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View Full Version : HOW FAST (Honestly)



rjlupo
04-08-2004, 08:30 PM
I have been reading many of the posts on this site and am curious as to the recording method used for some of these speed claims? I do not dispute that there are many fast boats out there, however I find it difficult to believe someone who claims thier classic runs mid 70's with stock 454/502 magnum power. As an owner of both a radar gun and a 22 classic (454mag,stainless marine exhaust, hp420 cam,etc.), my boat when stock ran avg. 63-64 mph, after mods 407 Hp at prop, avg. 68-69 mph. I have seen similar numbers turned by other stock/modified 22's. I am not trying to ruffle any feathers here just want to get some honest feedback!

Greg Maier
04-08-2004, 08:45 PM
Most in the speedboat community are referring to GPS Speeds when they mention the top speed of their boat. I think that most speeds advertised on here are accurate. The BS flag gets raised pretty quickly among this crowd when someone is advertising a speed that doesn't sound right. I have a 22 Classic with a 502/Blackhawk and she will run 78 mph any day of the week and a little over 80 when the conditions are right.

RickR
04-08-2004, 08:56 PM
>50 ;)

Tomahawk
04-08-2004, 09:10 PM
Welcome aboard RJLUPO. Most of us use hand held GPS units to measure speed. I can understand your question based on your experience with your own boat. Just realize that there are many more factors that will affect performance besides horsepower. Horsepower alone won't give you outstanding performance if most of the other factors are neglected. Yes, I believe that a 22 Classic with 502 Mag power can run 73 to 75 but not all do. A good running 454 would be a couple clicks slower. Blackhawks are a different deal!
Try to join us at AOTH IV, meet some of the guys and ask some questions. It's a great time.

gcarter
04-08-2004, 09:22 PM
My Minx will go as fast as my Explorer will pull it! :biggrin:

George :checkered

RedDog
04-08-2004, 09:45 PM
I have a 502 MAG 22C - GPS and radar will never lie

See attached... lost my goggles on this one :shocking:

mattyboy
04-08-2004, 09:50 PM
I don't have GPS , so I use a timing light ;) :tongue:


Matty

rjlupo
04-08-2004, 09:52 PM
Thanks to everyone who responded so quickly. I just wanted to give the specs. on the boat.

Boat: 1995 22 classic
Engine: 1995 454mag built to merc. racing hp420 specs.
Exhaust: stainless marine wet- silent choice
Drive: Bravo 1 GR 1.5
Prop: Mirage 23p and Mirage 25p shaved to ?
Performance: 407hp at 5180rpm

I can spin the 23 to +/- 5200rpm, 25 to 4950-5000, these #'s are only as accurate as the stock tach. Also all tests done in New Jersey on salt water during spring/summer air temp 70s-90s, water 70-77.

Rootsy
04-08-2004, 10:25 PM
and i reckon if i didn't have GPS, witnesses and a digital camera no one would ever believe me :rolleyes:

JR - non vortec equipped ;)

Tomahawk
04-09-2004, 06:30 AM
RJ - thanks for confirming props, gear ratio, rpm. I was thinking more about your question last night and was going to guess that you are running a Mirage or Mirage Plus prop. Your boat probably came with the standard Mirage 23" prop because that's what mine came with ('96 22 Classic w/454 Mag). Your prop specs and rpm sound about right but your speed does seem to off a bit from what some others are getting. Seems like your are getting a little more prop slip than need be. Since your boat is a '95, has your 23 Mirage been dinged up and repaired? And why has your 25 Mirage been "shaved"? Has that suffered some damage? If that is the case, your props may not be as efficient as they could be. A good Mirage Plus (as opposed to the old Mirage) 23 should run better than that and if you can turn a good clean Mirage Plus 25 at 4900, you should break into the 70s. As I said yesterday, this is assuming there are not some other things affecting your speed. (bent, dirty, heavy, straight, tab position, proper trim, etc., etc.)
Try going to www.boatpropellers.com and click on "Prop Calculator" Mess around with the factors there and you will see that prop slip has a significant affect on the results. IMO 10% is too high. With my slightly worked prop, I'm getting about 7% slip (not a Mirage prop).

Pismo
04-09-2004, 07:01 AM
1996 Classic 22, perfect bottom, waxed, no damage
45 hours on engine so very fresh
Mobil One oil
Fresh Water
1996 502 MPI Magnum totally stock - 415hp
Stock Bravo 1 Drive 1.5 ratio
Mirage Plus 25"
1/2 tank fuel
One 160lb person, no extra weight
Perfect fall conditions
55 degree air
50 degree water
Light wind so 4-5" even chop
Clear sunny dry day
250' elevation

Three individual runs on GPS (reset GPS each time)
74.3mph
74.4mph
74.5mph
on the rev limiter of 5050rpm, bouncing off slightly.

