2015 gti 130 V-TECH tuned breaks the 60 mph barrier

[gti 130 wow]

2015 gti 130 V-TECH tuned breaks the 62 mph barrier

Here is the information so far :
Tune : V-TECH stock tune
Impeller : Solas 11-19 Concord impeller and SS ware ring .
Speed : 60+ mph @ 7191rpm , 194 F , 4/5 tank
Fuel : 93 octane (US)
Speed is limited to 58+ mph when ever their is porpoising or water that's not flat and calm .

Future ?? Fill ride plate holes and get a Worx WR243 Intake Grate top loader

Note : The top speed and rpm were taken using the x package and not taken during the same pass.

 

[Greg]

Nice! Let us know when you need the WORX grate. We can hook it up for you.

 

[gti 130 wow]

Nice! Let us know when you need the WORX grate. We can hook it up for you.

That's why I added the part # to see if you had it . lol

 

[gti 130 wow]

I thought this would be a good time to update my results


Summer with temperature pushing 100 degrees and very warm water

Speed : 57+ mph @ 7000rpm , 194 F , 1/2 tank
Fuel : 93 octane (US) Max fuel consumption dropped from 10+ to 9+ gal/hr
A moderate drop in acceleration and maybe = top speed compared with the stock impeller but a big boost in fuel economy .

.............................................................................................................................................................................................

Fall : 9/23/2016 with air tempt of about 80 but with still warm water

Speed : 61+ sustained mph ( 62 peak ) @ 7220 rpm , 192 F , 1/3 tank , 10+ peak gal/hour
Fuel : 93 octane (US)

The time form 0 to 55 mph is less now very quick compared to the stock prop/ v tech combo so 220 rpm bump up + dense , cool air from the summer rpm is a big deal !. More top speed and snap acceleration = more fuel consumption but if I go easy on it the mpg gain is still there . I mean in the econo mode today I hit a sustained 40mph @ 5+ gal /hr up from about 36 mph in the100% stock configuration at the same 5+ gal/hr which is good for another 64 miles on a tank of gas . For people who like to travel long distances it shows that some may benefit with a V-tech / Impeller combo change . My GTI-130 today was able to obtain the stock top speed of 55 mph at half throttle so I think that's pretty impressive and explains the rapid rise to that 55 mph speed . . Lastly at this lower air tempt , the porposing problem just about disappeared which also may be a reason for the new top speed . Keep in mind that with this configuration , performance improvement is happening by increased efficiently and not by figuring out how to throw more gas on the fire . A full day of performance orientated fun cost me about $40 right now at $2.2 /gal or about 18 gal of high test gas .

 

[gti 130 wow]

Hp estimates

I have come up with the hp gain estimates using the following top speed and hp data from Rotex for the GTI hull boats and a process called interpolation .

GTI-130 : 56 mph at 131 stock hp
GTI-155 : 58 mph at 144 hp ( 6.5 hp / mph to gain 2 mph over the 56 mph point )
GTI-215 : 67 mph at 207 hp ( 6.9 hp / mph to gain 11 mph over the 56 mph point )

So to be conservative I will go with the 6.5 hp / mph figure

GTI 130 with a stock v-tech tune plus 11-19 concord impeller top speed so far is 62 mph with further gains hopeful as the temperature drops below about 80 degrees F .

So : 131 + (62-56)(6.5)= 170 HP which is pretty impressive
If anyone tells you that a V Tech tune is a waste on a GTI 130 , just send them to this thread.

 

[gti 130 wow]

Other people have attempted a v tech tune on this engine with lesser results .
I think that is because a tune can't do anything to influence the rate in which the engine is running out of breath as the rpm's climb . What a tune can do is increase the torque on this engine within the range of rpms the engine was designed to operate which in this case is 1800 to 7300 rpm's. So you replace the impeller with one that for a given speed drops the revs by about 250 rpms . Then after doing the tune , the additional torque restores the 250 rpm caused by the prop change and results in higher speeds . Because your still running in the engines designed rpm range , their is no change in peak fuel consumption cuz your not doing anything to change what the ideal air/fuel ratio is but just squeezing more energy out of the gas so its like free speed .

