Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Old 10-20-2017, 04:45 AM
JohnInReno's Avatar
JohnInReno JohnInReno is offline
Join Date: Jun 2005
Location: Prescott Valley/Chandler AZ
Posts: 326
Default Cut existing?

Originally Posted by rjcthree View Post
Can the standard Vetterman pipes be cut at an angle close to parallel to the fuse floor to come close to the turn down effect? I'd rather not add weight or parts. Does anyone have experience with this?
I too am interested in this. My exhaust sticks down at an angle and it looks like a cut parallel to the fuselage would help. However, I know Vetterman would be the answer man.
John Morgensen
RV-9A N946PM 600+ hours since 2013
Reply With Quote
Old 07-12-2018, 12:34 AM
AJ85WA's Avatar
AJ85WA AJ85WA is offline
Join Date: Sep 2011
Location: Perth, Australia
Posts: 267
Default Any info on this

I am still interestedd in this? Will a standard pipe cut down as suggested have the same results as a clamp on trun down tip?

Where have you guys purchased the turn down tips from?
AJ Wessels (Perth Australia)

Completed - RV6
Reply With Quote
Old 07-12-2018, 09:07 AM
Lars Lars is offline
Join Date: Nov 2005
Location: Davis, CA
Posts: 1,089

Originally Posted by edsong View Post
I wish they would quit calling our heat exchangers mufflers. They do nothing to (muffle) the exhaust noise.

To clear that up, Vetterman calls them mufflers because that's what they are. They are optional, and are described on the company website about half way down:

Vetterman claims a 6dB reduction in sound pressure over straight pipes, as noted on the page linked above. I have a set on my vertical induction Lyclone in my RV-7. I've never flown it with straight pipes so I can't comment on personal experience with noise reduction. They are bulkier than the Robbins Wings heat exchangers (heat muffs) that Vetterman provides for cabin heat on the straight pipe systems. The muffler system is also heavier than straight pipes, by about 2 pounds as I recall.

Can't comment on cabin heat improvement either, but I can say that the amount of cabin heat available from the mufflers on my RV-7 will have you looking for the exits on the coldest days if the heater valve is wide open. I've flown with an OAT of -20 degrees F and wide open was still too much.
Lars Pedersen
Davis, CA
RV-7 Flying as of June 24, 2012
700+ hours as of October 1, 2018

Last edited by Lars : 07-12-2018 at 09:11 AM.
Reply With Quote
Old 07-12-2018, 10:59 AM
Raymo's Avatar
Raymo Raymo is offline
Join Date: Nov 2014
Location: Richmond Hill, GA (KLHW)
Posts: 1,992

I only have one heat muff on my straight pipe system. 20 F and higher is my limit but I am also a southern GA transplant. I don't fly in colder WX
RV-7A - Slider - N495KL - First flt 27 Jan 17
O-360-A4M w/ AFP FM-150 FI, Dual PMags, Vetterman Trombone Exh, SkyTech starter, BandC Alt (PP failed after 226 hrs)
Catto 3 blade NLE, FlightLines Interior, James cowl, plenum & intake, Anti-Splat -14 seat mod and nose gear support
All lines by TSFlightLines

"The object of the game, gentlemen, is not to cheat death: the object is not to let him play."
Patrick Poteen, Sgt. U.S. Army

Last edited by Raymo : 07-13-2018 at 09:48 AM.
Reply With Quote
Old 07-12-2018, 05:13 PM
vetterman vetterman is offline
Join Date: Oct 2006
Location: TX
Posts: 44
Default Mufflers

I will try to answer a couple of item here. I tested the noise level of both the standard tail pipe system and the muffler system and yes there was a 6 dB difference. One guy was fussing about calling them “mufflers” but in the context of reducing noise it’s a common word. Go back in history of some planes like the cub and the unit was called a “spark arrestor” then one day later on it was called a muffler. Go figure. So the unit with a flame cone is not a true muffler by automotive standards but it does a good job of providing really good cabin heat and reducing noise a little. I might add one note here regarding noise. There’s the prop blast on the airframe, 200 mph of wind on the fuselage and air entering the cowl inlets and on and on- so the exhaust is what’s causing the noise inside. Really!!!
Now to address trimming tail pipes. I tested almost every combination I could think of and really never found any difference in performance, but what I did find is you don’t want the exhaust exit to be exposed to 200 mph of wind. That’s the ol “banana in the tailpipe syndrome” . Reminds of the time I got a call and the guy said all of the slip joints were leaking. The pictures he sent of how his tailpipes were cut solved the problem. Bottom line is leave the pipe as is, it was designed that way for a reason.
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 10:47 PM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.