P1 vs D1 Why do most think they need a D1 when most will never max out the P1?
12-24-2003, 02:14 AM
#21
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Originally Posted by ChrisB
But since ATI has decided that they will under *no* circumstances provide compressor maps to anyone it makes it impossible to properly spec out an ATI blower. So I would just get a Vortec 
12-24-2003, 07:03 AM
#22
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I've got a P1SC on my car and I wish I had gotten the D1SC so I could use a larger SC pulley to achieve the same boost. That being said, I don't have any belt slip with my current setup (MMS 7.85" crank/3.85" SC 6 rib). As far as maxing out the impeller RPM's is concerned, most people's setup won't get that far. The P1SC impeller redline is 60,000 RPM's.
P1SC Impeller RPM=(crank pulley diam./SC pulley diam.)*4.10*engine RPM
For me this works out to be 55,175 RPM's at 6600 RPM (I don't spin that high though). The limiting factor with my setup is not the supercharger but the MAF/stock computer. The MAF gets maxed out in the upper RPM range(>6200 RPM). NoGo has compensated for some of this with LS1edit, but to "max out" the P1SC I would have to go with an aftermarket computer (FAST or Accel) and a different belt system. I did add a very small shot of nitrous to cool the intake charge, but before we changed the tune to be safe with nitrous the car made about 580 rwhp which is probably enough for casual racers like myself. I have chosen to make this my end-point...for now.
So, I would advise anyone buying a new system to get the D1SC for the extra $300. However, It is unlikely that most users will max out a P1SC before the stock computer on a stock displacement motor.
P1SC Impeller RPM=(crank pulley diam./SC pulley diam.)*4.10*engine RPM
For me this works out to be 55,175 RPM's at 6600 RPM (I don't spin that high though). The limiting factor with my setup is not the supercharger but the MAF/stock computer. The MAF gets maxed out in the upper RPM range(>6200 RPM). NoGo has compensated for some of this with LS1edit, but to "max out" the P1SC I would have to go with an aftermarket computer (FAST or Accel) and a different belt system. I did add a very small shot of nitrous to cool the intake charge, but before we changed the tune to be safe with nitrous the car made about 580 rwhp which is probably enough for casual racers like myself. I have chosen to make this my end-point...for now.
So, I would advise anyone buying a new system to get the D1SC for the extra $300. However, It is unlikely that most users will max out a P1SC before the stock computer on a stock displacement motor.
12-24-2003, 09:18 AM
#24
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Maybe they have changed the specs but my user's manual says 60,000.
.P1SC-1
Anyway, that makes it even less likely that it'll get maxed out
.P1SC-1
Anyway, that makes it even less likely that it'll get maxed out
Last edited by Ken G; 12-24-2003 at 09:23 AM.
12-24-2003, 09:32 AM
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I think that's probably a misprint in the instructions. The D1SC has a 62,000rpm redline and the P1SC1 has a smaller exducer which should allow it to spin higher than the D1SC.
12-24-2003, 12:19 PM
#26
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Hey Ken, so you made 580 to the wheels at 6600 rpm before tweaking your tune? Was that tune perfectly safe and you now err on the rich side for the blast of N20?
Do you have a link to your dyno run?
My setup will spin the blower to 55K by 6,000 rpm. Sounds like I am gonna have a nice sized portion of low-mid range power.
Sweeet
Do you have a link to your dyno run?
My setup will spin the blower to 55K by 6,000 rpm. Sounds like I am gonna have a nice sized portion of low-mid range power.
Sweeet
12-24-2003, 02:50 PM
#27
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Heath,
Right after my forged internals went in we dyno'd the car and got the numbers in my sig. The day we did the nitrous tune we re-checked the baseline dyno and got 578-580 rwhp. No changes were made since the previous dyno (except the NOS 5177 kit installation) so we assume that the motor ran stronger because of break-in. The nitrous tune that NoGo did pulled some timing and richened the A/F. This tune got us about 505 rwhp without nitrous and 622 rwhp with a small shot of nitrous (0.022" jets). Unfortunately, we weren't able to get good torque numbers that day because the RPM signal was too fragmented to do a calculation. The graphs below show HP vs. speed (one from 8/03 and the other with nitrous 11/03) because of this (no torque numbers). The runs were to 6800 RPM to give you some kind of reference point. Also, you'll notice the A/F start to rise at the end of the runs. This is because of the maxed MAF. We decided to call it quits with the 0.022" jets.
Hope this doesn't make things more confused, Ken
Right after my forged internals went in we dyno'd the car and got the numbers in my sig. The day we did the nitrous tune we re-checked the baseline dyno and got 578-580 rwhp. No changes were made since the previous dyno (except the NOS 5177 kit installation) so we assume that the motor ran stronger because of break-in. The nitrous tune that NoGo did pulled some timing and richened the A/F. This tune got us about 505 rwhp without nitrous and 622 rwhp with a small shot of nitrous (0.022" jets). Unfortunately, we weren't able to get good torque numbers that day because the RPM signal was too fragmented to do a calculation. The graphs below show HP vs. speed (one from 8/03 and the other with nitrous 11/03) because of this (no torque numbers). The runs were to 6800 RPM to give you some kind of reference point. Also, you'll notice the A/F start to rise at the end of the runs. This is because of the maxed MAF. We decided to call it quits with the 0.022" jets.
Hope this doesn't make things more confused, Ken
Last edited by Ken G; 12-24-2003 at 06:47 PM.
12-24-2003, 03:07 PM
#28
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It does 
It's ok though, my car is not identical to yours. Just trying to get a feel for what I should expect. I initially thought 520 tops, but then I see your numbers and packy's numbers and think I for once may be underestimating things.
Time will tell.....
It's ok though, my car is not identical to yours. Just trying to get a feel for what I should expect. I initially thought 520 tops, but then I see your numbers and packy's numbers and think I for once may be underestimating things.
Time will tell.....
12-24-2003, 06:44 PM
#29
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Sorry, Heath. I just re-read and edited the post but it is still difficult to follow 
. The bottom line is I got 580 rwhp from a P1SC-1 at 10 PSI on a pretty good flowing 348 ci motor and conservative tune. You should be able to achieve or beat your goal of 520 rwhp without running huge amounts of boost with the P1SC-1 if your motor flows well.
-Ken
. The bottom line is I got 580 rwhp from a P1SC-1 at 10 PSI on a pretty good flowing 348 ci motor and conservative tune. You should be able to achieve or beat your goal of 520 rwhp without running huge amounts of boost with the P1SC-1 if your motor flows well.-Ken
12-24-2003, 08:07 PM
#31
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Comp Cams: 216/220 .521/.533 114 LSA. I've thought about changing the cam for something a little more aggressive and going with some 6.0L heads but until my driving skills can catch up with my car's HP I'm going to hold off.
-Ken
-Ken
