4588 real world speeds-gctid819267

[1thefox1]

Was looking at the review of the 4550 in 87 with twin 220hp (which I have) and was wondering what other people are getting. I'm talking of course with full gear and water and fuel. I get around 8mph at 1,500rpm, 12-13mph 2,500 rpm and 16-17 wot.

[Woodsong]

That sounds around what I get on my 1987 4550.

Per my GPS speed and original tach gauges (which may be +/- as far as accuracy):

1,750-1,800 RPM I get around 9 knots (10.5 MPH).

2,400 rpm I get about 11.8 knots (about 13.5 MPH)

2,900 rpm I get about 14.5 knots (16.5-17 MPH)

I usually have full or nearly full water tanks and 1/2 full fuel +/-. All speeds are faster than my previous trawler was at WOT.

[Destiny_4588]

Same general area as both of you are sharing....really these boats are very consistent unless you have a prop or engine issue

[Omega]

When I had my 87' 4550, it took me a long time to "dial in" the boat. But after I added longer trim tabs for lift, moved my dinghy so the motor faced forward to distribute the load further forward and a moved a few other things around, I was able to cruise in the 12-14 knot range and topped out about 17-19 knots depending on current, She seemed to run all day long at whatever speed I wanted. I took a picture one time coming home for the fun of it,,,

BJ

OMEGA

5788


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[1thefox1]

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"igiftmon" post=819411 wrote:
When I had my 87' 4550, it took me a long time to "dial in" the boat. But after I added longer trim tabs for lift, moved my dinghy so the motor faced forward to distribute the load further forward and a moved a few other things around, I was able to cruise in the 12-14 knot range and topped out about 17-19 knots depending on current, She seemed to run all day long at whatever speed I wanted. I took a picture one time coming home for the fun of it,,,

BJ

OMEGA

5788

Interesting, do you remember the models of the trim tabs you used? Your speed is pretty consistent with the magazine article.

[Omega]

I had Bennett trim tabs that I modified by adding 11 inches to the depth of, as I remember. It basically acted like a hull extension, but had significant less weight and was more adjustable. The only thing is if you do mod your tabs, be careful to pull the tabs up during docking if they're extended so you don't tear them from the ram if you reversed too fast... i never had an issue, but always kept that in the back of my mind, just in case.

I hope this helps,

~BJ

[Mikalkc]

We just did a three week Everett to Broughtons & return trip The GPS trip odometer says 695 nm. I ran between 1450-1550 for 80 % of the time with occasional higher or lower just to keep a relatively stable speed. Left with full tanks now shows a couple needle widths above 1/4 on each side. We hit quite a few marinas so while there was some generator use it could have been more. My gauges are fairly accurate based on previous fills so I would say I have 130-135 gal left onboard. Our speeds ran usually 8 kts (gps) with excursions from 5 to 11 depending on currents. I figured on about1.8 nmpg. I can never quite make the "advertised" speeds or mileage since I am sure I have a bit of "weed" on the bottom and our load balance isn't perfect, engines have 2450 hrs and injectors are "ok" but not new by any means. (I had Earl test them earlier this summer) I do try to work the trim tabs a bit to help keep the boat level without adding drag if I can. I would be interested in hearing more owners have to say.

[smitty477]

"1thefox1" post=819267 wrote:
Was looking at the review of the 4550 in 87 with twin 220hp (which I have) and was wondering what other people are getting. I'm talking of course with full gear and water and fuel. I get around 8mph at 1,500rpm, 12-13mph 2,500 rpm and 16-17 wot.

We owned a 1986 45 for about 6 seasons and a 1988 for 1-1/2 seasons both with 220 Hino's.

We cruised both at either 6 knots for economy or at 14-16 knots for speed but hardly any time in between. At the time we owned the 1986 there were 3 other 45's that we often saw and or cruised along with in this area of the NE - two are still owned by their original owners today (at least as of March of 2017).

All of us cruised at 14-15 knots when in a group but they all had differing WOT speeds not that the fact is overly important.

The slowest WOT speed was about 18 knots and the fastest was just a hair over 20 knots - he is a live aboard as well.

Our boat could get over 19 knots but never hit 19.5 in neutral waters/currents. We ran 22 X 21 props with 2:1 MG502 trans and had tuned props so we could always reach rated rpm +3-5% fully loaded. Many of the trips we made had a single leg of just about 100 nmiles and that was typically achieved by leaving around 6Am and arriving around 1:30 PM dock to dock - allowing for the 5 mph zones we typically averaged 15 knots or so for these legs.

The 47 we owned later on best cruised at the same 6 knots or so for economy and at 15-18 knots for speed with a WOT speed at about 22 knots.

[Papa_Charlie]

Our 4588 with the twin 250hp Hino's get right at about 1.9MPG running about 1450 rpms which produces about 8.5kts. When we took it out for sea trials we got 16kts max but as live a boards with everything on board, max speed is limited to about 12-14kts.

[1thefox1]

"igiftmon" post=819458 wrote:
I had Bennett trim tabs that I modified by adding 11 inches to the depth of, as I remember. It basically acted like a hull extension, but had significant less weight and was more adjustable. The only thing is if you do mod your tabs, be careful to pull the tabs up during docking if they're extended so you don't tear them from the ram if you reversed too fast... i never had an issue, but always kept that in the back of my mind, just in case.

I hope this helps,

~BJ

Something just crossed my mind, with the added length, it must add extra pressure to the ram?

[Omega]

I thought that exact thing and kept my eye on them at first. But after doing some basic calculations, the hydraulics seemed to have enough strength for the upgraded tab size. The biggest thing I figured out was there is a possibility to tear the tab from hydraulic when/if reversing too quickly, if they were in the down position. The added length can act like a sea bucket when down and put a lot of force on the tab/ram hinge. As such, I made it s piont to raise my tabs when docking. I never had any issue with the tabs pulling from the hydraulics or any failure of a ram. The change in the tab size helped a lot in the performance of the boat. I can't say the tabs by themselves was the save-all, but the upgrade along with the repositioning of my dinghy and other heavy items to redistribute boats loading seemed to improve things..

In hope this helps,

~BJ