i know i have to drill and tap a hole, but do i got pre- or post- turbo? which is easier? what should my EGT's max out at in each location?

 

I like the pre turbo thats what I have, cummins says you can run 1250* all day long anything higher than can be done but not for very long.

 

x2 for the pre-turbo. The only thing is, when you drill and tap your hole, make sure you get all the shavings out of the manifold before you fire up the truck, or they'll go through the turbo.

 

If you want to go post turbo you will have to weld a bung in post turbo.

Pre-turbo is the way to go as you get an accurate reading. If you go post-turbo you have to pretty much guess what the actual exhaust gas temperature is as the difference between preturbo and post turbo can be as much as 500 degrees.

 

make sure when you drill your hole in the manifold you do it towards #4,5,6 cylinders dont punch right in the middle of the manifold because you will hit the seperator in there also the farthermost cylinders from the raditor get the hottest so youll want to measure there. i have had mine past 1800 for short burst with no problem but try not to get over 1500 for more than a few seconds.

 

very good point, when I drill and tap the holes I start it before I drill. The press in the manifold blows all the shaveings out.

 

wouldnt firing it up make the shavings go thru the turbo? am i going to have to seperate the turbo from the manifold to do this?

 

No you dont HAVE to seperate it , theres a fair amount of pressure in there , enough to blow the shavings out . But , it shakes a bit and gets a little hot so drill a pilot hole first . I used a shop vac right next to where I was drilling at the same time and it worked really well . Also , you can dip your tap in grease or vaseline so the shavings stick to it when you tap it . Your hole will need to be drilled 2" up from your turbo/exh manifold flange and 5/8 towards your firewall from center . Stick that shop vac over the hole and it will suck out the little stragglers if any . Then start it and give the throttle a few bumps before you put your probe in.

 

all i did was separate the turbo from the manifold and shoved a reg inbetween then fired it up after i drilled the hole

 

I've had good luck with a little magnet to get all of the debris out of the manifold. My favorite one has a bendably wire that the magnet is attatched to. You can really get it down in there. I don't drill a pilot hole. Just go full size the first time. Less opportunity for stuff to get in there. Then, tap the hole with a greased tap. When you're done, make sure it's all clean inside with the magnet.