mcollinstn

Supercharging HP500's is a "known quantity". Lots of good build formulas out there. With the way you asked the question, though, I think you need to hook up with a good marine builder as suggested. They can provide a reliable turnkey package that you can trust.

If you were a wrench jockey yourself, there are plenty of ways to save a buck and get results, but if you aren't good at understanding tuning parameters and such, then you need to stick with the packages that have been sorted out and debugged.

As has been mentioned, your outdrives will be the weak link regardless of who builds the motors. Upgraded outdrives are also in the same ballpark as motor building. You can install some drive upgrades on a budget and hope you set them up right, or you can buy beefy aftermarket drives and be well assured.

You've entered a world of "disappearing value" in hopping up a boat. You pour money in, but if you haven't spent it in the right places, you break parts and lose your investment value.

For a guy who isn't a tuner himself, it's better to spend towards the "reliable and strong" side of the equation and slowly add performance.

The other way (adding performance without the correct foundation) yields impressive short-term performance improvements followed by expensive repairs. This is not the way to "build a performance platform" that will provide fun and happiness.

MC

Wasted Income

According to Fred, you shouldn't mess with them, because they are perfect as-is! LOL

http://www.mercuryracing.com/blog/%e...step-right-up/

Hard Charger

If those are the original blue motors with more than 250 hrs on them. I would rebuild the top end and upgrade the exhaust before anything else. Do a search on HP 500s. If you choose that route you might as well refresh the bottom end, upgrade cam, upgrade heads, ignition and exhaust. That route will provide you 600-650 hp per side and you'll practically have new motors for roughly the same cost as adding superchargers. After that run the s**t out the bravos until they blow up. When they do upgrade to xr's or aftermarket drives.

Wow that speed bug gets expensive. Here's a much cheaper way to get the same feeling. Smoke a fatty before each run, that way 60mph feels like 120mph.

A.O. Razor

I love this part. LMFAO

"And IF a modified engine survives, its torque output would be well beyond the capacity of any Bravo drive. BOOM! Instant, unhappy boater. More “Gee, I was just driving my boat at cruise and the damned Bravo…” (It seems the drive always gets the blame even when the engine is modified beyond drive capacity.) This makes me crazy. We develop engine and drive-lines as a system – matched to live together – and warranted because they do."

If the B1XR actually was up to, well, even the power of the 525EFI and 600SCI, he could be taken seriously.

Randy Nielsen

iTrader: (4)

I think if mercury really gave a crap about anything other than making money on parts sales they would design a drive somewhere between an XR & a#6 because it sounds like a lot of people are advising away from merc when someone wants to upgrade engine power. Now for the joke, A guy wrote in to Hot Rod mag, said he wanted to impress his friends on how fas his car was but did'nt have a lot of money. HR response bend the speedo needle just dont let em see the speedo at 50mph when the car is stopped.

pqjack

that's why marine speedos do not rest at zero when docked !!

blue thunder

I saw Mild Thunder had 2 bm 250 complete blower setups for sale in the swap section recently for 4.5k. You might see if those are still available. I put 525sc takeoffs (177s) on my 454s a couple years back and love the power and perf they added. It has not gone without breaking parts though as some have mentioned. But I love wrenching so it working for me. Your boat would be sick fast with those 250s on hp500s.

heres mild thunders ad. Best deal you will find...
http://www.offshoreonly.com/forums/s...-complete.html

tcelano

[QUOTE=Randy Nielsen;3560196]I think if mercury really gave a crap about anything other than making money on parts sales they would design a drive somewhere between an XR & a#6 because it sounds like a lot of people are advising away from merc when someone wants to upgrade engine power. /QUOTE]

Isn't it called an NXT-1? Allows the engine to be mounted in Bravo position, upgradable to NXT-SSM Lower. Granted there are cheaper ways to go about getting a 800-900 hp capable drive.

A.O. Razor

Well yes, but the price of the normal NXT1 is not low, and the NXT/SSM drive is really expensive. The Indy retails for about 30k and I doubt the price of the NXT/SSM is anywhere near that. Also, the B1 to NXT swap is not an easy plug and play thing, you'll need a complete rerigging.
Oh and you will also have to deal with the crappy merc service as well All in all, it's the Arneson ASD#7M or Indy if upgrading Bravo drives.

Randy Nielsen

iTrader: (4)

The NXT is the setup that runs a trans inside a standoff box isnt it? That would be another mercury product to fail only a lot more work to get to to fix merc prices everything they sell should be made of solid gold. After standing about 5ft from Fred K @ desert storm explaining to another gentleman that people that hop their boats up using anything other than merc stuff are stupid & deserve what they get when a drive blows up I held my tongue but wanted to tell him in front of the other guy that if they stood behind their products like they do their price tags maybe people would do that, & also some of the certified merc techs whose work I have seen & had to fix I wouldnt let work on my lawnmower let alone a 100K or more boat. The guy struck me as an arrogant azzhole & to think before hearing that conversation I was thinking seriously about buying a pair of 525s & letting them install them at one of the shops in town,take a longer vacation while I was there. Out the window went that thought . After I finish my house project I will be talking to Raylar , Maybe look into this Arneson bit at least I havent seen any threads on here about their stuff blowing up!