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Alumaman
Joined: 26 Jul 2005 Posts: 306 Location: Whitecourt
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Posted: Thu Jan 03, 2013 11:09 am Post subject: |
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wetahawk
Mod’s that worked to my 17ft 240 SJ when raced. Not all advised for an R class boat, if your planning to race, as you still want to have a boat that you will enjoy driving when you’re not racing. Also it was expensive, which I think goes against the spirit of the R class. But it gives you a place to start.
62 mph at 6000 rpm
Removed all carpet.
Removed floor panels.
Removed back seat and mounted front buckets there.
Added a 2ft. steering wheel extension.
Moved fuel tank back tight to the motor.
Moved oil tank to the back.
Used a smaller battery, and mounted it at the back.
Ran a 3 blade impellor.
Sharpened the leading edges of stator.
Ran the 3 blade impeller.
Ran the nozzle from a 175 SJ.
Ran the red wedge.
Didn’t use an air filter.
Removed reverse bucket.
Ran with engine cover off. (when not in white water)
Rebuilt impeller and wear ring O.D. to .125” over stock.
Ran impellor clearance of .018”
Knife edged the trailing edges of intake grate and radius the leading edges. |
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GB
Joined: 27 Jul 2005 Posts: 25 Location: Canterbury New Zealand
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Posted: Sun Jan 06, 2013 4:35 pm Post subject: |
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Bruce from the jet boat base has tried to get your boat running faster for racing - results not good you will a steptech hull!!!! |
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wetahawk
Joined: 05 Aug 2012 Posts: 20
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Posted: Mon Jan 07, 2013 6:08 pm Post subject: replying |
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hay guys
thx for some of your ideas about weight placment eq..
as for Bruce has tryed . what did he try? i cant see anything that he would of done to inprove speed?
only one of his stone stopping grills, wich il chance when testing for speed for stock one cleaned up,
i keep forgetting to gps it on weekends playing out at lake, i seems to be able to pull 5800rpm wether there just 2 of us in boat or 5 of us,
so i think il lookout for a 175 nozzle if there smaller id or fit a incert in one of mine to load it up a bit more,
theres also 30kg i can remove at the end of summer(rear seats& engine cover)
has any of the sj ex racers tryed spoon feeding there intake?
cheers |
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GB
Joined: 27 Jul 2005 Posts: 25 Location: Canterbury New Zealand
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Posted: Wed Jan 09, 2013 12:20 pm Post subject: |
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The Eagle steptech hull is a totally different hull design (you have a older Outlaw) I know Rob spent a lot of time with the intake / general balance of the boat they go really well but do require a higher skill level to drive compared to traditional hull that plans at low speeds.
Phone Bruce to get an idea on what he has done they were test running against my boat while in for Mtc, also Alumaman has a steptech sport jet (the same as mine) his alterations were an advantage against competitors racing in his class (we're not racing that class in NZ). |
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GB
Joined: 27 Jul 2005 Posts: 25 Location: Canterbury New Zealand
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Posted: Wed Jan 09, 2013 2:42 pm Post subject: |
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Sorry I may sound a bit harsh what I’m trying to say is just go race your boat don’t spent any money on trying for a little more speed because it’s already about 8kph down on a standard steptech! Most racing is about finishing and the sports jets are reliable so it will come down to your driving ability.
Hopefully I’m thinking about the right boat did you purchase it from the guys that completed the NZ marathon in it? |
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Itsworthit
Joined: 15 Jun 2005 Posts: 432 Location: Whitecourt
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Posted: Wed Jan 09, 2013 11:36 pm Post subject: |
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have you tried to weld some lifting strakes on the bottom of the boat? we tried a ton of things to get the sj pump to get better speed, nozzel insets dont seem to work with the axial flow pump, best advice, work on the hull, only change one thing at time, always take a gps and if avalible check corrected altitude |
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On-Track
Joined: 15 Jul 2010 Posts: 79
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Posted: Thu Jan 10, 2013 8:46 am Post subject: |
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I can see inserting a stock SJ nozzle that's located behind a steering diverter cone will not increase your speed. Your not getting positive water flow at the end of the nozzle like a posi-nozzle will give you. Using a stock 3 blade in a 240 pulling 6000 rpms with a 89mm insert in a posi-nozzle should increase you top end speed. As well your steering sensitivity and maneuverablity using a posi-nozzle will be a big improvement over a stock diverter nozzle. |
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wetahawk
Joined: 05 Aug 2012 Posts: 20
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Posted: Thu Jan 10, 2013 5:15 pm Post subject: |
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GB wrote: | The Eagle steptech hull is a totally different hull design (you have a older Outlaw) I know Rob spent a lot of time with the intake / general balance of the boat they go really well but do require a higher skill level to drive compared to traditional hull that plans at low speeds.
Phone Bruce to get an idea on what he has done they were test running against my boat while in for Mtc, also Alumaman has a steptech sport jet (the same as mine) his alterations were an advantage against competitors racing in his class (we're not racing that class in NZ). |
hay~! cheers for some info, dont think a rob ever owned it tho? i think tony brought this one into nz has a flat pack and put to gether so he said,
the fat boy racing had it,some where in there the intake was broken,as i have the invoice for work and parts done by bruce,
but i can see anything extra done apart from new parts to replace.this boat is a 07 none step yes, |
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wetahawk
Joined: 05 Aug 2012 Posts: 20
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Posted: Thu Jan 10, 2013 5:33 pm Post subject: |
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On-Track wrote: | I can see inserting a stock SJ nozzle that's located behind a steering diverter cone will not increase your speed. Your not getting positive water flow at the end of the nozzle like a posi-nozzle will give you. Using a stock 3 blade in a 240 pulling 6000 rpms with a 89mm insert in a posi-nozzle should increase you top end speed. As well your steering sensitivity and maneuverablity using a posi-nozzle will be a big improvement over a stock diverter nozzle. |
MINT! thx for help,il il go sort one! |
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