I'm working on installing my Isspo gauges, Tach, Boost and EGT.

Now I'm installing a post-turbo set-up...I know most prefer pre-turbo but my gauge is post and being a long time trucker I prefer it in this location. Anyway when installing the bung on the down pipe should I cut a hole big enough to allow the bung to sit half in and half out of the pipe? Or just cut a hole slightly bigger then the probe and then weld the bung on top of the pipe?

Now about my boost gauge set-up. There are a couple different fittings in the pack and I was wondering which one should/do I use. Here's a pic.



The one on the left has the connection for the tube and is a fine thread, do I drill and tap this one right into my air horn? Or do I drill and thread for the bigger fitting on the right, since it's a NC thread I believe. The little fitting fits inside the bigger one as well.

 

you can drill the downpipe just a little larger than the probe, I think I used a 3/8 bit. Then weld the bung on the top of the down pipe. As for the fittings you will have a plug in the intake you can unscrew,you don't have to tap one. Ithink the plug is 1/8 just use the fitting that fits.

 

My post turbo setup uses a hose clamp. The probe came with a hose clamp and a collar with a set screw.

 

Ohhh....never thought to look at the intake for a fitting. That would be much easier.

 

here are the fittings for the boost take off.



Apparently the small, TONS easier to reach one works just as well. I took it out and didn't feel any pressure coming from it though (rev'd it up and still notta, might have had a blockage from years of crude). So I used the large, totally huge pain in the *** one right next to it.

Small is 1/8" NPT and the large is like 1/2" NPT or something like that. The adapter for the boost line was 1/8" NPT also.

 

I hooked up to the small one and I'm hardly getting any boost to my gauge. I know the H1C's aren't know for their massive boost capabilities, but I was givin'er up the road and maybe saw 10lbs on my gauge.

Maybe I'll pop out the fitting and see if I get any blow out the hole.

 

I think my truck only made 12psi when it was stock. So that may just be the correct reading.