Who can figure this out?

[chrisk]

In 1994 Powerboat did a test on the 28 Cyclone with twin 465's / 1.36:1 gear ratio spinning a 25" 3mirage and the boat ran 85.2 mph at 5000 rpm's

In 1996 Powerboat did at test on the 28 Cyclone with tiwn 630HP's / 1.36:1 gear ratio spinning a 27" mirage and the boat ran 88.3 at 5200 rpm's

Thats a big horse power differnce for 3 mph... can any give any insight?

Below are the articles in pdf format

[Mr. Brownstone]

With the power that you have in your boat, I dont think you have to worry about it.

[Ratickle]

With the power that you have in your boat, I dont think you have to worry about it.

Now that's a bit rough.......


Makes no sense. I'd PM Doug and see what he knows about the two tests. Maybe one was at sea level and one at Lake Tahoe.....

[jdub]

Driver error... But you would think an additional 370 hp would net more than 3.1 mph. But like the article said water conditions in hot humid Florida most likely didn't help.

[LittleDcsRodShop]

The prop slip on the 630 boat sounds right, but something doesn't seem right about the numbers on the 465 boat.. the 630 boat comes out at 10% slip & the 465 boat at 2%.. Not saying the 465 boat wouldnt run that speed ect.. Just that somebody's test numbers probably arn't right.. It can't be the drive ratio #'s being off (meaning the boat actually had a 1.5 instead of the 1.36) because then it would go in the other direction & be completly impossible.. Not sure exactly what a twin 465 boat would run but I don't see why one with a good driver & the right setup it wouldn't run 85 mph.. Wasn't that the the 85 for 85k setup ?? So If I was guessing (which we all are) I would say that who ever was monitering & writting down the rpm's got there #'s off..
There are so many varialbles when it comes to testing two differant boats at two differant times, with probably differant drivers & differant people writting down the info.. I havnt read the articles but will definatly have to check those out !! If I was guessing again I would bet the 630 boat had some left in it & would turn those 27's a little tighter than 5,200..

[LittleDcsRodShop]

I just glanced at the articles & I am definalty gonna have to read through all of them when I get some time b/c thats good stuff !! I didnt realize that white & red boat had big power in it...

Jerry can probably answer this but how close were the 605's in that boat to the 605's that were originally in my boat ?? Both boats had to be built pretty close togather timewise.. Was Mr. Oaks Contender marine ??? Did he build both sets of engines ??

Back to the data #'s entered I did see that according to the article the big power boat was running 85mph spinning the 27's at the same 5k that the smaller powered boat was supposidly spinning the 25's at the same 85 mph.. With out trying to sound like a know it all or ben matlock, I see no way that the 465 boat could run 85mph at 5k with 25's.. Thats just under 2% prop slip so that aint happening & is pretty much impossible.. now if it was turning "say" 5400 thats a totally differant story & most likely the case... It also shows how important accurate #'s are when it comes to accurate info... 400 orso rpm's can make all the differance in the world..

[Mr. Brownstone]

Now that's a bit rough.......

It was meant to be a compliment on his new saber. Hopefully it was taken that way.

[chrisk]

I knew what you meant - thanks

[BGIII]

I thought there was a Hot Boat Magazine test that stated 92MPH for the 605/630 Cyclone?

[hotjava66]

I have been wondering the same thing. I didnt do prop slip numbers, scott's got them alreay . Just doing hp per MPH, and adding in the other test boat with 454 mags at 385HP, I come up with this: twin 385's at 75mph=10.3 HP/MPH, twin 465's at 85MPH=10.9HP/MPH, and i figured the 630's at 90MPH=14HP/MPH. I dont know the exact #'s No Excuses ran but lets call it 730's at 105MPH=14HP/MPH. Interesting anyway, first 2 numbers are close, second 2 numbers are close. Im sure HP/speed isnt constant, should increase with speed due to drag/wind resistance so maybe they are close. I was always told appx 12HP per MPH added speed. checked the slip on the 385 boat, at test #'s is 6% if i figured right. 465 boat 2.3%. 630 boat at 0% slip 97.76MPH so 9% slip at tested speed. Someone correct me or check these I have never done this before, just flexing my math brain, could be all wrong. Totally guessing on NE #'s too, What is normal prop slip, I have no idea? Probably varies a lot right? Using the Hotboat article that BG just posted 14% slip @ 93MPH

