BRX 2400 500R Repower

[Petrowell 1]

I am currently running a 400R / Sportmaster with a Lab finished Cut down and worked over Maximus 5 with 14" of set back. Aired right out I am getting jus over 85 MPH. I have eaten up a few of these props while surfacing, tearing ears and in one case pulling the hub apart. I am currently repowering the boat with Merc Racings new 500R and I am looking to run the 500HP CNC cleaver from mercury. Has anyone experimented with a Pulsare 2400 with the 1.60 gear ratio gear case on either a 450R or a 500R yet. Looking for a good starting point.

 

[Hayabusa]

Nice! That BRX is definitely booking at 85mph best I’ve done in mine is 83mph. What pitch you running? 26? I haven’t had the opportunity yet of running a 1.6 ratio on my BRX but I’ve run a few 300XS’s with 1.6 and thinking if I had a 500R on my BRX a good starting pitch would be a 29”, that would put me right at about 97mph

 

[Petrowell 1]

Nice! That BRX is definitely booking at 85mph best I’ve done in mine is 83mph. What pitch you running? 26? I haven’t had the opportunity yet of running a 1.6 ratio on my BRX but I’ve run a few 300XS’s with 1.6 and thinking if I had a 500R on my BRX a good starting pitch would be a 29”, that would put me right at about 97mph

Thanks for the reply! On the 400R the prop I started with was a 24 pitch Maximus 5 The prop diameter was cut back, the hub was shortened back to remove the bell, and a substantial amount of cup was worked into the blades along with tip cupping to increase bow lift, sharpened and balanced. After all of the work was done to the prop it is probably close to a 26 pitch. What I can tell you is that increasing the setback of the motor brought my top speed up by 7 +/-MPH, Inches of setback with the BRX = MPH.
What is your Engine, setback, prop combination that you run to get 83 MPH? Have you tried a CNC cleaver? The best top end I have seen on prime choppy conditions running in cool dense air was 86.3 MPH.

 

[Hayabusa]

My 83mph was done with a 25” BBlades Blaster and at that time I had 14” of set back, I didn’t like the amount of porpoising it had while at normal cruise speeds with that set back, constantly had to fiddle with the trim to try and get it stable, so I switched out and went to 6” and now it’s true and smooth in all conditions. I haven’t tried any CNC cleavers yet but I was thinking of talking with Dewalt and see what prop would get me back to 83+ with my current set back. Do you already have the 500R? That is going to be a pretty awesome set up, I was considering a 450 for a while but the prices for used haven’t come down much and still not may used ones out there yet so instead I might look into a tune my 400

 

[Petrowell 1]

I do see your point with the proposing, at lower speeds I do have to constantly adjust to find that sweet spot or just drive through it.
The 500R is sitting at my dealer, how ever it showed up with out the hydraulic steering assembly, could be waiting to mid September for that. It was very surprising how fast the motor came, especially up here in Canada. Hope to have it together before ice fishing season starts so I can try it out.
I will post some pics when it is rigged.

 

[Hayabusa]

Oh man I’m exited for you, that’s great. Is the 500R hydraulic steering different than the 400R’s? I know the 400R’s bolts right up to the 450R so I figured it might also bolt up to the 500R. Yup can’t wait to see how turns out, exiting times ahead

 

[jjg]

I am currently running a 400R / Sportmaster with a Lab finished Cut down and worked over Maximus 5 with 14" of set back. Aired right out I am getting jus over 85 MPH. I have eaten up a few of these props while surfacing, tearing ears and in one case pulling the hub apart. I am currently repowering the boat with Merc Racings new 500R and I am looking to run the 500HP CNC cleaver from mercury. Has anyone experimented with a Pulsare 2400 with the 1.60 gear ratio gear case on either a 450R or a 500R yet. Looking for a good starting point.

Whoever is working on your props is doing something very wrong to have that type of catastrophic failure to the prop and hub. Its either a severe out of balance issue or the modified geometry being applied is not correct.

 

[282]

Looking forward to performance #'s- it used to be huge having a 300 now with 400 and 500 it is going to get wild

 

[Hayabusa]

I do see your point with the proposing, at lower speeds I do have to constantly adjust to find that sweet spot or just drive through it.
The 500R is sitting at my dealer, how ever it showed up with out the hydraulic steering assembly, could be waiting to mid September for that. It was very surprising how fast the motor came, especially up here in Canada. Hope to have it together before ice fishing season starts so I can try it out.
I will post some pics when it is rigged.

How’s the repower project coming along? Up and running? How she look?

 

[Hayabusa]

I guess old man winter put the brakes on that proyect.

 

[jjjrick]

Oh man I’m exited for you, that’s great. Is the 500R hydraulic steering different than the 400R’s? I know the 400R’s bolts right up to the 450R so I figured it might also bolt up to the 500R. Yup can’t wait to see how turns out, exiting times ahead

The 500 steering cylinder appears identical on the outside, and yes the bolt patterns and tiller arm size are all the same for any AMS engine.

But the 500 cylinders are supposedly stronger internally, and come with ARP bolts for installation. The bolt torque is much higher than the 400R specification too. No more lock tabs, they come with thread locked, pre-applied.

Mother mercury also requires rear tiebar for multiple engine applications exceeding 90mph. Steering cylinder is sold separately on all 500s; not just the counter rotation units. Appears they’ve also stopped sending the WIF harnesses in the crates

I can assure you one thing: these 500s PULL!! Plus the extra 200rpm range helps keep prop pitch lower for holeshot. They don’t even build any boost psi until about 4000rpm, it’s a very strong engine!

 

[Hayabusa]

I’m still waiting and looking to see if any 24’ BRX owners have gone the 500 route, I was contemplating a 450 or 500 at one point but shied away from the 450 due to reliability concerns and the 500 is out of my budget for now so I went the tune way with my 400R, now it’s like I have a 500 on transom.

 

[jjjrick]

Nice, yep the 400r with a tune runs very well on a light hull. Biggest downside is finding premium fuel on the water.

However I can assure you it does not compare to the output of a 500. The safe tunes are around 435-440 at prop shaft. I’ve run many many boats back to back with tuned L6 repower to 450 and the 450 was always 1-2% faster top speed, and much faster acceleration.

Can’t beat the L6 reliability though.

There are a couple guys in FL who have rebuilt the L6 to over 500hp. But all on quad applications; and the lowers don’t last hahahah. But let me tell you they sound GREAT at 8,000 rpm

 

[Hayabusa]

I hear ya, luckily here for me 93oct is readily available and when I’m at a marina that doesn't carry 93 I’ll get Rec 90 and add Ace’s IV and I’m good to go. When I had the 300 on the back best speed I managed was 78-79, with 400R I topped out barely at 83 with an aft cockpit and bow covers on, now with the hot tune the other day my wife and I scooted across Lake Okeechobee heading out to Roland Martins doing 87, that was awesome!

 

[Petrowell 1]

Starting Repower...

 

[Hayabusa]

NICE!!!!

 

[Petrowell 1]

Ready to roll, now to sit and wait for ice to come off of lake.