Monsoon II Upgrade

[Lieutenant Dan]

I have what I believe is the Monsoon Series II engine...rated 325HP...in my 2001 SSLXI. My buddy's 2004 SSLXI has the "340" Monsoon. His boat kicks mine's butt in throttle responsiveness. I've heard that the 340 is really more like a 350hp motor and that the major difference was new intake and exhaust manifolds. Can anyone verify this? What else is different, e.g. ECM? Can a person get these parts aftermarket?

[UWSkier]

I'm not sure if the ECU is different, but I know the codebase definitely is. If the hardware is the same, you should be able to get the '04 software image installed on your ECU, then do the intake and exhaust mods. I'm pretty sure the internals of the engine are identical.

[wienrdog]

If I remember right, someone was looking at the manifolds/exhaust and each exhaust was $750 or so. Pretty pricey upgrade.

Edited July 23, 2007 by weinrdog

[Hman442]

If I remember right, someone was looking at the manifolds/exhaust and each exhaust was $750 or so. Pretty pricey upgrade.

A friend of mine upgraded the manifolds on his '01 Monsoon VLX. He noticed a difference - but was it a $1400.00 difference?

[John I.]

I have what I believe is the Monsoon Series II engine...rated 325HP...in my 2001 SSLXI. My buddy's 2004 SSLXI has the "340" Monsoon. His boat kicks mine's butt in throttle responsiveness. I've heard that the 340 is really more like a 350hp motor and that the major difference was new intake and exhaust manifolds. Can anyone verify this? What else is different, e.g. ECM? Can a person get these parts aftermarket?

I'll ask the obvious question, are both boats propped similarly?

[edwin]

I had the 325hp Monsoon in my SLXi, my brother has the 335hp Monsoon in his RLXi, I currently have the 340hp Monsoon in my RLXi. Without question, the 335 and 340 have a much stronger bottom end than the 325hp.

FWIW, we've run our RLXi's side by side on a few occassions...there's no performance difference between the two. Same out of the hole, same mid-range, same top end...identical. His has the cast iron manifolds,mine has the ETX.

If I recall, they changed the intake manifold from the 325 to 335, as well as some computer mods. That's where I'd look to start

[chadwick02]

I'd start at the propeller and go from there. That could make a HUGE difference.

[Lieutenant Dan]

I'll ask the obvious question, are both boats propped similarly?

Exact same prop....ACME 525 (or 515, I can never remember which one is the 13 X 12 standard)

[Lieutenant Dan]

I had the 325hp Monsoon in my SLXi, my brother has the 335hp Monsoon in his RLXi, I currently have the 340hp Monsoon in my RLXi. Without question, the 335 and 340 have a much stronger bottom end than the 325hp.

FWIW, we've run our RLXi's side by side on a few occassions...there's no performance difference between the two. Same out of the hole, same mid-range, same top end...identical. His has the cast iron manifolds,mine has the ETX.

If I recall, they changed the intake manifold from the 325 to 335, as well as some computer mods. That's where I'd look to start

Hole-shot is where I really notice it...

[mlange]

I'll ask the obvious question, are both boats propped similarly?

Exact same prop....ACME 525 (or 515, I can never remember which one is the 13 X 12 standard)

515