259 Convincor w/ 600hp
 

We have a 2000 259 Convincor w/ a 454 MAG EFI. Great boat, looking to add more power. Anyone running this boat with 600 plus hp? Can you run 600hp in this hull in front of a stock bravo 1?

Re: 259 Convincor w/ 600hp
 

i had a 97 253 with 570 hp. drive lasted 3 seasons. I upgraded to a teague drive and ran it for another 2 years with no problems. boat ran 80 GPS with a 27 Hydro.

Re: 259 Convincor w/ 600hp
 

I am in the process of doing about the same modifications to my '99 259. It had a 454 magnum mpi originally. I just built, dynoed and installed a 540 N/A Carb. motor. It dynoed at 679 h.p. @ 5800 and 661 torque@ 4900. I added a Teague Upper "XR" and Imco lower "XR". I have not yet run the combination, but I have been crunching some #'s. If I can spin a 26" P5X Hydromotive to 5800 rpm, I should get about 87 mph. I ran these #'s with Throttle-Up propellers, they seem to agree. I guess I will find ut in the spring for sure.

Re: 259 Convincor w/ 600hp
 

Vinny,
I hate to rain on your parade, but I think 87mph might be optimistic. I needed 750+HP to see 87mph. If your hull is more efficient maybe, but as I recall you don't have a step.
But, Good Luck.

I might be trying a -2" shorty Bmax with the merc maximus prop to get closer t o 110mph. Ether way we both need to get dialed in. The NYC poker will be here before you know it.

Re: 259 Convincor w/ 600hp
 

Dave,
I thought that was a little high also. These are the #'s that Throttle-Up gave me. If I have the power to spin a 26" P-5X to 5800, it will go 87 mph. The question is... Do I have enough power to do that? I guess we will see come spring.

Re: 259 Convincor w/ 600hp
 

Checkmate454MAG,
Your project sounds great. Just a few questions. Why did you decide to build a 540 carb motor and not rebuild and supercharge your 454 MAG? What will you do with your 454 MAG? Do you have hydraulic steering? How much money does a project like this cost? You stated that you ran 67mph GPS spinning a lab finished 26 Bravo 1. Our best top speed GPS (259 2000 Covincor 454 MAG MPI) is 65mph spinning a Mirage Plus 23. Can you tell me some ride characteristics of the 26 Bravo 1? Do you benefit or suffer hole shot, mid range acceleration? This forum is great.
RJBBC

Re: 259 Convincor w/ 600hp
 

RJBBC,
I was thinking of supercharging my 454 magnum, but decided it was not cost effective enough. I was going to go with a Whipple. But, by the time you add up the cost of the Whipple and the cost of rebuilding the motor to accept a Whipple correctly, it gets real expensive. Then would come my biggest fear. That is, having ECU troubles. Most of us, myself included, don't have the capabilty of mapping out our own fuel curves. Technology wise, for the average boat owner, we are just not there yet. Now I know that Whipple is supposed to be pretty good out of the box, but for me it is just easier with a carb.
The best part is, I still have a complete 454 Magnum sitting in the corner of my garage as a back up.
Yes, I do have full dual ram hydraulic steering and Dana Marine HP-1000 Tabs.
The picture is from this past season, before I changed motors or the drive.

So far to date, this project has cost me $23k, that is including the cost of a Teague Upper, Imco lower "XR" drive, that I picked up used. With the exception of the actual machine work, that number is with me doing ALL the work myself. That number includes the entire fuel system and all other misc. items.
With the Labbed 26" Bravo prop, I noticed a little more time to get on plane, slight mid-range power loss, but more top end. I never hammer it on a hole shot anyway, so I didn't care at all. With this prop, the boat rides high. I believe that a Bravo prop will lift the stern more than your Mirage Plus will.

Re: 259 Convincor w/ 600hp
 

RJJBC . We are running a 99 259 with a Whipple and until now no other mods to the engine. The 454 mag efi has performed very well so far. 280 hours, At 180 the stock outdrive broke a gear. Numbers are 77 on gps at 5100. We have seen a little more light, with a 28 bravo 4 blade. This winter we are putting a set of headers and roller rockers with new heavier springs. Reprogramming of the ECU is done by Whipple. Come spring we hope to see 80 with these mods and 5400 rpm (reset limiter) Hope this helps.

Re: 259 Convincor w/ 600hp
 

I had a '98 253 with a procharged 502. No drive problems for 250 hrs. Easy out of the hole, not too fast on excelleration, and watch your re-entry. She did 78 mph on gps. Would get a little squirly sometimes and you have to pay close attention to waves in the distance, they come up real fast at that speed and pulling back the throttle does not slow down very fast at that speed.

