Every Class 8 truck I've looked at has the pyro post turbo. What are your opinions either way? Those of you running V8's are you only reading one side of the engine? 1. Running it post turbo if the tip of the sensor breaks off it doesn't take the turbo out. 2. I think running post the temps evan out more. 1. Pre the responce time is faster.
If nothing else, pre turbo is hotter. Like monitoring transmission temperature, I want to know the HOTTEST it gets, not have a general idea of how hot it's getting.
As Tim stated, pre turbo gives you a more realistic picture of what the cylinders are seeing temperature wise.
If that's the case wouldn't you want to take your readings at either #1 or #6 cylinder as they're the most restricted spots in the exhuast manifold and tend to run hotter than the others?
Yes, one side. My view is that pre-turbo is quicker acting and lets you back off before the turbo starts getting toasty. Post does not see the temp increase until the turbo is already starting to get pretty hot. At least that appears to be the case since post is VERY noticeably slower reacting.
I agree with BadDog. I believe pre turbo is a better spot for it because by the time you get a post turbo reading it could be to late. IN my humble opinion pre turbo gives you a better idea of the egts your turbo is seeing. By the way wouldnt you get a cooler reading post turbo. I mean the exhaust as a little time to cool down before the pyro reads it.
Under load, post is pretty much always going to be cooler to some degree. But you can allow for that. The big problem IMO is with the temp lag when things are climbing fast. I've ridden in trucks with both pre and post simultaneously displayed and I was amazed at the lag. The amount of lag and the time required for it to show the increase that the pre was showing was far more than I would ever have guessed.
Yeah post readings run cooler by about 200*F from what I've read. I quess those who are running chipped out rigs might need the faster readings. The only big truck I've driven that ran over 900*F(post) was a I-6 Maxidyne by Mack. That engine was stickered for 1100*F(post) max.
I knew there would be a difference in te temp but i never really expected a 200 degree difference. Running 200 degrees over recomended max temp for very long might not be to healthy for a stock turbo
I always hear the thing about an EGT probe possibly breaking off and taking out the turbo as a reason for not running preturbo, but I've never actually met anyone who had ever seen it happen. Anyone here ever see it happen? Them probes look pretty stout to me. Mine is pre. 1. Reacts faster 2. Truer reading in an aftermarket job, IMHO 3. Easy install since you can drill and tap the manifold. 4. No guesswork as to what the actual turbo temp *might* be. Marc
