190/192/195 Speeds and Mods

[SamCF]

62.86 mph @ 8550 rpm. Half fuel, 1 adult and 1 child. Air temp 57, water temp 80. It feels like it's at the safe limit of the hull. I've never experienced chine walk, but right before I backed off it started a side to side bounce/lean. I would be really surprised if this hull could go any faster and maintain stability.

 

[swatski]

62.86 mph @ 8550 rpm. Half fuel, 1 adult and 1 child. Air temp 57, water temp 80. It feels like it's at the safe limit of the hull. I've never experienced chine walk, but right before I backed off it started a side to side bounce/lean. I would be really surprised if this hull could go any faster and maintain stability.

I would think stuffing the pump is not out of question at those speeds, with a shock-wave of water creating less of havoc it would in a ski of course but still - could get interesting!

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[SamCF]

I would think stuffing the pump is not out of question at those speeds, with a shock-wave of water creating less of havoc it would in a ski of course but still - could get interesting!

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I've read about the overstuffed pump issue with the skis. Usually ends up dumping the rider at high speed. Pretty scary.

On this run, GPS was showing 61.9 mph. I was about to back off, but figured bumping the trim up a little more wouldn't hurt. As soon as I bumped the trim, it started the side to side bounce. After we slowed down the GPS showed the 62.86 max. It must have lifted the nose and picked up speed then lost stability with more of the hull out of the water. I don't know what happened, but I'm not going to push the trim too high again at those speeds.

 

[DavisAR195]

I've read about the overstuffed pump issue with the skis. Usually ends up dumping the rider at high speed. Pretty scary.

On this run, GPS was showing 61.9 mph. I was about to back off, but figured bumping the trim up a little more wouldn't hurt. As soon as I bumped the trim, it started the side to side bounce. After we slowed down the GPS showed the 62.86 max. It must have lifted the nose and picked up speed then lost stability with more of the hull out of the water. I don't know what happened, but I'm not going to push the trim too high again at those speeds.

With all the mods that you have made, how has it impacted your fuel burn rate?

 

[swatski]

With all the mods that you have made, how has it impacted your fuel burn rate?

Not to talk out of turn, but...
My experience with just a reflash, with my N/A engines, the fuel economy is better.
How much? Hard to tell exactly, it is difficult to gauge as conditions always vary.
Another factor for me is that I always run on 93 octane with the reflash tune and 87 E10 when back in factory mode.

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[2kwik4u]

SO I'm perplexed about speed vs. power and the physics behind it. Clearly we have some great results here, and maybe this next set of thoughts should be in another thread, but I'm gonna toss it here and let hte moderators decide.

Here we go......Lets assume we have my boat ('17 AR190) with a stock impeller in good shape, a well sealed tunnel, and my L13 cone installed. I have good to excellent "traction" with the water at all speeds. In theory, the only thing that should increase my speed is an increase in RPM of the impeller itself. Pump more water, create more pressure differential across the nozzle, creating more thrust, and thus more speed for a given hull. Continuing on this line of thinking, lets say my engine uses 100% of my 180hp at 7,400rpm. Adding additional power without adding additional revs only lessens the percent usage on the engine correct? I've got more power, but I'm not spinning it any faster, so I'm not pumping any more water. The only way to increase speed is to increase flow and pressure differential across the nozzle. The only way to do this is to change the pitch and/or spin it faster....right?

Some of these assumptions are based on my boat being "dynamically limited" to 7,400 rpm. It's not an electronic device that is limiting my revs, but the dynamic interaction of the engine with the pump/hull/water system. The engine is creating exactly as much power as the pump (and other forces of drag) is consuming. Less pump would allow the engine to rev higher and hit an electronic limiter, more pump would drag the motor down to a lower rev range. If all I did was raise the limiter on my boat would I get more speed? I don't think that I would. So I need more power, to raise the revs, to pump more water, to increase pressure differential, to create more force, and then finally to get more speed.

SO.....is the only tangible effect of having more HP the higher revs, assuming all other variables are constant? What are the other governing powers at play here?

Looking at SamCf's mod list in his signature I see some power mods, some nozzle mods, and some impeller mods. Clearly the whole combination needs to work as a system (and his does to a great degree). I'm really just curious how all the variables interrelate to one another.

 

[SamCF]

With all the mods that you have made, how has it impacted your fuel burn rate?

Fuel mileage comparison @ 6000 rpm
Stock: 31 mph, 3.0 mpg
Modified engine/ 160mm pump: 34 mph, 3.3 mpg.

90% of our cruising is at 30-35 mph.

 

[SamCF]

SO I'm perplexed about speed vs. power and the physics behind it. Clearly we have some great results here, and maybe this next set of thoughts should be in another thread, but I'm gonna toss it here and let hte moderators decide.

