I have installed an ISSPRO pyro guage. The thermo coupler has a 1/4 in. bushing that taps into the turbo instead of an 1/8 in. bushing. Does anyone have the correct number for the 1/8 in. themo coupler that you tap in 1/8 in. instead of 1/4 in. I am afraid that the 1/4 in. will weaken the turbo permiting it to cause a crack or worse? Thanks-Ray

 

HOLD ON A MINUTE - why are you tapping into the turbo??

The correct place to tap is either the exhaust manifold or post turbo. I have never heard of anyone that tapped into the turbo housing.

Dont sweat the 1/4" hole just use a 1/4" X 1/8" bushing and some nickle antisieze. That will work just fine.

 

Your right after I sent the post I realized what I had typed. I should of said Exhast manifold. Will the adapter allow the thermo coupler probe to go through it? The ISSPRO guage didn't have any instructions except for post turbo then they supplied a 1/4 in. pipe fitting no 1/8 in. Maybe the instructions from tstproducts are for a different make of guage. Thanks for the heads up anyway.
Ray

 

I personally wouldn't be concerned if the port is 1/4'' or 1/8''.
The only manifold cracking problems I've seen can be attributed to not running the tap far enough down then over torqueing on the fitting to get it down to the correct level.

 

I got a 1/8 to 1/4 coupler and the probe part of the thermo coupler won't go through the bushing so I guess I'll go for the 1/4 in. tapped hole. I've got eveything else set up and looks pretty good. Although I got ahead of myself and thought red was positve but the pyro instructions said yellow was so I had to disassembly the pod and connect it back the way it was suppose to be. I checked the pyro by heating it up , it worked fine. Now I will get the tap chart out (use to know the drill size by heart} and find the right drill bit and go for it. Thanks Bill.