I see.... Yeah i have a labbed prop already. Tell me a bit more about the hydromotive nose cone please. I'm assuming it goes on the outdrive right? Where do i get one and how much?

[QUOTE=2BAD4U;3432712]SO... Your running 13psi on 8.2-1 on pump gas right? I have a 509 SRP Forged Blower pistons 8.5-1 and Scatt rod's. I wanted to take my M-3 from 5psi to around 10. Some dude at AZSM said it will pop and i'm crazy. I understand cars and boats are kinda like apples and oranges. I understand that boats are under more load and you are at higher rpms for longer periods of time. But I can take a 9.0-1 motor in a car and throw 14 lbs at it and have a 17 degrees of timing in it and not have to worry about detnation. So i couldn't see why I would have problems. I just put cometic head gaskets in and pro comp aluminum heads and studed them in. I can't imagine that i would see detnation with 91 oct. on 8.5-1 motor on 10psi at 6,000 elevation with only 8 degrees of total timing. But my buddy who has a Baja like mine but a 454 m3sc who is only running 3psi says i'm crazy.[/QUOTE

Unless you run 28-30 degrees of advance your exhaust valves will turn into glow plugs. Either they will tulip and fall off or they will cause the mixture to pre-ignite or both. That's one of the differences between cars and boats that people here have learned the hard way. Given your elevation, I'm sure you could run 8-10lbs with an intercooler on 91 with 8.5 comp. Above that, you better be careful.

[QUOTE=PatriYacht;3433157]Yeah... I have heard that. I hear that's why most all performance boats come with Inconel valves from the factory or have them put in. But i figured i could run that much boost. But wanted to hear a bit of insight on this. And see what other combinations some other people are running and what the out come of it. But from what i can see everyone seems to run in the 80's with ease. And on N/A motor's without force induction. But i'm sure it's due to elevation. The Lowest elevation lake near to me is 4,300 ft. Most other lakes around me are above 6,000ft. Cars typically run about a full sec. Slower here then at sea level. So i'm sure that has alot to do with it. But thanks again for your thoughts.

I am running a very conservative 3-5lbs on my 502MPIs. The Blowers are B&M 250s. The engine HP is from 575-600hp. I only run 93 octane. I have thought about getting some new pulleys and upping the boost to about 6-8 but right now the enginges run so well and they are very reliable. My boat with the 32P Bravo 1s runs about 88-90 GPS full of fuel (155 gals) and with all my stuff aboard (fenders, anchor, life preservers, cooler with beverages, etc.)

WoW, Just seems so fast to me. I'm only turning my 28 pitch bravo labbed prop 5,000 rpm. That equals out to be about 75ish mph with the slip i'm seeing. But we are talking about 6,000ft above sea level. The guy who owned the boat before me said he took it to Lake Havasu said he got it over 80. That was with the old M1 on 4lbs but he said he saw about 6 to 7 pounds when he took it there. And here at this elevation it was only gps 72 on the m1 with 4lbs. 26 pitch labbed prop on a good day. So i'm thinking there is a good 10mph difference between sea level and where i'm at. Atmospheric pressure at sea level is 14.7 pounds. From calculations at 4,500 feet i believe the atmospheric pressure is high twelves low thirteens. Which i guess equals out for around that two psi gain he was seeing. It's just nerve racking to read these guys running so well. But elevation makes a world of difference. Take for example my 2006 dodge charger. It's just a base model familly car SXT model with the 3.5L HO 250hp grocery getter. I took it to vegas and they are still in the 3,000 ft elevation mark. I kinda got on it from the light and the tractoin control light came on. I was like WTF? Was i on gravel? So next light i took the Traction control off and just punched it and the tires practically went into smoke. Just ripped em loose and fish tailing. Here the roads have to be pretty damp to even attempt to do that. And that was only about 1,800ft drop in elevation. Which i hear guys at the local drag strip say when they run their cars in Vagas they gain about almost a Half a sec. So makes sense i guess... But what kinda weirds me out is that the lowest elevation lake to me is Utah lake. It's like 4,300 elevation. I then take my boat up to Flaming Gorge which is 6,000+ feet elevation. I Maybe only see 2mph difference. I would figure more. ??? Because if my math is right and i reversed it down to sea level that way. If every thousand feet is about 1mph i would only see 4mph more at sea level then from utah lake. But i can't figure that being true due to what i have read and heard. So i'm a bit at loss. I can only imagine that their isn't as big of atmospheric pressure drop from 4,000ft to 6,000ft as there is from sea level to 4,000 feet. I see 5lbs at utah lake(4,000 ft and i see the same at 6,000ft. Same Pulley) So I dunno????

500 EFI's, Larger injectors, fuel lines, pump, and filters. Tuned. M3SC intercooled running 8-9 psi on pump 93 for 165 trouble free turn key hours, 830hp. Imco sc drives are another story!

Yeah down here in Lower Lousiana and Texas we are maybe 150-300 feet above sea level. I can turn the 32s to 5500 rpm (rev limit set at 5600 on my engines). I usually have about 13-14% prop slip. On my boost guages like I said I usually see between 3-5 psi max right now.

Nice... Good to know. What size pulley you run on the head unit? And about how fast are you going? What prop size as well?

Ron

30" bravo 4 blades labbed by mercuy. 95+ on limiters, full tank fuel 6 people full of weekend gear. Forgot the pulley size but will check.

It needs drives and 5 blades!