Fully trimmed, to the trim limit, seems to be the fastest.

No tabs

Clearly will not run this fast in the heat and humidity of the summer.

Cheers
SL

harbormaster
04-09-2004, 07:55 AM
rjlupo,

You will also find that the stock Fuel injected boats will run a bit faster than the stock carb boats.

Pismo
04-09-2004, 08:23 AM
I agree with gcarter, the fastest my 22 has ever gone is on the trailer!

What is AOTH anyhow?????


Cheers
SL

boldts
04-09-2004, 08:34 AM
rjlupo,

1998 22 Classic
454MAG Carb
Bravo1 - 1.36:1 GR
Fresh water

When I bought the boat, came with a Mirage 23" and ran 65.8 on GPS at 4600 RPMs

With a little help from some GA members, changed the prop to a 22" Turbo 1 and added a Hydromotive Nose Cone to the Bravo1. Boat now runs 69.8 GPS at 4900 RPMs. Actually, this was done in 2 steps, first the prop (68.7 GPS) then the following year, the nose cone to get another MPH. One thing about the nose cone, I believe the additional 1 MPH came from the added trim I can now run with-out the prop breaking loose of it's hold in the water. (Less slip) Remember, this is a stock 454 with a 1.36 gear behind it so the guys running the 1.5 gear should easily be in the low 70s.

I'm not going to dispute the EFI vs Carb statement, but I've been told the opposite, that the carb engined boats are faster.

Hope to have the opportunity to meet you at AOTH on Lake Cumberland in KY May 20th thru 23rd. Precission Propellers (Turbo) will be at the gathering with technical advice and props for those who wish to try their props on the boat. Last year, they even changed the prop for us. No wrench turning by the owner. Good luck in your quest for speed. :biggrin:

Last Tango
04-09-2004, 09:47 AM
AOTH = Awakening of the Horses
Lake Cumberland, Kentucky. A Spring dust off for Donzi Owners.
Major event, large turn out, lots of fun. Go to the Events and Gatherings section and you will find several lengthy and current threads for this years' event. Still time to make your plans. Also under the clubs section, click on the MidWest Donzi Club and you will see plenty there. "Bolts" puts on an awesome weekend. Try it. You'll like it.
Just click on the blue hyperlink on Scott's response just above mine.

Barry Phillips
04-09-2004, 10:16 AM
Just about any stock Bravo equipped 22 classic in good condition with a 454 mag-502 mag-496 mag-496 mag HO are going to run within 5 to 7 mph of each other depending on temp. water condictions, humitity etc. etc. They all should run between 68 and 75 mph with no BS factor. I had a bone stock 18 running a 250 hp - 350, equipped with a Bravo 1, turning a 23" SS Vengeance wheel. This boat ran a solid 65 mph confirmed and I have seen as high as 66.5 in ideal conditions, non confirmed. The boat was sold to a guy in Boston and is used on a lake in Maine. The new owner told the dealer he can't run faster than 62 mph with it and wants to get more power out of the motor. Although I completly aggree with the more power part, since the boat has a B1 drive, I feel he should learn how to use the power he has first. I guess my point is the driver has a lot do with how fast a boat runs.

Pismo
04-09-2004, 01:54 PM
Boldts,

Did your nose cone addition effect the steering at all? I have heard the steering gets trickier/touchier because you have drive in front of the of the hinge axis of the drive. Do you have external hydraulic steering?

Did you install it yourself? How tough?

Thanks very much,
SL

boldts
04-09-2004, 04:31 PM
Pismo,

I did not install the nose cone as I was afraid of not getting it on straight. I let a pro do the work. I do not have external hydraulic steering as of yet, but my Classic does have internal hydraulic steering so I did not notice any querkiness in the steering before or after the install. If anything, I found my boat to be even more solid both in turns and a staight line.

Another interesting thing I found after the cone install was that a prop I considered to be nothing but a boat anchor, (my 23" Mirage) is now a very good spare prop. My Classic used to porpose terribly with this Mirage on the boat. I no longer experience any porposing at any speed when running the prop. It's just still not as fast as my Turbo 1, so it remains a spare prop.

In my research of nose cones, I found that in the pleasure boating area, the pointed nose cones like you find on race rigs is not recommended because that point when trimmed out tends to pull the transom down, scrubing off speed. (Doesn't really make sense to me since I'm sure racers are using the trim on their boats) For that reason, I choose the Hydromotive wedge type nose cone. It's sole purpose is to deliver cleaner water to the prop and make the prop more efficient. I don't know, I gained 1 MPH with it and didn't do a thing to the engine. I believe I had about $150 in it installed? Have to find that invoice again to tell you for sure.

