Supercharger bolt-on

[Zackdogg]

This 440 is a dog, and I’m trying to figure out what to do. Does anyone know if a 440 can be converted into a 575?? I’m trying to figure out if I bolt a supercharger on. Try to find a 575, swap it, and see what I can get for my 440. Or sell this boat and start over, which would be, by far, my last choice. I’d much rather figure out how to get some power out of this thing.


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[dakota4ce]

Do you run at high altitude? My 440 is not a dog. I am at 1300’—


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[jslayde1]

Re-propping would be the first thing to do. I agree with Dakota - the 440 is not a dog for sure...

What boat as well as what elevation?

[MikeB313]

Any more info, what boat, how much weight are you running, prop, altitude, transmission? As dakota said, the 440 is not a dog.

[Zackdogg]

We run everywhere from sea level to ‘6200.. our home lake is at 4000’.. it definitely runs better at sea level, but still can barely hit 10mph to surf with full ballast and 10 people, can’t hit 12mph.. no PNP.. and that’s with a high altitude prop. Can’t get above 10mph with full ballast, and 12 people at any altitude.

At 5200’, with 7 adults, this past weekend, I couldn’t run more than about 30% ballast and get out of the hole.




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[Zackdogg]

2016 RZX with about 60 hours. I have 500lbs in lead, but threw 300lbs out of the boat. My dealer said the high altitude prop will “yank my arms off”, even on Tahoe (6200’), but I don’t consider 10mph to be yanking my arms off..

It takes forever to get on plane, even empty, at higher altitudes with more than 5 people in the boat.

I’m at a complete loss, without finding a way to increase the power.


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[Zackdogg]

As far as weight, 3000 ballast, and 500 lead, is unusable, unless we’re close to sea level and like 5 people on the boat.


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[chpthril]

and that’s with a high altitude prop.

And what is this prop specifically? This means nothing, especially since it would elevation, not altitude, as there could be a half dozen viable prop upgrades to the original stock prop.

[Zackdogg]

You’re right. Acme 2419.

I talked to OJ, and he said his I wanna say 985, I have it written down, would be the most torque he could provide, but it would be real similar to the 2419, he’d send me one, and I could return if it isn’t any better.

I’m hoping you guys are right, and there’s a more simple solution than putting a charger on this thing. I’d love to be wrong on this one.


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[chpthril]

You are in a unique position, running at near sea level as well as an elevation of 5200. I think you are going to need to run two props. One for the high elevation, and then another for the lower elevation in order to keep from pegging the tach. Something like the ACME 3091. 15D x 10.5P.

before making a prop change, I would have the dealer check the engine system. Hopefully your dealer is at the 5200+ range or can easily take the boat to the elevation and run it while monitoring the ECM data.

Are you using the proper octane fuel?

[Zackdogg]

You are in a unique position, running at near sea level as well as an elevation of 5200. I think you are going to need to run two props. One for the high elevation, and then another for the lower elevation in order to keep from pegging the tach. Something like the ACME 3091. 15D x 10.5P.

before making a prop change, I would have the dealer check the engine system. Hopefully your dealer is at the 5200+ range or can easily take the boat to the elevation and run it while monitoring the ECM data.

Are you using the proper octane fuel?

I’m completely fine with changing props for where we’re running.. our home lake is 4000’, and would like to be setup for that, 75% of the time. But I can’t run the weight I want, which is full ballast with maybe 6-8 people, and 12mph (at most) to surf. I’m not even close to being able to do that.

You’re saying 3091 for sea level, correct??

Maybe I order that 985 and give it a try up here.. I don’t know..

I’ve never run a drop of fuel that wasn’t 91 octane. I could try an octane booster, I guess, as well.

My dealer is 2 hours away, at sea level... they do have a guy at Tahoe, 2 days a week. Maybe he can check it out at that elevation. I’m at a loss, otherwise. As you can probably see, with trying to figure out how to supercharge this thing.




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[UNSTUCK]

All the 6.2 blocks and internals are the same. Ford just slaps a charger on it then indmar calls it a 575. The hardest part of the swap will be the computer tune which you will have to overcome. You cannot run a blower on the 440 tune. Indmar's proprietary computer cannot be tuned by anyone in the aftermarket as from my last check. To make matters worse, as of my last check, indmar will not sell you a new ECU. Ideally you are best friends with your dealers service guy who "might" be able to upload the tune from his indmar software, but I was told that probably won't be available for a few more years, until boats get older and start having computer issues. Right now everything is just swap out warranty work.

