I watched a few videos on the DA70 with stock DA mufflers. Now that I know how LOUD this engine is with that exhaust setup, I’m interested more now than before on just who can make a two into one header for it so i can mate it up to a MTW 110 canister.

DA does not have anything that will work. They make a 40, 60 and 90 drop. That’s it. They’re not available for custom work - I asked. I seem to recall someone here mentioning a fabricator. Anyone have any info I can use?

A good starting place for CG?

Originally Posted by marksz1

A good starting place for CG?

Between the center and the front of the wing tube is safe for start; then go through the trim flights process.

I’d start at 25 to 30 percent back from the leading edge of the wing at the fuselage. I’m sure others may have a better answer.

Herve?

That’s funny. Herve and I posted at exactly the same time. LOL

I thought I’d put this out for consideration by those who are considering going from stock mufflers to a canister on this aircraft.

Talked some more with DA this week. The 60mm DA 70 Y header has an actual drop of 63mm. If you use 2 of their DIY flat header exhaust flanges per side as spacers, that brings the drop to 71mm. The flanges are 4mm in thickness each. This is what I’m considering doing instead of brazing/building a custom set.

I am modifying a 90mm down to the needed 70mm. Not really a big deal for me, but not for everyone. Thanks on the CG responses! I can’t wait to fly this airplane.

I assume you’re cutting the exit portion of the header down to meet the requirement, then brazing on a new flange. Is that the plan?

There’s always a way...

Remove the flanges, shorten the tubes and re-braze them. Making a jig to hold the flanges in their exact positions. DA sells the brazing rods.

I’ve been told that TIG welding these results in a superior joint. With that approach, you have to hook up with someone that not only has such a welding rig, but someone who can actually use it and produce very good welds. Supposedly, much stronger than silver soldering them. This is why I chose the go the stacked flange route with the 60mm header. Good luck your project.

I bought a 90mm drop pipe from Desert Aircraft, modified it. Cut it and rebrazed it at 70mm. It’s a perfect fit. Flanges were re-used. I made a way to hold the flanges thru the entire operation.

Finally maidened my new Extra today
Super sweet
A huge shout out and thumbs up to PAU for a great product
And a LOT of thanks to everyone that posted on this page
Made the build go a lot smoother
Especially Tseres / your posts really helped
And your tail wheel setup with the glow tubing works great