Here we go......Lets assume we have my boat ('17 AR190) with a stock impeller in good shape, a well sealed tunnel, and my L13 cone installed. I have good to excellent "traction" with the water at all speeds. In theory, the only thing that should increase my speed is an increase in RPM of the impeller itself. Pump more water, create more pressure differential across the nozzle, creating more thrust, and thus more speed for a given hull. Continuing on this line of thinking, lets say my engine uses 100% of my 180hp at 7,400rpm. Adding additional power without adding additional revs only lessens the percent usage on the engine correct? I've got more power, but I'm not spinning it any faster, so I'm not pumping any more water. The only way to increase speed is to increase flow and pressure differential across the nozzle. The only way to do this is to change the pitch and/or spin it faster....right?

Some of these assumptions are based on my boat being "dynamically limited" to 7,400 rpm. It's not an electronic device that is limiting my revs, but the dynamic interaction of the engine with the pump/hull/water system. The engine is creating exactly as much power as the pump (and other forces of drag) is consuming. Less pump would allow the engine to rev higher and hit an electronic limiter, more pump would drag the motor down to a lower rev range. If all I did was raise the limiter on my boat would I get more speed? I don't think that I would. So I need more power, to raise the revs, to pump more water, to increase pressure differential, to create more force, and then finally to get more speed.

SO.....is the only tangible effect of having more HP the higher revs, assuming all other variables are constant? What are the other governing powers at play here?

Looking at SamCf's mod list in his signature I see some power mods, some nozzle mods, and some impeller mods. Clearly the whole combination needs to work as a system (and his does to a great degree). I'm really just curious how all the variables interrelate to one another.

The pump tuning is complicated, but really what matters is top rpm. The best hole shot will always be at max rpm as long as the pump hooks up good.

My 155 pump had crazy hole shot because I could spin it at the rev limit right at takeoff. Cavitation was a problem, and it would blow out easily if I hammered on the throttle. While hole shot was good, I had to work the throttle to keep it from blowing out.

The 160mm pump has 2 blips of cavitation and then hooks solid. It has smooth solid acceleration, but it holds rpms down until it's up to 20 mph. So this has really good hole shot without focusing on throttle control.

Tuning a jet pump is like tuning a CVT on a side by side or ATV. You want it just off of the rev limiter from hole shot to top end. Max thrust thru all speeds.

 

[DavisAR195]

After reading through this discussion and checking out Riva, Green Hulk and viewing several YouTube video's, I'm going to start out with a few small upgrades over the winter.
#1. Riva SVHO Replacement Performance Air Filter or a RIVA Power Filter if I can track down the same Sleeve @360dart used.
#2. Riva Engine Breather Upgrade
#3. Riva SVHO Intake Manifold Upgrade (Ribbon Delete)

@SamCF
I have been looking at the Lucky 13 Pump Cone, and saw in one of your post that you used all three washers. If I'm only running an intake and ribbon delete, would you recommend all 3 washers on a 160mm pump?

I figured this year I will focus on getting the engine breathing a little better, next year upgrade the intercooler then hopefully add a Stage 1 tune.

 

[SamCF]

After reading through this discussion and checking out Riva, Green Hulk and viewing several YouTube video's, I'm going to start out with a few small upgrades over the winter.
#1. Riva SVHO Replacement Performance Air Filter
#2. Riva Engine Breather Upgrade
#3. Riva SVHO Intake Manifold Upgrade (Ribbon Delete)

I have been looking at the Lucky 13 Pump Cone, and wanted to see if anyone has installed one on a 160mm pump and if so what spacer size worked best?

I figured this year I will focus on getting the engine breathing a little better, next

After reading through this discussion and checking out Riva, Green Hulk and viewing several YouTube video's, I'm going to start out with a few small upgrades over the winter.
#1. Riva SVHO Replacement Performance Air Filter or a RIVA Power Filter if I can track down the same Sleeve @360dart used.
#2. Riva Engine Breather Upgrade
#3. Riva SVHO Intake Manifold Upgrade (Ribbon Delete)

@SamCF
I have been looking at the Lucky 13 Pump Cone, and saw in one of your post that you used all three washers. If I'm only running an intake and ribbon delete, would you recommend all 3 washers on a 160mm pump?

I figured this year I will focus on getting the engine breathing a little better, next year upgrade the intercooler then hopefully add a Stage 1 tune.

The washers are for making small adjustments in your rpm. Instead of pulling and re-pitching your impeller, you can adjust with the washers. I would put all of the washers in, and remove what you need to get the rpms up. Typically the L13 cone will cause a 200 rpm drop without losing any top speed.

The best money you can spend on these boats is on a L13 cone and a JFizzle Intercooler.

