I Surrender! Time to Re-rig
 

Four years ago I undertook a project that would give us the ideal boat for our needs. My list was long: rough water capable with power, family watersports, carry a lot of passengers with lots of cockpit room. To satisfy the roomy cockpit requirement I selected the Pulsedrive - which required mounting the engines low in the bilge. The engines sit under the rear couch.

I endured fraudulently new engines ($$$), a botched rigging job ($$$) and a host of gremlins. This boating season has been our best so far, thanks to the efforts of Eddie Young.

I have come to the conclusion that the Pulsedrive is just not right for the Envision hull. The hull's inner strakes run all the way back to the transom, giving the boat a ton of stern lift at higher speeds. At speeds over 70 mph it's a handful. At speeds over 80 mph it's scary.

There are a few things I am going to miss: awesome docking manners, on plane at 14 mph, amazing wake for watersports, efficient crusing at 50 mph, and no drive breakage due to flying. The Pulsedrive would work very well in a vee hull needing stern lift.

Off into the sunset she goes.......

Do you spin the props in or out?
Does the bottom have a rocker in it?
What prop are you running?

I would look into shortening the stakes, B/P bottm and some prop work. Alot less money than re-rigging. Your package sounds pretty good. Alittle more work and you may be there.

What drives are you moving to?

I've tried both. Spinning in helps the bow at mid range, but the advantage is gone at speeds over 60 mph.

No rocker in the hull - I wish there was some

Merc 5 blade cleavers w/ rounded tips by Bblades

I've spent too much money on fixing the next thing that might help. Outdrives will allow me to trim the props and leverage the bow.

See my post in the technical section. I'm seeking opinions. :cool:

I would thing you are pushign the hull beyond what it is intended to do, not that most of us on here don't do the same. You have to be one of the few if not the only 80+ Envision out there. I think you should try some hull work too before scrapping the setup you have now, that rooster tail is just to cool to give up on.

I'm definitely pushing the hull design, however, there is someone at LOTO running a single 29 with insame power well over 100 mph using an extension box and beefy drive. The 29 hull is very similar to the 32.

Working the hull may fix my top end problems, and it may not. It may also kill my low speed performance which I need. My hull and bilge configuration prevents me from getting even close to neutral trim angle. Even if I reduce stern lift by trimming the strakes I'll still have the big diameter 5 blade props pushing up on the stern.

With outdrives I should be able to keep low speed functionality and have a better chance of curing my high speed ailments by leveraging the bow with positive trim. She's seen 85 mph with plenty of stick left and the bow pushing down. I'd like to she what she can safely achieve.

If someone has a miracle cure please let me know! :D

I have a 30' twin BBC 24 degree vee that eventually became perfectly stable at 100+MPH. In my experience, speed and stability came only after we got the length of the inter strakes right. The good news for your boat is that your strakes are too long: it is much easier (less $) to shorten vs lengthen.
A good place to start is to make the inter strakes somewhere around 12" behind the CG; this should be close. My CG was at 91". Maybe shorten them in three increments if you want to be conservative.
As to props, in my case the 5-blade props (Herring) added about 2 MPH in top speed but it was scarry loose at WOT. After testing turning them in and out at 105-107 MPH they never went back on the boat. Having the transom planted at high speed in a 30' something boat is important...based on the size of my balls.
My ideal prop shaft height ended up between .75 - 1.5" below the bottom on boxes. The speed was identical at both X's. I spent $25-50K the figure this out...probably a lot more but this is all I will admit to :D

I know one with a single 1250 in it, I hear it runs about a buck.

Frequency,
By the way, I don't know anything about an Envision hull. If it has a ventilated bottom, my straight vee experience likely does not apply.
Ben

The envision is a straight hull.

Isnt there some prop work that can cure your problems...or have you been there done that?

Our typical outing on the water involves two to three couples and their kids. It will be this way for the next 3-5 years. I could have easily put the same amount of cash I've spent into a mid 90's cafe or gun with good power and solid drives. It's just not the right time for me. So I'll make this thing work the best I can. I will miss the Pulsedrive for sure. The swim platform at the waterline. Running and docking in two foot of water (not two foot on the depth finder - two foot from the surface). A sweet rooster tail that you could just sit and stare at. But a 70 mph boat with a cool rooster tail is still a 70 mph boat. Can I run 90mph? Probably...but I won't like what Sir Issac does to me if I have a failure at that speed.

Yes, I've been there. The props are about 3 1/2 ft back from the transom. The best trim angle I can get and still be efficient is around 5 degrees negative. They will always push up. Round ears, cup and rake angle just can't overcome that fulcrum on the transom.

Over a buck ten according to our friends in Kaiser. ;)

Greg, I wish you the best.....lord knows you deserve a break! I wish I had some input that would work. From my own experience with my setup.....which is also in unchartered territory.....everyone else's ideas get very expensive! I know you know that all to well also. The prop change to the merc props was huge from the pulse props when I rode in it. I did not know that BBlades changed them to round ears.....what did that do? It floats great at midnight out of gas!! Eddie ran it out of gas on purpose so he could make a pass at me. Anyway, at least you can come up this winter and hang out at my shop and tell lies while Eddie is doing the perversion. We can knock back some diet Sun Drop.

I wish I could have seen you running on the water at Clinton as opposed to sitting on the trailer. I love the rooster tail!!

Ya, me too. I keep reminding myself of all the little things the rerig will fix. Better exhaust routing, clean up wiring and hoses, etc. Moving the engines back a foot will really help the boats CG too. In this hull, the benefits outweigh the advantages of the Pulsedrive. In a different hull, I'd keep it.

Just break out a few more thousand (BOAT) and hang some 6's off the back and you will still have the roost!!!!

Forgive my ignorance, but what is a pulsedrive? It sounds nasty!

"BOAT" Bring over another TEN Thousand.:D