Video - 210 FSH - Cobra Jet Steering Magnum AK with Fangs Test

[Cobra Jet Steering LLC]

The mega fangs that you have will work with the T V set they just have a extra cut out for my second tie rod on the inner set but I doubt that will make any significant difference in the results. And since those are already on the nozzles it makes your test easier to carry out.

 

[swatski]

Reverse is improved with enough throttle but not to the level I have seen in lateral thruster video.

This is what I wonder about. I would guess that strait line reverse is ten times better with MEGAs, but lateral thrusters push the stern sideways like nothing else. So if that’s what you need that’s what you need.
I would not trade anything for improved cruise and speed.


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[Foobar]

I would like to clarify something that will also be included in my third video:

I do not think the JBP lateral thrusters slow the top speed. I just happened to reach 50 MPH that day, which I had never done before. Top end speed is influenced by many factors. I highly doubt the JBP product would slow the boat by 5mph.

 

[Weeb]

The mega fangs that you have will work with the T V set they just have a extra cut out for my second tie rod on the inner set but I doubt that will make any significant difference in the results. And since those are already on the nozzles it makes your test easier to carry out.

Are you saying that with the magnum ak and mega fangs you can also add the thrust vectors? Don't the megas and the thrust vectors use the same mounting hole on the nozzle? Disregard I was thinking of the side thrusters with the mega fangs lol.

 

[Weeb]

My personal observations of the Cobras on the 210 FSH.

@Cobra Jet Steering LLC @JetBoatPilot

I upgrade my fangs to mega fangs yesterday and also had some issues with the directions or lack of I should say. I had to go on line and watch his video because I had four washers and no idea where they went. In the end I didn't use them because I never saw where they went in the video.

 

[swatski]

I would like to clarify something that will also be included in my third video:

I do not think the JBP lateral thrusters slow the top speed. I just happened to reach 50 MPH that day, which I had never done before. Top end speed is influenced by many factors. I highly doubt the JBP product would slow the boat by 5mph.

I agree, 5mph is a lot, I doubt the LTE and TVs are scrubbing that much off of the top. But there is no question that the LTEs and TVs cause some drag.

Here is what I find to be a pretty "informative" picture taken from behind the stern of a keeled 240 on plane, at speed.


Your 210 FSH keel/stern/ride plate may be a bit different but not by much. Anything hanging below the pumps will either slice or drag through water. The LTEs will drag below the pumps, no question about it, albeit probably not a huge amount of force as they seem to be slightly above the ride plates' plane. Same with the TVs - the reason they can pop up is actually because of drag/resistance of the cross member hitting the jet stream/wash, and laws of physics/energy conservation apply.

Again, this may or may not effect top speed in a measurable way when other things are limiting. For example, dirty hull, humid/hot air etc etc can have a dramatic effect on top speed that can obscure anything else. But under ideal conditions "smaller" factors can become rate limiting and impart a measurable effect on top speed.

I am fairly certain that Cobra Vipers - which can change the boat attitude - will have same effect on top speed under certain conditions - when pushing the bow down. But I have not been able to see any effects on top speed with Ultimates or Magnum AKs in my boats. Not exactly sure why. But - Cobra AKs are almost a foot above the keel/articulating hull (rudder) level and they seem to just slice through the water under the ride plates - not sure how deep below do they go when on plane, I don't have those pics w/fins - w/a GoPro on a stick, lol.

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[JetBoatPilot]

I'll try to go out and see if the lateral thrusters actually touch the surface of the water at plane speeds. My guess would be no but I'll double check asap.

 

[swatski]

The LTEs do sit above the ride plates' plane. Whether or not they drag the top speed down is a testable hypothesis. I believe @Foobar is the first on here to do this. Granted, it is a "n=1 experiment" for now, lol, but he has done more than anyone else here.

I'm sure others will chime in with their own observations as these systems become deployed in more boats.

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[Benny Sibbitt]

following

 

[Liveto99]

I just want play on that river! nice job.

