throttle and 1500F-1550F at sustained boost (~17psi). These temps were with a 12:1 air/fuel ratio. Ideally you would want to place one on each header, but I wasn't comfortable welding bungs onto my headers(since they're known for cracking). There is a slight delay in the temp readings...i'm guessing about 1 second, but its pretty accurate. Most folks, myself included would love to see an EGT that went to 1800F instead of 1600 since people seem to reach the limit of the gauge on these cars.

It's been a long time since I ordered mine, but I think jeg's had it for around $70.

toddk911

So would you say it is better than a standard air fuel ratio guage??

Mike S

I like it a lot better than the standard air/fuel gauges that you can buy for aoround $50. In my opinion, unless you have a wideband....an air/fuel gauge is useless. Too much dither, crappy resolution(we're talking about 0.1V or less changes to measure the mixture).

I don't think I would feel comfortable tuning the whole RPM range with just the EGT, but its better than a narrow band. A wideband is still necessary to get it absolutely right.

Just my 2 cents.

pk951

http://www.sdsefi.com/techegt.htm

Tuning Via EGT vs, Wide Band/ Narrow Band Meter

Some more info.

TonyG

I run both a Wide Band A/F (Uego) and the Autometer EGT.

They are both needed. Together, you can make the proper tuning adjustments.

I run the Autometer EGT probe, just like the one pictured, but with a bung welded into the #4 header primary, exactly 1" to center, off the exhaust port.

toddk911

Ok. I would not tune with it, just looking for an alternative to the dithering a/f guages. And for only 20$ more, sounds like a good buy.

How much temp differnce would ther be to know you are leaning out? or richening, etc.

Tony, is that where you are supposed to mount them?? Or you just had good results there??

Mike S

I'm not tony, but ideally I beleive you would want it as close to the exhaust port as possible. Make sure you find someone who knows how to weld stainless. There's a good chance of somebody screwing up those headers and they aren't cheap.

EDIT: Also, after reading some previous posts it appears that my temps are pretty much the same as everyone elses including Tony's. Although Tony's mountin location is higher up the exhaust than mine(about 12" i'm guessing) my temps are very similar. I don't think the exhaust temps decrease all that much as long as you mount that sensor before the cat. The velocity of the exhaust coming through there is pretty quick.

TonyG

You want to mount the EGT probe exactly as described in the instructions. And the the Autometer, it's 1" from the exhaust port. That's where I have mine mounted.

And concerning EGT's changing the farther you get from the exhaust port:
a) the farther you go from the exhaust port, up to the collector, the cooler your reading will be.
b) EGT's measured in the cross over will be actually hotter than what is actually coming out of the exhaust port because you have unburnt fuel that is in fact burning
c) if you mount after the turbo, your reading will be cooler than what is actually coming out of the engine
d) the farther from the exhaust port you mount the probe, the slower the response of the gauge.

toddk911

Ok. What does the display look like? Just a temp guage??

If you do start to lean out, how soon is that picked up by the temps increasing?? Or how quick do yo unotice the temps rising on the guage?

TonyG

The display looks like a regular 270 degree needle sweep Autometer gauge.

The gauge is actually pretty fast. What you see is not an immediate EGT... but rather the needle moving hotter or cooler. The response is pretty fast.

But like I said... it should be used with a WideBand setup.

Either side of stoich and see hotter or cooler temps when adding or taking fuel away.

Sean Hall

In one of my previous posts, I posted the link to the EGT kit from Summit. Its hard to find the kit via Summit's web site, so it may be worthwhile to find the link in the rennlist forum. try searching by my name.

When installing the EGT, be sure to consider the hard water line that lyes right above the exhaust manifold, and in the way of the ideal position of the EGT probe.

The kit i mentioned includes a bung that can we welded in. bear in mind the welding debris will go through your turbo if you weld it in with the manifold connected to the downpipe.

I've installed my EGT probe at the #4 port, but have yet to hook it up - hopefully this weekend.

Good luck,

Sean