4 pipe & 4-1 exhaust

[Warbirdsolutions]

Guys,
I'm looking for feedback on both the 4 pipe exhaust and the 4 into 1 exhaust. I'm interested in fit, sound, and performance. Anything you might like to offer would be greatly appreciated!
Thanks in advance!
Brad

[BillL]

I have the AWI 4into1 on an IO360. It has not run. I think the individual 4 pipes are probably the best performance. I got the AWI to reduce the effect on the exit flow area from the cowl. The AWI has studs welded to the pipe for the heat muff, so I a hoping that will suffice in cold ambients.

I haven't heard a 4into1 since the air-cooled VW days. It is pretty easy to tell the 4 pipe and 2x2 when flying over.

What plane/engine are you building or have?

[Flyguytki]

I had a AWI 4 into 1 on my Superior IO-360 with horizontal induction. The fit was excellent and needed no modification to the exhaust airbox or cowling. Now the sound, I never personally heard it however I was told it has a much deeper throaty sound to it compared to Vettermans. And not that I need to say it bud man does it look good.

As far as the heater goes you have nothing to worry about, the welded screws do what they are designed for and work great, I was never able to pull the heater more than half open before roasting.

I no longer have the airplane but I can still answer any questions you might have

[flyingriki]

Some of the racers at Reno swear by 4 into 1. Larry Vetterman did some extensive testing and found them wanting....
See his Web site for the writeup.

[Warbirdsolutions]

The airplane this is going into is actually a Rocket but powered by a Lycon built new 10-1 comp parallel valve IO-360. It has the Superior cold air sump and AirFlow Perf servo facing forward. I had a 6 into 1 system by Sky Dynamics in my last 6 cyl Rocket and loved it. I have never seen the 4 into 1 or 4 pipe system in real life. I have read the Vetterman comparison and it seems that they are all fairly similar. So - I'm hoping to get some real life feedback from those of you actually operating these 2 exhaust systems. I imagine the 4 pipe system would sound great and probably perform pretty well.
Thanks a million for your thoughts and opinions!
Brad

[RVbySDI]

I cannot give you any comparisons but I have the Vetterman 4-pipe exhaust on my ECI IO-340 with forward facing cold air induction. It performs as advertised. It does take up more space in the exit tunnel but does look cool sticking out the bottom. The plane has never flown without me in the left seat but others tell me it sounds pretty awesome from the ground.