Hi all,

I just got a Roush supercharger installed and have gotten the Nexus EGT gauge, along with a boost/vacuum gauge and Tranny temp. I will be installing my Magnaflow exhaust and Dynatech headers as soon as I get my tune from Mike Troyer. I also will be putting on the dual electric fans and ignition pack as soon as I get the order from mike. Thanks to Mike for the great deal

My question is how hot should my EGT gauge get before I have a problem. If i see it go over what temp should I stop. I also want to make sure that I had it installed in the right place. When I asked the shop they said it was in number 5 about 1 inch back. I think this is right from reading some other posts but want to make sure.

Oh, also what should I let my tranny temp get too.

Thanks for the help.

 

Call Mike and ask him about the temperatures.

 

Definitely, call Mike, he will know

 

the instructions say put the bung in number one. i went the other way since i have manifolds still and welded bung bout three inches above the front o2 sensor. i usually see 1000 deg while crusing most of time and bout 13-1400 at wot. this is with high flow cats though, it was bout 100deg higher with the stock cats.like they said give mike a call and hell help ya out

 

You will not see your highest EGTs at WOT. Cause at WOT your pcm commands a RICH condition.

 

sorry was thinkin wrong for a min then, highest ive seen while accelerating was 1400 or so on highway or with a trailer behind me

 

Hi cmany,

It is best to call us for this info, as it's really too detailed to get into here - there are numerous factors that are involved, from the type of thermocouple to it's placement, etc.

In brief -(and before I get started, please forgive me if we have perhaps already discussed some of this over the phone before, as I talk to so many people I sometimes cannot remember! ) - you will see your highest EGT's in a gasoline engine at cruise - it's not untypical to see 1400 degrees when cruising along at 75-80 mph going up a grade, for example, when you are in closed loop. When you got to WOT, the EGT's will go down if the vehicle is proper tuned & configured, but not, as one poster mentioned, only as a result of richer A/F's, but also there are a couple other factors that affect this too.

See, a richer A/F, up to a certain point, will lower EGT's in a gas motor - but also this is affected by timing *and* load - as load goes up, spark advance decreases in proper tuning - but as rpms go up, spark advance *increases* - so you actually have several factors that intersect that all go into making up what the resultant EGT's will be in any given situation.

Also, you need to be careful in your selection of gauges (and here I don't know if perhaps we have already covered this) - for example, in your boost/vacuum gauge, it needs to be a higher-end unit that has a barometric calibration in it, not just the typical $70 units, as that is the only way you will get accurate boost & vacuum readings under all conditions. This type of gauge must be connected to a power circuit that does not get interrupted while the engine is being cranked, and it calibrates itself each time you start the vehicle, you have to leave the ignition in the on position without starting the engine until it calibrates itself and zeros out - it's significantly more expensive, but the only way to have correct readings under all conditions. Autometer, for example, makes both types of gauges, and most people just go the cheap route with the $70 combo units that are not going to give the more accurate readings, so be aware of this. For example, on my Lightning that runs anywhere from 15-18 PSI, it makes a difference of 5 psi of boost in it's readings!

You'll want to talk with us regarding how & where to install both your tranny temp & EGT gauges, as probe location is critical, along with some other hints - just trying to help.

Good luck!

 

I can vouch for this. I thought that the ignition timing was retarded at WOT but I wasn't positive. My edge verified this today. The more throttle applied, the more advanced the timing got, until I reached WOT. It retarded over 30% versus "MAX load not WOT" So as Mr. Troyer said, that's another factor that determines EGTs. I was planning to post this, but Mr. Troyer beat me to it.

 

The Nexus gauges are top of the line from Autometer. Also, the EGT goes into to cylinder 5 which is the hottest and Autometer tells you exactly where to put the probe. We have already had this conversation on another post.

As far as EGT going down under WOT, what is that ? Down from what ? Do the engineers at Ford expect this ? Hmm.

Answer. A simple review the calculated Exhaust Temp Table shows that as the calculated Engine Load and RPMs go up so does the calculated Exhaust Temp based upon 14.64 Air/Fuel and MBT Spark. This is what the Ford Engineers expect to happen. It is real easy to see this by a simple datalog. Load the factory tune into the truck, hook up the datalog and select Inferred Exhaust Temp, monitor EGT with an EGT gauge and compare the results to the value datalogged. Did the calculated temp go up or down under WOT according to the datalog ? Did the temp go up or down according to the EGT ? Sure, we are running a richer mixture while in Open Loop and sure the spark advance is not as much with both runners open; but, in both cases, the answer is the temp went up under WOT to a point.

Oh and by the way. Getting the engine past 1350 while running 105 Octane E85 Ethanol is a chore. Normal crusing at 75-80 produces an exhaust temp of 1200 degrees in 90 degree weather and an intake temp of 100. Even at 100 MPH, 25.8 Spark, 99.3% Load, 4300 RPM, and a calculated Net Torque of 414 Ft/Lbs, I am still 100+ degrees under the calculated temp. Proceeding to 105 MPH and beyond shows the temp holding firm.