94 Square Nose Handling for Racing

Allistah

Slacker
Location
Bay Area, CA
Hey all --

I have a 1994 Square Nose SuperJet. I love it. I have some questions for all those that race this boat.

About myself:
Height: 5' 10"
Weight: 230 lbs

Ski info:
Pro-Tec Ride Plate
Jet Dynamics Intake Grate
Rear sponsons
Solar "I" impeller
Blueprinted Jet Pump
Everything else on the body and steering is stock

Engine runs incredible and has all sorts of power that I'm completely fine with. Here is the problem I'm trying to overcome. I get extremely tired after about 1 lap on this boat. Outside of just working out more, which I am doing to help from that angle, I want to know what else I can do to help this thing turn better. I feel like I'm putting all of my effort into getting this thing to turn without sliding out. Since I'm a heavier guy, racing with a full tank of gas seems to help it handle better and keep the nose down. A lot of the times I will use my shin to push down the sides of the tray to force the boat to dig in deeper on the inside edges.

Some people have suggested tubbies, some highly suggest new straight 0* handlbars that are wider (I have broad shoulders), one guy said that he put a bunch of lead under his gas tank and shimmed the intake grate and that made a big difference. Someone suggested a really long Worx ride plate. Not sure how much longer it is versus the Protec but I'll look into it. Another person suggested hull extensions as well.

It seems like there are quite a few SuperJet racers here so I thought I would throw it out there and see what you guys thought about it. I'm racing with people that weight 130-150 pounds so I need to change the configuration of my boat so that I can rail as hard as they do for much longer periods of time.

I know this won't ever be an SXR, but I'm pretty sure I can make some changes that will push it in that direction.

Thanks for any info anyone may have for me!
 
Blowsion Tubbie Destroyers for sure.....They make a black and white difference in handling...
Worx Dominator Ride plate works very well also. but definatly the tubbies first.... Do you have a Pole Spring?
 

Allistah

Slacker
Location
Bay Area, CA
Oh yes, I have a pole spring and theres pretty much zero weight to it. I had an old one on there from years ago that wore out and I didn't realize it so I swapped it out with a new one and now it weighs pretty much nothing.

Can you tell me more about how the Destroyers change the handling other than it makes it better? For instance, the SJ rides very flat. This is why I have to push the back corners down in the turns so I don't slide out. Can you describe the change in the way it handles with the tubbies?
 
I have the same problem on my roundnose. The simplest thing to do to limit sliding might be to try another steering ratio. If its too quick the boat will want to slide out more easily.

A long plate will help.

Also you might want to consider a different prop. I run a hooker 9/15 and that alone keeps the nose down a lot more than I initially expected it would. Although I am a light 150lb rider...

Another idea I would like to try based on my experience riding a gp bullet triple is to add maybe 10-12lbs lead around the midshaft area to keep the pump down.
 
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Tubbies are a must, add some grooves to your rideplate similar to a riva groovey and cut two triangle holes twords the rear of the plate on the angled part of the plate not the bottom, you can tryout adding shims on the rear bolts which helps push down the front, good in rough water but gets squirrelly on glass, 10-15lbs of lead weight under the front of motor I've herd helps a ton keeping that front end planted like a sxr or I just always have a completely full tank of fuel
 

Allistah

Slacker
Location
Bay Area, CA
Thanks for all the suggestions guy.. I really appreciate it.

Has anyone tried those hull extensions from Blowsion? When you look at the Destroyer tubbies on their site they say you should use the hull extensions with the Destroyers.
 
Jacobs had 12lbs under the gas tank I'd try that first. You don't want too much downforce.

Like tubbies its individual preference.

Sj racers I know don't use them on their main boat. IMO on a sj you are aiming to holeshot and use its quicker accel to pull you out of turns to compensate for having to slow down a bit more in turns.
 
I almost sold my superjet and bought an SXR untill I found and installed tubbie destroyers... I was very sick of skating through every corner wondering when it was going to catch and when it was going to slide..... If you look at the old hull design of the square nose or pre 08 superjet... you'll notice the hull is basically the same width from the front to the back... works great for going straight, but not worth a crap for turning...

Installing tubbies creates a parabolic shape. This is a must for turning agressively. The reason I recommended the longer ride plate. is to keep the ski flat, having the correct area of the hull and tubbies in the water, while turning under power..

Tubbies improve handling by adding bow bouyancy and create a parabolic shape that gives the ski something to lean on while turning. Works excellent in rougher conditions!!

The only downside to tubbies is when riding on glass calm water. They tend to want to pick a side while riding slow or when decellerating.. 30 Minutes of riding and you'll be used to that.. The plus's far outweight the minus's!!
 

Allistah

Slacker
Location
Bay Area, CA
Jacobs had 12lbs under the gas tank I'd try that first. You don't want too much downforce.

Do you happen to know if he ran with a full tank of gas with that weight under the tank? I'm also guessing that he doesn't weigh very much.. I'm not certain but I would guess he's not 230 lbs like myself.

I've made a list of items to do and I'll start doing them one at a time to see how things improve the handling. Next on the list is the wider zero degree bars.
 

Allistah

Slacker
Location
Bay Area, CA
I don't know for sure but it probably was a full stock tank.

He also used the shredmaster plate and a shimmed intake.

I heard someone else mention shimming the intake grate.. Do you just shim the front/leading side of it or both sides front and back? Any recommendations on how much to shim it?
 
I like 3's with ODI grips, plenty wide, as far as shims for your ride plate, just add some washers to the rear bolts between plate and hull, just one will make a noticeable change
 
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