Bob , I have an 85 Kevlar flat deck that I added a notch to as well . I also know Gary very knowledgeable and hell of a guy . I run 5 dives currently 2.5 inch below the deck ( they have 3 inch spcers ) props turning out . 605 N/A 725 power and it runs 76/77 on GPS . I have the wrong props as can't get it to rev more than 4300 rpm , but jumps on plane and runs strong . Going to loss 1 inch of spacer and try a different prop I wil be happy to see 80 mph out the old girl . More worried about getting on plane and running trouble free with the fam than ultimate tpop speed . Good lick with your experiments . RG

Rick thanks for the info. Gary ran his 5's typically spinning out with the motors at close to 1100 hp and I am thinking ran close to 100. Then put the 3A's on it and it dropped quite a bit. Gary ran 18 x 30 five blades with 5's and it controlled the proposing fairly well. With the 3A's it is almost impossible to control the porpoise below 55 or so. Right now I have Gary's same motors but freshened up with some 10-71 hi helix and they probably make 1000 a side. Boat runs right up to 87 or 88 fairly quickly. I have never even ran it to see what it will really do. I am thinking if the 5's work I should be close to what Gary had on top end and by spinning in control the nose a little more. Thought I might get lucky and find someone who has been down this road with this hull. Thanks

It would be interesting to get FF’s opinion as he is running a gun with no notch. Along with his buddy Rob. From what I can tell it was only on year or so the they’re gun was produced with no notch. But I do understand it was the same hull as a flat deck. Icdplbbshould also have some good input....
jr

Bob the one thing I have to say is that i do not have an issue with porposing . I run the 5's with no box and in addition my notch is a bit smaller than the one in your hull . I believe Gary run the 5's on boxes on your boat. J-Bonz is right Dan "ICEDDLLPP " ( i think thats how he spells it ) he runs one of the cleans and well put together flat decks I know of . He runs big blower power and 5's on boxes ( no notch ). He would the man to talk to . Cheers RG.

His has a custom notch, it may work better and alot more power, from my researxh under 800 hp and deep drives it does not really matter much, raising X and more power changes it all

The truth on porpoising on the big staright bottoms is it really isnt the boat, its just physics. when the boat is running at a certain rpm and starts to porpoise, it just at that point on a fulcrum where you don't have enough speed to keep it up and the weight is forcing it back down. tabs and drive fool the water and you can just bump up a couple hundred rpm and ride through it.

Rick thanks for the info!

I ran a 39 Sutphen for years with 5's on boxes spinning in. Side by side setup. The balance between the nose lift created by the lifting strakes and transom up lift was nice. Never a porpoising window. Basically rua drives flat to hull. In other words didn't have to use foot of drive to effect nose lift. Faster you went the cleaner the hull rode. Supposedly Richie maintained that somewhere around 105+ the hull would effectively achieve max lift and start loosing efficiency with increased prop slip. I am hoping the Cig has ample strake lift to achieve something similiar? Maybe I am all wet? Thanks for the info!

youre approaching it correctly, but not everything is going to be a "fault" of the boat, as youre pushing forward, the propulsion in the rear will give the boat some lift as well as the strakes. there will always be a point where the bow will want to fall forward where the rpm and speed isnt enough to keep it elevated, yet more than enough to keep it going hence the up and down bob/porpoising. as i said, its simple physics.

Well thought I would circle back with an update. Mounted the V drives spinning in, no boxes. Shaft is 1" above bottom. Gary had put a notch in that is 10.5" x 10.5" at keel. Put some 18" x 26" four blades that BBlades just did and added about.008 extra cup to them. 1:48 gears. Had the boat out once. I figured it was gonna be a handfull getting up. I was pleasantly surprised. Walked the sticks up to around 2600 where it got to about 25 mph, gave it a little more to get her to past the hump. About a 45 sec deal. I was happy with that. Got a bouncy nose deal coming in around 45 with drives all way in and tabs just past flat. Seems to fade away a hair over sixty. Ran it up to a little over 80 a couple times but had the drives tucked in with the tabs flat. Looking to see if I could get some bow steer going on but it seems ok. Now need to see what happens on the big end. Naturally the docking deal is always fun spinning in.