My Turbonetics ST install should be complete today. I had an EGT gauge installed with the kit.

What temps are normal for:
IDLE
CRUISE
WOT
TURBO SHUT DOWN
TEMPS TOO HIGH

Anything else I should be looking out for?

 

Exact temperature depends on the closeness to the head and each port will need its own sensor otherwise you are just reading an AVERAGE.
To maximize power you need the ability to INDIVIDUALLY trim each injector opening time.

http://www.robots.ox.ac.uk/~sjrob/Pubs/2004-01-1418.pdf

"At WOT, values between 850ºC (1562ºF) and 900ºC (1652ºF) are often considered ideal; temperatures below 800ºC (1472ºF) are considered too rich; temperatures above 925ºC (1697ºF) and approaching 1000ºC (1832ºF) are considered dangerously lean and can result in excessive engine detonation (knock) and possibly burnt or melted components (valves, spark plugs, pistons, rings). The placement of the EGT probe affects the measurement (the farther the probe is from the head exhaust port the cooler the temperature can be) as does the amount of ignition timing advance (more advance can mean cooler temperatures). " ????????

The major problem is the exhaust valves and the valve stem seals are not designed to handle the extra heat so their life is compromised........not to mention the heads and cooling system............every extra second at high temp is the killer of durability.

 

very good points, but in addition heat to an extent is the enemy to a engine in general.. making power.. creates heat.. so to make the most power possible you have to create a decent amount of heat, but to do so reliably you have to back up from that point. Hi egt's can lead to an array of disasters, cracked pistons, burned valves etc etc.

something in addtion you should keep a check on is AFR's.. some people tune/use afrs or egts alone, but together they definitely compliment eachother.

 

I have an Autometer EGT gauge. The install instruction says to place the probe 1 to 2 inches from the turbo exhaust outlet. Does anyone have a similiar set up that can tell me what their temps are?

 

Now that wideband AF gauges are available for a cost effective price, EGT's are a better indication of too much timing retard the higher the temperature goes than how rich or lean the overall engine is. If you have six installed then it can be used for individual fuel cylinder trim. I figured he is only puting in one so I was trying to give him a little clarification. Make sure you also have a WB O2 or else the EGT won't tell you much since 2 factors affect it directly(Air Fuel ratio and timing).

 

exactly.. i've tried tuning w/ the two seperately.. and from experience found out its always a good idea to have both.. and like he said there's plenty of inexpensive alternatives when it comes to widebands nowadays.. ie dynojets/innovate, etc etc..

as for actual temps.. thats gonna vary depending on alot of things.. if you dont kno how to tune.. i wouldnt really mess w/ that kinda of thing.. typically you could be looking anywhere between 1600-1800 degrees.. on the high side.. some cars depending on mods can go even higher.. srt's are in the hi 1800's stock!.. while we used to run a honda(stock internals) up to 1650-1675 before we cut power. the key idea is to find out where your car's sweet spot is using both and have your own reference.

 

Q45Tech,

let me pose a question. My probe is just outside (0.5") the turbo housing (turbine/wastegate outlet). My research indicated that the temps will be approximately 100 deg C lower just due to adiabatic expansion. However, in addition to that, I am approximately 4" away from the exhaust outlet of the head.

What would you say would be a correct correction factor. I am particularly interested in finding the fudge factor that would compensate for distance, rather than the expansion (as that one is known, more or less). Would you say 125 deg C is about right?

 

When the probe is AFTER the TURBO the exhaust temperature will be 100's of F LOWER than the exhaust port........because so much heat was removed to turn the turbo...............also what could be a destructive time lag to get the sensor up to REAL temp.

"Putting the probe after the turbo can create inaccurate readings because the exhaust gas will cool as it travels farther away from the manifold. This discrepancy can be as much as 250 degrees, which is far too big a margin of error. Also, depending on the power upgrades you have made, the turbo itself may throw off the accuracy of a post-turbo reading. If the turbo is a restriction, excess heat will build before the turbo as hot exhaust gas backs up, while post-turbo EGT will be much lower - resulting from the reduced exhaust flow which cools even faster than it would in a balanced system. This situation can be particular dangerous because excess heat will quickly build in the motor while temperature readings after the turbo will seem almost too cool."

 

wow...ok thanks

 

In order to use a cheap inexpensive EGT sensor and make it last manufactuers have you mount them after Turbo where it is pretty useless.

 

Well that's not very confidence inspiring. So what to do?

Recommendations?

 

Install 2 sensors [before and after switch between the two] and determine the exact amount of temperature drop for your set up.