Need More Speed! (496Ho Content)
 

Hey there,
I'm new to the forum and I have tried to do some hunting around with search on my own to find some answers, but I looking for peoples thoughts as many of you see very knowledgeable.

I don't have what you would traditionally call a "Go-Fast" boat, but I am hopeful that you guys can still help me out. Its a Riviera M470 with twin 496 Mag HO's. This past winter I went ahead and put Dana Marine's Thru-hull exhaust on her and figured I would see how the season went. I didnt see any real gains (just great noise!) so I am currently re-examining the props (still stock). But ultimately, I dont think props can possibly get me where I want to be (I currently top out 45-47 but want to be 55+).
This leaves me with either going for a Raylar kit that boosts me up to 525 or so, or going with a Whipple supercharger. Going with the whipple means I will have to swap my drives for something else (any suggestions?), but its something I would look into.

Thanks for any help guys!
Oh here is a pic of the boat:
http://i47.photobucket.com/albums/f1...IMG_0250_2.jpg
http://i47.photobucket.com/albums/f1...IMG_0239_2.jpg
http://i47.photobucket.com/albums/f1...IMG_0958_2.jpg
this is apparently the best pic of the headers I have :rolleyes:
http://i47.photobucket.com/albums/f1...1/IMG_0963.jpg

My biggest concern with the supercharger is there may not be enough airflow in the engine bay and temps will get too high....

Thanks again

Beautiful Boat !!

At what RPM is your top speed currently?. ie. how fast are the motors spinning?

Having asked that... I will tell you that I am a Whipple fan.

Since having a Whipple motor, I will never go any other route.
Power is fantastic, and Dustin Whipple has got to be the most helpful guy on the planet when it comes to boat motor setup.

1 vote for Whipple

Chris

I would also go with whipple,,and some low boost so u can leave the drives !!! I would not change them ,,just the props ofcorse.
If ugo with a max of maybe 600-620 HP u bee fine ,just take it easy when uget on plane and throttle right if u would fly ,,which probably is not gonna be that much with this NICE excalibur.

:ernaehrung004:

Thanks! Its a great boat, we have a blast with her!

Currently the max rpm seen is 5000 to 5200 or just under. I know thats a bit to high for her and she should be around 49-5000 range which i believe is a sign the props need to go.

The drives I believe are only rated to 450....so 600 is waaay out there for them no? lol

Another concern I have is that I could get new props for this season, but if I am doing Whipple for the new season, wont I just have to do new props again? That kinda wastes the money im throwing at the props for this year...is it worth it?

Don't get new props until after you do your HP upgrades. Your current props will give good baseline numbers, and help estimate what final size/ gear ratio will be best. Are you currently using the 2.0/1 gears?

Carder

Also ,,we call this boat a CONDO not a go fast !!! LOL
Like u said ,,waist of money with the props.
But i have seen regular bravos on 600 HP and the bravo 3 is basicly the same exept the lower and u need that lower to move that big boat.
i would do the HP and then see what it does ,,if u stay easy on the exelaration and don't fy to much ,,,should be fine,,,its the tourqe what kills drives not the HP !!!!!!

it's going to take some serious H/P to get a big boat like that to that speed, I think you are going to be sorry with reliability with your currant engines....big diesels are the way to go in something like that trying to run that fast...my .02....Rob

Haha....thanks.


I thought one of the biggest pro's to the whipple supercharger was that they are hugely reliable, ect? Like OEM ect? I know that going FI isnt going to be easy and that I will have issues, but I wonder unreliable the system will be?

I agree some big power will be needed, so I am looking at alternatives other then replacing the engines. Would you suggest I look at other options then whipple?

I have gotten up to 47 with the boat stock (i.e. No thru hull exhaust), so moving up to 55 shouldn't be terrible I would have thought. 50 is the minimum goal for the boat really...but 55+ would be welcome :-)
That said, I wouldn't think it would too hard to hit these goals?

How much does the boat weigh?

Chris

About 22,000lbs (dry) :o

You should go play around with this site to figure out how much hp you will need to go 55mph.

http://go-fast.com/boat_speed_predictions.htm

I entered in your boat weight at 23000 lbs and your top speed of 47 mph to come up with a constant.

I then plugged in 55 mph and solved for horsepower, and it spit out 1169 hp or about 585 hp per side in order to get to 55 mph.

I have found this site, and speed predictor to be very accurate.

Given your horsepower requirements to go 55, Whipple is the natural selection. They make a kit for your motor to take it to aproximately 620 hp per side which would take your top speed to aproximately 57 mph... or about 10 mph more than you are going now.

I have found the whipple kits to be very complete, and Dustin is the man when it comes to re-programming the stock PCM.

I would not hesitate in the slightest in recommending his products.

He is at the Florida boat show right now, but can be reached via phone most any weekday from 10am - 4 pm at 559-442-1261.

I am not associated with Whipple in any way... he is just that good of a guy in my opinion. He has helped me on innumerable occasions, while working on my own projects.

