Performance expectations with new engines
 

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.

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.

Also are you positive about your wheight #8400 seems light for a 1985 35' Cig mine is a '94 and is #9400 Dry.

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.

Re: Performance expectations with new engines
 

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

Re: Performance expectations with new engines
 

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

Re: Performance expectations with new engines
 

74-75

Re: Performance expectations with new engines
 

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.

Re: Performance expectations with new engines
 

Hmm, this is an old thread, I'm surprised to see it come back up. I ran the boat this past summer with the 540's, which ended up making about 675hp@ 5600, and ran a best of 68.9 mph on the GPS with 21p Mirage's. These were the props that came with the boat and the 330's, but I never got around to replacing them with props appropriately pitched for the 540's. I'm doing that this winter, my wife is getting me a pair of 25p Mirage Plus's for Christmas. I'm hoping for 75mph, but most importantly an increase in cruise speed. I was only getting 40mph at 4000 rpm.

Re: Performance expectations with new engines
 

My 1977 Mistress has twin 650 hr with trs 71 at 5500 using 24 hydromotive.