I think the idea put forth by Sea Doo that you can run a na engine with a 10.6 to1
cr or a supercharged engine on regular gas and not take a big hit on performance is flawed . Before modern software controlled engines , regular gas was only good for about a 9.4 to 1 cr and even that took some work to accomplish. The gain that I archived on this motor demonstrates what it can do with the proper high test fuel and a knock related , unrestricted tune .

 

[gti 130 wow]

1 weight : no supercharger / inter cooler / vts / boarding ladder etc . A person with a Na boat with this taller gearing ( more pitch ) , could leave the dock with 20% less fuel and have a similar performance orientated run time for another 20 lbs witch cumulatively adds up .

2 losses : energy to run the SC , higher oil pressure , much more rejected heat and the indirect cost of rejecting that heat energy , exhaust back pressure from running higher rpm as part of acquiring more hp .


3: a more favorable weight distribution.

4 : oil consumption continues to be nill so :
1: no need for a catch can
2: oil is not being diluted to much by combustion byproducts that includes water .
Before positive crankcase ventilation , oil change intervals were much shorter because of the polluting of the oil with combustion byproducts including water. So the more blow by you have , the more you need that suction from the engine intake to keep fresh air moving through the crankcase and prevention of a build up in gas pressure in the crankcase that can screw up the engines seals and shorting the life of your engine just for a few more hp.
3: My intake air is not being diluted to much by these power robbing combustion byproducts being fed from the crankcase ventilation hose .

I will add to this post as I think of more examples .

All these variables add up and explain why I can with a na engine get to within 6 mph of the sc model under the right conditions. Yesterday with temperates in the 60es , the engine peak sustained rpms went as high as 7350 rpms ( free air baby yea ) and for the first time In the sport mode under full throttle start , fuel consumption went momentarily to 11+ gal/hr but only was able to get to 61 mph I think because it was windy and their was a lot of chop ( Worx intake grate will help this ) I believe . When you see earlier that I made it to 61 mph at 7250 rpm , things could get interesting no doubt . I am hopeful that I can reduce that non US stock 6 mph difference keeping in mind on the US 65 mph ( coast guard restricted ) versions in general I am within 4 mph which is darn close so long as the outside tempt is below about 80 degrees . .

 

[Sea Dood]

1 weight : no supercharger / intercooler / vts / boarding ladder etc . A person with a Na boat could leave the dock with 20% less fuel and have a similar performance orientated run time for another 20 lbs witch cumulatively adds up .

2 losses : energy to run the SC , higher oil pressure , much more rejected heat and the indirect cost of rejecting that heat energy , exhaust back pressure from running higher rpm as part of acquiring more hp .


3: a more favorable weight distribution.

I will add to this post as I think of more examples .

Total nonsense. As posted before, I ride with a large group that has a mix of SC and NA skis. On average, we all return with the same amount of fuel. You need to think of it much differently. Think of it this way, both skis are identical up to 6000 RPM. The SC models have an extra oomph above that and spank the NA skis. Do they burn more fuel at WOT, yes of course they do, but you are going much faster.

The only advantage of owning a NA ski is lower price, and you don't need to rebuild the SC every 100 hours, that is it. The advantage of the SC ski is a lot more fun.

 

[gti 130 wow]

Your ability to maintain parity with na skis comes from the tall gearing (more pitch ) that your torquey engine provides that acts to hold the rpms down and provide a overdrive effect at lower speeds . With a torque enhanced v tech tune , I am able to have taller gearing (more pitch ) without paying a price with respect to top speed or acceleration while maintaining a max 10+ gl/hr max. burn rate that the sc skis cant come close to at higher equal speeds .

 

[gti 130 wow]

Compare to the tune of the spark

I was reading that the same idea I used for my performance up grade was applied to the 109 mph spark .
They got a tune combined with a suitable impeller to take advantage of the additional torque the tune provides . They also added a intake grate and air air filter on the throttle body to get the top speed up to that of a stock GTI -155 of about 58 mph .Because their for the most part doing it with torque instead of rpms like me . they should get a boost in fuel economy that may pay for their mods which is always good . So at 61+ mph so far with out the other mods they did , I am looking pretty good and hope to improve on my stats .

 

[gti 130 wow]

10/29/ 2016 Peformance update

Fall : 10/29/2016 with air tempt of about 70 degrees .