 

[sx998]

2015 SX192 52mph indicated and that is spot on to the GPS.
89 octane, SVHO intercooler, Cobra Jet Ultimate with Fangs, 1/4 tank fuel, 425lbs of humans.
Full load of people and fuel and it would be down 5-8mph or so.
Im happy with what the boat does. No desire for future perfomance mods. I'll just get the 24 in a few years when the kids get bigger.

 

[SamCF]

2015 SX192 52mph indicated and that is spot on to the GPS.
89 octane, SVHO intercooler, Cobra Jet Ultimate with Fangs, 1/4 tank fuel, 425lbs of humans.
Full load of people and fuel and it would be down 5-8mph or so.
Im happy with what the boat does. No desire for future perfomance mods. I'll just get the 24 in a few years when the kids get bigger.

Your boat is in perfect condition to see 52 mph with those mods. Good work!

I think the red boats are faster.

 

[Emptytemples]

Anyone near easton, pa or ocmd with a tuner I can buy a license for to flash my sx190? Gets about 42mph on a calm day with few hundred pounds of gear plus two passengers. Can't remember actual GPS speeds from this summer.

 

[swatski]

Anyone near easton, pa or ocmd with a tuner I can buy a license for to flash my sx190? Gets about 42mph on a calm day with few hundred pounds of gear plus two passengers. Can't remember actual GPS speeds from this summer.

There will be no gains in speed, unless you repitch the impeller to spin it at over 8,000RPM at which point you will need to make additional mods to not cavitate excessively on hole shot. Basically, you end up running two alternative setups, one for top speed and one for water sports/towing/heavy loads.
After messing with this and tuning everything for about a year I ended up running a setup for heavy load/max towing power all the time, and that was giving me 38-40 mph top speed and felt totally awesome in the water. (2012 SX190)

Keep in mind most all dedicated wake boats top under 40mph, most max out around 35mph when loaded (which does not seem detrimental to their appeal! lol) just to put things in perspective.

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[RookieJetBoater]

2015 AR 192. 220hrs.
Fizzle I/C with tapped strainer. 8100 Riva tune. Stock Boost. Stock Impeller
Air temp 80c, Water temp 75c.
51GPS. No heat soak.
Cavitation at WOT on hole shot.
Fizzle 20hrs no issues.
Tune 5hrs no issues.
Use 91Octane

 

[DavisAR195]

2015 AR 192. 220hrs.
Fizzle I/C with tapped strainer. 8100 Riva tune. Stock Boost. Stock Impeller
Air temp 80c, Water temp 75c.
51GPS. No heat soak.
Cavitation at WOT on hole shot.
Fizzle 20hrs no issues.
Tune 5hrs no issues.
Use 91Octane

Have you thought about using the Lucky 13 cone to help with cavitation?

 

[RookieJetBoater]

Cone is a good idea. Does it make sense to change out impeller at same time?

 

[swatski]

Cone is a good idea. Does it make sense to change out impeller at same time?

I do not know if you can get better hole shot with any aftermarket impeller. The OEM in 1.8s have the longest blades, the single engine OEM impellers being the longest/largest (as compared to twin OEM impellers, or any Skat or Solas model, dual impellers excluded). The L13 can help a ton, especially when paired with the OEM impeller. Fine tuning the impeller (especially OEM) by slight repitch of the trailing edge is easy and very effective (to dial everything in), but would do that last.
(My 0.02)

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[2kwik4u]

Cone is a good idea. Does it make sense to change out impeller at same time?

I have a much lower powered NA 190, but the L13 cone eliminated ALL of my cavitation on launch. Almost to a point that it's "over stuffing" the pump and not allowing the engine to rev up like it needs to. I ran all last summer with all of the shipped spacers installed. Going to attempt some "tuning" of the space count this year and see if I can get any better results out of it.

The biggest rule of tuning anything. Make one change at a time, evaluate the results, then decide a next step. If you change 3 things at once you won't know what change made the difference and which was a waste of time/money. For me, the L13 is a quick and easy thing to try with proven results.

 

[DavisAR195]

2017 AR 195 90hrs.
Ribbon Delete, K&N CAI Filter, Engine Breather Filter, Lucky 13 Cone, Stock Boost, Stock Impeller
Lucky 13 cone (No Spacers)
Air temp 40f, Water temp 48f.
50.8GPS. RPMs: 7,650
Reduced Cavitation at WOT on hole shot.
Use 91 Octane
Full tank, 1 adult, 200 lbs gear, no wind, calm water conditions

2nd test
Same conditions
Lucky 13 cone (All 3 Spacers installed)
50.0 GPS, RPMs: 7,600
Zero cavitation at WOT on hole shot.
The boat just launched.

@SamCF I was very surprised with the listed mod's that I didn't see any increase in speed. Before running a tune, I have been thinking about changing out the impeller. However I will be primarily using the boat for wake surfing and that is the main reason I got the lucky 13, was to reduce cavitation while loaded down with ballast. Thoughts?