ECU 185hp vs 215hp

[dsolie]

Re: ECU 185hp vs 215hp

pretty much. The water is induced after the j pipe to keep the box cool from the hot gases, as well as silence it a little.

[nazrin]

Re: ECU 185hp vs 215hp

should I pull it? It will not detune the exhaust will it?

[nazrin]

Re: ECU 185hp vs 215hp

checked oil level, on for 30, wait for 30, then checked, it was dead nuts in the middle.

[Technical Support]

Re: ECU 185hp vs 215hp

Your ok there. Maybe the supercharger is slipping a bit?

[nazrin]

Re: ECU 185hp vs 215hp

I was thinking that also, what is the torque spec on the shaft nut to pinch correctly on the slip discs?

[Technical Support]

Re: ECU 185hp vs 215hp

22 ft lbs is the nut, the Supercharger, broken in should be between 44-88 inch pounds for slipping

[nazrin]

Re: ECU 185hp vs 215hp

just pulled the craft out of the water and in the garage, I am trying to ID my prop. Can I get the SS# off if I remove the nozzel or where is this ID?

Anyhow, this is what it looks like: 4 blades and the trailing edges are straight(as seen from rear) not curved. What does that sound like, a prop for a 03 GTX-SC or something better. ie 04 GTX or 05 RXT? I know somebody had the pump replaced with a cast alum. body, but is the prop the same? My theory is the plastic body exploded and maybe damaged the prop so both were replaced, but don't know for sure.

Also the wear ring looks very good, very limited scratches and close, close clearance.

[nazrin]

Re: ECU 185hp vs 215hp

More updates,

OK, I pulled the last waterbox, and YES 1/3 louder at 2800rpm's my neighbor is going to love it (NOT), anyhow the conditions were not the best, I had 4 mph wind and about 4-5" chop and even with these condition, running upwind I was able to hit 70mph in about 3/4 of the pervious run distances, so I'm thinking with no wind and smooth water I may pinch off 71, also I did see 7880 rpm's so about 80-90 rpm's increase vs the two water boxes installed.

So, thinking to myself, I reduced restriction in the exhaust, by way producing more HP/torque. Was able to put a bit more break HP into the drive shaft, which turned the prop faster...

If one goes back and follows each step of my additions and changes, the rpm slowly increase. This all makes me lean towards the fact that I'm out of horses and the rpm's are limited by the prop resistance. MUST be a higher pitch prop on this craft. I have nothing else to really changed to make this a true RXT and get this 8100 rpm.

Once the water smoothes out I'll jump on it and post what I can do with the one water box in better conditions.

[nazrin]

Re: ECU 185hp vs 215hp

Did some more runs, but the water is a bit too choppy to see what it can do top end mph, did do 7890 rpm's this run, but here is something I didn't notice before, after removing the second water box, this craft has more, noticely more low end torque, if you stand way back moving about 2-4 mph and WOT the entire craft comes out of the water and squeaks, like WOW, I found a new trick, I was not able to do that before, if must be a substaintial gain in low end torque on this powerplant.

Here is the real question, am I crazy or removing this waterbox making my jet colum move above the waterline behind the craft? I can wag the jet colum back and forth (it seams to be out of the water) like a fishes tial at about 40mph and have very little rock on the craft, its like a fish wagging its tail behind the ski. Am I loosing propulsion with this condition? Is the ski really that much more light in the rear? Is that what a pump wedge is for?

[dsolie]

Re: ECU 185hp vs 215hp

You can do that to any ski depending on how you ride, VTS position etc. Your hull creates a cavity in the water it's traveling through, so you have a trough behind your ski...

Having a wedge puts the nozzle up 1.5 degrees +/-, so yes, that will give you more of a noticeable "tail". Too much "tail" and you can loose speed, since a portion of your thrust is being lost in the air, not in the water that it's pushing upon.

[Technical Support]

Re: ECU 185hp vs 215hp

Naz, the 185 hp uses a different wear ring, the impeller is smaller than the 215, the 215 wear ring is set for a 158.5 mm impeller. the drive shaft is also different, the 215 uses a larger splined shaft. You are most likely seeing your power difference due to the 185 impeller set up verses the 215 set up. I forgot that you never changed the pump set up over.

[nazrin]

Re: ECU 185hp vs 215hp

So, what is the mm of the 03GTX?

My pump is alum, I would expect it has the 04 GTX pump on it, is that the same size as the 03GTX? Can a RXT pump fit on this craft, or is it too big?

if my craft's pump is smaller than the 215hp, that would increase the resistance on the prop thus limit the RPM's, also increase the jet column speed, pushing this craft faster than what a stock RXT runs. If this is all correct than wouldn't that put undue strain on the reduction nozzle, and or pump housing?

[nazrin]

Re: ECU 185hp vs 215hp

You can do that to any ski depending on how you ride, VTS position etc. Your hull creates a cavity in the water it's traveling through, so you have a trough behind your ski...

Having a wedge puts the nozzle up 1.5 degrees +/-, so yes, that will give you more of a noticeable "tail". Too much "tail" and you can loose speed, since a portion of your thrust is being lost in the air, not in the water that it's pushing upon.

Well, I was never able to do that with my 185hp or this 215hp engine with two waterboxes. I've tried every trick in the book with my GTX-SC, including newly invented "triple axel jump"!!!! Been throne off three/four times mostly with 3-4 beers attempting this stunt.

So yes, my tail up higher is loosing thrust, I would expect that. So would this removal of the box allow this to happen, due to less weight? Studying the tail, I can swear it looks higher in the air than before.

[nazrin]

Re: ECU 185hp vs 215hp

You can do that to any ski depending on how you ride, VTS position etc. Your hull creates a cavity in the water it's traveling through, so you have a trough behind your ski...

Having a wedge puts the nozzle up 1.5 degrees +/-, so yes, that will give you more of a noticeable "tail". Too much "tail" and you can loose speed, since a portion of your thrust is being lost in the air, not in the water that it's pushing upon.

Ok, I hear ya. The light bulb turned on. You are saying no matter how low or how high the back of the craft is the jet column is always above the grove the boat is making.

That would make sense why the pump is above the water line.

That said, seeing these large jet boat with a huge rooster tail behind the craft, that must be done by pointing the jet column towards the water (unlike a jet ski that directs the jet more parallel to the water), why couldn't we angle our pumps just a bit towards the water so this high speed column of water is resisted by its incompressibility and defected upwards to make this awesome rooster tail, and possibly increase propulsion? Why do we not do this?

[Technical Support]

Re: ECU 185hp vs 215hp

The 2 housings except the same out side dia.of the wear ring, the 215 ring is thinner to except the 158.8 mm impeller. The 185 impeller is about 155 mm in dia. you can swap the wear rings and use a RXT impeller but you also need to go with the larger dia RXT drive shaft.