Ok, if a guy wants to run a 50HP tuner on a 6.7 just how necessary is it to have a pryometer for the EGT ? I remember back when I had a 6.0 that seemed like a really big deal at the time.....

 

depends on the person... all my tuned diesel never had an egt probe....

of course I was not the first one to do 'this' tuner on 'that' motor, so others I trusted had done the research and in all cases I knew I didn't need one with my driving style...

now, with the 5th wheel I have now and if tuned, I might reconsider, but never had issues before...

 

The stock programing on a 6.0L put you close to the max EGT temps. A tunner was pretty easy to push you over. And it really depended on how you drove and what you tow.

I saw my 6.0L hit my threshold several times when I was towing. Usually when on a moderate grade that wasn't quite steep enough to get the truck to downshift. The engine would ( for lack of a better word) lug and be working hard at 2000 rpm and my temps would soar. As soon as I'd notice and kick it down a gear and get more RPMs, the temps would drop right off.

I'm sure the same concept will apply to the 6.7L engine. They are pretty finely tuned engines. Pouring extra boost or fuel will result in higher temps. Only a gauge will warn you if you are getting to high.

The challenge on the 6.7L is where to locate the probe? Since the exhaust exits in the center of the engine under the turbo. You don't have a convient exhaust manifold to drill.

The 6.7L does have 4 EGT probes already in the exhaust stream. That data can be viewed with an after market monitor like the Edge Insight. But all the probes are several feet downstream. Basically Pre and Post DPF and SCR. Most of the time my egts never exceed 950° But I have seen them hit 1200° during active regen. The question then is if it is 950°at the DPF, how hot is it at the Exhaust port?

 

Not nearly as high as you would think. Pay close attention to the pre-DOC temp under those conditions. During active regen, the temperature increase is not created at the motor. The extra fuel injected on the exhaust stroke is burned by the DOC and the temperatures increase from there. It is possible to have 950 at the DPF while not creating much more than 500-600 at the exhaust port during a regen.

 

Matt that is my point. The EGT probes being down stream, Don't truely reflect what the EGT is leaving the combustion chamber. So under heavy load/acceleration it may show 900° but at the exhaust valve it may be 1300° we don't know.

 

There are EGT sensors closer to the turbo than donwstream on the exhaust on the 6.4. I cant imagine why they would remove them on the 6.7. Vloney or one of the other Ford Techs can probably chime in on this but on the 6.4, the pyro gauge is as simple as plugging int othe OBDII sensor. No need to drill and tap like you did on the 6.0 liter.

 

Closest Pyrometer to the turbo on a 6.7 is right in front of the DPF. Over 5 ft downstream from the turbo.

If running a tuner, the EGT readings from the factory pyros are useless. You have two choices with pyros on the 6.7 - Delete the emissions and put a pyro in the EGR block-off plate and have true pre-turbo readings or run tuned w/o proper EGT readings.

Pre-turbo are the only EGT readings that have any meaning.