 

[Cobra Jet Steering LLC]

As far as speed increase My own observation with new Yamaha skies 1800 and supercharged 1800 engines only.
I actually felt that the computer was holding the top end back at first but after 10 hours on the engines it felt like they ran noticeably faster however it may have just been that the rings were seated etc.
The only way to really know is to reverse the process and see what the results are, and that is a lot of work.
You will however notice a reduction in reverse power due to the way Yamaha creates the reverse thrust when backing straight .
The nozzle has an angled water exit opening under it that operates when the reverse bucket is closed in order to redirect the reverse water jet at an angle under the hull.
There is a very small area between the nozzle and the ride plate end where that reverse thrust must travel to get under the boat to push the boat backward, when backing off a trailer , boat lift or beach this thrust requires some force as does stopping to avoid hull contact with a dock, rock or other boat etc.
As I said many times my mega fangs enhance this reverse thrust and help produce a more concentrated reverse thrust. This is obvious in the videos. Although the side thruster does not take any of that straight reverse thrust according to what I have been told.
The very presence of the body of that part is located in the path of the reverse thrust exiting the bottom of the steering nozzle .
If the water exiting the bottom of the nozzle encounters an obstruction as it attempts to get to the area under the boat some of that reverse thrust is diverted and some of that diverted water will divert even more of the reverse thrust thereby lowering it's effectiveness or force. The way to check this is to make or imagine a straight line following the angle of the nozzle reverse opening on the bottom of the nozzle and see if it overlaps any of the body of a side thrust unit on its way to the bottom of the boat.

 

[swatski]

You will however notice a reduction in reverse power due to the way Yamaha creates the reverse thrust when backing straight .

I have been asking about this, how is the reverse in strait line.
I frequently operate under less that ideal conditions when launching from the trailer, or the lift, such as in low water and I need all the strait reverse I can get (and then some on occasion... lol).

I do not see how the above statement from @Cobra Jet Steering LLC would not be true: when I look at the LTEs, it is obvious they are in the path of the water that provides reverse thrust (as in strait reverse).
Just as in the pic I posted above, or looking at this


Not everyone will care, for some owners the ability to push the stern sideways may be more important than the reverse. But I find these boats to be more than nimble enough when it comes to moving the stern sideways, especially twins with independent throttle control.

Would be nice to know how much of the strait reverse thrust is lost with LTEs (vs no LTEs). I can tell that in the MEGAs vs no MEGAs testing of mine the reverse is massively imrpved, but I have not measured it or put a number on it. What would be a good way to do it?

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[Foobar]

The lateral thrusters do not block straight reverse. Here in my install video you can see a view through the nozzle.

at 11:23 in the video:

 

[swatski]

The lateral thrusters do not block straight reverse. Here in my install video you can see a view through the nozzle.

at 11:23 in the video:

@Foobar I appreciate (and frankly admire) all the testing that you have done and published here. This is a ton of effort, mostly thankless. I'm learning a ton from your posts.

Are you saying the strait line reverse with the LTEs is the same as with no LTEs?

I know from my first hand experience/observations that with the MEGAs one gets a very tangible boost in reverse thrust, and I have gone on the record here. I don't know how it works with LTEs first hand, but I would think - the opposite would be the case.

There is no question that some of the water shooting out of the bottom/reverse nozzle opening would be obstructed/diverted by the LTEs - you can certainly see them in the water path through the reverse nozzle.
I think I can see it in your vid, sort of, I think. Here is another pics I have come across (not from your vid) maybe more clear:




I love that old proverb (in its original version): "the proof of the pudding is in the eating".
I think it really is true - we can talk and theorize about the merits of various jet propulsion mods here ad nauseam but until someone actually performs the real world testing it means nothing.


Importantly/for the record:
I have zero affiliation with Jeff/Cobra LLC; never talked to the man in person or over the phone; I have never been reimbursed for any of the tests I have done with Cobra products; I have paid for all the components I tested and I received no discounts beyond group/seasonal buys; never tested a free-of-charge Cobra product.


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[Weeb]

I would think in theory anyways if both nozzle are straight and they blow 30 percent out each side the boat should stay straight while going backwards as long as all things are equal, rpm's, wind etc.

 

[Foobar]

I posted a video of my opinion on the JBP vs Cobra Jet in the General forum.

 

[swatski]

the boat should stay straight while going backwards

Right, but the "vector" of water thrust (force) will change, will it not? - if you start pushing the water sideways or down (the LTE is still in the way even when steering strait) it will diminish the "strait line" reverse thrust. Hopefully not by much.

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[JetBoatPilot]

If the wheel is dead straight no water is diverted when in reverse. This was important to me to be able to retain max reverse thrust for instance while backing off the trailer.

When we tested with Yamaha engineers they actually commented that they were pleasantly surprised that the reverse thrust and speed was much greater than they anticipated.

 

[WTScott]

Foobar,

Is your 50 top speed speedo or GPS? Seems a little high based on other boats.

Thanks for all the work.

 

[Foobar]

Foobar,

Is your 50 top speed speedo or GPS? Seems a little high based on other boats.

Thanks for all the work.

Both. GPS and speedo are within 0.2 to 0.6 MPH of one another.