Nizpro Marine's 633-Horsepower Supercharged Yamaha

**Scream And Fly** · 05-30-2023, 03:10 AM

Nizpro Marine created this 633-horsepower supercharged monster, and You all need to check this out because I am blown away. They focus on upgrades and modifications to Yamaha outboards and they developed the superchargers for those engines entirely in-house. The engineering involved is phenomenal. Here's the description of the 633R from their YouTube page:

Nizpro Marine has developed the worlds most powerful outboard.

You start with Yamaha’s brilliant, and dare we say venerable 4.2l V6. You add a custom plenum (hence the red alien), separate, additional raw water cooling, and Eaton’s R1900 supercharger on top. Yet the really brilliant effort is in the re-map of the factory brain.

Now the 633RR adds a bigger pulley, new injectors, forged pistons, new valve springs, ported heads, and billet conrods, then some other more incidental bits too like throttle body and injectors, as well as a new drive leg. All very cool stuff, and the reason the whole thing is as bullet proof as the standard 300hp from Yamaha.

**hellbents-10** · 05-30-2023, 06:35 AM

I think the total weight comes in close to the 450R like this. What a power house! I do wonder how the lower unit handles the big power!

**jmatak9** · 05-30-2023, 11:11 AM

yes!!!

**JPEROG** · 05-30-2023, 01:33 PM

Maybe they will be bolting a new merc. sportmaster to it.--impressive for sure.

Joe

**mr fun** · 05-31-2023, 03:13 PM

$ ? $ ? $$$ ?

**Tcatrett** · 05-31-2023, 03:36 PM

Bad A$$!!! Looks like it will be hard on equipment.

**Turtleherder** · 05-31-2023, 06:31 PM

Found a write up that said, as per Nizpro, it weighs 591 lbs. and produces 490 ft lbs of torque. It also said the lower is rated to 650 ft lbs of torque and you can get 1:35 or 1:50 gears.

**FUJIMO** · 06-05-2025, 06:53 PM

...ttt...

**Greg G** · 06-06-2025, 09:59 AM

Originally Posted by Turtleherder

Found a write up that said, as per Nizpro, it weighs 591 lbs. and produces 490 ft lbs of torque. It also said the lower is rated to 650 ft lbs of torque and you can get 1:35 or 1:50 gears.

591 lbs is impressive. Did this project get to market in any fashion?

**mistah_max** · 06-06-2025, 10:52 AM

a friend of mine is running a supercharged SHO on a 21 cougar on race fuel and its supposed to be around 550hp.he has a yamaha ecu with a tune for the race fuel and another one with a pump gas tune at 450hp. we inquired about the 1.5 gears but we where told they werent in production ( this was last year). this video is a couple of years old and nothing is advertised on their site about boosting power up from the 450hp to 633.

the boat is a absolute rocket and a handfull. hes dialing in the steering this year because the uflex silversteer wasnt enough. hes going with the MCR double side ram steering kit.

he's running some 34-38pitch dewald 4 blade cleaver props and has a coned 1.75 and 1.62 lower done by hydrotec. snaped a driveshaft with a big prop and the 1.62 gears last year on acceleration.

other then that, not problems whatsoever. after the supercharger kit is installed, its virtually impossible to get to anything located in the lower front of the engine because it fills up all the leftover room. its a bitch to word around but the thing hauls!

**Greg G** · 06-06-2025, 11:00 AM

Interesting info and very complete, thanks for posting. So this particular upgrade sounds to be a bit more skunk works seeing as Nizpro does not push PR on it.

It also looks like you personally are running a Nizpro "tune only" SHO ? What has your experience with that been?

**RBT** · 06-06-2025, 08:23 PM

Originally Posted by JPEROG

Maybe they will be bolting a new merc. sportmaster to it.--impressive for sure.

Joe

A lot of Tuffs are NizPro powered to avoid the abomination of a gearcase the mercs come with. I wish I could bolt Yamaha case to my
300r

**CUDA** · 06-06-2025, 11:02 PM

How come no twin Pinion gearcases,

ZF was making transmissions and dual pinion gearcases that handled 700 hp no problem,

for Seven Marine.

Some diesel outboards use a belt to drive prop shaft, but like dual pinion you need a transmission

Either way smaller and trouble free LUs

**RBT** · 06-07-2025, 05:48 AM

Originally Posted by CUDA

How come no twin Pinion gearcases,

ZF was making transmissions and dual pinion gearcases that handled 700 hp no problem,

for Seven Marine.

Some diesel outboards use a belt to drive prop shaft, but like dual pinion you need a transmission

Either way smaller and trouble free LUs

GREAT question. That 5.44 diameter sportmaster is a total disaster. Then they upped the diameter on the 500r and made it even worse. So much so that the 500r wasn’t any faster than the 450.
Apparently merc did make a twin pinion case but the bean counters killed it as assembly is a lot more complicated.

**JPEROG** · 06-08-2025, 10:04 PM

The cases are working for me after lots of propeller and height experimentation. Diameter and rake are a big deal with these cases. I have not seen a single instance where a 500R is not faster then a 450R when they are set up correctly (addtl. 200 rpm and 50+ hp increase). Water pressure on the 500 is more crucial and I am running remote pick-ups in conjunction with the case pick-ups. We have run lots of comparisons with 28 (single), 32, 36, 39, and 42 cats. I have zero time in a V bottom with a V8 but Scott at Velocity and Ryan at Sunsation have said the same and they have a bunch of both 450 and 500 set ups out in the market. I have several friends with NorTech center consoles, MTI, and Cigarettes that have re-powered with 500s and all have gained top end.

There is a guy in WI that I spoke with running a 21 superboat at 100 mph with a new 300R. Again, lots of prop testing and he might jump in on this thread if he sees it.

Joe