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Vetterman Exhaust Turn Downs

Chachi7565

Well Known Member
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Hi, I just got some of Vetterman's exhaust turn downs to put on my relatively-new-to-me RV-8A (how long can I keep saying that? I bought it in October...) as the builder used the stock aluminum ramp and not stainless.

My current exhaust tips are already almost touching (See pic) I assume I need to trim off the ends before installing the tips, but I'd like to see an example of what right looks like. Can anyone share a pic of their RV-8A exhaust with the turndowns?

Thanks!


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This is an RV14A (not an 8), but same issues. These turndowns come from Vetterman (who made the exhaust) - they do not require any exhaust trimming but rather sleeve over the exhaust with a locking screw. No problems after 1200 hours.
 

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I'm interested to know about this as I have the same plane and exhaust. Is it necessary? I sincerely doubt this panel is stainless steel on this plane

In my experience, if there was anything "optional" on my plane, the builder didn't do it - which is why I've been so critical of Vans not speccing best-practice changes as standard and discontinuing less robust ways of doing things.
 
I'm interested to know about this as I have the same plane and exhaust. Is it necessary? I sincerely doubt this panel is stainless steel on this plane

In my experience, if there was anything "optional" on my plane, the builder didn't do it - which is why I've been so critical of Vans not speccing best-practice changes as standard and discontinuing less robust ways of doing things.
Many years ago, when my RV-8 was new, I notice some cracking in the tunnel area. I happened to be at a fly-in with Vetterman - he looked at it, reached into his baggage compartment, and handed me a set of turn-downs. I put them on, stop-drilled the cracks, and the cracks have never grown in the 20+ years and 2300 hours since. Based on that one data-point, I think the turndowns are a good solution to preventing the cracking, and there is very little downside to having them. Just my opinion and experience.
 
Come to think of it, I'm wondering if my pipes have a "built in" turndown, as they are different in appearance than these. I'll try to find a pic to post or take one tomorrow when I go fly.
 
Many years ago, when my RV-8 was new, I notice some cracking in the tunnel area. I happened to be at a fly-in with Vetterman - he looked at it, reached into his baggage compartment, and handed me a set of turn-downs. I put them on, stop-drilled the cracks, and the cracks have never grown in the 20+ years and 2300 hours since. Based on that one data-point, I think the turndowns are a good solution to preventing the cracking, and there is very little downside to having them. Just my opinion and experience.
I experienced pronounced “drumming” of floor panels right from initial flights caused by exhaust (and maybe propeller) pulses. The problem was largely mitigated by the exhaust turndowns and addition of carpeting.
 
On an RV-8, not an -8A. I didn't have any belly ramp skin cracks on my current RV-8 (my previous RV-8 did) but wanted to reduce the floor vibration and prevent future cracking. Vetterman sells turndown extensions and straight extensions. I already had the turndown exhaust, but they were short. So Clint at Vetterman's sent me two short, straight extensions. They are each attached by one bolt.

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And the instructions:

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The OP said he had the turndown extensions (as opposed to the straight extensions). As the instructions say, the turndown extensions can be adjusted to be angled in or out slightly.
 
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Looks like later exhausts are extremely downturned to solve the problem. This is mine. I can't help but think this is less efficient for cooling flow, but if the floor isn't stainless, maybe it has to be like that.
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Does anyone make a stainless floor part for this swap? I don't have a break, and can't find a service willing to make the radius'd bends... so on my quickbuild RV-8 it just has to stay aluminum unless there's a place to buy the part from. I was debating riveting a stainless sheet over it externally...
 
Your pipes have much more turndown than my Vettermans purchased in 2024.

Looks like later exhausts are extremely downturned to solve the problem. This is mine. I can't help but think this is less efficient for cooling flow, but if the floor isn't stainless, maybe it has to be like that.
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Your pipes have much more turndown than my Vettermans purchased in 2024.
Fascinating. I'm wondering if it's an 8 vs. 8A thing. 8As are a tough exhaust fit from what I've seen and heard.

Even with this much turndown, it has blasted the paint off part of the ramp at ~280h
 
Does anyone make a stainless floor part for this swap? I don't have a break, and can't find a service willing to make the radius'd bends... so on my quickbuild RV-8 it just has to stay aluminum unless there's a place to buy the part from. I was debating riveting a stainless sheet over it externally...
I just made a double skin by riveting a single sheet of stainless to the aluminum cooling air exit ramp. No fancy bends required. It's not quite as elegant a solution as remaking the whole part from stainless, but should be effective enough.

The other problem I was trying to solve is slowing down an engine fire. There's a nice stainless steel firewall. But that hot, burning bits of engine and compromized fuel lines are being blown out the cooling air exit, and along the aluminum belly of the plane. A stainless exit ramp should buy a few more minutes over the stock aluminum exit ramp.
 
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