Curious - Why do the AR / SX series of 190 seem faster than the FSH ??

[Riff Raft]

Just curious about this as I've been testing WOT lately. As I read through threads, it seems that the SX and AR boats have no problem hitting 40 mph (sometimes 40+ mph ) and the FSH are typically mid 30s ? I recently did the ribbon delete and added 6" K&N filter. I saw a gain of approximately 200ish rpm and about 1.5 mph. Feels better, definitely louder at WOT, but I'm going to design/build a sound dampening bucket to put over the K&N to direct/muffle noise while still allowing 100% air flow.

ONLY speaking about the 1.8L N/A engines. So, any ideas on why the AR/SX boats are faster given the same length and engine?? Thoughts? Facts?

Thanks!

 

[TimW451]

Less aerodynamic? No top vs T-top; flat, tall console vs raked windows?

 

[mwalker4]

2019+ 190s usually have top speed in mid to high 30s. The 2018 and previous boats were faster. So you need to know the year of the posters boat.

 

[2kwik4u]

Year of the boat is the first thing. The pre-'19 boats are faster by a scosche. '19 + boats got slightly less running surface, a revised transom, and I think 4-6in more LOA. That slowed them down slightly.

Aerodynamics of a sloped windshield versus a flat windshield. Same with a flat windshield and a T-Top compared to a sloped windshield and a deployed bimini.

I would also wager that weight placement has something to do with it. More structure on the FSH models, and that structure is closer to the bow. The 19ft boats are SUPER sensitive to weight placement, and the more weight you move to the front the slower it gets. I would be curious to see how weight distribution varies between the two boats.

I can't get Yamaha's website to load currently to compare dry weights.

 

[Riff Raft]

Thanks for the responses guys... I've been wanting to open up a discussion on this. T-tops and aerodynamics are obvious and real factors for sure, I was just wondering if there was anything else... perhaps not so obvious, that owners may not know. My 2017 FSH Sport 190 has 16 hrs on it. (long story short, previous original owner took it out just a few times a year until a serious neck injury caused him to sell). Perhaps just Marine Corps OCD, but I always top fuel off when coming in, so all data is with full tank, me and wife (350# ish) , a 40# blue heeler, and a full cooler. Boat has house and start batteries port/stern, and a trolling motor battery starboard/bow. No water or leak issues (previous owner covered that), and deleted scupper valves.

The ribbon delete did add great midrange response and 200 more rpm, but only about 1.5 mph top end. I'm not willing to spend $1000.00 on a Riva ECM flash for 2-300 more rpm.

FWIW - On another note, I may be one of the few guys with a 190 to have had the TV fins and LTV, as well as the Cobra fins to compare. Before I get poked in the eye for describing my experience, my background is growing up on Pensacola Beach with lots of boat and swim time, RECON Marine with lots of Zodiak experience in waters/currents of all kinds, owned everything from small skiffs to 20'+ Grady Whites, and Yamaha FX SHO Cruiser skis. All that to say that in the currents in my AO, the Cobra fins provide a huge advantage over the TVs. Also, after some very thorough testing (we like backing into sandbars for relaxing), the LTV seem to take away way too much of the reverse momentum/thrust... even in straight reverse. I can see how they may help more on the twin engine boats, but the twin engine boats already have the advantage of twin throttles. I have photos showing the extent of LTV full reverse interference if anyone's interested. Not starting a pro or con debate about fins, just saying that it's best to analyze the products' various performance advantages and choose the one that works best for the AO you will be in 80-90% of the time.

Thanks again for the feedback folks!

 

[bigwaves]

Thank you for not starting a pro and con debate about fins. I’m sure that won’t happen here…??

 

[swatski]

Thanks for the responses guys... I've been wanting to open up a discussion on this. T-tops and aerodynamics are obvious and real factors for sure, I was just wondering if there was anything else... perhaps not so obvious, that owners may not know. My 2017 FSH Sport 190 has 16 hrs on it. (long story short, previous original owner took it out just a few times a year until a serious neck injury caused him to sell). Perhaps just Marine Corps OCD, but I always top fuel off when coming in, so all data is with full tank, me and wife (350# ish) , a 40# blue heeler, and a full cooler. Boat has house and start batteries port/stern, and a trolling motor battery starboard/bow. No water or leak issues (previous owner covered that), and deleted scupper valves.

