Sportmaster modifications?

[200valeroyt]

I'm curious as to what modifications can be done to a stock SM and what kind of gains can be expected in top end speed? If any? Are the xr6 cases worth the effort of beefing up? So far, I can't complain with the current handling, just wondering if there's significant speed to be had with modifications? Thanks

[Sonik]

The most popular mod I'm aware of is profiling the skeg to match a 200 case and removing material from the port side rear of the torque tab so it looks more like an add on. Net result is a swapt tamer as opposed to the factory wedged shape. I've also seen a few where guys fill in starboard side water intake port (as viewed from the rear). Rumor has it, it reduces the disturbed water on the prop entry side of the case.....don't know if there is any science to back it up or not. So me guys blunt the cases and/or flatten the area from the tip of the bullet to the root of the skeg along the water pickup area (supposed to allow the boat to get up and ride on the case better). Titus is a good guy to get ahold of for info on sporty mods. I'm sure others will chime in and give other sources for mod info.

As for the XR6 case, if its built well to withstand surfacing, it's good for 2-5mph all day long on the right boat.

Now, one thing I happen to like about the sporty IS the size and beefiness of the skeg. While it might be a touch slower than a profiled skeg or coned 200 or torquemaster, I like the idea of having as much skeg in the water as possible. Guys like us run propshaft heights above the bottom so what is left in the water?? I'm just leary about messing with a good thing.....call me old fashioned if ya like. :D

[Capt.Insane-o]

I'm curious as to what modifications can be done to a stock SM and what kind of gains can be expected in top end speed? If any? Are the xr6 cases worth the effort of beefing up? So far, I can't complain with the current handling, just wondering if there's significant speed to be had with modifications? Thanks

There is, but I'd rather have some skeg than have to get out and walk...again.

[aaronmt73]

Blunt/round the nose to the size of a marble, it allows cleaner water to get to the prop.Modify the skeg to match the 200 skeg.On a heavy boat I wouldnt touch the skeg however itll be good on yours.No one thing will add a 3 or 4 mph, however combined they may get ya where ya want to be.Take your time and goes slow you cant put it back.

[200valeroyt]

Thanks guys. I wish there was some way of knowing exactly how straight the case was running at wot. I'd think you could then modify skeg / tab to each boat setup? Guess that's part of testing though. What is the main purpose of the reduced skeg with the "allison mod"? More speed?

[Sonik]

Thanks guys. I wish there was some way of knowing exactly how straight the case was running at wot........

There is....if you're running cable, its as simple as finding your center and marking the steering wheel with a piece of tape @ the 12 o'clock position. If youre running a front ram hydraulic, find your center, tape mark your clamp @ center and do the same with the steering cylinder.....point a go-pro or equivalent at it and go for a ride.

[200valeroyt]

True. I'd suppose that would be as accurate as possible.

[1BadAction]

Is 2mph worth weakening your case and killing it's value?

An XR6 case with a cone will run a good bit faster with the same prop if your engine has the balls to turn it, and on a V bottom the handling is amazing. Problem is, they are weak no matter what you do with them. Cut down large case guts will buy some time but the casting will eventually fatigue and crack.

[200valeroyt]

That sounds about right.