BlackRx7

Okay I just got my Autometer Phantom pyrometer gauge in today, yah only 0-1600 F degs, now I did search and after a long time of reading I still see mixed opinoins On

1) where to install the probe
2) what temps should I be reading
3) If I choose different locations won't the readings be different?

Scott 89t2

best place is in the exhaust manifold. but unless you remove it, it's a bitch. easiest place is in the downpipe next to 02 sensor.

2: 1400-1450F or so at wot

3: yes

BlackRx7

So those are the temps I should see if I install it in my downpipe? I would install it in the exhuast manifold, but I was reading that Ted had seen temps of 900C and thats much more than 1600 F, where my gauge tops out at....do you have an egt scott? also how do you have those three gauges mounted in your pic? not sure if i should move my a/f gauge to under my sterio...but it your setup looks pretty kewl

1987RX7guy

iTrader: (3)

i believe he has a two gauge pod and a single also


EDIT:: I just want to know what you use EGT for??

Scott 89t2

yes
yes

bottom one is a custom mount where the triangle vent is. I love the location

http://www.1300cc.com/mycar/IMAGE013.jpg

BlackRx7

one last question....so I assume thats where you installed you egt probe? did you tap a 1/8th NPT whole or did you use the clamp method?

1987RX7GUY they tell you the temp of the exhuast gases, and from there you can tell if mixture is rich or lean depending on the temps seen, hotter = lean, not as hot = rich

BlackRx7

and what should I see under normal driving?

jon88se

My NA sees about 625 celcius @ 60 mph cruise. I get a solid 820 on a full third gear run to redline (i.e. did a lil leaning with the AFM till I hit that mark). I think fourth will yield a hotter temp but I haven't had the stretch of road to do it and I think I'll leave that for the dyno w/ the wideband (looking at your EGT at 120 mph isn't smart - either i'll end up w/ a blown motor or a crushed car ) She runs real strong though for an NA, I'll dyno in the coming months before I swap in the TII. On a full throttle 3rd gear run you can feel the powerband dip and drop from 3-4K (flat spots, leaning the AFM leans out the whole signal, not per rpm range/point like an AFC) but as soon as 5K hits it really gets going and thats where I saw gains from the AFM. My WOT EGT's are good though, the probe is right after the manifold in the downpipe.

dr0x

Remove the twin scroll in the manifold and put the probe in that hole.

gsracer

does anyone else regret removing their twin scroll? I have full exhuast and a mbc set to 10 pounds but I still feel some major lag with the twin scroll removed. I'm putting it back on.

BlackRx7

That woulda been too hot for my gauge...plus the hole 1/4 NPT and the probe is 1/8....also my turbo spools pretty much the same did you port match the exhuast runners on the turbo? but then again I have a ported motor...

Just got done installing and test driving and in 3rd gear at 7k rpms I got 1300* F and about 800*-1000* F at idle. I mounted my probe about 4" down from the turbo/mani on my downpipe....so I am running rich but how rich is 100-150 degrees below what I should be running?

Ryde _Or_Die

Well I have mine in the DP right about as close to the turbo as possible. I see like 800C max just about. Farther from the turbo, the cooler obviously. 4 inches into the DP isn't too much, but more than mine. What are those temps in C?(sorry I am too lazy to look it up )

BlackRx7

800* C equals 1472

C* x 2.178 =F*

Wankel7

As you start leaning your mixture.....the EGT will get getter hotter hotter hotter...until it falls....cooler cooler cooler.

There are two ways to look at it. You could take away fuel until you see peak egt and then take a little more away. That would be best economy at wot but very dangerous.

You would probabaly want to lean it until peak...and then enrichen it a little bit.

It seems it would take a constant rpm.....constant boost for a time duration. Not just a full throttle run and then make changes.

Seems like you need a VERY long road....a friend to help you.

Probally, take it on the road....you drive and floor it....then hold the brake to get the constant rpm and constant boost. While a friend adjusts your fuel based on egt....and Air/Fuel if you have the wideband luxery.

James

2R7T

yes

no

C = (5/9)(F - 32)

BlackRx7

uhh I solved for X....seems like it works to me...

Scott 89t2

it might work for one number...

1c = 33F

-40C = -40F

yours doesn't work..

2R7T

you said 800 *C is 1472 *F which is true. But 800 x 2.178 equals 1742..

also by your formula 0 *C would equal 0 *F

BlackRx7

damn my dislexick *** anyone wanna answer what I posted above?

Wankel7

Ok, I know nothing about cars and how they use egts.

Let me tell you what I know about aircraft and egt. There is NO TEMPERATURE TO USE!!! In fact, in most small airplanes the egt gauge has no numbers. Just hash marks. Why? Because the number is not important. The trend of the needle is what is important.

I believe tuning your car with an EGT would be no different. You are tuning based on a needle trend.

A spefic temp. would be futile. There are to many variables to it .

I believe my posted above method is the best way to tune.

It seems to me using some other members temp would be risky. What if the outside airtemps are different? What if the air flows different through their engine bay and affects the exhaust pipe's temp, what if what if what if.

You should tune with your egt based off of trend. Ignore the numbers. They will be different day to day.

James

dr0x

I dont see why people want EGT gauges. There are so many variables that affect the resulting #, it kind of makes them useless. For you to tune off, stupid idea. Go to a dyno and pay the 50$ to use it.

Wankel7

Rock on man....what a pain in the *** to use the gauge correctly.

Nice tool, if you have the coin to use it right

James

Scott 89t2

your right, there is no common # to use. each car will have it's own. but they are not far off. and when in the same car, do not change much at all.

the biggest change in temp is where it is located. which is why when I give temps out. I tell them where it is.

the best, and only real way to tune is with a good wide band o2 sensor. at this point while tuning. look at your egt gauge and get the readings.

now the next day, week later, or year later. when you are tearing around. and the egts go higher. you know you have a problem and can let off. this is why I have an EGT. not to use for tunning.

dr0x

Makes sense. But a lot of people with EGT's couldnt tell you where their peak should be.

Wankel7

Intresting, seems to be a good back up to tuning already done.

Could you use the EGT to tune like was talking about.

Constant load (constant rpm, boost, thottle pos.) and add/subtract fuel and use the needle trend?

Like an airplane?

James