Re: 259 Convincor w/ 600hp
 

lesterloy,
Thank you for the insight. How many hours did you have on the engine when you added the Whipple. Did install the Whipple yourself or did someone else install it for you? I am also curious if any adjustments had to be made with your hydralic engine hatch arm since ours rubs against the stock intake as it is. Did you add hydralic steering? How much did the upgrade cost? Sounds like the Whipple upgrade has proven to be fast and reliable, good stuff.
RJBBC

Re: 259 Convincor w/ 600hp
 

Which 502 were you running and what kind of outdrive and did you have any steering on it

Re: 259 Convincor w/ 600hp
 

Bravo 1 drive, factory power steering. The 502 was a new long block from www.1800runsnew.com 435 hp.

Re: 259 Convincor w/ 600hp
 

I have a different setup but with a 28 Convincor W/ 454 mags and Bravo 1's, I installed Whipples and I think they are great. I'm running 28p Hydro's and get a little too much stern lift. I installed the Whipples myself and except for a few custom brackets that I made, it was very easy. I have carbs engines and boost referencing was a trick but once I understood how it worked it was a piece of cake.

Re: 259 Convincor w/ 600hp
 

RJJBC Regarding your questions about our Whipple, Priemere at Gun lake Mi installed it at about 10 hours. Hatch clearence was a problem in front of hatch, sawzall time. We dont feel we need hydraulic steering yet. This is the old style unit Whipple says they have a better one out now, clearence,programming are supposed to be better. The only drawback i have found is it is rich at idle and start up causing soot on transom and can foul plugs. We are happy with it, hope this helps .

Re: 259 Convincor w/ 600hp
 

Did you have hyd steering on it and what prop were you running Im thinking I will go the same so I dont have to change outdrives I have a 97 242 convincer Im running a 7.4 with pro charger 5lbs of boost Im hoping to get 80 on gps

Re: 259 Convincor w/ 600hp
 

I had this boat in 1997 with twin 200 mercs stock it ran 75 mph but I thought it was going to break in 1/2 but i loved the way it responded and handled at that time most boats couldn;t break 60 mph hard to believe how far we;ve come

Re: 259 Convincor w/ 600hp
 

mboger, tell us more about your setup, im particularly interested. mines a 98, have you been running the procharger yet or sounds like it was just installed?? i just pulled the 7.4 to drop in a 502!! just wanted more "real life experience here!!" what prop are you running?
kevin :drink:

Re: 259 Convincor w/ 600hp
 

Hey RJBBC, I read in Powerboat magazine a Q and A similar to what you looking into. I'm not sure whitch issue it was, but a dude with a 24 Outlaw and 454Mag MPI was woundering about the same things as yourself. If I remember right Bob Teague encouraged a total outdrive replacement rather than upgrading your bravo,pumping up the heads, exhaust headers, hyd. steering, prop change,and probably some more stuff that I can't remember. If you put 600+ ponys in that boat I hope you put a cool name on it. Because thata what I'll be looking at when you blow by me! :eek:

Re: 259 Convincor w/ 600hp
 

I got the procharger together for last july fourth weekend and havent had a problem with it the main thing is to keep the oil changed about every twenty hous of so I picked up about 12 mph running a 26 bravo four blade Im going to try a lab 28 this spring a friend has I was hitting the rev limiter in the fall when it got cooler I just made a deal on a 540 I think that I will put in over next winter with the pro charger Im hoping to the 100 mph mark with it

Re: 259 Convincor w/ 600hp
 

cool, so you went from the 7.4 to 7.4 with procharger, imguessing from 58mph to 70mph? sounds great to me!!! did you do hydraulic steering yet? hows it handle at 70, fun to drive?

Re: 259 Convincor w/ 600hp
 

No hyd steering and handles but thats about as much as much I would go with out it got 73 out of it last fall very cool day and pushing it hard

Re: 259 Convincor w/ 600hp
 

Kevin where are you from anyway

Re: 259 Convincor w/ 600hp
 

Rockford Illinois, im just now setting up a 502, have considered a procharger but i gonna go NA for a while!! Im always doing the guessing game on what speed i should be runnin. what kinda HP was yours gettin (estimated? or dyno?) im hoping on hitting that 70-72 range or better!!
if i estimate what youve got i would say mathematically youd be around 460-470 hp, right?

