KraftWerks C38 Supercharger Kit FAQ Thread
#124
#126
ok so after blew my f20c engine , I decided to go with the f22c that time , I have to swap my pulley from the rotrex ( 95mm now )
so now I have to bought a new pulley , im looking for 14psi , cj told me 90 mm but when I look at the spec on a topic I see 13 psi at 8200 rpm not 14 ? can someone explain me plz thanks
AP1 Comes with 128mm Crank + 100mm S/C Pulley for 9150Rpm Redline @ 12.5psi
Option 1. AP1 128mm Crank + 95mm S/C Pulley for 8900Rpm Redline @ Approx 14.5Psi
Option 2. AP1 128mm Crank + 90mm S/C Pulley for 8450Rpm Redline @Approx 16.5Psi
AP2 Comes with 128mm Crank + 90mm S/C Pulley for 8200Rpm Redline @ 13psi
Option 1. AP2 128mm Crank + 85mm S/C Pulley for 8000Rpm Redline @ Approx 14.5Psi
Option 2. AP2 128mm Crank + 80mm S/C Pulley for 7600Rpm Redline @Approx 16.5Psi
why cj told me 14 psi with the 90 mm ?
And how many rpm I should go to be safe ? I heard a lot goes 9000 with f22 but I wil def not do this but 8250 or 8450 are safe ?
so now I have to bought a new pulley , im looking for 14psi , cj told me 90 mm but when I look at the spec on a topic I see 13 psi at 8200 rpm not 14 ? can someone explain me plz thanks
AP1 Comes with 128mm Crank + 100mm S/C Pulley for 9150Rpm Redline @ 12.5psi
Option 1. AP1 128mm Crank + 95mm S/C Pulley for 8900Rpm Redline @ Approx 14.5Psi
Option 2. AP1 128mm Crank + 90mm S/C Pulley for 8450Rpm Redline @Approx 16.5Psi
AP2 Comes with 128mm Crank + 90mm S/C Pulley for 8200Rpm Redline @ 13psi
Option 1. AP2 128mm Crank + 85mm S/C Pulley for 8000Rpm Redline @ Approx 14.5Psi
Option 2. AP2 128mm Crank + 80mm S/C Pulley for 7600Rpm Redline @Approx 16.5Psi
why cj told me 14 psi with the 90 mm ?
And how many rpm I should go to be safe ? I heard a lot goes 9000 with f22 but I wil def not do this but 8250 or 8450 are safe ?
#127
Not sure if he meant its possible to hit 14psi... i saw anywhere from 11-13.3 psi on my -81 blower as ambient would change. My tuner set my RPM limiter to 8200rpm. Some go to 8400 with the standard pulley. I wanted to have some margin, so was ok with 8200 as my limiter. Still made 419whp/277wtq on a dynojet with insane Miami, FL heat & humidity.
Glad you were able to source another motor. What was the final verdict on that blown motor?
Glad you were able to source another motor. What was the final verdict on that blown motor?
#128
8200 rpm is stock. 8500 rpm is the equivalent F20 piston speed and happens to be where the F22 cams start to choke the motor, however when your boosted that isn't really relevant anymore, so safe piston speed is the main focus. Nothing wrong with 8200, except that your sacrificing your rpm range (mph per gear) which the ap2 is desperately short on, without compromising the engines safety. I always took my stock F22 to 9k when supercharged and never had a related failure, pointless now that I'm back to N/A, but I still rev it out to 8400-8500 because that's where the motor stops making power.
These high revving engines, along with the power delivery of a centrifugal blower makes sense to maximize the rev band because that's where this combo yields the most power delivery. Lowering the rev band and adding more boost is inefficient, other then with a larger 2.4+ stroked motor where the powerband is shifted down (but these motors dont make the most efficient supercharged options for that reason) Its always better to air on the side of maximum boost at the maximum rpm this engine breaths. Stock 8200rpm minimum for F22 and stock 8900k Minimum for F20. Select the appropriate pulley for those target rpm ranges to capitalize on the blower and engines performance combination.
These high revving engines, along with the power delivery of a centrifugal blower makes sense to maximize the rev band because that's where this combo yields the most power delivery. Lowering the rev band and adding more boost is inefficient, other then with a larger 2.4+ stroked motor where the powerband is shifted down (but these motors dont make the most efficient supercharged options for that reason) Its always better to air on the side of maximum boost at the maximum rpm this engine breaths. Stock 8200rpm minimum for F22 and stock 8900k Minimum for F20. Select the appropriate pulley for those target rpm ranges to capitalize on the blower and engines performance combination.
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JSAUNDERS12 (05-12-2021)
#129
Not sure if he meant its possible to hit 14psi... i saw anywhere from 11-13.3 psi on my -81 blower as ambient would change. My tuner set my RPM limiter to 8200rpm. Some go to 8400 with the standard pulley. I wanted to have some margin, so was ok with 8200 as my limiter. Still made 419whp/277wtq on a dynojet with insane Miami, FL heat & humidity.
Glad you were able to source another motor. What was the final verdict on that blown motor?
Glad you were able to source another motor. What was the final verdict on that blown motor?
8200 rpm is stock. 8500 rpm is the equivalent F20 piston speed and happens to be where the F22 cams start to choke the motor, however when your boosted that isn't really relevant anymore, so safe piston speed is the main focus. Nothing wrong with 8200, except that your sacrificing your rpm range (mph per gear) which the ap2 is desperately short on, without compromising the engines safety. I always took my stock F22 to 9k when supercharged and never had a related failure, pointless now that I'm back to N/A, but I still rev it out to 8400-8500 because that's where the motor stops making power.
These high revving engines, along with the power delivery of a centrifugal blower makes sense to maximize the rev band because that's where this combo yields the most power delivery. Lowering the rev band and adding more boost is inefficient, other then with a larger 2.4+ stroked motor where the powerband is shifted down (but these motors dont make the most efficient supercharged options for that reason) Its always better to air on the side of maximum boost at the maximum rpm this engine breaths. Stock 8200rpm minimum for F22 and stock 8900k Minimum for F20. Select the appropriate pulley for those target rpm ranges to capitalize on the blower and engines performance combination.
These high revving engines, along with the power delivery of a centrifugal blower makes sense to maximize the rev band because that's where this combo yields the most power delivery. Lowering the rev band and adding more boost is inefficient, other then with a larger 2.4+ stroked motor where the powerband is shifted down (but these motors dont make the most efficient supercharged options for that reason) Its always better to air on the side of maximum boost at the maximum rpm this engine breaths. Stock 8200rpm minimum for F22 and stock 8900k Minimum for F20. Select the appropriate pulley for those target rpm ranges to capitalize on the blower and engines performance combination.
for me I would not really wants over rev the engine maybe 8250 max 8450 so I should just put the 90mm pulley and get maybe 13-14 psi to 8450 that's right if im understanding good ?