Fresh Air Exhaust Install

[smedman]

Ever since we got our Bu a few years ago (primarily to wakesurf) I've been interested in the Fresh Air Exhaust in order to reduce Carbon Monoxide fumes in the surf zone.

Larry Mann, the owner of FAE and trickboardz lives about 20 mins from me and he and I have met at several different events in the last year or so. I offered to let him use my boat as the test subject for a FAE install with the Manual Wedge.

He came over a couple of weeks back and installed a modified wedge in order to test it out before installing the FAE.

There are two parts for this mod -- the "plate" and the "wing".

In order to make the FAE work with the Manual wedge, the brackets have to be in the down position at all times.

So if you are going to be driving down the lake (not surfing or boarding) you will want to be able to remove the wedge (wing).

The plate makes it fairly easy to do with bolts that allow the wing to lock into place and be removed.

The first step was to remove the wedge and replace it with a bracket plate

We wanted to check to see how the boat would drive with the bracket plate in the down position -- since this is how it will be with the Wedge (wing) removed and the FAE installed.

So -- took this for a test run with the boat unweighted --- should have taken a pic -- but the wake seemed like the normal ski wake -- as if the wedge was up.

Then - I tested with the "Wing" installed:

(for testing we installed it with a nut and bolt, but on his production models he is going to put on a quick release instead. The small ring is for a lanyard that will prevent dropping the wing into the great deep.

Larry's "Wing" handled just fine and the surf wake was normal is if the original "Wedge" was still there. Woo hoo!!!

[smedman]

A few more pics of the install

Removing the baffles / flaps

adding the pipe fittings

testing fit

[smedman]

tightening things up

installed

installing support bar under swim platform

[smedman]

swim platform back on and ready to ride.

i had a chance to ride with the FAE installed once before taking my prop into nettlesprops for repair last week.

All i can say is "Amazing!!" -- I was completely baffled by the lack of noise in the surf zone. It was like going from driving an old Chevy truck from the 70s, to now driving a soundproofed SUV. Smooth!!!

right now my prop is in the shop but should have it back this week and will be out riding more and will post up more feedback.

Larry is working on another plate with a quick release that he'll be bringing by this week as well.

Very excited about this!!!

[D-GOOSE]

How do you lift the wedge up? I'm sure your still uploading pics. LOL

I like this model better then that huge thing I seen in the past.

[smedman]

How do you lift the wedge up? I'm sure your still uploading pics. LOL

I like this model better then that huge thing I seen in the past.

Hey Greg,

I'll post up some more pics soon and it should explain --

I know this will sound a bit strange -- but you actually remove the wedge/wing and leave the brackets in down position at all times.

Doesn't affect the wake at all as far as I could tell on my test runs. Only issue is you will likely have to get in the water to remove the wedge/wing. But then again, if you are getting in the water anyway....

[superjet]

Just curious....why not design it with two exhaust pipes instead of merging into one? Wouldn't that allow you to still raise the wedge up and down?

[WakeGirl]

The one big pipe puts the exhaust in the path of the prop wash. The theory is that it pushes it back, away from the boat. 2 pipes wouldn't accomplish that.

[D-GOOSE]

Plus I'm thinking two pipe's going on the side of the wedge would mess up the wake.

[Chia]

How do you lift the wedge up? I'm sure your still uploading pics. LOL

I like this model better then that huge thing I seen in the past.

Hey Greg,

I'll post up some more pics soon and it should explain --

I know this will sound a bit strange -- but you actually remove the wedge/wing and leave the brackets in down position at all times.

Doesn't affect the wake at all as far as I could tell on my test runs. Only issue is you will likely have to get in the water to remove the wedge/wing. But then again, if you are getting in the water anyway....

is it possible to design the wedge brackets so they raise the wedge vertically, kinda like a drawer slide?

[smedman]

is it possible to design the wedge brackets so they raise the wedge vertically, kinda like a drawer slide?

that could be interesting -- not sure... but I'll throw that by Larry -- he always likes a challenge

[Badger]

Can somebody please clarify for me? Is the exhaust gas funnelled into the part that looks like a fin, and then released under the water through a hole at the bottom?

If so, are there any backpressure issues? It's hard for me to see in the pictures how big the new exhaust hole is.

[PDR447]

so floating wedge owners are SOL?

I'd like to see him maybe make a "dual" version that would still allow full use of the wedge(and allow floating wedge boats to use it). even if it's not as good as the single it would still be better than nothing.

