Engine/Transmission (1998.5 - 2002) Moved pyro probe, WOW!

[MRose]

My pyro was in my exhaust brake housing and with my mods would see 950-1000 on 5x5 on a long drag pull with no load. Always added 300 since it was post turbo. Drove my buddies pickup with the pyro in the manifold, loved how resposive the pyro was. Moved it to the manifold and wow, scary. Went and drove some hills and made some pulls and I could hit 1500plus easier than I wanted to. Forget the 300degree diference, be aware.

 

[Mark Craig]

MRose,



You are exactly correct, we have been preaching this for years, these trucks are not semis with muilt range transmission's and 2200 rpm redlines. Now think about adding a heavy trailer and a 6% grade!! Kind of scary sometimes. Pre turbo only is my moto!



Mark @ DPPI

 

[KLockliear]

You are exactly correct, we have been preaching this for years

Mark @ DPPI

Ditto. Gotta be pre-turbo.

 

[Vaughn MacKenzie]

Good work MRose. The 300F rule comes from the old days of basically stock 12-valve engines (less HP) with larger exhaust housings and doesn't apply any more. I've posted about that several times. I've heard of more than 500F difference reported by someone with two probes.



Vaughn

 

[WestTN]

A difference of 300 degrees would only occur at one specific intersection of boost pressure and rpms. Varying either changes the other. THAT is the reason you need to read the temperature where it is affecting critical parts and not infer it from a measurement elsewhere. The turbo extracts power (heat) from the exhaust stream to do its work. Exactly how much depends on several factors. The critical parts to protect are the aluminum pistons and the valves which get cooling only while seated.

 

[Devan Manis]

MRose, how did you block off the old hole for your pyro?

 

[J.Keith]

My question is do you have to pull the turbo to tap in pre?

I've heard that you can fish out enough of the particles with a magnet that it will not damage the turbo. Any truth there?

Right now I'm post turbo but I would really like to go pre turbo if I could do it without taking the turbo off.

 

[redfuelrules]

putting the pyro probe in pre-turbo was really easy. The ex. manifold drilled & tapped VERY easily as it's cast. I was able to get most of the metal filings out w/ a magnet. Another tip from somewhere on this site is to frequently coat the drill bit & tap w/ lithium grease or something similar that the filings will adhere to instead of falling into the manifold.

 

[MRose]

It drills easier than mild steel, kinda scary. Magnet, magnet, magnet, then more. Tapping the manifold makes the scariest chunks of metal. And yes good heavy grease. 1/4" pipe thread plug was all I used to plug with. Didn't like the thought of brass with different thermal expansion rates so went with plain steel.