What are the difference between the function of having either of these gauges? It seems as though they would do the same job.

Also, I've heard that a stoichmeter is a waste, and an EGT meter is the best way to verify if you have a lean or rich condition. Is this correct?

 

EGT=Pyro

Both a Wideband and Pyro are useful for tuning. I begin a tune with a WB and now i use a Pyro to check too.

 

I was just wondering, because I see two different gauges for sale, and I thought they did the same thing. I wanted to purchase one so that it would already be installed before I go turbo in the future, but wasn't sure which one to purchase.

 

The next thing to figure out is what probe do you want to go with.... some probes are better, faster, then others. Get a good probe.. its worth it.

Also.. location of the probe. I think I remember the correct placing of the probe was something like 1.5xs the diameter of primary from the exhaust port. Ive heard of some people putting the probe in the header collector, but if Im not mistaken thats WAY off as far as temp accuracy goes.

 

I am using the probe that came with the autometer guage. Post if you have any more info on the probes.
For NA it would be around 1.5-2" from the exhaust port. But for turbos autometer calls 6" down from the exhaust housing. I have mine right at the end of the manifold.

 

Actually, Autometer says 1-2 inches from the cylinder head, or 1-2 inches from the turbo exhaust outlet, only 6 inches if you use the clamp method which seems more difficult to me.

http://hp.autometer.com/instructions...nstruction.pdf

 

It doesn't seem as though that would work well on an STS car, since the temp would have too much time to cool.

 

On an STS car you're better off running the probe 1-2 inches from the cylinder head instead of at the tail pipe.

 

That seems to make more sense.

 

97
Yeah, your right got confused between the clamp and thread in off the top of my head. I used the clamp in method just below the manifold for now. I am going to try right off the exhaust port and after the turbo for comparisons.

 

would it not be more correct to run the EGT probe before the turbo because the turbo converts the heat & gas energy to mechanical energy, thus giving out a cooler exhaust.

 

Yeah, it probably does. Alot of tuner guys run them before the turbo, probably just as many run them after the turbo. Autometer probably doesn't want you starting a lawsuit cause a 5 year old probe broke and went flying through a turbo spinning at 100,000 RPM. Imagine the carnage. So they tell you to mount it after the turbo and if the probe breaks it just flys through the exhaust and doesn't hurt anything. Mounting the probe after the turbo on an STS kit would be silly, just put your hand up to the exhaust at your tail pipe and see how hot it is.

 

Good point. I have used the hand test, but will double check with the meter when i get a chance.

 

Good thing Autometer includes like 20 feet of cable with their EGT kits. Don't forget, you aren't supposed to shorten them either.

 

On turbos (single, engine bay mounted) you generally want it before the turbo, just before the turbine housing. One bad part about running the probe on just one cylinder is that it doesn't give you an indication on what the other cylinders are doing. Each cylinder will tend to run at it's own disharge temp, which is usually different from the others due to inconsistencies in air distribution during the intake phase (i.e.- some cylinders get better intake tuning which allow them to injest more air). Mounting it just before the turbo gives a better indication of what all the cylinders are doing as a group. On rear mounted, like in the STS setup, you'll want to mount it as close to the engine as possible due to the cooling effect Luke mentioned.

The absolute best way (and most expensive) is direct cylinder monitoring by EGT probes in each primary via laptop. Cal Hartline's GN has this feature along with an individual cylinder control computer. It's so finely tuned he drives the car a few days a week to work in florida, yet can stop by the dragstrip and bust off a mid-8 pass in the 1/4 at any time. Each cylinder has it's own set of injector duty cycles to follow to make up for faults in the intake tract. The car is a monster and a perfect example of what excellent tuning can do. Check it out: http://www.gmhightechperformance.com...TP_0403_BUICK/