I just ordered the Magnaflow 4" SS system which has the bung installed in the downpipe for the pyrometer(which I also ordered). I'm new to diesel's so excuse the newbie question here: is installing the sending unit in the downpipe post-turbo(after the turbo)? And if that's right, I've read different posts saying that the best location for the sending unit is pre-turbo. How would I go about installing it that way? Just to throw in another question, the directions say to drill the manifold for installation. Is this the best way to install? And if so, is that pre or post turbo? I know alot of you guys know the answer to this one, I've tried searching posts and just haven't gotten definite answers. Thanks to everyone out there!

 

Hey there.... The vote of almost everyone on this site is going to go pre-turbo....in the manifold. You will want to CAREFULLY dirll and tap a hole, use a magnet if posible to get ALL the metal fillings out of the manifold, (also dip the drill in oil, so it will keep shavings to a minimum) and install a thermocouple into the hole.... Pre turbo gives you a MUCH more accurate reading about what is happening in you engine. Exhuast Gas temperatures, (EGT's) can be much lower after the turbo, affecting the accuracy of the reading. It's better to knowing befor you have a problem, and pre turbo will allow for that.... Good luck w/ everything!!!

 

Since your downpipe has a spot to put a pyrometer, you could mount one there and also one in the manifold. That way you could have two gauges, one pre-turbo and one post-turbo. I have seen several guys that have done this.

 

I would definitely mount the pyro pre-turbo. There can as much as a 300 degree difference from the exhaust manifold and post turbo locations.

 

Can you mount the sensor in the manifold without removing it I didn't think there was room don't have one yet but it's on the list. Plus I like the idea of the pre and post pyro sensors.

 

Pre turbo is more accurate and reacts quicker. I've never run two gauges at the same time but I have moved mine from pre to post and now it's at pre turbo where it will stay. Post temps were up to 450* cooler than pre turbo under some situations and at other times they were about the same. Since there is such a variance it's hard to set a safe max. temp post turbo.

My thermocouple is in the driver's side exhaust manifold.

 

At motorhaven here there's a Isspro gauge designed for post turbo mounts. If all i have on my truck is a tymar intake and 4" exhaust, i have no intent on getting a chip anytime soon and i don't tow much of anything very far; will 300 +/- degrees really matter to me? That way i know for certain my turbo won't get damaged.