Whipple 600sci upgrade documentation
11-28-2009, 09:18 AM
#41
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11-28-2009, 10:55 AM
#42
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Eddie
11-28-2009, 01:38 PM
#43
Chris
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Thanks Eddie for the response......
To figure this out mathmatically, you figure out the psi of the engine... one atmosphere = 14.7 psi at sea level ... therefore 7.5(compression ration) x 14.7psi = 110.25 psi cylinder pressure. Pretty darn low.... Add to that the 12psi the blower is introducing, and you come out with 122.25 psi for cylinder pressure... still very easy for 93 octane to control the combustion speed (no pinging). Effective combined compression ratio would be 8.32 to 1.
In Eddies example of 9 to 1 compression ratio, cylinder pressure would be 132.3psi, and the supercharger would add another 12psi to make cylinder pressure 144.3psi or about 9.8 to 1 total compression ratio. Still managable by 93 octane fuel.
So... with a 7.5 to 1 compression ratio, you would have to run aproximately 22lbs of boost in order to reach the combined compression ration of 9.8 to 1 that Eddie and others have safely run.
Short story... we are not pushing this motor very hard in order to acheive the horsepower levels we are at... it is just a good motor combination!
Hope this helps,
Chris
P.S. The boost on the stage I is 8-10 lbs. ... stock is 5-6 lbs
To figure this out mathmatically, you figure out the psi of the engine... one atmosphere = 14.7 psi at sea level ... therefore 7.5(compression ration) x 14.7psi = 110.25 psi cylinder pressure. Pretty darn low.... Add to that the 12psi the blower is introducing, and you come out with 122.25 psi for cylinder pressure... still very easy for 93 octane to control the combustion speed (no pinging). Effective combined compression ratio would be 8.32 to 1.
In Eddies example of 9 to 1 compression ratio, cylinder pressure would be 132.3psi, and the supercharger would add another 12psi to make cylinder pressure 144.3psi or about 9.8 to 1 total compression ratio. Still managable by 93 octane fuel.
So... with a 7.5 to 1 compression ratio, you would have to run aproximately 22lbs of boost in order to reach the combined compression ration of 9.8 to 1 that Eddie and others have safely run.
Short story... we are not pushing this motor very hard in order to acheive the horsepower levels we are at... it is just a good motor combination!
Hope this helps,
Chris
P.S. The boost on the stage I is 8-10 lbs. ... stock is 5-6 lbs
Last edited by CB-BLR; 11-28-2009 at 02:51 PM.
11-29-2009, 10:47 AM
#45
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I am sure they are using Cometics. They will outlast the rest of the engine. I have yet to have a problem with a Cometic gasket. And I have really tried......1400+ hp and 50 psi of water pressure for well over 100 hrs.
Eddie
Eddie
11-29-2009, 01:36 PM
#46
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Why is it that a 525 with a whipple can make 775hp with only 7 psi of boost and a 600sci needs 10-12 to make 750hp? I realize that the 525 has a little more comp. and a little bigger cam. I'm not trying to secound guess any one but that still sounds little a lot of boost. My new nordic 28 is being built with the 600sci and i know i will need more power when the warranty is up but i don't think i would fill good about running that much boost on pump gas. How much boost does the 700sci have to make 700hp? The cam is only slighty bigger in the 700 over the 600.
chris and eddie thanks for all the info
chris and eddie thanks for all the info
Last edited by sport; 12-01-2009 at 12:01 AM.
11-29-2009, 05:16 PM
#48
Chris
Gold MemberThread Starter
Why is it that a 525 with a whipple can make 775hp with only 7 psi of boost and a 600sci needs 10-12 to make 750hp? I realize that the 525 has a little more comp. and a little bigger cam. In an old boat i had with a 509 and roots type blower on pfaff's dyno at 7.5 psi of boost it made 844hp and with 8.5 psi it made 868hp it had the same cam specs. as the 525 and had brodix heads with 8.3 comp.. I'm not trying to secound guess any one but that still sounds little a lot of boost. My new nordic 28 is being built with the 600sci and i know i will need more power when the warranty is up but i don't think i would fill good about running that much boost on pump gas. How much boost does the 700sci have to make 700hp? The cam is only slighty bigger in the 700 over the 600.
chris and eddie thanks for all the info
chris and eddie thanks for all the info
The 525 has 8.75 to 1 compression, and a much healthier cam than either the 600 or 700.
The 700 requires 8-9 lbs of boost stock in order to acheive 700 horsepower (measured on two analog boost guages) at 5400 rpm.
You are underestimating the difference that the compression makes in these motors.
525 - 8.75 x 14.7 = 128.63 cylinder psi
600 - 7.50 x 14.7 = 110.25 cylinder psi
_______________
18.38 psi difference in cylinder pressure.
Chris
p.s. you will love the 600 in your Heat
Last edited by CB-BLR; 11-29-2009 at 05:26 PM.
12-01-2009, 12:12 AM
#50
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the 600 / 700 is way detuned. How about the NXT trans? What are they rated at and are they breaking? I have only heard of two; one being driver error and the other was in a cat that is run hard in rough water - never heard the real deal on why it broke.
