I was just wondering if anyone has added Whipples to their 358. I am looking at doing it this winter and was just wondering what kind of speeds and handling changes to expect. I have th HP 500EFI's right now with XZ drives. Anyone else??

Upgrade the drives is a must. As far as Whipples. Don't know, but you will have to change props and possibly gears to allow for the increased horsepower. A friend of ours (Beakboater on OSO) put Whipples on his 35 Fountain and absolutely loved them. Might want to PM him for input.

I've done a good deal of research into this and I don't think the drives will need to be upgraded as long as you don't hammer it out of the hole. I would like to know about your friends experience with the Whipples on his Fountain. I'll PM him see what he ran into. Thanks

On a 358 hull I would be inclined to concur with 43. You'll spank those drives my friend, just a matter of time. Far different CG, weight distribution and x-dim than a 35 beaker. On that hull it's hard enough to keep them from grenading with 575's much less 650-720hp. Depending upon what kind of speed gain your looking for there are other options for enhancing the performance on that boat. Granted, none will give you the immediate boost of the whipples but if your thinking a drive upgrade isn't required I'd strongly suggest you have a spare drive handy

When you say an upgrade what are we talking about - different drives altogether or additional internal parts?

Well if I were you I'd talk to Charlie Amman with that Agitator Skater boat. That dude blows more drives than anyone else I know He runs big blower motors via the bravo's a lot and knows them well.

Post in the tech section he can give you way more insight on the drive strategies. I just ran a lot of juice with the Sonic's and after you get them over 85mph or so with bigger ponies they have a tendancy to eat up the stock bravo. The bigger and heavier the boat the bigger the appetite

Just don't want you to be disappointed after spending the time and money on the whipples.

Probably the least expensive route is get a spare XZ and get real good at rebuilding them. There are 4x4's and b-max etc, etc not cheap and for the amount of extended service a questionable call for rate of return.

The oil bath in the XZ seems to be the weakest link, I'm not sure if a "fix" has been discovered.

Another consideration for the 358 is blueprinting the hull, that seems to cut the drag, reduce the porpoise and give it a bit more transom lift reducing the stress on the lower case. Especially in the area where the notch was removed. Good luck!

Dano,

When you suggested to Blueprint the hull on a 358 are you saying that because they have a tendency to be that far out WACK or just trying to eliminate any variables. I was thinking of having my 2001 358 checked for straightness. My 358 does need quite a bit of tab to keep the nose down at cruising speed. Also my boat has a notched transom.

Yes, with the notched transom even more so. What year is your boat?

Mine is late '02 - no notch in the transom.

Dano,

2001 358 notched transom with 500 EFI's. Boat seams to run well 5200 RPM's 28 Bravo's I think Labbed. No GPS but speedo hold real steady between 78-80