More speed please
03-20-2006, 10:02 PM
#41
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Re: More speed please
Originally Posted by CayFomula
Unfortunately none with sound, next time I take it out for a hard run I will carry the video (maybe if I record the GPS they will believe me 
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03-21-2006, 06:07 AM
#42
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Re: More speed please
If I remember rightly the weight on a 272SR1 is 6700lb dry and I would assume I am right around that because what I have saved with aluminum heads and the stainless marine manifolds I added back with the superchargers, XR drives and radar arch. The rest of the hull is stock i.e. full cabin: refrigerator, porta potti and all.
03-21-2006, 09:51 AM
#44
Toxic FORMULA
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Re: More speed please
Originally Posted by FormulaM2Formula
Hi Mopower,
Did you remove the silent thunder box after your engine upgrades? I'm thinking that sounds like a really huge gain for a stock engine. With all your upgrades intact though, the reduced back pressure probably made it come alive.
Garrett
Did you remove the silent thunder box after your engine upgrades? I'm thinking that sounds like a really huge gain for a stock engine. With all your upgrades intact though, the reduced back pressure probably made it come alive.
Garrett
Last edited by mopower; 03-22-2006 at 09:26 PM.
03-21-2006, 11:15 AM
#46
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Re: More speed please
NADA has my boat weighing in at 5750 dry, the big blocks cant make that much of a difference. NADA may be off though. this is the conversation I expected on this topic. Now i know big power = go fast.
03-21-2006, 01:16 PM
#47
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Re: More speed please
Thanks Flatout, as long as you are getting the information you are looking for I'm happy to keep the conversation going.
On the weight you might be right, I got my figure from a very old magazine article.
If you are going to put the money in to go fast, my suggestion would be keep your eyes open for a pair of Bravo drives and then start looking at motors. However if you know for sure you are going to do this then there is what looks to be an excellent deal on a pair of 577ci motors in the Swap Shop section (if I could afford it right now they probably wouldn't be there). They would get your boat motivated. Having said that there is no substitute for forced induction, I believe the only thing better is big cubic inches with forced induction
On the weight you might be right, I got my figure from a very old magazine article.
If you are going to put the money in to go fast, my suggestion would be keep your eyes open for a pair of Bravo drives and then start looking at motors. However if you know for sure you are going to do this then there is what looks to be an excellent deal on a pair of 577ci motors in the Swap Shop section (if I could afford it right now they probably wouldn't be there). They would get your boat motivated. Having said that there is no substitute for forced induction, I believe the only thing better is big cubic inches with forced induction
05-07-2006, 07:14 PM
#48
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Re: More speed please
Originally Posted by CayFomula
If you are every in Cayman I will happily prove it to you. Ask HadrcoreAO what he thinks since he and I have ran a few times.
Anyway on the motors, they were stock when I initially installed the intercooled Whipples and IMCO 2" shorties. it ran about 84-85 on GPS. I then rebuilt the motors, added Dart Pro1 heads and a custom grind cam and increased the boost to 9# and saw very little difference until I removed the silent thunder exhaust at which point it ran 92 right away. It accelerates very strong, I can roll into a marked 1/4 mile at 20mph and hit 90 at the finishline.
If you would like to calculate it I am turning 5800rpm with 30" pitch labbed Bravos on 1.5 ratio XR drives and I consistently get 14% slip.
Anyway on the motors, they were stock when I initially installed the intercooled Whipples and IMCO 2" shorties. it ran about 84-85 on GPS. I then rebuilt the motors, added Dart Pro1 heads and a custom grind cam and increased the boost to 9# and saw very little difference until I removed the silent thunder exhaust at which point it ran 92 right away. It accelerates very strong, I can roll into a marked 1/4 mile at 20mph and hit 90 at the finishline.
If you would like to calculate it I am turning 5800rpm with 30" pitch labbed Bravos on 1.5 ratio XR drives and I consistently get 14% slip.
Cay,
Where did you pick-up the other 8mph from your earlier post?
I thought the mags were not available for 272 SR-1's in 89? I believe this was your quote:
I have a 89 272SR1 with twin 454Mag Bravos (carbed) it ran 67mph on GPS totally stock engines and drives with non-labbed 3 blade props. Added Stainless Marine exhaust but it made no difference to the top speed. I added IMCO 2" shorties and went to 71mph on GPS with a good set of Hydromotive 4 blades.
I then added Whipples and went 84 with labbed Bravos.
I want to add "chargers" and "lowers" next year too. How did your 272 react out of the hole with the shorties and hard turns?
05-07-2006, 09:39 PM
#49
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Re: More speed please
mtgbiker, I rebuilt the motors and while I was at it I installed custom grind cams from Crane and CNC'd Dart Pro1 heads. With this combo I am now able to run 9# boost on pump gas but didn't see much difference until I removed the Silent Thunder platform at which point I picked up 7mph.
On the handling with the Shorties, I can literally jump on plane like a ski boat if I get into the throttle pretty hard but in general it gets on plane pretty good, the minimum planing speed is now about 3-5mph higher though even with the 4-blades. It is almost impossible for me to get on plane with 3-blades now. As far as in the turns it feels like it is on rails, no problem what so ever.
On the handling with the Shorties, I can literally jump on plane like a ski boat if I get into the throttle pretty hard but in general it gets on plane pretty good, the minimum planing speed is now about 3-5mph higher though even with the 4-blades. It is almost impossible for me to get on plane with 3-blades now. As far as in the turns it feels like it is on rails, no problem what so ever.
05-07-2006, 10:42 PM
#50
Re: More speed please
Originally Posted by CayFomula
mtgbiker, I rebuilt the motors but didn't see much difference until I removed the Silent Thunder platform at which point I picked up 7mph.
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