The ribbon delete did add great midrange response and 200 more rpm, but only about 1.5 mph top end. I'm not willing to spend $1000.00 on a Riva ECM flash for 2-300 more rpm.

FWIW - On another note, I may be one of the few guys with a 190 to have had the TV fins and LTV, as well as the Cobra fins to compare. Before I get poked in the eye for describing my experience, my background is growing up on Pensacola Beach with lots of boat and swim time, RECON Marine with lots of Zodiak experience in waters/currents of all kinds, owned everything from small skiffs to 20'+ Grady Whites, and Yamaha FX SHO Cruiser skis. All that to say that in the currents in my AO, the Cobra fins provide a huge advantage over the TVs. Also, after some very thorough testing (we like backing into sandbars for relaxing), the LTV seem to take away way too much of the reverse momentum/thrust... even in straight reverse. I can see how they may help more on the twin engine boats, but the twin engine boats already have the advantage of twin throttles. I have photos showing the extent of LTV full reverse interference if anyone's interested. Not starting a pro or con debate about fins, just saying that it's best to analyze the products' various performance advantages and choose the one that works best for the AO you will be in 80-90% of the time.

Thanks again for the feedback folks!

If you really want to get to the bottom of it, you would almost certainly need to be willing to play with the impeller(s).

First test would be, if you switch to a faster/smaller pitch impeller - are you gaining RPM and start hitting electronic limiter - at about 7,800 RPM.
If not - meaning you don't hit the limiter with a smaller impeller, that would tell you there is something else limiting your top end, maybe worth chasing it. If you do, you could try to find the best impeller shape and pitch for your boating style. I firmly believe the OEM for single (190), 6CW, is the best overall, but they can be off-specs sometimes by quite a bit, even brand new from factory, blades may need realigning, so maybe worth checking. And then, you could try repitching, and changing impeller styles, playing with the L13 cone, and so on. And so on, rinse and repeat.

But you may also wait for a cooler, dryer weather and see how much that would help. Assuming you are not at elevation.
Dirty hull could be worth a few mph, or more. etc.

I could probably send you a couple of impellers to play with; it is a lot of work though, "is the juice worth the squeeze" situation; and if your impeller has never been off the shaft, it could be a handful, too. At the end, it just depends

--

 

[Ericd]

Is there a difference in hull design?

 

[Riff Raft]

I'm not sure... that's one of the things I was wondering. With the same engine in all, it has to be something mechanical/measurable. The T-top drag is obvious, but I wouldn't think it would be that much... not as much as a bimini. Of course, even with ribbon delete, I'm still at 7450-7500 rpm max. Perhaps some of those guys are running mods/ecm flash we don't know about.... like someone mentioned earlier about knowing the boat being compared to.

Thanks for the replies.

 

[Zizzou 192]

Is there a difference in hull design?

The hull below the rub rail is the same, the boat above the rub rail is different.

That narrows things down to weight distribution and wind resistance, which is a big deal in boats with fickle top speeds.

 

[Farmdog267]

I wonder if the center console design with the weight and taller structure in the center vs both sides of the SX or AR and those sides being more aerodynamic comes into play. Certainly it would for balance and ride comfort to a degree but I'm now wondering how much the design difference plays with speed.

 

[2kwik4u]

@Riff Raft I got $5 says it's the batteries and equipment in the bow.

I can scrub 4-6mph off my top speed by moving 200lbs from the rear seats to the bow. Not that batteries are that heavy, but the hull is that sensitive.

 

[TimW451]

Somebody with an SX or AR has to have looked at the differences in top speed based on the position of the center window and lower divider. Both the magnitude of difference and which is fastest may be telling towards the original question.

 

[Riff Raft]

@Riff Raft I got $5 says it's the batteries and equipment in the bow.

I can scrub 4-6mph off my top speed by moving 200lbs from the rear seats to the bow. Not that batteries are that heavy, but the hull is that sensitive.

Roger, and thanks. I tend to agree. I should probably pull the bow/trolling battery and mount as I don't even fish anymore. This is strictly a pleasure sandbar-hopping vessel. Heck, If I do that , I have a really nice remote controlled trolling motor that came with it for sale (I don't leave it mounted so results are sans trolling motor).

BTW - What is your top speed and RPM?