[Chia]

so floating wedge owners are SOL?

I'd like to see him maybe make a "dual" version that would still allow full use of the wedge(and allow floating wedge boats to use it). even if it's not as good as the single it would still be better than nothing.

i agree, why does it have to funnel into a single exhaust. the fresh air exhaust could come out of each exhaust port on the boat and angle to the middle of the boat. i would think the stresses would be the same as going straight down.

[SacRiverRat]

I think it goes into one for structural purposes. Lot more stable having a connection to the two exhaust ports, and then the support bracket. You'd have to do a bunch of support brackets for each exhaust if they were individual. Think of the stress on those pipes dragging through the water

[smedman]

so floating wedge owners are SOL?

I'd like to see him maybe make a "dual" version that would still allow full use of the wedge(and allow floating wedge boats to use it). even if it's not as good as the single it would still be better than nothing.

I think Larry's looking into any option for floating wedge. He has working designs for the Power Wedge already. He is a small business only has so much time.... maybe if I had the floating wedge he would have tried that first

For a dual version, I believe it is as SacRiverRat said --- would probably be difficult to support the thing properly. The way he has it set up it is well supported.

[smedman]

Can somebody please clarify for me? Is the exhaust gas funnelled into the part that looks like a fin, and then released under the water through a hole at the bottom?

If so, are there any backpressure issues? It's hard for me to see in the pictures how big the new exhaust hole is.

Hey Badger -- I'll post up some more (better) pics soon.

Yes, the exhaust is funneled into the center part -- it is a pipe that starts off round at the connection, but then stretches into a flatter tube and it actually has a fairly large hole at the bottom. It gets skinnier as it goes down to provide less resistance to the prop wash.

[winddawg]

I gather from the pics and the explanations that once the FAE is installed you are now bolting/unbolting the "wing" part of the wedge while underwater when you want to change modes instead of folding it up and down. That will be a nice challenge with a little wind and wave action. If you happen to install it improperly and load the wedge I can see that really causing a lot of damage to the wedge assembly.

Was any consideration given to attaching the FAE to the wedge and having the FAE assembly fold up and down with the wedge? With this concept when the wedge is up the FAE is folded out of the way and not attached to the exhaust and when the wedge is folded down then you simply attach the FAE to the exhaust. If the pivot points could be worked out then the FAE would hinge up and down and maybe only require one bolt on each side of the exhaust.

This concept would not work for the floating wedge boats.

-Dave

[smedman]

Hey Badger -- I asked Larry about your backpressure question -- he sent me this -- maybe cut and paste from his website...

FAE and Boat Engine Performance

We are often asked if Fresh Air Exhaust (FAE) reduces the flow of exhaust gasses or creates excess back pressure.

When you talk to people knowledgeable about exhaust systems for engines, you will get ALL kinds of different answers. And usually their answer is correct within some parameters. The following is not written to refute anyone; we just want to point out that with exhaust systems there is not a single correct way to build them.

FAE has been installed on several hundred boats with about 95% of our customers satisfied with their boat and engine performance. FAE is a dynamic exhaust system, not just a pipe. A swirling exhaust stream will evacuate faster than a straight flowing exhaust stream. As the exhaust stream passes through the FAE it is set into a swirling motion and therefore evacuates faster. In other words, FAE is more efficient than straight pipe. Also, due to the patented shape of the FAE, when the boat is moving forward, as the water flows past the downpipe, a venturi (vacuum) effect is created. This venturi effect helps to evacuate the exhaust stream faster. A faster flowing exhaust stream results in reduced back pressure.

With FAE installed, on initial acceleration from stopped, there will be a small increase in back pressure within the exhaust system. This small increase in back pressure will likely increase the torque of the engine, thus improving take off acceleration and pulling power. As the boat speeds up, the venturi effect on the downpipe increases, thus removing the exhaust stream quicker. Consequently, between the initial low back pressure and the swirling and venturi effects FAE is a dynamic exhaust system that “adjusts” relative to the boat speed.

Boat engine manufacturers do not design nor certify boat exhaust systems. The exhaust valves on boat engines are heavier duty than typical on car engines to accommodate the various exhaust systems in the different brands of boats. Boat engine manufacturers specify that the exhaust backpressure not exceed 2 psi. They do not want 2 psi exceeded as it may impair engine performance.

Our testing has shown that FAE does not increase exhaust backpressure above 2 psi except at wide open throttle, at which time we typically see back pressure of 3 to 3-1/2 psi. We advise not running a boat at wide open throttle for more than a few moments, whether FAE is installed or not. With FAE installed, the typical boat loses 1-1/2 to 2 mph of top end speed.

