SX 192 Mods

[SamCF]

Too bad all of these mods require cutting holes in your boat. It hurts, especially below the water line

 

[DBamaC]

What did you do with the original hole for the exhaust?

 

[SamCF]

I've been brainstorming on the fresh air / quiet surf exhaust idea. Ordered all of the parts tonight. I still have a week left at work, the wait is killing me.

It's going to be slick.

 

[BakedZiti]

Hmm, how to explain to the wife why all of this is necessary...

 

[haknslash]

Hmm, how to explain to the wife why all of this is necessary...

Use the safety factor angle. All the extra power would mean you can get out of harms way faster!

 

[SamCF]

Hmm, how to explain to the wife why all of this is necessary...

I just do what I want and deal with the consequences.

For real, you better double check your work before you haul the family to the lake. Nothing puts the brakes on future mods like a break down that was self-inflicted.

I can hear her now. "Is this going to break our boat?" "Is this going to void the warranty?"

 

[Midnight2V]

I saw this and I know it will be much further down the road, but it will probably be a very worthwhile upgrade.

https://rivaracing.com/i-24077507-riva-yamaha-svho-65mm-throttle-body.html

I asked Riva about it, and they said it will fit the SHO but would only be beneficial at boost levels similar to what a SVHO puts out. I'm pretty sure you fall into this category SamCF. I am thinking of doing it after I increase my boost level. I'll port match the intake manifold opening to the Throttle body and gasket.

 

[SamCF]

I saw this and I know it will be much further down the road, but it will probably be a very worthwhile upgrade.

I asked Riva about it, and they said it will fit the SHO but would only be beneficial at boost levels similar to what a SVHO puts out. I'm pretty sure you fall into this category SamCF. I am thinking of doing it after I increase my boost level. I'll port match the intake manifold opening to the Throttle body and gasket.

I've seen that, but can't find a review. Sounds like it would be for higher rpm and boost. The ET low boost wheel actually makes about 1-2 psi less than the stock SVHO at 8500 rpm. Some of the SVHO skis are running 21 psi @ 9100 rpm on the stock throttle body. I bet they would see huge gains from that piece.

I have seen some that did the ribbon delete and port matched the intake manifold instead of installing the spacer. That's what I'm going to do if the manifold has to come off for any reason.

 

[SamCF]

Dodged a bullet this weekend. I noticed a slight hesitation when trying to accelerate hard. Got home and pulled the spark plugs and they were dry and white. Didn't show that they overheated, just running lean. Pulled the fuel pump and found the filter and pump body full of disintigrated silicone. The water meth injection is probably all that saved my motor.

I had a high volume fuel pump that I was planning to put in, so I cleaned everything and put the new pump in.

New top speed today. Ran 60.14 with 2 adults, 3 kids, 2 coolers and full fuel. Unloaded the coolers and family and ran 61.5 mph with just myself in the boat. The impeller just got back from Dean getting a repitch, so its running 8500 rpm now.

That's all I'm going to do as far as performance goes. Just going to enjoy it and get the surf setup dialed in.

 

[Midnight2V]

@SamCF, I was working my brain, and I came up with an idea to prevent a lean out condition while at the same time giving the ability to generate some serious low end torque. I'm kind of excited about this.

I may implement this on my project...or not. I know that you are currently dealing with a problem of running out of injector, and that you don't want/need more speed. No problem, it fits perfect with what I have in mind.

What if there was a way to have both more low end torque without having to worry about excessive boost up top and leaning out? I had to reach into my hotrodder bag of tricks, but I think I may have something worthwhile. One of the things that makes this even better than my old hotrodding projects is that the supercharger impeller in our motors is directly coupled to the crank, that means it can't overspin like a pulley driven centrifugal on an automobile.