McGary911
04-09-2004, 06:03 PM
My 22' Criterion has an injected 502, which i figure makes around 450 hp. i run a 23 mirage plus through a TRS drive, which is not the most efficient drive around, but it sure is strong. I've seen 74.3 on the GPS so far, with a light fuel load and 2 people in the boat. I plan to play with a few props this season and see where that gets me.

RJLUPO, welcome to the board. Where in jersey are you from? I'm in belmar, and tend to run in the atlantic and barnegat bay......who knows, maybe ive seen you on the water?

Sam
04-09-2004, 07:51 PM
AOTH = "Awaking Of The Horses". This is an event that takes place every year in May. As far as I can tell it has always been held at Lk Cumberland Ky. In a nutshell 40 to 50 Donzi nuts trailer their boats to Lk Cumberland have have a ball for 3-4 days. When their not screaming down the lake you might find them changing props or having a cold one. There are planed runs to various sites on the lake that might take us as far as 50 or so miles and then stop for a nice lunch. And then there is always a trip to the falls for a HUGE Donzi raft up. Trust me if you want too meet a great bunch of guys and gals that love boating this is a must event. You can also check it out on the Midwest Donzi Club web site.

Sam


;)

goatee
04-09-2004, 09:10 PM
witness to root....
go to AOTH!!!!

Air 22
04-09-2004, 09:53 PM
22 Classsic Stock 1995 454MAG w/ Stainless Marine Manifolds/Exhaust & Keith Eickert Flame Arrestor, 1/2 Tank Gas, wife(123lbs, 2-kids 100lbs total and me 190lbs) and all that good stuff up front ...6 vests, 2 anchors etc.... :lookaroun 65degrees, water temp 58deg, 10knot wind, 6-12inch chop, 1998 Mirage Plus 23, stock Trimmaster Tabs.
GPS = 68.8 and 68.4 repectively @5000rpm. Hopefully 70.0 on my own w/ 1/4 to an 1/8 tank of gas...A Turbo 25 will also help... :biggrin:
NOW GPS = 0.0 :splat: hope to change that soon when she's back from the doctor.... :biggrin:

Pismo
04-10-2004, 08:48 AM
Air22,

Did your Stainless Marine manifolds give you much? How do you like them, easy to install?
Thinking of putting a pair on my 502 Magnum 22 Classic.

Thanks very much,
SL

Air 22
04-10-2004, 09:57 AM
Pismo...

I love my Stainless Marine Exhaust/Manifolds. They are worth every penny. Lowest $$ i could find was through CP Performance...They claim 3.2-6.0 mph are possible and send info stating so. The engine does breath better and the weight savings are tremendous. VERY EASY to install :yes: you need a couple of hours, 9/16 wrench and possibly 5/8th, a screw driver. The hard part is removing the "OLD" stuff. A rusty bolt or two is possible so be prepared :rolleyes: . Have someone help lift out the old manifols/risers...they are very heavy :eek!: The new Stainless Marine comes w/ all the gaskets, directions and RTV sealant . Go to the Stainlees web site and get directions on how to measure for your risers. I had custom extensions made so you want exact numbers for installation...ie line up exhaust w/ existing tips etc.. :yes:
http://www.stainlessmarine.com/bigblock.html
http://www.stainlessmarine.com/hitorquetailpipelayout.html
Over all it was an easy job...be carfull when removing/installing the manifolds...sparkplugs like to snap when bumped by accident..... :rolleyes:

YOU WILL LIKE THE RESULTS..... :biggrin: If you need more info...I'd be happy to help... :yes:

rayjay
04-11-2004, 03:37 PM
Pismo...

I love my Stainless Marine Exhaust/Manifolds. They are worth every penny....YOU WILL LIKE THE RESULTS..... If you need more info...I'd be happy to help... :

Pismo, Which Stainless Marine manifolds did you put on? The Hi-Torque II or III?

rayjay

Formula Jr
04-12-2004, 04:54 AM
Just about every speed boat I've ever piloted had a "sweet spot." And its usually a very narrow window when the conditons are just perfect. For instance, you would gain 3 mph on a following small chop (cause the chop is going at least three miles an hour, airs out the boat and your wind resistence is 8 to 10 mph less at that point) instead of flat water. Boats run better in salt, and better still at sea level. Some donzi designs don't have a sweet spot and you can't make them sing and dance no matter how you try: The 22 classic isn't of this ilk by the way.
Also, some of us sand the wetted surfaces of the hull with 170-200 grit to free the boat of water tension.
Correct drive trim is really important to maximum numbers. I rode with a guy once with a Magnum Marine that he said never broke 55 and he thought the boat was over rated. He never trimmed it out and just ran her flat cause he thought boats should run flat. Finding that sweet spot was a revelation to him once we got the drive trim figured out (boats are three dimentional) and we were running in the 60's. But that introduced the whole aspect of jumping, running roll, landing roll and just trusting the boat, knowing that the boat, will correct.

