Supercharger
08-09-2012, 11:27 AM
#46
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If my pulley system does not create enough boost at low RPM, I may mount an A/C compressor clutch pulley that will cut out when equilibrium is reached between the SC output and turbo inlet, and setup a bypass. That way I can overdrive the crap out of it at low RPM's when i need the boost most and kick it out automatically when the turbo kicks in.
08-09-2012, 12:21 PM
#48
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CFM goes down as the PSI goes up, but to answer your question, I don't know exactly. The best I can do is glean others numbers and shoot the averages until I actually get it up and running.
08-09-2012, 05:21 PM
#49
If you want to convert to cfm (cubic feet per minute) you need to multiply. One cubic foot = about .028 cubic meter.
Since cfm is measured in minutes, and cubic meters is measured in hours, you need to multiply by 60(minutes in an hour).
Needless to say, an engine is an air pump, and a blower is an air pump. If the blower can only move half of the air the engine can move in one revolution, doubling the ratio(2:1) will only get you to what the engine would do by itself. I realize that the ratio is over 2:1, and even one psi at idle would be nice, but is it worth the work and parasitic loss? SPEED THAT SUCKER UP!!!
08-09-2012, 05:36 PM
#50
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So a straight six fills a cylinder every 120 degrees, and that is where you are getting your 180 cubic inch volume value. If the supercharger displaces 90 cubic inches (is that per revolution or static, I don't know) then you are right. I will have to overdrive the crap out of it. No biggie, I can do that. Still need a read on how they calculate volume on these superchargers....
08-10-2012, 11:18 AM
#52
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Yes you do, 10psi free reving last night before more slipping.
Cummins 3924977 Accessory Drive Adj Pulley is an 8 1/16in 8 groove pulley.
Once the bypass on the s/c opens, stress or the amount of power used to spin drops noticiably because the s/c stops whining and is just spinning not creating boost
My setup is drivin at a 4.2 ratio, at 3500rpm (pretend redline) my s/c will be spinnin 14700
Cummins 3924977 Accessory Drive Adj Pulley is an 8 1/16in 8 groove pulley.
Once the bypass on the s/c opens, stress or the amount of power used to spin drops noticiably because the s/c stops whining and is just spinning not creating boost
My setup is drivin at a 4.2 ratio, at 3500rpm (pretend redline) my s/c will be spinnin 14700
08-10-2012, 11:50 AM
#56
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it would get to 5 psi trying to leave the driveway and yes, its noticable i cant remember exactly, not the soberest of people when i have friday off 
i am dealing with slipping and last night it ran off the edge of a pulley, ripped belt up and stopped me 60 feet short of actually seeing how it ran, talk about bein mad those belts are expensive
i am dealing with slipping and last night it ran off the edge of a pulley, ripped belt up and stopped me 60 feet short of actually seeing how it ran, talk about bein mad those belts are expensive
08-10-2012, 11:57 AM
#57
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I just ordered a large pulley for a Ferd power steering pump. That ought to get me some revs!
Keep us posted on how it's going, and drink lots of coffee!
Keep us posted on how it's going, and drink lots of coffee!
08-10-2012, 09:55 PM
#58
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no pulls, good test drive and lots of tuning to do. transition from super to turbo could be smoothed out.
turbo opens bypass for super and boost drops before it rises.
afc is too loose and turbo takes a little long to come on
top end is great and all around driving is more responsive and "easier" i guess id say but man oh man the whine is something else, it could become annoying on a long trip
turbo opens bypass for super and boost drops before it rises.
afc is too loose and turbo takes a little long to come on
top end is great and all around driving is more responsive and "easier" i guess id say but man oh man the whine is something else, it could become annoying on a long trip
08-12-2012, 12:49 PM
#60
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Very, but hit a few issues.
Need to redesign my belt layout and put tensioner on bottom side of s/c pulley
Also need a tighter turbo, ive seen 19 on my housing but its a 71mm exducer also so looking for a 64 s300 or hx40/ t4 but i believe i can tune my afc to get my turbo to come on quicker
good things, went to the woods yesterday without a s/c belt and runs fine, pulled several large trunks at a time with no problem.
I hope your setup goes smooth i wish i could of mounted mine where you have it in your pictures but my cummins is in a chevy
Need to redesign my belt layout and put tensioner on bottom side of s/c pulley
Also need a tighter turbo, ive seen 19 on my housing but its a 71mm exducer also so looking for a 64 s300 or hx40/ t4 but i believe i can tune my afc to get my turbo to come on quicker
good things, went to the woods yesterday without a s/c belt and runs fine, pulled several large trunks at a time with no problem.
I hope your setup goes smooth i wish i could of mounted mine where you have it in your pictures but my cummins is in a chevy