I have an early 2012 400ss with 525s and Bravo Three XRs. I love the boat but would love to have the power the Ilmor 400 has.

Does anyone know of someone that's done Whipples on a 525 400ss? I assume a drive swap is neccessary. Suggestions? Any guidance would be appreciated.

Thanks,
Jim

Plenty have done Whipple additions to 525's in other boats but as suspected, that won't be your problem....the drives will be. Talk to Arneson about a ASD conversion first. When I discussed my 382 with them they said 10 mph at WOT AND cruise should be expected with the same engines. If you could achieve near that in the 400 then engine mods might not be needed........and if they are later you have the drives to handle it.

In the long run, it might be less aggravation just to have Formula convert the boat to the Imor package. At least that way, everything will still be warrantied, and you'll have some seriously heavy-duty drives...

t500hps, I don't have any experience with surface drives. Do you think they make sense on a 17k lb luxury cruiser/go sorta fast combo?

C-Spray, I like the way you think and Ryan is looking into it but I've got a feeling it's going to be insanely expensive.

Plenty of 50-100 ft motoryachts run them so I'm willing to bet they would do well on your boat. Google them, lots of pics of big boats with that cool rooster tail!!!

JimB - checkout this thread - very cool: Arnesons on a 47' Wellcraft

The boat will handle its best and perform way better than the other alternatives with the Arnesons. Proven reliability and speed on Formula hulls!

And that boat is way larger, way heavier (25K) and has 1100 motors!!

Thanks guys and thanks Rik for the info via email. I think I might take t500's advice and put the drives on first then add the Whipples later if needed.

Jim - Your profile says MN so I asssuem you are on the St.Croix.

Drives may be more of in issue in Ocean waves and conditions. You have pretty calm water vs. those conditions.

If you go easy on acceleration and roll the power on vs. slamming it I think the sterndrives would serve you for several seasons.

I would consider engines first then drives when and if needed.