Here it is...Imagine if you used a BIGGER wheel, giving you more low end torque, more boost lower in the rev range, and the ability to pitch up on the impeller and get on plane at lower RPM - more useable on-plane RPM. You run a BOV immediately after the supercharger to protect the supercharger clutch from compressor surge. At the same time, you install a WASTEGATE after the intercooler to limit the peak boost your supercharger can make. Both valves tap off of the same vacuum line. Imagine if your motor could get to 6psi by 5000 RPM, peak at 9PSI by 6500 RPM and maintain 9 psi however high you wanted to spin the motor. The intercooler never heat soaks because you're never generating more than 9 PSI, but you have 9PSI way sooner in the RPM band. 9psi is just a number I grabbed out of the air, I'm sure it doesn't matter and that each person could set it up according to their supporting mods.

It eliminates the issue where the boat is limited by a lack of boost to reach top speed, as boost is available before you ever need it. It also eliminates the problem of boating at elevation in thin air. If you need more boost, change a spring in 2 minutes.

There might be a tiny hit on fuel consumption while the wastegate is open but I bet it would be worth it. As far as failure analysis, my idea is to use a wastegate that fails open so you can't cause an overboost condition..

How does that sound?

 

[swatski]

Pulled the fuel pump and found the filter and pump body full of disintigrated silicone.

Is that the factory pump? Should it be a maintenance item - to inspect it? Would that silicon come from the fuel tank in any way that'd be obvious when looking at it?
Sorry for many questions!

--

 

[SamCF]

@Midnight2V I think there was a discussion on Greenhulk about lowboost and high rpm vs high boost low rpm.

It sounds like it would work. My only concern would be excess heat from dumping unused boost.

I've been going over what the next power upgrade would be for myself, and decided it wouldn't be worth the money/loss of reliability. I've had a close call with low fuel pressure, and the tune was conservative enough to avoid engine damage. I'm focusing on eliminating vibrations and soundproofing right now.

After the 61.5 mph speed run, I pitched that impeller up to drop rpm to 8300. My favorite combo now is the twin prop with factory pump cone. Brutal hole shot, and still runs 57-58 mph @ 8150 rpm.

 

[SamCF]

Is that the factory pump? Should it be a maintenance item - to inspect it? Would that silicon come from the fuel tank in any way that'd be obvious when looking at it?
Sorry for many questions!

--

It was the factory pump and filter. I dont know where the silicone came from. I've pulled it twice now to clean the filter. I'm looking for a larger in-tank filter, but have had no luck.

I would check that filter once a year. It's very small and can clog easily. Just pull it and rinse it out with Carb Cleaner.

 

[Midnight2V]

I thought about the dumped boost as well, and I thought the best thing to do would be to pipe the waste gate to a T for the engine compartment blower and send it straight out of the engine compartment

 

[SamCF]

Cruising the lake today, and a BAJA went by wide open. I had to put the top down, then catch up and pick a race.

Called him out at 0:23, I had him until we hit some brutal waves at 0:48, caught back up at 1:20 but hit a bottle neck crowded with 2 kayaks and another boat. He jumped back in behind us at 1:47, but I was already up to speed and he couldn't hang in the corners. Wife was SUPER pissed, but it was a blast.

This was with the twin-prop only turning 8200 rpm @ 59 mph.

 

[Seibert74]

That was freaking amazing!

 

[swatski]

Cruising the lake today, and a BAJA went by wide open. I had to put the top down, then catch up and pick a race.

Called him out at 0:23, I had him until we hit some brutal waves at 0:48, caught back up at 1:20 but hit a bottle neck crowded with 2 kayaks and another boat. He jumped back in behind us at 1:47, but I was already up to speed and he couldn't hang in the corners. Wife was SUPER pissed, but it was a blast.

This was with the twin-prop only turning 8200 rpm @ 59 mph.

F@@@ing awesome.

—

 

[4wheeldeal]

This was with the twin-prop only turning 8200 rpm @ 59 mph.

Love it good job!

 

[DavisAR195]

@360dart

Air intake question: Reading through your post you mention you got the aluminum sleeve through Riva, I was unable to find it on Riva's website. Do you remember where you got yours or what size sleeve you purchased?

 

[360dart]

I ordered it thru EBay because it was free shipping. There is only one size. It's all the same on the 1.8 Yamaha engine...