top speed questimate
#1
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top speed questimate
Hey Nordic guys...I have a 97 heat closed bow non step of course and I'm in the process of doing some engine upgrades and just curious what kind of top speed I may be looking at when I'm done...it had originally a 525 sc that I'm building and putting a bigger blower on and from what I've been told I should be in the 650 hp neighborhood with a 1.50 outdrive with 2 prop options...28p bravo untouched or a 30 pitch labbed bravo 1 both 4 blades...boat has a noseconed stock bravo lower
I know I'm flirting with disaster with the outdrive so that can go without saying just looking for guesses on a top speed
Boat ran 75 on cooler days with the 525 with a chiller at 6 lbs of boost with the 28 pitch prop
thanks for any guesses
Stewart
I know I'm flirting with disaster with the outdrive so that can go without saying just looking for guesses on a top speed
Boat ran 75 on cooler days with the 525 with a chiller at 6 lbs of boost with the 28 pitch prop
thanks for any guesses
Stewart
#2
Just my .02, but I'd guess if your in the 650 hp range, and spinning that 30 efficiently in the 5400ish range, I'd say low eighties wouldn't be out of the question, I think the stepped heats with the 600 setup run in the low 80's
#3
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That's what I was hoping for low to mid 80s...I think my exact words were if this boat doesn't run 80 after all this I'm gonna sink it hahahahaha
#5
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me too thanks!!
#6
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Little update on this...best I saw so far was 79.5 gps but...that was when the exhaust valve stuck so basically on 7 cylinders 5 lbs boost out of the 8-71 with the stock 28 bravo...seeing how fast it climbed to 79 I truly believe consistent 84-85 is attainable with tuning and prop work...I'll update this once the motor is back in and I get her back out...assuming the dreaded white stuff(snow) doesn't hit me first hahaha
#7
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Little update on this...swapped to a 1.36 ratio shorty and ran best with the same 28 I had been running...untouched bravo 1 ran 82 mph gps at 5000-5100 5 lbs of boost...motor is coming out for some head work that once again my builder screwed me on and a new cam...wanting to twist it to the 5800 neighborhood so I'm thinking 85 with prop work is easily attainable
#8
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Also tried an untouched 26 bravo 1 and it ran exactly the same except for a good amount of chine walk at 80....that's what made me dive into my motor and do some researching...long story lol