Performance upgrades

[Brianrzr]

I have the 350 hp 5.7. Basically a GM small block that’s been marinized. Has any body tried any performance improvements such as cam swap, head work?

[boatwakes]

If it's efi, you're in for some money if you want anything more than stock HP out of it ($10k+) and those gains are minimal, less than 400hp. The cams are ground to a specific horsepower profile which will require a computer (ECM) reflash if you change it. Basically you're asking for trouble on a towboat if you want to add more HP. The marine engines (pre LS) were not designed to maintain the HP of their automotive counterparts due to continuous duty load factors.

[TeamAllen]

Changing he prop to fit your needs is probably easier and cheaper.

[UNSTUCK]

I'm looking into adding a supercharger to mine this spring....if I keep it. The biggest problem I am running into is finding someone that can tune Indmars proprietary ECM. If yours is PCM it may be easier or harder. I have not found anything to suggest that any GM engine was modified from its original intended use (the auto world) other than maybe the oil pan, exhaust, cooling additions and sometimes intake changes. I know for a fact that my L96 is a stock truck motor with exhaust and a tune. That makes it a perfect candidate for an LSA supercharger. It would of course have to be tuned. If I cannot find someone to tune it then I would have to swap the ECM to something that tunable. This isn't a big deal either, but I haven't been able to figure out if Zero Off will still work with the new ECM. Worst case is I would have to change out the throttle system to a cable and run Hydrophase. I know my way around LS engines very well so this isn't a difficult task. I would save a lot by doing the install myself. I figure it will cost about $6k on the high side and $4200 on the low side. What the option fee for a raptor supercharger or even the older LSA optioned motors? $12k-17k?


A prop change works great up to a point. Unfortunately to do what we do at our elevation, it required a prop that runs the engine at 4500 surfing and over 5000 cruising at a SLOW 22 mph.

[Brianrzr]

Mine is an Indmar also. It seems to be impossible to find information on them. I figured tuning the ECM would be the biggest hurdle. Please keep me informed what you find out. I agree about props, I have been completing a lot of prop tests for my employer and the results are not what people think. But that’s for another thread.

[bsreid]

What prop are you running?

[Germaine Marine]

I have tested countless props on almost every current Tige engine/trans package. The correct prop for what you are intending is absolutely critical in performance, and can be drastic. Keep in mind, their are countless props with countless combos. Knowing exactly what each element does and controls is essential. You can spend hundreds of hours messing around with props that wont do you a bit of good because you are not even at a decent baseline with diameter/pitch and cup.

[freeheel4life]

My question would also be how much weight are you running in your 20ft RZR that weighs less that 4k lbs?? Tige put that same Indmar 5.7 in RZ2 and in Z3s in that same period of time, cant recall for sure but think `14 was the first year that was the switch from PCM to Indmar. I have run both here at 3000 ft with lots of weight and had no problems. 1235 is a good all around here with weight and that motor and if you wanted to run heavy we would run the 2079. My thought process would be why do you need more out of said motor?

[bsreid]

Unless you’re at crazy elevation, the 335 is more than enough. We are at sea level, acme 1433, weighted evenly with taps 3, upwards of 3k in ballast and no problems what so ever. At times we wished we had the 1235 for a little more power.

[Brianrzr]

I have the stock Acme 1631. I know another prop will shift power around the rpm band, but there is not a problem more power won’t fix. Actually I don’t have any problems, I love the boat it does everything I want it too. I just like to build engines.

[freeheel4life]

Well there are plenty of bolt on mods for the 5.7 out there but as mentioned you will run into ECM tuning issues. If you have Diacom you can change CAL files but as far as I remember from my indmar training there isn't really drastically different tunes for that engine. Each one was manufacturer specific and some manufacturer didn't run knock sensors so the tune is a little "safer" in that in runs fat fuel and retarded timing to keep it safe. Your Tige should have the knock sensors and in turn have the more aggressive tune.
So short of dropping a 6.0 in it I don't think you would get very far with bolt on mods, without doing what unstuck is talking about doing for ECM

[UNSTUCK]

Mine is an Indmar also. It seems to be impossible to find information on them. I figured tuning the ECM would be the biggest hurdle. Please keep me informed what you find out. I agree about props, I have been completing a lot of prop tests for my employer and the results are not what people think. But that’s for another thread.

