How Much Pro Sport Full Throttle Trim?

[David Lanham]

I'm curios as to how much trim other Pro Sports require for full throttle top end running.

Seems like mine requires more and more trim as my boat ages.

In ref to the pro max 20 inch mid: 0 = full tuck and 10 equals full trim just before tilt mode.

Mine ends up near 9 sometimes 9.5 to obtain best top end numbers. It used to be in the 8 range.

So how much do you other PS owners require?

No doubt the HP mid section guys with single ram trim with no trim sending unit have a different reference point.

 

[BigRedAlli]

All depends on which prop I'm running. On my manuel trim gage 8= netural trim, I usely end up around 8.75-9.25. I'm usely running light load- Me and the Wife small cooler and a few fishin poles. Certer steer sitting inline. 260 Bob's 200 case.(took the Sporty back off, it sucked :laughing)

 

[GotMyAlly]

On my smartcraft trim guage, it has a range of 0-10 and I believe mine is neutral trim at about 7.2 - 7.5 if I remember correctly. Usually running by myself I trim it to about 7.6 - 7.8 depending on how heavily loaded I am. With a partner, I usually go to about 8.0. Really heavy partner, extra heavy load, maybe 8.1-8.2.

David....are you going by a smartcraft trim guage? Have you tried re-calibrating the guage?

 

[wj225]

I am with you on the excessive trim. Most any prop that I try requires me to use a lot of trim to get it aired out. I am no where near neutral trim, if I want to get descent top end speed. It does seem to vary some depending on prop. I am running an Allison-cut sportmaster.


Bill

 

[Bob Ant]

I may be wrong but I thought it was 2 degrees positive off of neutral.

Bob Anthony

 

[ALLISONMAN]

what you messure as neutral trim is false because of the effect of lip and the attitude of the boat running will be different and cannot be measured on the trailer or land!! you can just about never get the area in front of the pad level to the water when running unless you are at very extreme speeds with flat attitude of the boat and proper fore/aft balance and the amount of lift in the gearcase/propeller all play part of "actual neutral trim"

 

[GotMyAlly]

What i am calling neutral trim is propshaft level with the pad.

 

[Bob Ant]

That's what I assumed it to be allso.

Bob Anthony

 

[froggy]

I have a Stainless Marine trim gauge on my 280. I have neutral trim marked (where pad and prop shaft are both level). I also used an inclinometer on my lower unit to discover that one full gradiation (from, say, 8 to 9), on my trim indicator, equals 2 degrees of incline.

In stock trim, I had to trim the snot out of my 2003 above 97 mph due to the pad lip wanting to make the nose drop (that's what it's designed to do). I have modded my pad lip, and other stuff too, in order to not have to trim the snot out of the boat above 97mph.

I run neutral trim, with a fishing load, at all speeds. Sometimes I run 1/2 to 1 degree of positive trim if the boat doesn't want to break loose quick enough, but 95% of the time I just trim to neutral and leave it there until it's time for another holeshot.

I don't recommend, what I did, to the faint hearted or to the lower HP folks.

Just my $.02

froggy

 

[CHRIS IND]

Neutral Trim

Neutral trim is usually expressed in terms of the propshaft relative to the water surface, not to the hull. The hull can be at 2 degrees to the water, but if the shaft is parallel it's usually called neutral trim.

DL, your hull may be changing. The resin will continue to cure for years after the boat is originally built. That's why the finish will settle on older boats. Ever go out in the garage and smell that "new" boat kinda smell on a hot summer day? It's 'cause it's still "gassing off"

Chris

 

[catfish123]

On my XB2003 with 13.5" setback and 225X, I run it about half way between the half way mark and the top mark where it goes into tilt mode. This is on the in-dash trim guage that came on my boat. It differs slightly from prop to prop but I haven't noticed any change in the optimum trim height over 8 years of having this boat.