Eagle 45 SG vs Eagle 45 SGX questions.

[dwb2620]

I have an 45 Eagle SGX hull that replaced an Eagle 45 SG hull that broke in half in a crash several years ago. I am running the SG sponsons with the SGX hull. Even though the boat runs really well, it wants to walk the sponsons very very bad halfway down the straights, which can carry into the turns unless I blip the throttle to set the turn fin in the turn.

As currently setup, the front of the hull is angled down and both sponsons were also angled down in the front. Recently, In trying to follow setup instructions, the top of the hull and the top of the sponsons are supposed to be fairly close to flat level. The only way I can get to that point was to lower the rear boom block by 3/16ths of an inch which raised the front of the tub and got both sponson tops close to being flat and then put another 3/16th wood shims under the rear of the sponsons to get the top of the tub flat.

So, I have a couple of questions regarding what are the differences between the two hulls.

1) Are there ride height differences between the SG and the SGX sponsons? In looking at pictures I found on Andy Brown's CMDRacing.com website it looks like the SGX sponson have ride pads. Where as my SG sponson do not have those ride pads.

2) What thickness are those ride pads on the 45 SGX?

3) Were the SGX sponsons taller?

I am going to try and take pictures for y'all to see my setup issue. The other differences I see is that the SGX hull has a center ride pad and narrow ride pads on the rear sponsons which raises the rear of the SGX hull on my setup table.

Any ideas or help would be appreciated.

 

[Greg Wannamaker]

SG or SGX, the set up is pretty much the same, set the boat on a flat, level surface, resting on only the ride surfaces, adjust the boom tubes such that the top of the hull is level and the sponson tops are level, now measure the bottom of the tub to the table both back at the back of the boat and at the rear boom tube, the front measurement should be maybe 1/16 higher than the rear measurement, in this way you will have the appropriate aerodynamic tub lift. From what your saying about having to angle the tub and sponsons, something is wonky in these basic measurements and your generating too much tub lift. As for SG vs SGX sponsons, that’s not such a big deal and there are so many versions of them, I would suggest you focus on the base line set up measurements first, once their correct, your boat should only require minor tweaks as it should fly neutral now. There might not be space for ride pads, I’ve run many Eagles both with and without ride pads, the theory with them is that once up on plane very little of the boat comes in regular contact with the water and therefore is faster, many of my fastest Eagles do not have ride pads. Don’t get hung up on that, trim it neutral and open it up, tweak the small bugs out and you should be off to the races.

I have found all my Eagles to trim pretty much the same every time. Hope this helps to remove the mystery.

 

[Greg Wannamaker]

Just thought of one more thing, you might find that the sponson you have might be too tall and your having to overcompensate for that, you might fix that by adding ride pads at the back or you might need to do some surgery on the front sponsons to achieve your baseline measurements, hopefully not but sometimes you need to when your retro fitting parts.

 

[ace]

Are you adjusting the turn fin after setting the ride height an sponson angle,did the turn fin bend when you crashed it ,check that

 

[Andy Brown]

The best fix is to mill down the rear boom block and also the front block if needed until the tub and sponsons are level.

If you want to add the pads, they are 3/32" thick. Width is not critical. 1.0" to 1.25". Then just mill down the blocks until everything goes to level.

The original SGX 45 was actually about .100" high at the transom compared to a point measured at the rear boom.

The SG sponsons have more AoA than the SGX sponsons, so leveled sponson tops will probably be way too loose.

As Brett Ward mentioned, the turn fin could be, and probably is the main problem. The back of it may be too high.

 

[dwb2620]

Thanks Andy, Greg and Brett for your responses. I lowered the rear boom block which helped a lot. But to get the tub and sponsons completely level, I am going to have to lower the front boom block. Right now it is close to where it needs to be. So, I am going to run it tomorrow to see how it handles on the water.

Also, I do know that I need to check the turn fin angle and alignment. I'll be checking the turn fin setup today.

Thanks again for the suggestions,

David Buck