[BGIII]

Hot Boat tested (printout attached) the 630 boat at 92.5MPH. When the original Cyclone was for sale several years ago, the owner at the time told me the boat ran 83MPH every time out and 85 that one perfect day. That was with the 465's upgraded to 500HP's (which was shortly after the testing) and with 610 hours on the engines. Considering the boats were built and tested back in the mid-90's with standard three blade props, no nose cones and presumably deep drives because of props and water pickups, I think the top speeds and the difference between the two is probably about right. I'd bet they both could run faster and the difference between the two might be greater with today's drive and prop technologies applied. I'm pretty sure that 92MPH in a 28' boat was considered pretty frikken fast 15 years ago.

[saber28]

if anyone would like to provide a set of 630's, i'll be glad to recreate the trials for you

[LittleDcsRodShop]

So what does the boat have in it now for power ?? How long were the 605's in the boat ? Were they just in there for the test ?

Btw: I Love that shot you posted !! The boat sits NICE !!

[LittleDcsRodShop]

I read through both the articles and they were really good reading.. This thread has got my adrenaline flowing again !!

So which one of you reading this has some custom paint work they need on a bike ??

[BRD]

Hot Boat tested (printout attached) the 630 boat at 92.5MPH. When the original Cyclone was for sale several years ago, the owner at the time told me the boat ran 83MPH every time out and 85 that one perfect day. That was with the 465's upgraded to 500HP's (which was shortly after the testing) and with 610 hours on the engines. Considering the boats were built and tested back in the mid-90's with standard three blade props, no nose cones and presumably deep drives because of props and water pickups, I think the top speeds and the difference between the two is probably about right. I'd bet they both could run faster and the difference between the two might be greater with today's drive and prop technologies applied. I'm pretty sure that 92MPH in a 28' boat was considered pretty frikken fast 15 years ago.

Guys ... there's some awesome video of that one runnin HARD from one of the Pier 33 poker runs back around 96 or 97 ? Maybe Marc can dig it up for us ? That boat ROCKED ! Ran it in Key West once Teague was done with it during the PBM test . . . thats when I decided I needed to move on the "85" boat !

[saber28]

boat has 454mpi's , there was nothing in it when i bought it "new" in 1998. it still has all the heavy duty stuff, hdy. steering, double tie bars, hd gimbals etc. would like to spend the 20k + to put some big power in, but its hard to rob your biz. for the cash.

[LittleDcsRodShop]

Guys ... there's some awesome video of that one runnin HARD from one of the Pier 33 poker runs back around 96 or 97 ? Maybe Marc can dig it up for us ? That boat ROCKED ! Ran it in Key West once Teague was done with it during the PBM test . . . thats when I decided I needed to move on the "85" boat !

I would Love to see that video, along with any other Saber footage he has..

[LittleDcsRodShop]

boat has 454mpi's , there was nothing in it when i bought it "new" in 1998. it still has all the heavy duty stuff, hdy. steering, double tie bars, hd gimbals etc. would like to spend the 20k + to put some big power in, but its hard to rob your biz. for the cash.

Thats interesting.. Its cool that you are the original owner of the boat.. Btw: Welcome to Serious Offshore !!!

[BGIII]

She's a runner.

[LittleDcsRodShop]

Quote from BGIII "I'm pretty sure that 92MPH in a 28' boat was considered pretty frikken fast 15 years ago."

I think thats pretty fast in a conventional bottom 28 even by todays standards !! I'm impressed that the regular bravo's held togather so well, 605is allot of inches !!