pre turbo or post turbo

[ckusy]

Have an o6 on order and planning on gauge installs. Do I go pre turbo or post turbo and why? Also on boost gauge 0-30 or 0-60 p. s. i. From posts I've read the isspro gauges seem popular. Any info or suggestions would be appreciated.



THANKS IN ADVANCE

 

[terrywerm]

This is just my personal preference, but I'd go pre turbo on the pyro. If you are planning on leaving the boost stock, the 0-30 will suffice, but if you plan on bombing, you'd better look at the 0-60 PSI for the boost gauge. I was always told that pressure gauges are most accurate in their mid-range, and if you ran your boost all the way up to 30 PSI or so, the 0-60 would be just right.

 

[PatrickCampbell]

PRE for most accurate readable results. POST if you are too lazy to remove the turbo.

 

[rweis]

Pre turbo for sure. Reading boost gauge values in the middle of the range of the gauge is correct and ) - 60 allows for more bombing that you thought you would do.



Bob Weis

 

[NIsaacs]

Post works for me, it has nothing to do with being lazy, it's where I want it!





"NICK'

 

[JasonCzerak]

With extream care and slow drilling and taping with lots of grease and large magnets, cleaning of the bits frequently. One can tap a pyro hole pre-turbo without removing the turbo.



I wish I wasn't so lazy as to where I tapped it. I wanted it closer to #6 or right at the turbo back side collector.

 

[RustyJC]

Pre-turbo if you want the most accurate, meaningful information, especially if you're planning BOMBs down the road.



Rusty

 

[ndurbin]

Pre-turbo install on the pyro. Grease the bit and tap and use a small pencil magnet that you can fish around inside the hole. Another tip is (and this is very redneck) get a small piece of hose that well fit into the hole, rig it up to the end pipe on the shop vac (duck tape works for this) and slip the hose in and fish it around like the magnet.



Definitely 0-60 boost.



The Isspro's match up nicely to the OEMs, and there is a wide variety of mounting solutions for the 3rd gens. I have yet to see the new Optix line from DiPricol, but their previous series also matched up nicely.



Nathan

 

[Buffalo]

If you loosen the bolts on the turbo just enough to allow it to drop a bit so you can slip a piece of cardboard (cut from a cereal box) into the space between the turbo & the manifold, it will trap the metal shavings.



When you are done drilling & tapping, blow the shavings off with an air hose, pull the cardboard out & tighten the bolts & you're done.



Joe F. (Buffalo)

 

[PatrickCampbell]

sorry, did not mean to insult but i can't see why you would chose to do it post-turbo.



i did my 03 PRE without removing the turbo... not proud of it.



the 01 turbo is right in your face and really easy to take off.

 

[Dieselnerd]

I chose post turbo for several reasons:

1. That's where Cummins recommends it.

2. I am stock and want to monitor turbo cool down after heavy towing.

3. I plan on remaining stock, if I planned power upgrades I would go pre-turbo.

 

[NIsaacs]

Years ago when manifolds and turbos were single entry, pre was where the truck makers installed the pyro. Now with split entry manifolds and turbos, they are placed post. Why? I don't know. Maybe because monitoring 2 or 3 cylinders, pre turbo (split entry) wasn't as good as all 6 cylinders post??



Does pre turbo respond quicker than post? Yep! But does it really matter or do we know the exact temp, melt down occurs or when? Do the hot rod trucks back off before the end of the 1/4 mile or before the sled stops them?



Post turbo for daily drivers and for towing, will react more than quick enough for your safety.





"NICK'

 

[RustyJC]

Post turbo for daily drivers and for towing, will react more than quick enough for your safety.

Not with a modified tow rig like mine, and Cummins' published post-turbo guidelines don't apply after I've added more fuel (and, correspondingly, more BHP. ) Moreover, there's not a fixed differential between pre-turbo and post-turbo readings - the difference will vary with load and boost.



