Thread: New Seadoo RXT Project
05-20-2007, 08:06 PM #1
New Seadoo RXT Project
Im a new member from the middle east, I just bought a Seadoo RXT.
2 degree wedge kit
Solas 14/17 prop Note: Rpm with OEM Prop 7780
Rpm with solas prop 7620
Speed 65 mph on GPS which seams to be low
I want to reach the 70s what next any clues
Im thinking SC impeller "Green Charger"
Riva front airfilter.
05-21-2007, 01:19 AM #2
At the very least, I would buy the R&D 4" SC adapter for $40 and then 7' of Kanaflex hose, part# 620WD from www.morelandholse.com. Run the hose to the front of the engine compartment and tie down so it doesn't flop around. You can also remove the stock ducting in front of the seat area that goes down to the bottom of the boat if you are not concerned about tipping the boat over. While you are at it, rip out the rear ducting hose too. This should get you more air flowing into the boat and make better use of the 4" intake.
This should be your next step and is a cheap and easy mod. You want to get that prop spinning closer to 8100Rpm. The 4" intake will be a good step in the right direction.
Fill the ride plat holes with marine epoxy. Jerry has a how-to on this site. You can also purchase a set of Jerry's skegs which you can attach to the ride plate. (you can purchase through the online store) This will help with handling and is good for 1mph.
If you go for the Green SC Wheel, then seriously consider getting the metal SC washers at the same time. Have someone that knows what they are doing do the install of the new SC wheel with the metal washers. This will prevent the notorious ceramic washers from falling apart and taking out your engine. It will also prevent premature slipping of the SC wheel and you wondering why the boat is off 700Rpm or more for no apparent reason. This can happen at any time.
Next step would be the external SC Inter Cooler...which Jerry just so happens to have on sale through the end of the month.
You will of course need a new prop to take advantage of the increased power of your mods at this point to keep your RPMs below the red line and maximize your new power for the desired accelleration and speed.
Then at this point you will become bored and desire more power and speed. Jerry of course knows this and thus has plenty of more go fast parts for sale in his online store.
Isn't this fun!
05-21-2007, 08:11 AM #3
If you add the intake and supercharger wheel that would be good. The external intercooler will help get you past 70. Remember to add the 42# fuel injectors when you have a bigger SC and an external IC. In my list of mods i'm currently running i have the 14/17 prop and i'm still at the target rpm of 8100 with a little 8150. I haven't tried a different prop after i added the external IC on mine.
Here is a thread to check out. It also has a thread link within it you should check out. Both are about what mods on a RXT
Last edited by HoopsRXT; 05-21-2007 at 08:23 AM. Reason: added info
05-21-2007, 10:40 AM #4
Just raced an Ultra 250 today while doing another testing session
Same mods I did nothing
With a full fuel tank
65.5 mph 7680 rpm
I raced the Kawasaki 4 times ,rolling we stayed together
From a dead start I beat him by about 1 Jetski length and he stayed on my tail. (I think I have better acceleration top speed is very close)
This Kawasaki had an exhaust and an air filter.
By the way the speed figures I give you might be low but you have take into account that our waters are very hot and so is our weather.
05-21-2007, 01:43 PM #5
With a Riva Stage II and no wedge (Solas 14-19 prop) at 1,200' elevation and 95 degree heat, I was turning 8100Rpm. I am sure I was doing just over 70mph at that point.
Hoops, with that 14-17 prop, I would think you would be banging all over that rev limiter? With the external IC, Vortech SC, Riva intake, etc. you are basically at a stage II RXT or am I missing something here?
05-21-2007, 08:58 PM #6
Not to hi jack this tread, but xenonx i don't think i'm not on the limiter. I'm not running a wedge either-more wet surface area. I am going to try my 13/19R tomorrow and see what it does.
05-23-2007, 09:54 AM #7
"4 inch Air filter
I fitted a custom made 4 inch Air filter with a 4 inch flex hose and a 3 inch to 4 inch teflon adapter on the SC.
I removed the duct at the front and placed the filter right on the opening.
then I drilled two 2 1/4 inch holes on the plastic sheat under the seats (Only in RXTs) right on top of the air duct to breath in more air to the engine compartment.
I took it for a run too bad didnt get a gps with me. I am guessing 1.8 more miles ........ I will find out next time with my gps...
Rpm Jumped to 7780 to 7820
Which is about 140 to 150 more rpms
Still no SC Impeller no intake grate no epoxy filled ride plate......... no turbo no nitrous lol.
I have all summer to have fun
I have a Motec M800 ready to fit and tune on my ski any time this month once I am free from tuning @#%@$# cars skis are much more fun and challenging.
05-23-2007, 12:28 PM #8
- Join Date
- Jan 2006
- Puerto Rico
05-23-2007, 01:52 PM #9
I already have an M800 on my drag car so it will only cost me the price of a wiring harness to fit it as I will wire it my self.
I will tune it my self so it will be cheaper for me than fit a Rotax Racing or Riva ECU. (I have been tuning Motec Since they released the M800)
I already tuned an RXP who had a rotax racing ECU on his ski we gained 1 mile over it .
Trust me it is not the ecu it is the person who tunes it.
Even if I considered buying a new one I can sell it used for 15 % depreciation.
so I will only lose 15 - 20 % which is about $450 to $500 .
Trust me I did not take this decision before I tried it on another ski.
05-28-2007, 06:20 AM #10
Took my GPS with me this time
3/4 Tank I let my friend drive the ski for a top speed run.
aN AMAZING 67.7 ( 2 miles)
Unfortunately when I drive I only get upto 66.9-67 although he is double my weight. This Defies the laws of physics lol.
I think I will stick to the 67 figure .
Both of us ride it with the superman position he is double my weight so he probably lifts it more than I do causing less drag.
I am happy with the filter results.
(The best Bang for the Buck)
I guess now I will repitch my propeller so that the rpms jump to the 8000s
Then I will try the 13/17 3 blade skatrack
I am doing this to find the best setup for my current mods.
Then I will go to a different stage of mods
14/17r solas 4 blade
Custom 4 inch air filter
2 degree wedge kit
Opas Block offs
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