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Quote:

Originally Posted by kachinapowerboats (Post 2230808)

I have another customer running twin 975's in one of our 34's and he is running about 116mph. Believe it or not he decided to go with XR Drives. He says the #6's rob way to much HP so they may be part of the problem along with the big props?

I'm willing to bet he'll regret that move. :(

Quote:

Originally Posted by kachinapowerboats (Post 2230804)

I have to agree that it is the torque management system. A Merc racing engineer came out to assist and certify my guys in the installation and he deemed it normal. Bottom line is the customer is bummed about it. He loves his new boat but claims he regrets the power train decision he made. We are running a 5 blade maximus , cnat recall the pitch at the moment but it is the one that performed the best overall. My customer tried a 4 Blade Bravo and he says it helped a little out of the hole but killed his top end. We have done 720's from Teague and they performed awesome! The 700sci is a beast and a hell of a motor but I think Merc needs to Torque management issue soon! P.S. The reason my customer chose the 700 is becuase he lives in Lake Tahoe and is at 6800 feet. The one cool thing is he only lost 2mph with the altitude chane from Phoenix to Tahoe!

Did the customer ever check it with a scan tool, see what the timing and manifold psi was when it felt low on power? The 700sci run very conservative timing down low, which I assume is for the tranny. I've been working on a boat that took the 700sci out, put a 598ci 1200hp engine in. Although it only idles at 750, it doesn't have a shift interupt in it and it bangs like you can't believe during shifting. I'm working on interupt to help it, but so far, everything has held up, although the drive has made handling extremely bad. Gonna try again this weekend, have the X dimension 3" higher than a Bravo, and now have gone to the 5 blade mercury cleaver (#6 prop). Its a Vbottom, and it just goes where it wants, very little steering control. That was with it only 2" higher than a bravo application. I'm actually thinkin it needs to go even higher, but thats not really feasible.

I'm sure they are just trying to save the driveline...because they never who is going to be running the boat...if you know what I mean...and probably the cam/head package to produce those H/P #'s may very well be laxed on the bottom end...can't have it all sometimes ! Rob

I have no lag with my engine. It's not a Merc 700, but it is a similar mechanical engine. So the difference will be the softwear.

On another note, why is your customer concerned with the hole shot??? If the boat gets on plane, thats all that should matter. he isn't hurting anything or stressing anything out with a soft hole shot. Why people hit WOT before on plane to me is just stupid and purposly abusing the equipment. These aren't drag boats.....

Check out this video, if you haven't already seen it. There is CERTAINLY lag before the boost comes up, built into the software. Otherwise, this guy would have left his drives on the bottom of the ocean. These are Merc 600's. What an idiot, by the way!
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Quote:

Originally Posted by pasquesi (Post 2550353)

Thats what I mean, idiots like that. Drive mechanics must LOVE those guys.

twin 700's 40 pitch props no lag. 33 Eliminator.

Quote:

Originally Posted by Canada Jeff (Post 2550325)

In some boats, when they have such large props, and low rpm ranges, they may need some extra torque down low, but like you said, with drivers like that, you can't always have the best of both worlds. I wonder if the 700sci equipped with #6 drives have a different program.

Dustin

Quote:

Originally Posted by B BOATER (Post 2550719)

twin 700's 40 pitch props no lag. 33 Eliminator.

Do you have # 6's or NXT's? By the way, I have a 33 as well.