A much more feasible solution would be to go to a 2:1 transmission. You would need all new parts from the transmission to 17" prop and everything in between. Basically turning your RZX into an RZX3. My home lake is 4200'. On July 4th we ran our biggest crew yet, 14 people, mostly adults and older youth. The 440, 2:1 and 17x14" prop did great, with PNP bags full, and on 87 octane. Once I get some funds I will get some custom PNP bags that will add about 800 more pounds midship. I already tested a 1000 bag on the floor and the boat pulled fine with it full. I have not been to our higher mountain lakes yet, but suspect it will do okay. I would not expect the same performance though that we get at our normal lake. Actually I'm even thinking about the 15 pitch prop to bring RPM's down a bit more. Fully loaded we were surfing around 3900-4100 RPM's at 12ish MPH.

[Zackdogg]

All the 6.2 blocks and internals are the same. Ford just slaps a charger on it then indmar calls it a 575. The hardest part of the swap will be the computer tune which you will have to overcome. You cannot run a blower on the 440 tune. Indmar's proprietary computer cannot be tuned by anyone in the aftermarket as from my last check. To make matters worse, as of my last check, indmar will not sell you a new ECU. Ideally you are best friends with your dealers service guy who "might" be able to upload the tune from his indmar software, but I was told that probably won't be available for a few more years, until boats get older and start having computer issues. Right now everything is just swap out warranty work.

A much more feasible solution would be to go to a 2:1 transmission. You would need all new parts from the transmission to 17" prop and everything in between. Basically turning your RZX into an RZX3. My home lake is 4200'. On July 4th we ran our biggest crew yet, 14 people, mostly adults and older youth. The 440, 2:1 and 17x14" prop did great, with PNP bags full, and on 87 octane. Once I get some funds I will get some custom PNP bags that will add about 800 more pounds midship. I already tested a 1000 bag on the floor and the boat pulled fine with it full. I have not been to our higher mountain lakes yet, but suspect it will do okay. I would not expect the same performance though that we get at our normal lake. Actually I'm even thinking about the 15 pitch prop to bring RPM's down a bit more. Fully loaded we were surfing around 3900-4100 RPM's at 12ish MPH.

That is extremely useful info, and thank you!! I knew the block was the same, and wasn’t sure if the SC was the only difference. Wasn’t sure about pistons, heads, and injectors. Didn’t consider the tune, which would be a major sticking point.

Sounds like a night and day difference to me. Sounds like we run pretty close to the same altitude and crew. With a crew of 14, I would be lucky to be able to run 30% of the stock ballast, 0 PnP, and 0 lead. So maybe a total of 800-1000 total ballast. And I would struggle to hit 11mph, with that.

Maybe the trans, which has been mentioned in other posts I’ve made, is a viable option. I would probably always fear reliability with an add-on supercharger, which I wouldn’t have to do with the trans, as well.

Thanks for the reply and ideas! I appreciate it. It sucks to even have to figure this stuff out with a $100k boat. It really sucks when I’m out with the rest of the guys I’m with running G23s, and they aren’t having an ounce of struggle.

I saw someone say “you should have bought your 2nd boat first”, and I couldn’t agree more. I would have a 575 and triple axle trailer, and it would have transom straps. I love 90% of this boat, but have some pretty significant disappointments in a few pretty major areas.


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[bsreid]

I’ve got a 16x12.5 on order for my rzx. Which should bring down the rpms and give more power to reach the surf speeds. I run 4900 in weight with 440.

The thing with the 15x10.5 yes you will get better surf speeds and torque but your rpms are gonna jump through the roof.

[Zackdogg]

That will be even worse for me, out of the hole, correct?? Maybe I’m wrong, if I am, I’d love to hear that.

That’s the one thing I can’t spare. If I can’t even hit 10.5-11mph, I can’t give up an ounce of bottom end.. I’ve already lost some top end with the 2419, but would gladly give up a couple more mph to be able to surf the way I want. We aren’t on any huge lakes, except for tahoe, which I’ll never attempt to cross again, and if I can run 30-35 at 4500-5000rpm, I’ll survive..


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