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Originally Posted by darin
(Post 2697065)
I dont know exactly what the 278 performance is but I have a 1998 272. When I originally purchased the boat it had the stock 454 with the side load Whipple Charger and bigger injectors, the boat ran 81 on GPS after trying a few different props. In 2006 I pulled the 454 and went to a 540 with eldebrock marine heads, 871 blower shop blower with the super chiller. The best I got out of it was 87 on GPS when i blew the drive. I pulled the drive and went to the IMCO Extreme. The best i got out of it was 92.6 on GPS.
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scoop
Actually I do not run a scoop, all I did was cut the hatch and let the breather come through.
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Originally Posted by darin
(Post 2697880)
Actually I do not run a scoop, all I did was cut the hatch and let the breather come through.
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Originally Posted by BAJA WILL
(Post 2694820)
I have a customer who is wanting to build up a 278 Performance, he wants at least 80mph we have never built one that fast and was wanting to get an idea of who has??
I am thinking at least 600hp, but would really like to hear from anyone who has put some HP behind a 27 Performance Thanks WILL:ernaehrung004: Currently I'm running a procharged 540 with fuel injection. I spent alot of time on the dyno this go around so I dynoed it both blown and with the blower un-hooked. My hp numbers are going to be a little high compared to the way merc test their motors,my dyno runs were at the more generous sae rating of 60 degrees vs 77 degrees that merc uses and I did not have a water pump on it either. It was ran with cmi headers though,not dry dyno headers. Motor made 1115 hp /1037 ft lbs tq w/3.70 pulley (13 lbs boost) on 20% race gas/80 % 92 octane-have never ran w/this set-up in the boat (YET) 1057 hp/1009 ft lbs of tq w/3.85" pulley on 93 octane-have seen 98-99 mph turning labbed 32 merc 4 blade 5900-6000,runs 95 turning labbed, up-pitched 30 pitch merc 4 blade 6100-6200 made 1037hp/971 ft lbs of tq w/4' pulley-runs 92-93 mph w/labbed merc 4 blade 30 pitch I also dynoed motor w/ blower un-hooked,motor made 657 hp/665 ft lb of tq ,now remember this was at the more generous 60 deg sae rating w/no water pump,these numbers would probably be closer to 600-620 hp aplles to apples so this should be comparable to a merc 600 sci. Boat has ran 76 mph turning a labbed 26 pitch 5500-5600 with this set-up. I was actually out testing/tuning the efi program tonight with this same set-up until dark,it ran 74 gps with imco-2 shorty and a labbed 26 merc 4 blade w/ "baja cup",wasn't the 80 mph I was hoping to see. Past motors-boat new ran 62 stock w/ 502,we are at 670 feet above sea level,ran 64 with 10 gallons of gas ,no extra weight what so ever,never tried a ton of props back then either. Built the first blown 502 w/merlin heads,unknown hp boat ran very high 70's,never dynoed that combo but estimated it around 650-675 hp Built my first blown 540,made 620 hp/700 ft lbs of tq,boat ran SLOWER directly off the dyno then the 502 ran,75-76 mph turning a slightly modified 26 pitch. Turned the boost up,gained 2 mph,turned it up some more,broke into the 80's. Turned the timing up a few degrees,gained another 2 mph,turned timing up another 2 degrees,broke into mid 80's occasionally,we estimated the "new" hp to be mid 750's. Built a bettter 540 blower motor,made close to 950 hp. Boat ran high 89's w/ 4 big dudes in the boat and 70-80 gallons of gas turning 30 labbed merc 5900-6000. Ran 92.8 (best) w/same motor turning 32 labbed 4 blade running light. Smitty |
Originally Posted by Smitty
(Post 2695106)
That 600SCI will only get you upper 70's to low 80's
Artic Friends/ AKA the other Smitty :) has about 1000 blown hp in his rig and he is right at 98 mph consistently. And he has his motor dialed in. :) |
Thanks for the input, for what we are up to price wise I can damn near put him in a 30 OL with twin 496 HO and run 80mph.
OK thanks WILL:drink: |
Wild Card has a 25 OL with 600SCI, extension box, and 2" shortie and not sure which prop,think it is a 30", but he runs 84-85. He moved up from a 525 to the 600 and went from 81 with the 525 to 85 with the 600.
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any pic s of your 272 im lookin at this size of a boat,
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3 Attachment(s)
Originally Posted by injun
(Post 2713367)
any pic s of your 272 im lookin at this size of a boat,
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Holy chit your so fast in that second pics your just a blurrr:ernaehrung004:
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