• Welcome to Jetboaters.net!

    We are delighted you have found your way to the best Jet Boaters Forum on the internet! Please consider Signing Up so that you can enjoy all the features and offers on the forum. We have members with boats from all the major manufacturers including Yamaha, Seadoo, Scarab and Chaparral. We don't email you SPAM, and the site is totally non-commercial. So what's to lose? IT IS FREE!

    Membership allows you to ask questions (no matter how mundane), meet up with other jet boaters, see full images (not just thumbnails), browse the member map and qualifies you for members only discounts offered by vendors who run specials for our members only! (It also gets rid of this banner!)

    free hit counter

Possible Scarab/BRP Rotax Reflash/ECU upgrade

ScarabMike

Jetboaters Admiral
Messages
2,223
Reaction score
2,061
Points
302
Location
Green Cove Springs, FL
Boat Make
Yamaha
Year
2022
Boat Model
AR
Boat Length
19
Ive been in contact with RIVA on their ECU refash, and piggy back ECU's. It seems that the ECU in our boats is the exact ecu that has been in use since late 2011. According to them, we may be able to squeeze out an additional 50hp out of a stock supercharged engine with no other modification other than a p.n.p. unit. Im sure with some bigger injectors, and fuel pump, you can get even more ponies.

They are looking to get more info on impeller specs, and other odds and ends.

Here is some info on their product.
http://www.rivaecu.com/AP_overviewSDecu.shtml

More to come!
 
That 50 out of the 200 hp version?
And can ya get 50 more from the 250's? My goodness a 600 hp boat would be fun!
 
I will tell u right now that the 165 will only do 60 plus for short bursts. Because with that shallow hull, you'll fly outta the boat! Similar to my exciter. I hope people do buy them and enjoy the heck out of them! I wish i still had my boat and then i could go out and go nuts for a bit.
 
Ive been in contact with RIVA on their ECU refash, and piggy back ECU's. It seems that the ECU in our boats is the exact ecu that has been in use since late 2011. According to them, we may be able to squeeze out an additional 50hp out of a stock supercharged engine with no other modification other than a p.n.p. unit. Im sure with some bigger injectors, and fuel pump, you can get even more ponies.

They are looking to get more info on impeller specs, and other odds and ends.

Here is some info on their product.
http://www.rivaecu.com/AP_overviewSDecu.shtml

More to come!
Hi ScarabMike,have you or do you know anyone that has upgraded the ECU/p.n.p to get more hp/rpm out of the 250hp supercharger on scarab? I would love to get as close to 60mph as possible without potential engine damage. I'm currently getting 7900 rpm at 51/53 mph.
Bryan
 
Hello ScarabMike
Has the ECU upgrade for us become reality?
 
I would love to get 51 mph out of my boat. I barely get 46 mph and that's with only one person in the boat.
 
Hello ScarabMike
Has the ECU upgrade for us become reality?

*bump*

Old thread...but I'm interested. Any news on if this happened?
 
I am really surprised you guys with 250 hp on the 165 aren't hitting 60!
My exciter probably bumped a bit past oem power but less than 300 and was hitting over 60 and i think it did 65ish. I kept up with my bil and his baja which did 70! Until the first ripple in the water anyways! And that was with wife pregnant and cooler of stuff! Man, so that was a long time ago!
I would look at the intercolers first and make sure you are stuffing good cold air in there.
The ecu thing will only help much if you have optimized everything else i would imagine. Some, but not the same
 
There quite a few upgrades, but not much info about the performance improvements on the boats.

For the 250hp motor you can add the ET137 wheel to the supercharger (X-Charger) for more boost. I see they now make an adapter so you can install the 300hp supercharger if you want. Upgrade the external instercooler to a more efficient one. Add a fuel pressure regulator, bigger injectors, air intake, programmer to get more rpm. SeaDoo used to be a 1-2 years behind onthe boat motors, if they continue that tread, the 300hp motor may be available to the boat builders for 2018 or 2019.

On my Challenger I upgraded to the ET 127 wheels in my superchargers, top speed is the same, as I have not switched impellers and the rpm limit is still 8000. Acceleration feels quicker and I have more cavitation if I just go from idle to WOT, and not ease the throttle up. I'm planning to order the impellers from the 510 hp boats to see if top speed is increased any.
 
The ECU reflash equipment looks like its only 900.00
 
Guys, Im going to post what Riva has told me on this. Because of the weight and mass of the boat, they dont like to get into reflashing them. They told me its very difficult to get the "sweet spot" on boats because if you get too much HP and TQ, then you have to look for a good prop pitch to work with the tune. Then you have to make sure you can puch that much additional flow through the venturi without causing cavitation that will destroy the pump, and overheat the engine.

But they will flash the ECU for you if you send it in so they can get the stock information, and adjust it to what you want. One thing that would be nice is raising the RPM to 8400-8600. That can be done if you have a way to maintain 93 octane. Another thing you can do is change the 159mm wear ring, and impeller to a 161mm from the 2016 seadoo with either the stock 161mm prop, or the Riva 13/18mm one. The only difference of the two is the wear ring. The pump assembly is identical. But the new OEM props can push 30% more water and create more thrust.