I went straight to Indmar through email and was very impressed with the information they gave me about what they did to my engine. I think they gave me all this information to scare me away from doing anything, but actually made it easier when I'm ready to go. Mast Motorsports is the only company I found that said they might be able to tune the Econtrols ECM. If I understand it right, there are two styles of these ECM's. They can tune one of them. Not the other. I just haven't uncovered my boat to look at which one I have, yet.

Props can be a pain to play with. Nettle Props and Acme have been absolutely awesome to work with on my search for the perfect prop, which I decided doesn't exist, despite what has been said on here.

[Germaine Marine]

the perfect prop doesent exist meaning? One that can be a tug boat and cruise at 35? yeah you are prob right.

If you are talking about finding a prop that can give your boat tons of bottom with top end being the sacrificial lamb then I say you absolutely can. You can talk to nettle and acme until you are blue in the face..... Their is only really one guy that I would talk to in regard to props and that happens to be the original owner of acme and thats Todd Diekevers. He has been paid to stay on with acme for a certain amount of time but that guy can tell you anything and everything you would need to know the same goes for Eric at OJ

You can custom tweak cup to do some pretty awesome things performance wise. Obviously the motor package with your current boat is a little under powered for elevation and weight, however I would be shocked if it truly was unfixable with a custom prop. Granted you have to be prepared to give up on one end of the spectrum. From what I remember you just cant get enough bottom right?

[UNSTUCK]

the perfect prop doesent exist meaning? One that can be a tug boat and cruise at 35? yeah you are prob right.

If you are talking about finding a prop that can give your boat tons of bottom with top end being the sacrificial lamb then I say you absolutely can.

You can custom tweak cup to do some pretty awesome things performance wise. Obviously the motor package with your current boat is a little under powered for elevation and weight, however I would be shocked if it truly was unfixable with a custom prop. Granted you have to be prepared to give up on one end of the spectrum. From what I remember you just cant get enough bottom right?

To recap from an earlier post:

A prop change works great up to a point. Unfortunately to do what we do at our elevation, it required a prop that runs the engine at 4500 surfing and over 5000 cruising at a SLOW 22 mph.

Can you imagine trying to get across Powell going only 22 at 5k? What would you consider to be a safe cruising engine speed? 3k? I'm ok doing it at a slow 22 mph, but I just can't be happy doing it at 5k rpm. Props, as you said, will not get me what I need. You can tweak cup all you want and it will totally change the prop, but you will never get more than a few hundred RPM change. At least I didn't.
Look what Tige is now doing. 2:1 transmissions and 17" props. That is one way of solving the problem. Also notice that the engines are only getting bigger too.

My prop list from last summer:
1st. 1235 Fast, good prop for listing stock ballast. No chance with 5000 lbs ballast.
2nd. 2937 SLOW, great prop for 5000 ballast. Our best surf prop. All around too high rpm for my comfort.
3rd. 2315 Dont really remember this one. Think it was still too high of RPM but wouldn't pull the full ballast.
4th. 2419 Good for about 3k lbs ballast. Usually around 3900 rpm surfing. Cruising still high and slow. We kept this one as the best compromise.

My goal is to surf at 5000 lbs ballast at under 4000 rpm and cruise in the upper 20's closer to 3000 rpm. The Supra SE 550 I tested in November blew me away at its power with that much ballast and LOW engine speeds, so I know it can be done.

[bsreid]

As we go back to the OP in this thread.

He’s running a very different boat than you, 3000lbs, 94” beam boat with probably the same engine as your massive mb. Granted he’s probably at a little higher elevation but that rzr hull is so versatile. You aren’t going to be putting 5k in a rzr, trust me I’ve tried... So with 3k in ballast the engine has more than enough power when properly propped. Cruising around 29mph right at or less than 3000rpm and pretty much the same for surfing with taps 3. And surfing listed will be less. Yeah going over 40 isn’t going to happen but really why wants to do that?