Rusty

 

[NIsaacs]

On your modified tow truck, if you used 900 degrees as a caution and 1000 degrees as a max, post turbo you will be safe. Temp readings post turbo, will react fast enough, regardless of your mods, for safe towing. I doubt that you will out accelerate a post turbo pyro when you are towing your loads. If you were drag racing or pulling a sled, you might out accelerate a post turbo pyro, but you wouldn't be watching it anyway, and if you did you would ignore it anyway or lose.





"NICK"

 

[KBaucom]

pre turbo and a 60lb boost gauge if you don't then you will wish that you did

 

[RSimmons]

I went post turbo based on advice from some old big truck driving friends. They had a valid argument. If you keep the truck and EGT gauge long enough, the thermocouple will sooner or later break or burn off and eat the turbo up on a pre turbo installation. I tend to keep my trucks until the wheels fall off and are not worth putting back on. So, for me, post made the most sense.

 

[Bob4x4]

This is just my personal preference, but I'd go pre turbo on the pyro. If you are planning on leaving the boost stock, the 0-30 will suffice, but if you plan on bombing, you'd better look at the 0-60 PSI for the boost gauge. I was always told that pressure gauges are most accurate in their mid-range, and if you ran your boost all the way up to 30 PSI or so, the 0-60 would be just right.

The 600/610 trucks are over 30 psi stock



Bob

 

[dodgeguy44]

Mine is post-turbo 'cause it was a very easy install and I believe for towing when it hits 950 I know it's time to let off a little, never had to but that's my high mark.



As for the probe burning off; I have never seen or heard of one burning or breaking off in 27 years around trucks but it could happen none the less.



Enjoy your new ride!

 

[RustyJC]

On your modified tow truck, if you used 900 degrees as a caution and 1000 degrees as a max, post turbo you will be safe.

I have a friend who has a truck configured similar to mine. He has 2 thermocouples, 1 pre-turbo and 1 post-turbo. At light loads, he sees about a 150 degF difference between the readings. Dragging his 5th wheel up a steep grade, he sees as much as 500 degF difference between the readings.



If I had taken you at your word and used 1000 degF as a maximum, I could be seeing 1500 degF pre-turbo dragging my 5th wheel up a 5 mile grade and very likely would have a nice hole in #6 piston.



By the way, I have worked in technical management for a manufacturer of large industrial engines for 32 years. We provide thermocouples at each cylinder's exhaust outlet as well as just in front of each turbocharger as standard equipment. We only provide a thermocouple after the turbocharger (post-turbo) if the customer requires it.



Rusty

 

[joaker]

For what it's worth, I have run a single pyro in the post and pre-turbo configuration, and for a single, I prefer the pre-turbo route, simply because htere is no bashing around as to what temp is the "safe" temp, and I finally know for a fact that there can be a HUGE difference between pre and post, when my thermocouple crapped out, I switched to the Spa, dual EGT Pyro guage... and quite frankly I love it, I was dead set against it at first simply because I like the way an analog gauge is easy to tell safe from not safe, but after a bit of learning, I found out that you can program two alarms on your digital for each pyro! So for example I have the first warning come on at 1375 pre turbo, and the second at like 1450 or so Pre turbo, and if you wish you can also set two more alarms for your post turbo pyro too. The other thing I really like is that it records the high values on each of them too, as we all can attest to, you don't always look at your gauges while doing a run on the 1/4. . lol Lastly, in regards to the difference in temp between Pre and Post... I have seen a bit over 600 degrees difference in a hard pull with a lot of fuel being dumped to it, on average it seems to be around 100-200 difference, and while decellerating, I have seen just about 500 difference in the opposite direction, it is really interesting to see how much heat that turbo holds!! I am very partial to this Pyro setup, it will tell both and take up the space of only one. As to the boosty gauge, I would personally opt for the 60lb version, but depending on your shop, they may take your 35lb back when you need to up grade for a minimal cost too.