Offset turbo flange?

[JimmieD]

Looking at installing a 4" exhaust right out of my H1C using a 3" to 4" adapter. That's going to put the downpipe right up against the wall, so wondering if anybody has seen some kind of offset flange/adapter, cast iron for turbo exhaust inlet, to let turbo move forward? Thought I saw some somewhere and can't find them now.... Thanks!

[cumminsram]

To make my 4'' exhaust fit I just had to cut a 1'' lip that sticks out on the firewall and mine fit. Sorry dont know about the adaptor.

[JimmieD]

Thanks, C/R. Mine will need an adapter from 3" to 4" right at turbo exhaust outlet, then my downpipe elbow. The space taken up by adapter will add at least 2.5" to 3.5", and that will put the downpipe elbow up against the firewall.

Fortunately it's an older truck that I just did extensive floor pan, firewall and cab support work to. Not all that big of a deal to pop out the floor section over there to clear downpipe, but an offset turbo flange seems easier, if I can find one. Thanks!

[dpuckett]

I had a 3-4 adaptor, then installed it right at the end of the 90deg elbow bed. Trimmed the end of the stock DP just far enough back to install the clamp, welded it to the adaptor. It cleared the firewall nearly as well as the stock 3" piece (2" clearance or so). Wish I had a picture of the truck to show y'all.

[JimmieD]

Thanks dpuckett! I may have just found the correct adapter that is only about 1" in transition from 3" to 4". This will solve the problem. My install is in a 60's Dodge truck so things are a little different from a normal 1st Gen. Thanks, and I'll post the part if I find it.

[PToombs]

I took a 3 to 4 adapter and cut the center transition piece out of it. Welded the flange to one end and elbow to the other. It figures that it is the worst looking weld on the exhaust, where you can see it!

[JimmieD]

Thanks, Pete! Y'know, I've got a really great old Millermatic 35, been welding for 40 years, and my downpipe came out SOOooo ugly ha haha! Some days ya got it, and some days?

I couldn't find the part I needed because I was looking for a 3" to 4" ADAPTER, then I remembered 'plumbing' is different. I typed in 4" to 3" REDUCER in search and there it was! Instead of a long taper it's a no-transition reduction from 4" to 3".

http://www.supertruckusa.com/products/77620_962.htm

Price is right, and I hope it's a heavy enough wall thickness. This is not the 'adapter' that I mentioned above, but a different part.