Re: 259 Convincor w/ 600hp
 

Im around 440 hp where do you boat at around rockford I use to live in Il myself north of chicago I have done a little partying around rockford a couple times had a friend that lived there do you ever go to lake cumberland
We are thinking about doing the poker run in chicago this summer

Re: 259 Convincor w/ 600hp
 

been houseboating two times on cumberland, beautiful place!! keep me posted on the poker run, never done that yet!! we'll see how the boats runnin. so did you say you bought a 540 or what?

Re: 259 Convincor w/ 600hp
 

Im working out a deal to put an addition on a friends house in cumberland this year for the engines it is brand new and with all on it what he says it should produce about 650 hp havent seen all the reciepts yet and he is the mechanic for me on everything

Re: 259 Convincor w/ 600hp
 

Scott,
I read the same article. Bob Teague made some great points. It is one thing to build a 600HP motor but there are some other things to consider when increasing the performance on your water craft; drive, hydraulic steering, k-planes, he even mentions sport style life jackets. I'll agree with every upgrade, life jackets maybe a stretch but they"re cheap. Sounds like maybe you had similar thoughts w/ your old 24 Outlaw. I would to like to see a reliable, safe 75mph, however dumping 30K into your boat and decreasing the boat's value may be somewhat foolish.
Rob

Re: 259 Convincor w/ 600hp
 

Rob
I have a great idea why dont you find a used block and build it up, then just swap your motors when your ready. That way if you sell it you can put the mag back in it. The other thing Scott C. and myself were thinking was why not just buy a 500 EFI and put it in then you could sell your motor and your boat is worth more money :D :D I would think that would get you at least very close to 75 MPH. Your outdrive could hold up to it, and you could always add sterring later if you feel you need it. Just my thoughts. :evilb:

Re: 259 Convincor w/ 600hp
 

Sounds like a good idea.

Re: 259 Convincor w/ 600hp
 

checkmate454mag,
Why did you add full hydraulic steering and Dana Marine HP-1000 Tabs while running a stock 454 MAG? Was this just a stepping stone expense in your quest to build your mountain motor? Did you notice much difference in the handling of your boat with these upgrades while running stock power?
RJBBC

Re: 259 Convincor w/ 600hp
 

Rjbbc,
That is exactly right. It was just a stepping stone. It helped to ease the expense of doing it all at once. I noticed a big difference in the handling with the tabs and steering. Those stock insta-trim tabs were not good enough to run the ocean and still keep the bow down. But, I guess they were never designed to do that. They worked fine if you had an uneven load, but that was about it.
With the full hydraulic steering I noticed a much more positive feel to the wheel. It has absolutely no play left to right anymore. In my opinion, it is a must have even with you are running 60 mph. It is just safer.

Re: 259 Convincor w/ 600hp
 

Vinny-
When you planning to launch that thing? getting pretty close....

Re: 259 Convincor w/ 600hp
 

Dave,
My seasonal storage starts May 1.. I will be ready to go.

Re: 259 Convincor w/ 600hp
 

I plan to hit the water April 1. The new bmax shorty and a maximus prop. Testing must be done early. Good luck!!!

Re: 259 Convincor w/ 600hp
 

April 1. That is going to be cold, especially up there where you are. Better get some heat in that thing.

Re: 259 Convincor w/ 600hp
 

Anyone out there try to beef up their 454 Mag without adding forced air induction? How much hp can you gain with high performance aluminum heads, an aggressive cam and headers? Thinking about changing the fuel injection to a carb. Any ideas or suggestions?
RJBBC

Re: 259 Convincor w/ 600hp
 

Adding 100-150HP N/A is possible, but it will cost ya.

Re: 259 Convincor w/ 600hp
 

i think im going out tomorrow!!!, not in my checkmate, no motor in yet, but my buddies stingray is ready to go, gonna be 70 or so :D

Re: 259 Convincor w/ 600hp
 

lesterloy,
I think we are going to Whipple our 454MAGEFI as well. What prop were you running with the 77mph and 5100rpm? How many hours did it take to install? The mechanic who will install the Whipple mentioned he does not have the machine to reprogram ECUs. Do you need to reprogram the ECU or does Whipple give you a new computer with their kit? What did the unit cost? Any mods. to the engine compartment to create space for the supercharger?

Re: 259 Convincor w/ 600hp
 

Hi all, newby here. I read all these posts about the big HP to go fast in a CKmate. I have a 502 in my 1990 251. It porpos' like crazy at low speeds, the faster I go the less it does it. The wife hates to go fast but ya know, she has to go. Could this be the prop or the bottom? I cant afford the big engines and drives, so I need to stick with what I got.

Thanks for the reply's. If any.

Neal