Nitrous Oxide on a boat
 

Whats up all!
Sprung for another larger boat this year -purchased a 38 Scarab AVS(1999 with less than eighty hours on it)The boat has 415 H.P. MPI,s 502 ci engines.. any way I ran Nitrous Oxide on My last boat with 454 ci Engines for 24 years with no problems ( yes I said 24 years and no blow-ups) Now Im looking at adding Nitrous to the new engines but Im not up to speed on the fuel injection . Is anybody out there into this type of install thanks ?

Jim

Unless you have a tunable ecu and injectors large enough to handle the additional fuel requirements of the nitrous you should probably stick with a wet system.

fuel injection is great but I'd rather be blown!!!

going supercharged is a lot more money -$10,000 + compared to a couple of nitrous systems for between $1000 and $ 1400 for the last two systems that I installed on the 34... They may not last very long before you have to refill the bottles (about 3 to 4 minutes) but how long are you going to race some guy out there anyway!!! Its all about who is faster !!! Most of the time they have no idea what you are running any way ---- a lot of cheap fun if you are very carefull.

Jim

And how many times did you fill those nitrous bottles over that 24 years and at what cost????

I dont know how long your boating season is where you are but we are on Lake Erie ;we get maybe 4 or 5 months to boat ..so I would say I have used the bottles maybe 3 or four times a season at $ 50 a bottle ... There were seasons that we never used the bottles at all for other reasons,sickness, other interests,ect. After 24 years of the same boat ,it just wasn't fast enough to keep up with traffic; but it was still there and we could turn it on at any time... The guy I sold it to has NEVER used the bottles.

Let me make this perfectly clear--- installing Nitrous on a boat is a VERY tricky install and I do not recommend this to any one unless they know exactly what they are doing and take a lot of safety measures !!! Safety shut off switches, automatic fire suppression system ,stainless braided fuel lines, and no bottles in the engine comp. or the cockpit ect. ect.
Your down side at the very least could be two junk yard motors......... Jim

i always heard that you cant really prop a boat with nitrous. to get the best hp the nitrous can put out,....you need a bigger prop. but when you're not using the juice, your prop will be too big for your normal hp.....and your only using juice 3% of the time.....so you're gonna be over proped 97% of the time ???

I ran a 250 hp kit on my Daytona, never changed props, surprised a few people, it was fun.

GPM ,
need to pick your brain on these 415 MPI'S !. is there an O2 sensor on these engines ? 2. what is the fuel pressure in P.S.I. Im told by Dyno Tune Nitrous there is a schrader fitting that you can plug into on the fuel rail??? thanks Jim

How much HP are you looking to add ? I don't think you'll find an 02 sensor on a stock motor. I think you would be best off using a plate under each throttle body and a stand alone fuel system for the n02.

GPM, I ran 100hp nozzles on the old boat but would like to jump up to 150 for the new engines; plan to use a wet system with fogger nozzles...

Jim

Some kind of timing retard and you're ready to go.

You can get fuel from either end of the rail. The end by the dist has a threaded plug and the front end has a schrader valve to release pressure manually.

GPM,SMITTY
Thanks for the info guys --- Have a Merry Christmas!!

Jim

Where do you send pictures to be posted for this site?

***

I think you forgot about the rev limiters. If the boat is propped correctly now it's not going to run any faster mph it will just hit the limiter faster. And if you put the big props on, it won't get out of it's own way unless you are on the juice. When I ran it on my drag car a 10 lb bottle would last 120 seconds , makes for a real short boat ride. Just my .02 Jeff

Anyone ever use nitrious on Mercury 300X outboards ??? "HIGH LIFE"

hey i was just wondering thoughts on nitrous on my application. I have a fresh rebuilt 454 full roller engine was a 454 mag. I just wondered how anyone has done it in the past and how much it helped.

