NASCAT

Generation IV engine packages released in Miami are now a 650 V-10 & 725 V-10 up from the previous Gen III 625 & 710.

They sound like an Indy / IRL car at speed but relatively quiet when compared to a BBC.

LapseofReason

Do you know if they have an ecm/knock sensors like the Merc so if you need gas and cant get 92 oct it will pull the timming back so you can run lower oct fuel? It's not easy to find 92 around here.

NASCAT

I am not positive on that. They recommend 91 & I've run 89 in my previous boat that had a pr of 625's in it.

Marginmn

iTrader: (1)

SO how are they achieving the extra HP? If it's via an ECU change can the older engines be bumped up to the new standard?

C_Spray

iTrader: (2)

These are new generation engines, and share almost no parts with the old ones. All are uprated by 25 hp over the previous generation: 575, 650 and 725 now. The 575 and 650 have variable valve timing, but not the 725. The previous "710" was actually a "7-10", meaning 700 hp/10 cylinders. All are built on the regular V-10 assembly line, although the 725 gets special internals. The web site is due for an update.

Can't speak for the sound, but the car suffers from only being able to hear one bank of the engine at a time. I suspect that it's better with both tailpipes pointed rearwards. Does anyone have any good YouTube links?

fantastixvoyage

iTrader: (1)

Haven't followed them in awhile, did they keep the variable cam timing as found in the new Vipers or lock it out? I would assume lock-out as it doesn't serve the same purpose as the automotive brothern...unless it helps with emissions.

Uncle Dave

You can hear my 7-10 in the video section under "710 singing".

And you can it hear it start and idle as well as sruise and run as well in another video - I think I called it Uncle dave something.

Sounds like a cross between a big block chevy and a Ferrari/Lambo. Which makes sense because its right in between cylnder wise.

Sounds completely unlike the auto app- (which has not reached the 700HP threshold yet from the factory) I never did like the sound of the car.


Uncle Dave

stainless

Has anyone tried y-pipes on these?? seems like it would help the torque and the sound??

Uncle Dave

Not sure-Mine have zoomers on them and they are VERY quiet.
Too many sound level tickets at the dock these days.
The engine power is rated and dyno'd with the CMI's the engine ships with.

UD

fantastixvoyage

iTrader: (1)

If I remember right its been done at least once. The V10s do sound great. Nice crisp revving engine.