Project 311 SR1
 

All 311 Owner's

I just recently purcased a 1991 311 SR1 with 502's. I am turning this boat into a project. I am currently making a race fairing that is five inches shorter in the front than the original windsheild. I am also planning on painting and updating the entire boat to 2004 graphics, white dash and new style rub rails. So seeing that the cosmetic side of the boat is taken care of it is time to start in on the motors. The boat now has labed 24P bravo's with stock 502's and will reach top speed of ~67mph. I would like to know what this boat will run with 500HP per engine. Is it possible to reach 75mph? What other add on's have people tried on a 311 that work well. Also what hasn't worked well. I would like as much info on this boat as possible before I start buying parts. Thanks in advance of any information.

Don

Don, I own an 89' 311 with 454 mags. I've updated a few things, rub rail is now white, painted the hatches on the foredeck white, changed the graphics a little. I swapped to Hydromotive Quad IV Intimidator props and gained a solid 6/7 mph at 3300 rpm's cruise and 3 mph on the top end, measured by GPS. Originally the boat had Mirage props on them. Boat now runs much higher out of the water as they are real ass heavy. The Quad IV's provide a lot of stern lift thereby reducing drag considerably. The guys at Hydromotive told me exactly what to expect and why and they hit it right on. Here's a couple of before/after pictures.

Before

sorry this isn't a very good photo.

bone stock
 

I have a 87 311, 454',420 motors, mirage 25"s, bone stock, 69.5 gps. Post some picks of your progress id like see them..

int pick

Eliminator 190, I just love your graphics!:p

Is that a Spargi wheel? I bought one and can't get it mounted.

Russ, what's the top speed of your 311? I don't want you walking away from me Thursday!:)

I don't know, I've never run it top speed. According to GPS it's hit 71/72, but usually it's just upper sixty's. Depends, like everyone else, what I've got on board and how much fuel. If the tanks full that adds like 1300 hundred pounds. I like to cruise around 55 or so. I get my best gas mileage there. That what those props did for me. I went from 47/48 to 53/54 at same rpms. Besides, after this past summer, I'm afraid of breaking something. I leave the racing for the high horsepower guys. I just love to watch. p.s. you hose me with that damn rooster tail of yours and you're gonna have a "black talon" "up your pipe". snicker snicker.

Please take note of my signature!:D

Please take note of my "avitar".....
Joe, I'm really looking forward to this.

Good point! I thought that maybe you were just a big Paladin fan!:D

Maybe I should come to this shootout better heeled!:p

This is the 1991 311 that i bought back in november. Of course this is the before picture.

Here are the up dated graphics that will be on the boat by spring. The only difference will be were it is red in the picture it will be Teal and were it is purple it will be pink. Other than that it will be the same graphics with a white race fairing. So what do you Guys think?

Where are you getting your race fairing?

I am in the process of building my own. I am using the original frame cut down of course as the skeleton frame of my fairing. Then I am in inserting wood into the sides were the glass was inset. In the front I am using a thin water resistance plastic to make the form for the round windsheild. This will all be covered with an expanding foam and cut to the right shape and then fiberglassed for added strength.

dgduck13,
I currently own a 1988 311 with Bravo ones and 454's.
The motors produce 530 HP at 5500 rpm, but I have it proped to turn 5200 rpm which is 512 hp. I currently have Bravo 26" 4 blade props and will top out at 74 mph with a 50 mph cruise at 3500 rpm. The boat runs the same top end with quad IV Hydromotives but a slower cruise. With 25" Mirage 3 blade it will run 75 mph, again with a slower cruise and not as smooth and doesn't handle as well as 4 blades. I'm sure if I had the props labbed I could get more top end and maintain the great cruie speed that I have now. I am not that concerned with the top end because I don't run it that hard unless I need to smoke a cigarette. Also the boat is for sale.

Don, sounds like the old girl will look killer. try spinning the props "in" one time to see what happens.

Hi Wes-
I was thinking the same thing. I have been talking to a few people up here in the frozen tundra and they mentioned that turning the props inward will get me a few MPH. Every little bit will help. Thanks for the advice.

"Wags", are you Quad IV's the same pitch as the Bravo 4 blades? If so, I'm surprised your cruise speed is less. I tried a set of Bravo 4's on mine and lost 3 mph at cruise, but I'm running much less horsepower than you. Don't know what difference that would make but maybe something. Just curious, that's all.

Next week I'm going up to Innovation Marine to talk to them about some "motor work". Russ

Outlaw
Which pitch hydomotive props do you have on your boat? Are they labed? Which rotation are you running (in or out )? Sorry I have more questions than answers. Thanks for your help.
Don

"DG", My Hydromotives are 24 inch, however they were tweaked a bit at the "prop shop" and now they're 25's.
I figure I must also be getting a lot less slip at cruise with these props than my old Mirage. The first time I tested and compared, I couldn't believe the difference. Swapped back to the Mirage then back again to the Quad IV's. All speeds by GPS. Results were the same. I gained a solid 6 mph at "cruise rpms" and 3 on the top. With the Mirage 23's my cruise speed was 47, now it's 53. Outlaw rides much higher and at a better angle than before. The way I modified my "silent thunder" I can hear the difference when the boat is lifting out of the water, the enlarged holes in the bottom of the muffler box is now higher off the water resulting in more noise. By the way, I gained 300 rpms by the mods to the silent thunder. I also cut the partitions out that are "glassed in place" in front of the rectangular exhaust outlets. Runs and sounds much better. I run them out but I am going to try running them in just to see the difference, though I love the way the boat handls around the docks. I can parallel park it. Russ

Russ
The silent thunder on my boat is also modified , but in a different way. There are three 1 inch holes drilled on the inside of the platform. Also the flaps are removed and it looks like the partitions are also removed. It is a little louder than my dads 272 but it is not horable.

