32 Dominator - lifting strakes removed
 

I have a 1996 Dominator that I'm working through some minor issues on. Not seeing the speeds I think I should be given what appears to be a healthy pair of 502 Mag MPIs.
The bottom of the boat was modified by some prior owner, the aft 2-3 feet of the lifting strakes were removed. Apparently this boat had some big [blower?] motors in it at some point, as evidenced by through-transom water pickups that are now blocked off.

Presumably someone removed these strakes to settle the stern at higher speeds with big power, but I wonder if their absence is hurting me now with mild black power?

To get into specifics, I'm seeing a max of 72mph with Hydromotive Q-IV 26P @ 4800 rpm, and a max of 68mph with Bravo 1 24P @ 4900 rpm.

The boat always feels stuck to the water, which is fine and stable at cruise, but I'm used to a lighter feel from conventional v-bottom boats I've had before. Is it just the pad that is giving me this sensation, or could it be the absence of strakes?

I also have a pair of Mirage Plus 25P on the way for testing.

Thanks for any input!

Boat is definitely slower than it should be with 502's and the pad isn't what is making it feel stuck to the water. For reference of speed a buddy had a 2000 Dominator with 454 MAGs turning labbed 28" Bravo 1's at 5,000 RPM+ at 75 MPH. At that speed the stern was not planted and would move around a bit on the pad.

Good thing is a good guy/shop can make and attach new sections of strakes. Back in the early 2000's I was at the factory up in Algonac and the first time I met Wayne Schaldenbrand he was under a 32 race boat adding on extra sections of strakes. I'd contact the factory or find another Dominator to get the exact length of what the boat came with and go back to square one.

Thanks for that info. Kinda what I suspected.

I believe the strakes originally ran all the way back to the transom, but I'll call the factory and confirm.

I agree. I used to have a ‘94 with twin 7.4L/330’s and all out on a good day would touch between 69 and 70mph. That was with standard 25”pitch props on Bravo 1’s closer to 4700RPM (been a decade so don’t hold me to gospel on RPM’s)…does seem with healthy 502’s there’s some speed being left on the table.

I hate people that think they’re friggin marine engineers and go F up a fine design. The pad boats had their upsides and downsides…but that’s any hull. Hope you get it resolved.

Do you know what your hull/boat weighs?

Mine specifically, no. Estimated 6500 based on published stats.

not sure which drives you have or what gear ratio that you're using, but seems that you should be getting more top mph than you're seeing. you should be able to see 5000 rpm with your 2x502MPI's. if boat seems 'stuck' to water, wondering if hull is water-set, maybe you can check weight? Strakes would be helping if more aftward, but don't think absence would make the big difference that you're seeing?

Drives are 1.5 ratio, confirmed.

I will check weight next time it's on the trailer. It lives on my lift so I'll wait til winter to do that. But yes, I wondered if there is some hidden weight somewhere.

The missing strakes are aft -- a prior owner removed the aft 3' or so from the transom forward.

Bravo drives? Might check weight, maybe boat has soaked up some water over years

Yes, Bravos.

Thanks for the input, it's appreciated.

I just got off the phone with Wayne at Sunsation. He does not believe that the removal of the aft portion of the strakes is the cause of the poor performance.

He said that removing the strakes would make the boat squirrelly, especially over 80 or so, but he does not think that's where my missing speed is at.

I'm gonna spend some more seat time playing with trim a bit to see if I can get a few hundred RPM more but I'm starting to worry that there's a lack of HP for as-yet undetermined reasons.

agree that strakes is not likely culprit. lack of hp or boat is overweight (water retention?) should be checked.

Yep. Going to recheck compression and also do a leakdown on both motors.

You seem to be down quite a bit of available top speed, so i'd check both 1) engine (300 RPM won't get you there) and also 2) check hull weight to specification OR check hull for waterlogging.

Right, will do, next time it's on the trailer. Not in a rush as long as it's still running really well other than at top end, so it will stay on the lift till summer is over. Thanks!

From the information I’ve gathered, a lot of guys remove the strakes on the single dominators to free up the hull because the cg is so much different….ie the bow seems planted. The strakes from the factory at least on mine have some 1/8” hook built in to aid in planing and keeping the stern heavy transom out of the water. I have not heard of any gains from removing them on a twin but have considered removing the hook from them. I would be afraid of how squirrelly it would be with them completely removed at higher speeds. My pad does not really have any hook to it where you would be running once it’s moving. Post some pics of your boat!

PS Definitely do a leak down that can tell a lot as much of a pain as it can be in that tight compartment lol

I did a leakdown, found one cylinder on each engine questionable. 46% on Stbd and 18% on Port. Thread about it in the Q&A section here. Compression numbers in there as well.


https://cimg7.ibsrv.net/gimg/www.off...5f751d95fc.jpg

You have Jimboat offering advise, I would be listening!

Yep, next time it's on the trailer it will get weighed. For now I'll enjoy the rest of the season unless something breaks.