It is also important to note the similarities between FAE and Inboard/Outboard (I/O) boats. I/Os typically have the same V8 engine as inboard boats. On the I/O the engine has two exhaust pipes that join into one exhaust pipe and the exhaust exits underwater through the propeller. With FAE two exhaust pipes join into one exhaust pipe and the exhaust exits underwater behind the propeller. I/Os have been in operation for decades with no problems from back pressure.

[smedman]

I gather from the pics and the explanations that once the FAE is installed you are now bolting/unbolting the "wing" part of the wedge while underwater when you want to change modes instead of folding it up and down. That will be a nice challenge with a little wind and wave action. If you happen to install it improperly and load the wedge I can see that really causing a lot of damage to the wedge assembly.

Was any consideration given to attaching the FAE to the wedge and having the FAE assembly fold up and down with the wedge? With this concept when the wedge is up the FAE is folded out of the way and not attached to the exhaust and when the wedge is folded down then you simply attach the FAE to the exhaust. If the pivot points could be worked out then the FAE would hinge up and down and maybe only require one bolt on each side of the exhaust.

This concept would not work for the floating wedge boats.

-Dave

Dave --yes you are correct. I had the same concern, but am the "test subject" for Larry, so I'm willing to give it a try. It will require getting in the water to change modes -- but I figured I'll be getting in the water anyway, so not that big of a deal. (I'll tell you in a couple months ) As for improper install - from what I could tell it would be pretty hard to install improperly as there is really only one way for it to go on and be properly seated...

As for the folding idea -- seems interesting -- I'll pass that by Larry...

[smedman]

Here are a few more pics of the FAE.

Hopefully this gives a better view of the main exhaust tube where the two exhausts meet and swirl out under the water.

[Malibu Marshall]

Is there any relevance to this modification? To me it seems like it would choke up your exhaust and rob horsepower from your engine. When was the last time anyone died from Carbon Monoxide poisoning while wake surfing? Excuse my ignorance, I've been drinking a little bit tonight

Edited August 1, 2008 by Malibu Marshall

[smedman]

Is there any relevance to this modification? To me it seems like it would choke up your exhaust and rob horsepower from your engine. When was the last time anyone died from Carbon Monoxide poisoning while wake surfing? Excuse my ignorance, I've been drinking a little bit tonight

All good questions -- from what I've been told from Larry (and he's done lots of testing) is that any effects on the horsepower are very very minimal. In one test they got 2mph less top end speed than without FAE. In my post to Badger I copy/pasted Larry's response to this FAQ...

As for someone dying from CO poisoning, there are many documented cases, although I don't think there are any specifically when wakesurfing. Some have occurred while "platform dragging" (or teak surfing). The CDC says that Carbon Monoxide is the "silent killer" -- most people don't know they are under its effects.

As for me -- I've noticed that after surfing I sometimes get lightheaded, or can get a headache (common effects of CO poisoning).

Also - we have our 9mo and 2yr old on the boat and my wife is very sensitive to any fumes.... Studies have shown that CO can affect an unborn baby, etc....

http://en.wikipedia.org/wiki/Carbon_monoxide_poisoning

The other thing that I really like about it is how quiet the boat is when you are riding -- you can actually hear your music without causing the riders in the boat hearing damage...

[Arctic Slalom]

yes, i bet that thing is super quiet.....it makes those SS turn downs look like childs play

keep at it smed, i think it's a kewl idea

smed,

i didn't read all the other comments....here are a few of my thoughts.

can you design 3 or 4 different wedge (sizes and approach angles) plates for different effects? I saw that it looks like your wedge fin is removeable?

why can't the exhaust 'pivot' down just like a wedge? still keep one outlet location, just let them pivot down together?

i like the thought of the wedge going up and down on a slide so it doesn't interfere with your exhaust.

in another thread someone (black pearl, maybe) mentioned something about a port or starboard 'mini-wedge'. that would be sweet, but it would really mess with the handling of the boat.

Edited August 1, 2008 by Arctic Slalom

[greenbay]

On 28.7.2008 at 9:04 PM, smedman said:

tightening things up

installed

installing support bar under swim platform

Hy Smedman, 

could you do me a great favour and send me the pictures how you built the wedge, 

they are somehow invisible on the page. Would be awesome! Thank you a lot in 

advance! Best regards

Andreas 

[email protected]