Thanks again

 

[Riff Raft]

On a side note, I will have a pretty much brand new set of Thrust Vector fins and Lateral Thruster for 190 boats for sale very soon.... VERY reasonably priced.

 

[2kwik4u]

Roger, and thanks. I tend to agree. I should probably pull the bow/trolling battery and mount as I don't even fish anymore. This is strictly a pleasure sandbar-hopping vessel. Heck, If I do that , I have a really nice remote controlled trolling motor that came with it for sale (I don't leave it mounted so results are sans trolling motor).

BTW - What is your top speed and RPM?

Thanks again

I can get ~42mph at ~7650rpm on a great day. Most days I get those revs, but only around 40mph or so. Really depends on the day, the number of people and things like that.

L13, sealed intake tunnel, and ribbon delete really solidified the performance for me.

 

[Riff Raft]

I can get ~42mph at ~7650rpm on a great day. Most days I get those revs, but only around 40mph or so. Really depends on the day, the number of people and things like that.

L13, sealed intake tunnel, and ribbon delete really solidified the performance for me.

Thanks... haven't looked into the L13 at all. How does it help... any other thoughts on the L13 gains?

 

[FSH 210 Sport]

Roger, and thanks. I tend to agree. I should probably pull the bow/trolling battery and mount as I don't even fish anymore. This is strictly a pleasure sandbar-hopping vessel. Heck, If I do that , I have a really nice remote controlled trolling motor that came with it for sale (I don't leave it mounted so results are sans trolling motor).

BTW - What is your top speed and RPM?

Thanks again

Your trolling motor batteries, assuming a 36V troller, add 150-180 pounds just forward of the center of gravity, that will have an impact on top speed. That’s basically another person on board or an additional full tank of fuel in weight.

-Is the fuel tank the same size as the other boats?
-Are those other boats hitting these higher speeds with a full tank?
-Are you running 86 (R+M/2) octane fuel?
-When was the last time a fresh set of spark plugs were installed?
-Are you in fresh water or salt water?

@swatski pointed out some great points on the impellers!
-What condition is your impeller and wear in?
- Have you checked the gap between the impeller and wear ring?
-Looks like you are close to max RPM, but still have an additional 300 RPM you could gain from a little less pitch or possibly a blue printed stock impeller.

 

[2kwik4u]

Thanks... haven't looked into the L13 at all. How does it help... any other thoughts on the L13 gains?

The L13 keeps cavitation at bay. I can load the boat with 8 adults and 3 coolers. Hit WOT from a standing start and the pump just hooks up and pushes. Same with just me and a cooler on the boat with a 1/2 tank of fuel. Light load, heavy load the pump reacts the same. "Loosing traction" with the water is no longer an issue.

I would notice before when pulling a tube that I could cavitate the pump really easy with a heavy left turn. Right turns were better, but not as bad. Think pulling a tube and hitting the gas at the same time as you turn the wheel. Engine would spin up and you could hear the pump making noise. The L13 reduced that considerably and added "traction" in the corners. It's not completely eliminated in that case, but it's improved.

Seal the intake tunnel and put an L13 on there, and the consistency of performance will go up. Total increase to top speed might be +/- 0.5mph. It's very marginal in that regard. But the consistency is much improved.

 

[Riff Raft]

Your trolling motor batteries, assuming a 36V troller, add 150-180 pounds just forward of the center of gravity, that will have an impact on top speed. That’s basically another person on board or an additional full tank of fuel in weight.

-Is the fuel tank the same size as the other boats?
-Are those other boats hitting these higher speeds with a full tank?
-Are you running 86 (R+M/2) octane fuel?
-When was the last time a fresh set of spark plugs were installed?
-Are you in fresh water or salt water?

@swatski pointed out some great points on the impellers!
-What condition is your impeller and wear in?
- Have you checked the gap between the impeller and wear ring?
-Looks like you are close to max RPM, but still have an additional 300 RPM you could gain from a little less pitch or possibly a blue printed stock impeller.

- 30 gal tank
- Not sure
- mix of 87/93 octane marine fuel
- New plugs /full service in May... only 5 hrs on them. Boat only has 15ish hrs on it
- Salt and brackish

- Impeller/wear ring like new... only 15 hrs - no damage
- Gap is good
- perhaps

Thank you