Fastest SOB hull???

[TooStroked]

Velocity V7 21 Australia .............. 400 R

Attachment 497326

This picture shows another interesting side effect of going with the big four strokes. Coming out of the hole now comes with a ton of bow rise - even with tabs down.

[WavetoWave]

Any suggestions as to which prop? (Not that any of them are actually available these days.) But I have all winter to find something.

What RPM was the 30" Bravo turning? It's a great prop to get a baseline, they run a little light in pitch, meaning a 30" Bravo is more like a 28" in other props. You're probably going to want to spin it right up to 6,200 if you can. 84 MPH is a huge gain over your 2.5, and 88 MPH is incredible.

Depending on your RPM, I'd be tempted to try a ProMax, Hyrdromotive quad 4 OT or larger diameter OB SST. Engine height will be critical, it can run really high.

The best prop isn't necessarily the fastest, it's the one that is the most drivable and efficient. (In my opinion). Sounds like yours is running really good in general.

[FUJIMO]

...if you find the bravo one you like, may i suggest you then send it out to have it labbed. makes a nice difference. overall speed & performance will improve, and the r.p.m.'s will be generally reduced by 200-300 r.p.m. makes a huge difference, if on multi-engined rigs too...

[Greg G]

This picture shows another interesting side effect of going with the big four strokes. Coming out of the hole now comes with a ton of bow rise - even with tabs down.

Is that what is happening with your P22 and the V8?

[Greg G]

...
I wonder how the guys running 450's on there SOB are managing set up.

Hallett 210, Bullet 2150 S from Oz, and Progression 22 with 689 pound supercharged 450 V8's

[Greg G]

....
The folks down under tend to figure this stuff out pretty quickly. Force 21 with a 450 bolted on the back. Might be worth an email.

[Greg G]

...
A couple of overseas rough water 23 footers with 450's on the back from Bernico and Force. Like the OP said, 21'-24' bring one, bring all, but no lake boats!

[Rak Rua]

Not a single but Aussies have never been scared of extra weight out back. (21’ Haines Signature)
Impressive trim tabs.





RR

[TooStroked]

What RPM was the 30" Bravo turning? It's a great prop to get a baseline, they run a little light in pitch, meaning a 30" Bravo is more like a 28" in other props. You're probably going to want to spin it right up to 6,200 if you can. 84 MPH is a huge gain over your 2.5, and 88 MPH is incredible.

Depending on your RPM, I'd be tempted to try a ProMax, Hyrdromotive quad 4 OT or larger diameter OB SST. Engine height will be critical, it can run really high.

The best prop isn't necessarily the fastest, it's the one that is the most drivable and efficient. (In my opinion). Sounds like yours is running really good in general.

The Bravo 1 was turning 6,200 RPMs at 84 MPH and was quite user friendly. I'm thinking a 32" might be interesting. It did not like coming out of the hole though. The BBlades Blaster ran 88 MPH just below the limiter, but wasn't nearly as fun to drive. (And I'm being kind there.) It did hop right on plane. The ProMax is on my radar screen, but Wildman (Randy) said I won't like it unless I run it pretty high up on the jack plate.

[TooStroked]

Is that what is happening with your P22 and the V8?

Yupper! I think just about anyone running a V8 on a smaller SOB will run into the same effect. It's not bad, but it is quite a bit different than the old 2.5. You do have to double check what's in front of you before jumping on it though.

[WavetoWave]

110 mph with the nizpro 450. Some of the ski race boats run big power sterndrives too. I don't know anything about the sport but they pull two skiers.

[Greg G]

Is anyone running the Nizpro units here in US waters? I believe they have been very well received in other parts of the world.

This is courtesy of Mr D ...........

Heres the email response I recieved from Nizpro:

Hello Christopher

Firstly, thanks for your interest and posting links of our Supercharger kit for the V6 4.2 Litre Yamaha kit.

I have now read the comments posted on the links you provided, so I now have some idea of the questions forum readers would like answered.
We have a company policy of not directly adding comments on public forums, as it becomes impossible time wise to answer individual questions on multiple forum sites along with not wanting to tread on forum advertisers toes. I am happy for you to repost my answers to your email questions if you believe it to be appropriate.

Below seem to be the most common asked questions.

April fool’s joke? No it certainly is not, this is the real deal. We were certainly a little amused when it became public on April 1^st in the US (April 2^nd here in Aus)

Does the standard engine cowl Fit? Yes the cowl remains 100 % untouched, we do add a 104 mm { 4 inch approx. } spacer that is attached to the standard cowls internal latch points, the standard latches are then bolted to the spacer. The cowl then simple goes on in the standard manner.