I had nos on my 89 challenger v24. At the time I had nos on it the engine was pretty much a stock 454/365 Mag with a 420 camshaft in it. I used nos for a couple of seasons and it was a grin. Those boats had a pretty slippery hull so the gains were pretty good at an instant 7 to 8 MPH. It was fun however I would never do it again. I drink way to much to use it without the concern of blowing an engine.

getrdunn,i have many drinking friends who have a boating problem,including myself from time to time.lol:lolhit:

OK, I was thinking it was only me. Why is it so easy to pound down a case of beer on the water. Before you say OH that's nothing but I'm talking by 3:00 in the afternoon. I had to switch to light beer due damage control and black outs. LOL... I finally got old enough to only watch rather than participate in all the boat launch fights also. I'm suprized there are not more home videos of such. :coolcowboy:

hay my buddy put that on his boat bad news first time crack the head . next time it was the drive to many things to go wrong and break put a big motor in you boatyou will be happyer

How much do you want to run, set it up like a car with a dry kit, high pressure fuel pump, msd ignition, great for running big pitch props, I run it with a 525 EFI with just a 125 HP (.0625 Jet) with a 36" Pitch Bravo 1 prop and 1.36 gear runs 125 MPH at 5400 RPM in my 2000 Powerquest 280 Silencer, runs perfect, superchargers over-heat engines and engine compartments, and also push RPM's over the torque band, torque push the prop not horsepower.

Your running 125mph in a powerquest with stock 525's with a a shot of NOS? Sounds like one hell of a boat...tell us more. Do ya got any video of you hitting the juice? Your right at 8% slip that an outstanding #. Last but not least..... Now that you have gone 125 do you feel your " quest for power" is over?

If my donzi doesn't go 100 with the new motor it's getting two 80lb. Tanks in the bildge. And I'll definately stuff it...

How are you running a 125hp hit with a DRY kit on an engine with NO mass air meter? I've been using nitrous on injected car engines longer than I can remember so I'd love to hear how your doing that.

Cigboat, your easiest way to do it is to run a WET kit with a nozzle similar to Nitrous Express' Shark nozzle. I'd watch your plugs carefully to make sure no cylinders are leaning out. The way your intakes are designed to only flow air and where the nozzle will be located, some cylinders will see more extra fuel/nitrous than the others. Most importantly, run a fuel pressure safety switch to shut down the squeeze incase your fuel pumps have trouble keep up with demand.

Giving advice on a 4 year old thread. Fail.

Fawk :picard1:

125 in a 280 silencer with 650hp? Must be a magical hull. Where do you come up with this garbage?

I put a NOS kit on a friend's Mirage 21' powered by a 350 Magnum. Comments listed above were similar to this experience. We moved up 2" in prop pitch and even that wasn't enough to handle a 75 h.p. shot as the engine would jump to an indicated 5700 r.p.m.s. With the 2" larger prop it was over-propped off the bottle.
The plus side was a VERY angry sound at WOT on the bottle and a 4 m.p.h. gain in top speed. The was on a quadrajet setup. We stayed with the smallest jets in the kit as the engine had cast pistons and we didn't want to mess with adding a timing retard. NOS (back in the days when Mike and Dale owned the company) said the small jets were safe to run with everything else stock.

He must mean km/hr haha

That's nothing. Check out his first post on this site: http://www.offshoreonly.com/forums/p...ml#post4064606

I must be doing something wrong. Years back I could only get 191mph out of a single engine 30ft deep vee with a 502 . :party-smiley-004: :poopoo: Joking of course...LOL.

Man I'm gonna put me a big ole bottle of NOS on my boat when I get it back from my engine builder.Big as I can fit in the engine hatch.I just hope he does not visit oso. hf...

Darr?

NOS 125 HP isn't really that much on a 525 EFI, a stock 280 hull isn't going to take much more than that, more than 650 HP, the drive will have to be rebuilt, so that's probably about it, 125 MPH on the water is like 250 MPH on land anyway (this was a modified NOS kit for an LS3 Camaro). Videos coming soon. Powerquest may be coming back, I might even buy it if the offer is right.

No, it's MPH, because I can run a 36" Pitch Bravo 1 prop, the biggest thing that fit on that will fit on that shaft, and this is with a 1.5 gear with only 4000 RPM prop speed, 140 MPH is possible with a 1.36 gear (4500 RPM+ prop speed) but I don't think this 2-step hull will take it, it would need to be a 3-step hull with a cross-nylon composite similar to the Fountain racing hulls (25% lighter, 3X stronger), I have another 280 Silencer that has a cross-nylon composite hull licensed out by Fountain that goes significantly faster, this one also has an XV-Extended Drive with electric steering booster pumps to allow easier steering at higher speeds.

Give ah the dinnah!!!!