Speed : 60+ mph @ 7400 rpm , 192 F , 1/2 tank , 10+ peak gal/hour
Fuel : 93 octane (US)

As the tempt drops , the PWC is becoming under propped resulting in a 1+ mph drop in top speed as peak rpm at top speed rises out of its designed 1800 to 7300 rpm range to 7400 rpm but the build up in torque within the ideal range range continues to go up .
Today in the sport mode from a start ,rpms went to 8100 rpms , fuel consumption went from a usual 10 gal/ hr spike to 11 gal/hr and the boat was up on plane and level in 2 seconds flat . When cornering speed is much better maintained and fuel consumption has gone up a bit which is what you would expect as the pwc becomes under propped
So for someone who lives in a very cold climate it would be time for a second bump up in pitch starting at 18 then to 19 and now on to to 20 that would bring the speed of the boat closer to the 65 mph ( stock coast guard speed ) target then the 62 mph momentary peak I got on a 80 degree day I would guess. As someone who lives in Va Beach , I would need a summer and winter impeller so I will just stick with what I have .

With each season the nature of the improvement changes compared to stock but with the taller gearing is always holding down fuel consumption and thus makes it a pay for itself mod . To put this in perspective , I have run my pwc over 300 hours in the last 12 months and burned ""at least "" $3400 worth of fuel . It looks like I dropped fuel consumption by 15% or $510 if I had this configuration for the last 12 months so even if the tune provided nothing to me but a drop in long term fuel consumption , it would still be worth it being a tune is but a one time , $600 purchase .

 

[gti 130 wow]

1 Comparisons to some other pwc's using boat test .com data

Top , peak speed :

Yamaha VXR with high out put 1.8l engine, 180 hp : 66 mph ( powerful engine + low weight = impressive )

GTI-130 with V-tech tune , est 163 hp : 62 mph (low weight devoid of extras + boost in torque throughout its entire power with V- tech that did not add any weight or drag ) .

(GTX 4-TEC Supercharged , 185 hp : 60 mph The SC just made up for the weight of the heaver 4 stroke sc , pwc + fiberglass hull compared to the older , smaller 2 stroke .


Sea-Doo XP DI
(w/ 1 x 130-hp two-stroke : 61 mph ( low weight + good power = impressive results )


Change intake grate : not for me for 3 reasons

1: the drag it causes may cut fuel economy and I am already burning about 18 gal/day .
2: Not all that fun bouncing around in chop on a GTI hull at full throttle so only interested in going fast on flat water .
3: Like exploring creeks . Last weekend it took an hour to get a plastic Gillet men's razor out of the jet pump . A top loader will just help scoop stuff up .

Air Intake and exhaust : The engine intake and exhaust is the same one used on the GTI -155 pwc with a 7500 rpm power peak so already somewhat low restriction with it's 7300 rpm peak .
The V-TECH , soles upgrade actually lowered my average running rpm ( recent 7220 rpm for top speed ) by producing gains with torque and not more rpms resulting in less pumping losses including the stock intake and exhaust .

 

[Sea Dood]

Dude, please give it up. Two points that you don't seem to comprehend in your never-ending quest to bash SC skis for no reason:

1. You cannot compare different hulls with their relative speed vs HP.

2. Speed on water is not linear with respect to input HP to output speed, especially with an inefficient jet pump.

Another thing you apparently don't know. Sea Doo GPS clusters, like the one you have, typically read 2 MPH fast. You are doing a real 58-59 tops. And BTW, your photo could have been taken after going downstream, LOL

 

[gti 130 wow]

Speedometer accuracy was verified using my Garman Nuvi 65 GPS . Because neither unit reads in tenths , their could be some splitting hairs here. Also the sampling and refresh rate of the Sea Doo unit is much beter then your typical GPS that may account for the disparity .

 

[gti 130 wow]

Well for me 50 degrees is about my limit low for riding my pwc and that was what yesterday was.
As the water tempt dropped , my top speed dropped from a high of 62 to just below 60 mph as the water got colder and the rpms at top speed move above its ideal range .
So to get the speed back up , I did two things .
1: Filled and painted the ride plate and intake grate holes .
2: Painted the bottom , flat surface of the ride plate with duplacolor auto paint and waxed the painted surface .

