Re: more 272 mods
 

Thank you very much,if that is true the longer stub yoke that I can get locally in a few days will fit instead of having to wait 120 days plus for the shorter one,thanks again,Smitty

Re: more 272 mods
 

Smitty, the raised extension box will work well on your boat, I reckon. I am so impressed by the 3" raised Imco box on my 25 Outlaw. Propshaft to pad went from 7 1/3" down to 4 1/3", the holeshot is great and the handling is incredible. It feels like a bigger boat and flies and lands smoother and straighte than it ever did before. I recorded 79,6 mph on the recall on my Livorsi GPS at the weekend and I haven´t even tried for top speed yet. I´m still running the 525 but hope to have enough hours on it by the weekend so that I can peg it and trim for speed.
I´m running a merc labbed Bravo 28 and it feels really good on the boat. No cavitational starts, no blow out in the curves. No chinewalking yet, but i´ve been running in choppy condition. we´ll see. The Imco driveshaft system works really well but is only possible on a boat like the 25 because there is enough space the raise the motor up the three inches, The drive is a standard XR.
Good luck with your installation.
Stephen

Re: more 272 mods
 

Dock, I don´t doubt your experience with a 25 with an ext. box, however I can only confirm that the box has made my 25 considerably faster and more capable than it was before and some four to five mph faster than Baja claims a 525 powered 25 would be.
I didn´t even expect this much of a performance gain.

Re: more 272 mods
 

Thanks for the info Stephen. I have heard the same results from Bawana on a box install on a modified 272. Still researching how much driveshaft angle will be safe and debating if I do the mods now and risk missing any prime boating season or wait until fall,only supposed to be a high of 71 here this weekend. I'm not great at waiting,Smitty

Re: more 272 mods
 

Smitty, did you get your top on?

Re: more 272 mods
 

Its still sitting in my living room :D ,business has been pouring in but it looks like another big lull may be starting. The way I do stuff like that is I buy it then it will sit around months until 3 days before I really need it then I'll be furiously working on it :evilb: ,Smitty

Re: more 272 mods
 

Update, decided to plunge into it NOW instead of waiting till fall. Boat is now ripped apart into ten million pieces,motor is swinging in the air,bought 5 1/2 " stainless transom bolts fri for the box,angle finders at graingers,longer water pump hose etc. It is usually crappy boating in june around here anyways,cold etc,of course it 90 plus this weekend. My goal is to have motor and box bolted on boat and aligned properly by tommorrow night and be putting heat treated gears in the lower and gimbal back on next weekend. Bought imco steering ram mounts thru mr gadgets too,showed up yesterday. I'll post a new thread in general tech discussion with before and after results in few weeks plus pictures,Smitty

Re: more 272 mods
 

Done,been running it with box,haven't got a clean wfo run yet but my observations so far-boat now has a slight front to rear porpoise cruising 45-60 it didn't have before unless I dig tabs in one ore 2 numbers higher,boat flys flatter and you can definately feel that C/G has moved back further. As far as anything "strange" when crossing wakes I haven't felt anything yet. Results are inconclusive so far but should be able to get a good gps run this wknd. Boat does feel more stable in 1-2 footers,doesn't have any problem getting on plane but I am running 4 blade prop and I only moved drive up 1 inch so I didn't expect change to be drastic,Smitty

Re: more 272 mods
 

Great! Sounds good, Smitty. Your experience seems similar to mine. However, I haven´t had any porpoising whatsoever, but the occasional brief chinewalk turns up (70 - 75 mph) in smooth conditions. The level "flying" sensation is amazing and can really be exploited. If I read your info right, your propshaft is 6 1/2" below the pad. With the power that you have in there the improved airborn control will be really useful.
I can see you will be raising drive the second inch pretty soon.

Got 81.2 mph @5300 rpm out of my 525 hp at the end of the last poker run (on my way to the slip, alone, 1/4 tank).
Stephen

Re: more 272 mods
 

Ran boat yesterday with full intentions of some real high speed results,cranked it up,hit 89.6 turning my 32 pitch labbed and blower started screeching,impeller ate into housing. I was seeing mid 89's with more weight in the boat and 30 pitch prop,saw 92.8 last fall with the 32 pitch so I have yet to see any gain BUT blower self destructing obviously kept boat from running out to true top end. Looking for another procharger m-3sc now,probably be a few weeks before I see real top end and results,Smitty