Don

:cool: Don, like I said I removed the partitions that were "glassed in", directly in front of the rectangular exhaust outlets, and where the small circular holes in the bottom of the box were, are now big honkin' rectangular holes, big enough I worry about Pelicans making nests up there. You can really hear the difference when the boat lifts out of the water. It starts to really roar. I love it. Am going to end up taking the silent thunder off, going with some new thru hulls, and putting on an Extreme Marine tubular swim platform to keep my wife not quite as mad as usual.

Formula Outlaw,
The Hydromotives are also 26" they are the Quad IV Intimidator's and they definitely cruise slower than the Bravo's, approx 2 mph. I believe they have a Quad IV X that is set up more for our older style hulls that would cruise better than the Quad IV. I also tried turning the Hydro's in and it picked up 1 to 2 mph on the top end but porpoised in the mid range, But the boat will act differently with less pitch so give it a try.

Formula Outlaw,
What do you have for motors and drives? What top speed are you getting and what rpm are you turning at 53 mph?

Wags, I'm running your basic 454 "mags" and Bravo 1 drives. According to my GPS, I've hit 71/72 but only twice and both times I was light fuel load. Also believe I was running with the tide which will make a difference. It runs 67/68 consistently and 69 with a light fuel load.
I figure the biggest difference came from A) less prop slipage and B) the Quad's are raising my boat out of the water much more than the original Mirage 23's. The guys at Hydromotive spent about 45 minutes on the phone with me when I was making the inquirery and they told me exactly what to expect and why. They hit it right on the head. Those new 5 blade Hydro's are supposed to be pretty good. Like I said, I think I was getting a lot of prop slip with the orignal Mirage props.
Obviously this is just a guess, but I'd bet I'm running at least two inches if not more higher out of the water. A buddy of mine put the Quad's on his 32 Fountain and he got similar results. Russ

Wags, something else I just remembered. I seem to get a larger speed increase per 500 rpms from say like 3300 to 3800 than I do from say 3800 to 4300. Don't really understand that. I was considering putting a set of nose cones on the Bravo 1's but I'd like to hear some feedback or opinions before I spend the dough.

Russ,
Tom and Gary at Hydromotive are very knowledgeable and helpful and I will be contacting them for props on the 382 this summer. It sounds like your boat runs very strong for the set you have, up here in the fresh water the 311's with mags run more like mid sixty's. It takes a lot of power to move these 311's but with a couple 500+ hp motors it acts like a totally different boat.

Russ,
I have the Hydromotive nose cones on mine, I can't tell you how much it helped because I built the motors and put on the nose cones in the same winter. Tom at Hydromotive recomended them so I went for it. Jeff

Jeff that's good enough for me. So far the guys at Hydromotive have been RIGHT ON with what they have told me. I mean they hit it exactly with the props. How did you install them, particularly what did you use to "feather" the edge in, marine tex? I want to try to get 600, or a little better, out of each motor without supercharging if possible while still being reliable. I can't afford exotic motors that have to be freshed every 50 hours. I need something that with good routine mainentence and not abusing them will hold together. What would your guess be for top speed with say, 625 a side? My goal is 80 or a tad better. Russ

then again, maybe a set of prochargers would accomplish what I want set at around 5 psi. I'm' open to suggestions. I'd really like to see mid 80's if I can do it reliably.

Here are some pictures of the frame of my race fairing mounted on the boat. The frame still has to be fiberglassed, smoothed and painted, but at least you can get an idea of what it will look like.

Here is another veiw

and one last picture!

The fairing looks cool. I'd like to do something similar. Pleae post pictures of the finished product when you can.

Russ,
RedDog382 would be the one to tell you about 600+ HP, I believe he had approx. 630 HP and broke the 80 mph barrier with his 311 . To get over 600 HP with the 454 naturally aspirated you will need high compression and higher rpm that will only help on the big end because you will have to run a lower pitch to get the rpm. Don't get me wrong, I love HP but a high torque motor can turn big props and get a good midrange and have the reliability we all need. I never ran a blower, but to get the numbers you want from the 454 and keep the rpm down you might need to go that route. Jeff

Russ-
What RPM's are you running at WOT? Seeing that you are planning on doing all this motor work I don't think that you will be able to spin your props anymore? I was wondering if you would want to part with your Hydromotives?

Jeff, what exactly do you mean by "high torque" motor? I'm guessing cubic inches. I'm hoping Innovation Marine can give me a few choices. I don't want to lose a good cruise speed for a couple mph on the top. And reliability is the key issue. I'm not sure if it is worth building up my motors or just starting over. Any suggestions?

As you know, all boats run a little stronger in salt water than fresh.

Thanks, Russ