Results

Here is the information so far :
Tune : V-TECH stock tune
Impeller : Solas 11-19 Concord impeller and SS ware ring .
Ride plate and intake grate holes filled and bottom , flat surface of ride plate and rough epoxy surface of ride plate holes painted and waxed .
Speed : 60 to 62 mph peak @ 7340 rpm peak , 190 F , full tank down to a third .
Fuel : 93 octane (US)
Not much porposing today so maybe today's mods have helped ..
As you may have seen on previous posts , my top speed was dropping as it got real cold but after this most recent enhancement its back up again which I see as promising .

note : because the engine cooling system on my NA pwc is the same as the sc ski , I think I may have enough reserve cooling capacity to get away with painting the bottom , flat part of the ride plate but we will just have to see as it gets warmer . As far as bang for the buck , I got a 5 mph bump up on my na pwc for about half the cost then for example those people with a GTR 215 pay to get the same 5mph bump up by installing a RIVA stage 1 upgrade while maintaining a peak 10gal/hr fuel flow rate and improving the the cool , torque derived low pitch sound of the engine and not the noise level of my ski .

 

[gti 130 wow]

Performance update

Well I finally got around to filling the intake grate holes 3 in back and one in front and all the ride plate holes .
I would say that it really did not do much for top speed so for that it may require much higher speeds .
It did make turning easier with more snap and less loss of speed when cornering .
More important for me , it greatly reduced the times that proposing occurs . When it does , the magnitude up the up and down movement is much less which is super for this non vts pwc.
I can't wait until spring when the higher water temperature drops the max rpm at top speed to about 7220 rpm which is the rpm I broke 62 mph ( 2 mph above the 185 hp sc model )last year . Also peak fuel consumption is holding at 10 gal/hr compared to about 17.5 gal/hr for the GTR 215 which should help out big time next month when they go to the higher priced summer grade fuel. This is accomplished somewhat with the GTI - 130 somewhat lower rpm biased cam relative to the 155 model or to put it another way , this is ( 62+ mph @ 7220 rpm ) one torque e mf .lol
I think its fun to try to build speed on a craft that will never reach risk your life levels which I guess existed during the time before superchargers were introduced.
I also got a free app to measure moving data for the I Phone called Escenda .

So far max .5g and 0 to 30 in 3.3s which is the same as the original 185 hp SC version (boat test.com ) minus the reliability related drama which is impressive with just a V Tech tune. I think once the water temperature goes up and the pump gets a better grip on the water, these figures should improve.

 

[gti 130 wow]

4/14/2017 Ride plate break through

After much experimentation, I have finally found a spray that will reduce the friction of the ride plate and not wash off.
Its WD 40 silicon water resistant spray.
Here is the link to it .

https://www.wd40specialist.com/products/silicone-lubricant/

Be live me this stuff really works.
After a ride it beads up on the plate like wax but over sized.
Today I made it to 61 mph @7400 rpm on 2/3 of a tank.
The speed was rpm limited cuz that rpm is out of the engines power band.
It only works on bare aluminum and not on painted surfaces.
For top speed only put in on the bottom flat surface of the plate.
When applied to the angled part of the plate the back of the boat was dancing causing the pwc to lose its grip on the water not very fun to ride and actually dropped top speed to 58 mph.
Or coarse if your someone who is in to tricks and want a loose back end then this stuff will give it to you. Also at full speed the wake dropped to almost zero and proposing is now a non issue that I am sure is also helping performance. It only cost $5 a can so give it a try just make sure the surface is clean and the stuff has time to dry. After this improvement along with filling the ride plate holes, I am confident that I might break my top speed of 62+ mph when the prop better matches the water tempt with a top speed at about 7250 rpm's. I am very happy with this cuz today I was able to spend a lot of time above 60 mph.

I have looked at some GTR 215 videos and found that the acceleration of my pwc today is now on par up to the hp peak of my motor that now occurs at about 53 mph . Above that speed , I am losing hp while the sc pwc just keeps building power and does not drop off until about 63 mph. Its done with less weight , less ride plate friction, a tune that requires high test fuel,
and lower pitch prop 11/19 vs 14/19 . Again I should point out gains while still at about a max 10gal/hr burn rate vs a whopping 16.5 for the GTR and 13.5 for the Na 1.8l Yamaha.