Performance expectations with new engines
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Anyone have a good idea of what I can expect performance/speed-wise from my '85 35' Cigarette Mistress with 600hp@5500rpm, 675ft lbs @ 3500 rpm T-540's with TRS drives and weighing in at ~8500#? I know there are other similar Cigarette's out there with similar setups.
The boat was originally equipped with 330hp 454's and was good for 60-62mph. The speed predictor at go-fast.com says 80-82 mph with 1100 combined hp and 8500#, but I think that is probably overly optimistic. I'm not looking for the highest top speed possible, just overall respectable performance. 75 mph would be nice though. TIA.
The boat was originally equipped with 330hp 454's and was good for 60-62mph. The speed predictor at go-fast.com says 80-82 mph with 1100 combined hp and 8500#, but I think that is probably overly optimistic. I'm not looking for the highest top speed possible, just overall respectable performance. 75 mph would be nice though. TIA.
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Monty,
Remember that the speed calculator at Go Fast is based on Prop shaft HP not crankshaft. For example a Merc 500HP has 470 at the prop. That calculator has always been pretty accurate when all the information is fed in.
Good Luck.
Remember that the speed calculator at Go Fast is based on Prop shaft HP not crankshaft. For example a Merc 500HP has 470 at the prop. That calculator has always been pretty accurate when all the information is fed in.
Good Luck.
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GLH,
That's a good point about crank vs. prop hp. My 540's should make 590-600hp, so I used 1100 combined as the hp input, figuring a drivetrain loss. I based this drivetrain loss on my automotive experience knowing that automatic transmissions and drivetrains generally lose around 15%. But that's with a 4 speed automatic tranny, driveshaft, differential, and rear end. I figured that was a conservative drive loss. Maybe I'm wrong, but I would have thought the loss would be less on the boat as a result of the much simpler drivetrain( 1:1 Velvetdrive's w/ TRS) compared to a car.
I could also be wrong about the weight, but I was told 8500# was about what it weighed.
That's a good point about crank vs. prop hp. My 540's should make 590-600hp, so I used 1100 combined as the hp input, figuring a drivetrain loss. I based this drivetrain loss on my automotive experience knowing that automatic transmissions and drivetrains generally lose around 15%. But that's with a 4 speed automatic tranny, driveshaft, differential, and rear end. I figured that was a conservative drive loss. Maybe I'm wrong, but I would have thought the loss would be less on the boat as a result of the much simpler drivetrain( 1:1 Velvetdrive's w/ TRS) compared to a car.
I could also be wrong about the weight, but I was told 8500# was about what it weighed.
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my mistress is closer to 10,500. i'm ready to freshen or repower this winter. the engines are already out & stripped.i'm considering 540's anyone want to gues about top speed???
trs drives
trs drives
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You may want to get in touch with "Stalkin" (James) from the boards. He just sold his Mistress and replaced it with a sweet T/S Tiger. But he'd have all the info you'd want since he built the motors in his Mistress I believe. He lurks every once and a while on here but just PM him, he's approachable and a super cool guy.
Tank
Tank
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It's probably a kevlar boat, do you have a picture of it inthe water? Wasn't this Fred's old boat? I'm sure he would know. We had a Kevlar Mistress w/330s ran about 62. With 500hp it ran 70mph.
LS JR.
LS JR.
Last edited by lucky strike; 12-23-2004 at 12:01 AM.
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Originally Posted by lucky strike
It's probably a kevlar boat, do you have a picture of it inthe water? Wasn't this Fred's old boat? I'm sure he would know. We had a Kevlar Mistress w/330s ran about 62. With 500hp it ran 70mph.
LS JR.
LS JR.