Chris

Hey Chris,
Thanks very much for the site! I will be sure to play around with it. It sounds like Whipple (at least on paper) is a good fit for what we want to do.
Things are a bit crazy my end, so I'll try to call Dustin next week to touch base with him. I sent Whipple and e-mail the other day but never got a response, I forgot about the boat show haha. I feel less ignored now ;-)

Thanks again!

[QUOTE=DeepBlue47;2799033]Haha....thanks.





What did you mean with HAHA ????

About the drives or the Condo ?! LOL

[QUOTE=daredevil;2799239]Both...lol

I'm pretty sure I'd have to replace the drives because I can't see myself getting out on the water and giving the throttles a little bit of a punch every now and then :)

Don't be afraid to go the Raylar route either. Ray has got his parts down to a sceince on the 496. The 103 kit costs about $6K and with the exhaust you have already upgraded to it will put you right where you want to be at around 560HP. I am sure he will chime in to give you some more information but he to is probably at the boat show.

What RPM's where you turning at wide open throttle with the STOCK exhaust system?----and then did you see any RPM gains with the addition of new aftermarket Dana exhaust???

How about the midrange?---Did you notice any more "kick" (torque)or speed increase in you midrange crusing speeds?

In either case, I am glad to see that you added/upgraded to a better breathing exhaust system on your engines FIRST! Now, your engines are ready for the internal upgrades and possibly more bolt on upgrades!

Personally, I think I would skip the supercharger style of upgrade because your boat is WAY too heavy with those Bravo outdrives that have engines with superchargers. The torque comes in like GANG BUSTERS and you will have drive problems for sure! Unless of coarse you upgrade to a much stronger drive over the Bravo One.

I think Ray from Raylar would be good assistance to you on the engine stuff.

I've got some experience with setting up Whipples on a 400ss Formula. This boat had 500 efi and Bravo 3 X drives. Speed went from upper 50's to mid 60's. We then swapped the B3 for B1 XR drives. We gained a couple of mph with stock props. Then sent the props to Bblades for labbing and ultimately were able to break 70 mph. I can help you with setup and Whipple purchases if you decide to go that way. I've also done several Raylar 496's. I don't think the 525 Raylar kit would meet your goal though. BOth are very dependable. Keep in mind the Whipple requires 91 octane fuel.

Give me a call or email me. Bob 830 6935591 [email protected]

I am currently running 2.0/1 gear ration on the drives and have a prop pitch of 22....i dont know the prop size, but I have a part number if that is any help.

I am pretty sure the props need to be changed, but not sure to what...any thoughts?

How about the drives? I have seen many ppl talk about the 1.5/1 ratio, but I really have no clue regarding props and drive ratios. If you know of somewhere for me to find some info I'd love to read up about it and get a better idea.

Thanks guys :ernaehrung004:

Thanks for the info! You seem to have some great first hand knowledge so I will try to shoot you an e-mail to clear up a few things.

Thanks again :)

Don't forget these...will help keep those suckas cool.
http://www.driveshowers.com/

Big Boats - Special Considerations Required !
 

DeepBlue47

I've got a fair amount of expierence obviously with the 496 engines and Raylar has worked with some customers on large performance boats and cruisers and I might have some good advice and ideas for you if you want to push you BIG-BROAD BEAM- HEAVY BEAUTY a little faster and still have the engines and drives stay in whole condtion over some time!
We've worked with several big boat boaters and shops with Whipple prepped 496's and Raylar HO525-HO600 normally aspirated 496's. There is to much information, thoughts and such to discuss here in detail and how they will ultimatly affect the overall performance of your boat and obviously there are various options for changes and upgrades.
The Whipple supercharger systems are excellent, beautifully engineered and manufactured wonderfully as marine supercharger systems and with the right engine preparation to your engines internals they would produce excellent results if properly set up and dialed in for your boat.

Our Raylar 496 upgrade systems and higher horsepower 496 engines also offer excellent possible upgrade options.

We should however discuss your particular boat, ultimate drive ratios and upgrade options and needs as well as how you will be using and running the boat and what type and quality of fuels you have available in your boating area and what type of budget you're thinking about or have set for this project.

The overall running economy of your boat and boating and what your future possible resale plans may be for the boat, as these will also be affected greatly by your choice of upgrades.

If you would like call me toll free at (866) 496-8181, we can discuss your needs and wishes in greater detail and if Raylar can be of assistance in your investigations and solutions we would be glad to help contribute to a successful outcome for your project.

Best Regards,
Ray @ Raylar

Hi Ray,
Thanks for contacting me!
First, I'd like to apologize for such a long delay in my response. I have a lot going on at the moment and I'm afraid online forum's have dropped off a bit.
Anyway, I would like to get in touch with you to discuss some of our options and how we can ultimately reach our end goal. I would love to pick your brain about a few other things like drives, props, ect.

Whats the best way to contact you? Phone? E-Mail? On here?

Thanks,
:ernaehrung004:

Call me at (866) 496-8181 M-F 9 to 5 Pacific time and we can discuss your situation and I'll try to lend some advise and thoughts that may help in your quest.

Best Regards,
Ray @ Raylar