Which Yamaha model does the Nizpro Supercharger kit fit? Our Supercharger kit fits all F series 225, 250 and 300 V6 4.2 litre models. It also fits all 200, 225 and 250 SHO V6 4.2 litre
Models

Is reliability and durability compromised by adding a supercharger to a naturally aspirated engine? Firstly let me say that the 4.2 Yamaha V6 is an amazingly well engineered product. Any owner of one can be assured just how good these engines really are and how under stressed they are in standard form. In its highest production level { 300 HP } it’s making a mere 71 hp per litre at a lazy 6000 rpm maximum engine speed limit..

Countless production engines are now found in both naturally aspirated and forced induction derivatives with very few and in some cases no internal mechanical changes. When changes are made they often consist of a simple static compression ratio change.
If very high outputs are required you may find differences in connecting rods, the addition of piston that have pressure feed oil cooling and possibly different exhaust valve material in turbocharged engines.

The standard 4.2l V6 Yamaha is engineered as standard with high quality connecting rods, oil cooled pistons and a compression ratio that is low enough to suit forced induction. So it is a brilliant platform for forced induction.

In terms of power output per litre the closest current example is the Mercury 400R at 2.6 litres it’s producing 153 hp per litre, over twice that of the 300 HP Yamaha in standard form. It does this at 7000 rpm some 16 % higher than the Yamahas 6000 rpm and with approximately 2.2bar absolute boost pressure being applied. Don’t forget the supercharger requires crankshaft horse power to drive it. This could be in the order of 50 to 70 horse power. So what is being measured at the prop shaft is not what is being generated at the crankshaft. In truth the 400R is now producing in the order of 173 hp per litre. This alone shows just what an amazing job Mercury have done with the Verado 400R especially considering the duty cycle marine engines are operated in.

Getting back to the Nizpro Supercharged Yamaha, it is now producing 107 hp per litre or approximately 115hp per litre accounting for the drive requirement of the supercharger. This is 50% less power per litre than the 400R at 600 rpm less. With approximately .7 bar less absolute boost pressure.

Now it’s hard to argue that given two identical engines one producing 300 hp and the other 600 hp that the durability will be the same at peak power. However given that very few people even in a marine application will hold their engines a 100% of the time at peak power, rpm and load for the entire life of the engine, this story of durability starts to change.
The higher power engine if prop’d accordingly will now achieve the same cruising speed at lower engine rpm, this in effect will prolong engine parts given their slower rotational speeds. Think of this a little like a low speed diesel engine {Truck}vs. a high speed petrol engine. {Car}

We started this project in 2013 and to accelerate our own durability testing program we are running our pre-production tests at well beyond the 450hp power level, Higher rpm with substantially higher boost pressures than what the production 450hp package will be released with. Up to date we have seen zero failures of any kind using a standard Yamaha 4.2 V6 engine.


Lower Unit strength? Currently we have seen zero lower unit gear failures. We certainly understand that at some point the lower unit will become an issue and are already taking steps to be able to offer upgrades.

What does the supercharger package include? This is the short list not including clamps, nuts and bolts. etc.
· Nizpro Supercharger unit
· Twin water to air intercoolers
· Moulded intercooler hoses
· Intercooler water outlet fitting
· Intercooler Water pick up
· Upgraded fuel injectors
· Upgraded fuel pump
· Drive belt and pulley system
· Wiring loom extensions direct plug in
· Fuel filter relocation bracket
· Intercooler water filter
· Air box
· Cowl extension piece
· 450s Sticker kit
· Direct ECU flash tool with plug in harness
· ECU Licence
· Nizpro Marine 450 Horsepower ECU calibration



Price and availability.
The official release will be at the Sema Show in Las Vegas on October 31^st 2017.
Over the next couple of months we will be looking for the premium dealers around the world to install, service and carry stock of the Nizpro Supercharger upgrade packages.
Prior to the release we will be offering a very limited quantity of kits to selected dealers to be installed on boats for display purposes.
Supercharger packages ordered prior to the official release will be $9995 Usd + shipping and import taxes.

Due to being inundated with emails I have yet been able to reply to all of you, please allow me a little time for my reply.



Regards

Simon Gishus
Director

[hellbents-10]

The Nizpro deal has always intrigued me but I have a few questions.
1. Water pickup for high speeds and running the gear case very high. Also can the lower handle the heat from running high?
2. Gearcase/propshaft strength?

[David]

Yamaha SHO 1.62 gear set (hydrotecmarine.com)
HT 9800 Yamaha Heavy Duty propshaft (hydrotecmarine.com)

[XstreamVking]

I know a guy that has had a nizpro on a Lake and Bay 20' flats boat. It has never lived up to its claimed potential IMO. It's shown running with a big CC at close to 90. https://www.youtube.com/watch?v=3_IK-Adcs28