Engines (and Drives) are not all the same, even if they are stock. Like every thing in life they follow a bell curve with how everything works together gear and friction wise. There are upper and lower ranges. Some engines, fuel systems and drives are pure gold right out the door. Some start out on the lower side of the curve.

You will get you five mph very soon by asking here.

Pismo
04-12-2004, 06:50 AM
The Hi-Torque II with Silent Choice, have not done it yet, still thinking. Hearing Lots of opinions, some say top end gain, some say no top end gain but midrange gain. Either way I don't think it will be earth shattering change. The weight loss will be nice. The $1600 won't.

fasttrucker
04-12-2004, 09:39 AM
Carb VRS Fuel Inj....A carb is better if you use a high performance intake manifold.Iam using a single plane victor jr.When I built my 500hp+..I wanted to keep my computer+fuel inj.But my meck. said I whould be missing all the free hp that my holly double pumper+Victor Jr. make.

TBroccoli
05-20-2004, 01:12 PM
rjlupo,

1998 22 Classic
454MAG Carb
Bravo1 - 1.36:1 GR
Fresh water

When I bought the boat, came with a Mirage 23" and ran 65.8 on GPS at 4600 RPMs

With a little help from some GA members, changed the prop to a 22" Turbo 1 and added a Hydromotive Nose Cone to the Bravo1. Boat now runs 69.8 GPS at 4900 RPMs. Actually, this was done in 2 steps, first the prop (68.7 GPS) then the following year, the nose cone to get another MPH. One thing about the nose cone, I believe the additional 1 MPH came from the added trim I can now run with-out the prop breaking loose of it's hold in the water. (Less slip) Remember, this is a stock 454 with a 1.36 gear behind it so the guys running the 1.5 gear should easily be in the low 70s.

I'm not going to dispute the EFI vs Carb statement, but I've been told the opposite, that the carb engined boats are faster.

Hope to have the opportunity to meet you at AOTH on Lake Cumberland in KY May 20th thru 23rd. Precission Propellers (Turbo) will be at the gathering with technical advice and props for those who wish to try their props on the boat. Last year, they even changed the prop for us. No wrench turning by the owner. Good luck in your quest for speed. :biggrin:

Hey Boldts,

Which way is your gear ratio?? I always figured a 1.36 gear turns the prop faster than a 1.5 gear. Meaning more speed out of a 1.36 than a 1.5, considering all other things being equal.

Tom

DickB
05-20-2004, 08:06 PM
Found this: http://gpsinformation.net/main/gpsspeed.htm

Says GPS is probably accurate to .5 mph although makers may claim .1 mph.

JimG205
05-20-2004, 08:44 PM
george I have you beat-'86 Minx,350 cu in SBC,alpha one-Rolls 2160,03 Ford Expedition XLT-75 GPS on I-95???Why all the Fuss????? :beer:

Fish boy
05-20-2004, 09:57 PM
Heck, my boat is slow enough that I could probably lie and add 15 mph and no one would raise an eyebrow. Just glad I am faster than Budmann... except when he is towing me in ;)

rayjay
05-21-2004, 07:25 AM
rjlupo,...I'm not going to dispute the EFI vs Carb statement, but I've been told the opposite, that the carb engined boats are faster....:biggrin:

An engine doesn't see, or even care, if you have EFI or a Carb. All it sees is how much mixture (air plus fuel) gets into the combustion chamber, gets burnt (and when), and then exits the combustion chamber. If two engines are exactly the same and dynoed under the same conditions except one uses EFI and the other uses carb(s) but both see the same mixture (amount and air/fuel ratio) in the combustion chamber at the rpm's for peak torque and hp they will make the same peak torque and hp. A properly set up EFI has (or should have) the advantage of being able to better control the mixture at varying rpm's and under different conditions (temp, humidity, etc.). With this statement I am discounting cost, wet vs dry flow, and whether or not there is a properly set-up EFI (or Carb) system available for your engine.

rayjay

Donzi Blackhawk
05-21-2004, 01:21 PM
My old Blackhawk was almost fast.

Fish boy
05-21-2004, 01:30 PM
My old Blackhawk was almost fast.

Almost???? You have a gift for understatement ;)

BigGrizzly
05-23-2004, 08:04 PM
RaJAY IS correct. The problem is the person making thoes changed on the carb. The injectors and ECU mapped correctly almost works on boats. With out O2 sensors they arn't any better tham a carb. If you don't beleive me then come to an event I'll take you for a ride in my old carbureted blower motor as we idle out to open water, then role the throttle on. Most people think it is injected.