Future Allison boats

[GPI Racing]

Catfish,

The 2003s I have to deal with on a day by day basis are much like yours. I've tried the 13-14" set back route. It works Ok. I have found that when working toward the transom I got a boat that was better OVERALL. When the loads changed the boat had less of a change. Consistency. The best overall boat had 8" on it. Propshaft was 3/4" below. It went just as fast on topend but didn't have all the compromises everywhere else. The best part was it was easy to drive. Very little trim and it didn't matter what water conditions were. There is only one way to find out but the overall drivablilty was the benefit we gain going closer.

The owner said this. It was like getting radial tires for the first time on a car. That is how the boat felt before and after.

Randy

 

[catfish123]

Randy............Thank you very much for the information........it certainly is interesting.

 

[John Richied]

Catfish. You are certainly running at the upper end of the XB-2003/225 owners running 94-mph solo and 92.6 mph with two in the rig not stripped down.

If you have the manual Allison jackplate that adjusts in three setback increments, its and easy adjustment moving the setback/jackplate in that is well worth the try. You can always move it back if you don’t like the results.

 

[catfish123]

I wish it were that easy........I have a Detwiler hydraulic plate that has an extension piece hooked to it. If anyone in here is running an XB2003 with a 225 Promax with 8 total inches of setback, I would like to hear your input on this with topend numbers, etc.

 

[John Richied]

On the Detwiler hydraulic plate that has an extension piece hooked to it, can you remove the extension and have less setback? If so why not give that a try?

As great as your XB-2003 is running with a little 225 you might not find much on the topend, but better holeshot and handling, with less backwash when ya shut down. If it’s easier to drive, it will be easier to drive faster… ya never know until ya try it.

 

[catfish123]

OK John and Randy.................you both got my interest up enough that I went out to the driveway and did some serious measuring on my setback. It looks like overall it is 13 1/4" and the setback plate is exactly a 6" plate so if I get rid of that I would be 7 1/4" off the transom. Do you actually think I could do this without losing any topend??? For me even this is a major undertaking....LOL..........no way to do this myself but if I get any feedback at all from someone who has done this with good results, I'll find a way!

 

[fishnfireman]

I have seen a time when just loseing that shut down hook would be worth a couple of mph on top.

i was having fits with my old 2003/280............it would shut off at wot just like you pulled the kill switch. it was very intermitent and we chased the problem for months.

Got to where It would make you a little gun shy to run over 70.. just about the time you would think it was fixed..and make a couple of good high speed runs------ Mo&%4 shi*4 HOLD ON ---. stop ---pull shorts from crack.. refire and start over BIGGG pucker factor :!:


turned out to be a bad switch on the shiftter would tell the mtr it was in neutral when in fact it might be turning 7grand

 

[fishnfireman]

catfish,

you can do it with a little help...
put the mtr down with a soft piece of wood under the skag.
use the trailer jack to take wt off the transom.. use a tiedown strap or rope to secure the mtr to any thing up high --Tree limb--- eye bolt in garage ---just something to keep mtr from falling over and
support a little of the wt while you loosen the bolts carefully.
The transom bolts on these boats will not have to be held from the front.

there should be enough slack in all the cables to slip the jack plate out or reset in different holes.

poor folks have poor ways
a fly wheel ring and a car mtr hoist wiork much better.

 

[John Richied]

With your 225 I don’t think 7.25” of setback would be enough on your XB-2003.

Now if you could try 10” of setback… that would be a nice starting point.


I do have a Merc lifting ring and a chain and a tree will work too... LOL My boys bought me a cherry picker for Christmas. :wink:

 

[catfish123]

Fishnfireman.......I think I saw you post in here somewhere that you moved your setback in quite a bit like I'm thinking about and you lost 2-5 mph???? What can you tell me about that? Thanks

 

[chad202]

Randy, should more drag be an issue with the shaft at 3/4" below with only 8" of setback. I'd think the lu will be close to the same drag cause the only reason I can run mine at 1/4" above is because of the 14" setback. If I were to move it closer but leave at the same height is would slip more. But with it lower, it's should be close to the same amount of drag?? This is very interesting and something to look into.

 

[fishnfireman]

Catfish,
yes you did ... I will have to look up my old boat to get the exact measurements. My memory is kinda like some of my parts (foggy)

And I did not do much testing or record keeping I just knew that it made for a better hole shot with the braket off. When I put it back on it would pick up a few on top end.

Also my test are not real scientific I am 1 hr from the nearest water so it might be a total different day and even lake when I get to run again after changes

 

[GotMyAlly]

I'm glad you asked that, Catfish! I'm planning to try less setback on mine soon. It'll be easy for me to do....I have the adjustable plate.

 

[GPI Racing]

Chad,

Here is the part that most miss and why I think everybody is on the kick to run the gearcase above the pad. Your gearcase, even though it is 1/4" above with a straight edge, is not running above the bottom when you're out on the lake. Because your so far back and the boat runs at a 5-8 degree angle of attack, the water rises off the back of the boat and the gearcase is under the water. When you go with a shorter set back you naturally have to run the gearcase deeper. Because the effect of the water off the back of the boat is not as much closer in, your really running at the same place. The drag therefore is no different.

I have hung my head over the back of the boat and witnessed the effect hundreds of times. If you do the geometry it makes sense. Also keep in mind that steering your boat with just the skeg is a job that is next to impossible on most of the heavy (relatively) boats we all have. A light race boat may be able to get by with it. You need X amount of blade in the water to achieve thrust. One blade paddling sideways isn't going to get it done on a 1800-2000lb boat (all gear and people).

So, don't be too concerned with gearcase drag, it is not that big of an issue. If you do your homework and get the case to travel through the water straight (very important), the case has very little drag but excellent lift.

Randy

 

[chad202]

Randy, dats what I was saying but I'm just not as technical as you. :lol: Makes sense to me.

 

[GPI Racing]

I knew you had the idea but to keep confusion to a low level here on the thread I felt the need to elaborate..

Randy

 

[fishnfireman]

Randy,

How can I tell if the LU is tracking straight :?:
especialy with Hyd-steering :?:

 

[GPI Racing]

Hang your head over the back and look. I know sounds bad but it's really not. If it is tracking poorly the water coming off it will be to one side. It only takes a peek.

Randy

 

[msethsmile]

setback

Does this mean I should take my 20" setback and put it on the shelf?
Will the shelf support it?

 

[cj707]

setback and hook

Now that were running less setback, don't we need to sand off some of the hook on the pad? I run an 03/280 with a huge fishing load. And it seems like .090" hook in the pad is too much even for a full load. I want more bow lift and less stern lift. Even running heavy. I used to run a Ranger, and the first time I saw a boat with a hook on the pad...I laughed my a** off. Now I own one. But I guess the PC word is "Lip"

Lars