These 250hp Rotax engines are very powerful, and you can get a ton of HP, and TQ out of them. But, because of the different environment with these boats, its all about $$ and R&D. So who is going to be the first guinea pig?
 
@ScarabMike or @Ron@Scarab, would either of you be able to get the impeller specs from the 500hp 215 HO? Are they still 159mm or 161mm? I've looked online briefly for the specs / parts list, but didn't find anything.
 
@ScarabMike or @Ron@Scarab, would either of you be able to get the impeller specs from the 500hp 215 HO? Are they still 159mm or 161mm? I've looked online briefly for the specs / parts list, but didn't find anything.
Those are 159mm. The only 161mm impellers are on the 300hp seadoo crafts. I though I was clear on my last post above.

As far as pitch, Im not sure.
 
You need retainers and heavy duty valve springs to raise the rpm that high. And you'll need more power to raise the rpm. It's not going to just go higher cause the limiter was raised.
 
You guys are funny messing with the internal workings of such a intricate engine.... Just be safe out there, I had a friend mess with his merc. and it blew up. He was a lead tech for ford too so he knew what he was doing.
 
MIke, I also called riva recently and was told they wont touch my chaparral boat ECU. Is it possible to upgrade the pump to the Riva solas 14 vein pump with a 161mm impeller? will this bolt up to my 2018 VRX 223 with dual 250 4tec? Then you would have to do something to increase horsepower, I understand there is the ET147 supercharger compressor wheel upgrade. But seems that one way or another we need to update the ECU to 8500 RPM redline and or some tuning... I also understand the injectors and or a fuel pressure regulator would be require. The scary thing is on a dual engine boat all of this is x2 and your talking easy $4k+ in parts. If we knew the results I would be ok with it. cheaper than buying the newer boat with 300Hp engines. I am in the tahoe area and would love to upgrade the power to compensate for the 10-15% HP loss due to 6200Ft. I have hit 55MPH with sea level impellers. I cant complain but I am a hot rod car guy and love to find well done upgrades. Seems like if someone did the research this could be sold as a kit... many would invest in it. If I could get 60mph at altitude.. be worth it to me. Speed increases are exponential in boats. You need a lot more HP than even 100 more to get small top speed increases.

Guys, Im going to post what Riva has told me on this. Because of the weight and mass of the boat, they dont like to get into reflashing them. They told me its very difficult to get the "sweet spot" on boats because if you get too much HP and TQ, then you have to look for a good prop pitch to work with the tune. Then you have to make sure you can puch that much additional flow through the venturi without causing cavitation that will destroy the pump, and overheat the engine.

But they will flash the ECU for you if you send it in so they can get the stock information, and adjust it to what you want. One thing that would be nice is raising the RPM to 8400-8600. That can be done if you have a way to maintain 93 octane. Another thing you can do is change the 159mm wear ring, and impeller to a 161mm from the 2016 seadoo with either the stock 161mm prop, or the Riva 13/18mm one. The only difference of the two is the wear ring. The pump assembly is identical. But the new OEM props can push 30% more water and create more thrust.

These 250hp Rotax engines are very powerful, and you can get a ton of HP, and TQ out of them. But, because of the different environment with these boats, its all about $$ and R&D. So who is going to be the first guinea pig?
 
I agree this is not something to mess with. But I do not agree with you, heavier valve springs are only required if your getting float.. ifyou have increased the tune and boost along with higher RPM you should get more HP. Now you maybe right in that that RPM is not safe without other mods.. but I doubt it.
You need retainers and heavy duty valve springs to raise the rpm that high. And you'll need more power to raise the rpm. It's not going to just go higher cause the limiter was raised.
 
Anyone some news on this?
I have some experience with chiptuning cars and i think upgraded fuel for ignition-timing and max-rpm adjustments should take us to 15% hp increase with those engines. No other mods should be needed.

Anyone ?
 
Guys, Im going to post what Riva has told me on this. Because of the weight and mass of the boat, they dont like to get into reflashing them. They told me its very difficult to get the "sweet spot" on boats because if you get too much HP and TQ, then you have to look for a good prop pitch to work with the tune. Then you have to make sure you can puch that much additional flow through the venturi without causing cavitation that will destroy the pump, and overheat the engine.

But they will flash the ECU for you if you send it in so they can get the stock information, and adjust it to what you want. One thing that would be nice is raising the RPM to 8400-8600. That can be done if you have a way to maintain 93 octane. Another thing you can do is change the 159mm wear ring, and impeller to a 161mm from the 2016 seadoo with either the stock 161mm prop, or the Riva 13/18mm one. The only difference of the two is the wear ring. The pump assembly is identical. But the new OEM props can push 30% more water and create more thrust.

These 250hp Rotax engines are very powerful, and you can get a ton of HP, and TQ out of them. But, because of the different environment with these boats, its all about $$ and R&D. So who is going to be the first guinea pig?
What are the part numbers for the impeller and wear ring for a2020 165 Scarab Ghost with 300 hp.supercharged that improves performance over stock
 
Back
Top