Centrifugals and Screws, CompRatio vs. Boost and Detonation?????
#12
1975 X-18 Donzi, Arneson
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Thanks..TC.
The blower is turning 42,780 @ 6,300 rpm 3.8psi.(@ intake manifold) Not sure what boost is at 6800rpm but blower would be turning 46,200. I have a 5" pulley on the blower, 7.65" at crank shaft and the SCM3 blower is a 4:44 unit.
Never checked the pressure just after the blower.
The blower is turning 42,780 @ 6,300 rpm 3.8psi.(@ intake manifold) Not sure what boost is at 6800rpm but blower would be turning 46,200. I have a 5" pulley on the blower, 7.65" at crank shaft and the SCM3 blower is a 4:44 unit.
Never checked the pressure just after the blower.
#13
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Hey Geoo,
Did you build your 434 sbc with a standard 400 block or did you go with one of the aftermarket ones like Dart or Motown.
I am getting ready to build a 427 sbc and can't decide weather or not I should use one of the aftermarket blocks?
Thanks ------- Tee
Did you build your 434 sbc with a standard 400 block or did you go with one of the aftermarket ones like Dart or Motown.
I am getting ready to build a 427 sbc and can't decide weather or not I should use one of the aftermarket blocks?
Thanks ------- Tee
#17
JimV, It's getting really close. The only snag is you need a stellings ext box for the bravo 1 drive. I have the unit and will take pictures this weekend. Any questions let me know. Marty.
#18
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TC- what would be your guess the lose that geoo is getting from all of his plumbing? The tests that you did was with less pipe & 90's, right? If you are guessing 10% than 738hp will have a HP increase of 74HP, another 4 mphs
#20
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10% is my best estimate but that's based on the compressor map for the Vortech V-7 YS trim compressor which according to the literature is similar in performance to the M3SC. That doesn't mean the compressor maps are the same but let's say they are.
GEOO has only ~4 psi intake pressure because he probably has very good breathing cylinder heads. But the compressor probably needs to deliver 8 psi to get through to the intake manifold. I'm estimating 4 psi lost through the intercooler, elbows etc. This has nothing to do with the pressure drop when you cool with water.
If the loss through the intercooler, elbows etc. was reduced to 2 psi, then the compressor only has to deliver 6 psi to begin with, not 8 psi. So you could actually change the pulleys to spin the compressor slower and make the same HP, maybe a bit more since the air leaving the compressor is now cooler.
Of course none of you guys are going to slow the compressor down, so what happens is the compressor delivers more air, since you have reduced the resistance of the air pathway. This is where the extra HP comes from.
Hey cobra marty - I can't wait to see the pictures. Keep pushing man!!
GEOO has only ~4 psi intake pressure because he probably has very good breathing cylinder heads. But the compressor probably needs to deliver 8 psi to get through to the intake manifold. I'm estimating 4 psi lost through the intercooler, elbows etc. This has nothing to do with the pressure drop when you cool with water.
If the loss through the intercooler, elbows etc. was reduced to 2 psi, then the compressor only has to deliver 6 psi to begin with, not 8 psi. So you could actually change the pulleys to spin the compressor slower and make the same HP, maybe a bit more since the air leaving the compressor is now cooler.
Of course none of you guys are going to slow the compressor down, so what happens is the compressor delivers more air, since you have reduced the resistance of the air pathway. This is where the extra HP comes from.
Hey cobra marty - I can't wait to see the pictures. Keep pushing man!!
Last edited by tomcat; 11-08-2002 at 10:25 AM.