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Originally Posted by rmbuilder
(Post 3000937)
The 600 SCI camshaft has become the point of greatest restriction at this point in the testing. The limitations of the 600 SCI camshaft is; compared to the 700 SCI, it has some 18⁰ less intake duration, .056” less lift @ valve (roughly 10%). That being said, the 700 SCI camshaft is significantly less aggressive than the 525 EFI. Cam selection for this series of engines was weighted with a bias toward warranty issues rather than performance.
The very short valve open time and limited valve curtain area builds manifold pressure disproportionately to rate of cylinder fill. In this instance boost is more a measure of restriction than a performance parameter. A swap to a less restrictive camshaft will increase power while decreasing boost relative to output. Bob Thanks Bob, So what you are saying is that with the 600sci cam... boost is building in the manifold, but not getting to the cylinders because of the short duration, and minimal lift of the cam. This is also exactly what Dustin explained to me. Makes sense, Chris |
Originally Posted by Beak Boater
(Post 3000773)
But typically dont you raise the rev-limiter to 5800 rpm with your upgrade? I am assuming that the torque management system is programed to protect the NXT trans. It can he a pain it the butt with a heavily loaded boat.
Originally Posted by Whipple Charged
(Post 3000944)
Yes, 5850. Yes its in there for protection for people who go right to WOT off idle, never recommended, no matter what
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Originally Posted by CB-BLR
(Post 3000838)
Merc smartcraft/race view still works.
Chris |
Originally Posted by lavey jr
(Post 3000997)
So everything will work the exact same and the screen will display all of the vitals through out the added rpm's? And the screen that shows each hour minute second at each rpm will go all the way up to 5800 rpm?
Chris |
Originally Posted by Whipple Charged
(Post 3000947)
I really don't know of anyone that's had any problems. We've had a few with water psi issues, but that was the same as stock. So there is no negative feedback to speak of.
Mark knows his stuff for sure! Do you agree that keeping the same props will keep some of the load of the NXT |
at least 40 psi at WOT
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Originally Posted by gnorthga
(Post 3001061)
What kind of water pressure do you want to see
If you are having water pressure issues on either a 600 or 700, contact Dustin directly... he has fixes for this. Chris |
Originally Posted by aTX427
(Post 3001128)
I had big time water pressure problems with my boat in stock form. Dustin helpe me out BIG TIME. The engines would go into guardian mode intermitently throwing overspeed errors even through I was no where close to the rev limiters. Turns out, water pressure is a non-sticky code, meaining it does not show up as an error on the display or in the Freezeframe.
If the water pressure is not at least 20psi at 4,200 rpm's the engine limited power in guardian mode to 70%. Since the engine was still spinning around 4,000 rpm's when the engine issued the Guardian code, it would then issue an overspeed error (70% of 5,400 = 3,780). The next threshold is at 4,800 rpm's, where you need at least 28psi of water pressure, othewise the same probem occurs. It took hours upon hours of data logging. Neither the dealer tech's nor the Mercury techs could find a problem. I would still be chasing this problem if it was not for Dustin. He calls me the next day and says it is water pressure. I opened up the water channel that feeds my offshore pickups and the problem is solved. The water flow is so good, that had to install pop-off valves that engage at 45psi to bleed of extra pressure, so I would not worry one bit about re-routing the intercooler pickup location in the system or increasing flow to the intercooler with a bigger feed. |
Originally Posted by CB-BLR
(Post 3001022)
Yes,
Chris |
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