Updated Single Turbo LT1 dyno numbers.
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Joined: Nov 1998
Posts: 762
From: Huntsville, Alabama
Well what gets me is why the turbo #'s are so much lower then the S-trim at the same boost level. The only things I could think of that were maybe causing that was, headers or crossover to small or maybe the cam he was using has to much exhaust duration and he's blowing boost out with the turbo.
Jose
Jose
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Joined: Jun 2002
Posts: 2,456
From: sarasota, fl
Originally posted by JZ 97 SS 1500
Well what gets me is why the turbo #'s are so much lower then the S-trim at the same boost level. The only things I could think of that were maybe causing that was, headers or crossover to small or maybe the cam he was using has to much exhaust duration and he's blowing boost out with the turbo.
Jose
Well what gets me is why the turbo #'s are so much lower then the S-trim at the same boost level. The only things I could think of that were maybe causing that was, headers or crossover to small or maybe the cam he was using has to much exhaust duration and he's blowing boost out with the turbo.
Jose
is he using the same compression and engine setup?
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Joined: Jan 1999
Posts: 884
From: I reached back like a pimp and smacked that LS1....
My headers are 1 5/8. Crossover is 2.5. The engine is exactly the same as when I had the blower on it. Same CR/cam, everything.
I will overlay the turbo and sc dyno curves, but the turbo has ALOT more average HP and torque. (And also much more peak torque)
The supercharger had an air/water intercooler, which, may be optimal for one dyno run but it's unlikely that it was efficient enough for me to actually see 634rwhp by the time I'm going through the traps. I wouldn't be suprised if my car was actually faster at 12psi now than it was before (even considering it dynoed less).
Another thing is the turbo peaks at 5,500 and the SC peaked at 6,100.
I posed the same question to Innovative as to why I wouldn't see the same amount of HP at the same boost level, and they said that boost PSI does not equal CFM. They said that while the S-trim at 12psi was at the peak of it's efficiency and airflow, the GT80 turbo is only beginning to work.
They also said that only a roots blower makes boost because of the restriction the engine poses, and that a centrifugal blower or turbo actually compress the air before it reaches the engine. An example would be you can drive the turbo and leave the outlet open to atmosphere but still get a boost reading. Meaning, boost PSI does not equal CFM.
I would also consider a cam change to something more turbo specific, but I'm not sure what or when.
I'm by no means a turbo expert, but I'm happy with the results even if it makes less PEAK hp at the same PSI.
I will overlay the turbo and sc dyno curves, but the turbo has ALOT more average HP and torque. (And also much more peak torque)
The supercharger had an air/water intercooler, which, may be optimal for one dyno run but it's unlikely that it was efficient enough for me to actually see 634rwhp by the time I'm going through the traps. I wouldn't be suprised if my car was actually faster at 12psi now than it was before (even considering it dynoed less).
Another thing is the turbo peaks at 5,500 and the SC peaked at 6,100.
I posed the same question to Innovative as to why I wouldn't see the same amount of HP at the same boost level, and they said that boost PSI does not equal CFM. They said that while the S-trim at 12psi was at the peak of it's efficiency and airflow, the GT80 turbo is only beginning to work.
They also said that only a roots blower makes boost because of the restriction the engine poses, and that a centrifugal blower or turbo actually compress the air before it reaches the engine. An example would be you can drive the turbo and leave the outlet open to atmosphere but still get a boost reading. Meaning, boost PSI does not equal CFM.
I would also consider a cam change to something more turbo specific, but I'm not sure what or when.
I'm by no means a turbo expert, but I'm happy with the results even if it makes less PEAK hp at the same PSI.
Registered User
Joined: Dec 2001
Posts: 180
From: Texas
Originally posted by INTMD8
My headers are 1 5/8. Crossover is 2.5. The engine is exactly the same as when I had the blower on it. Same CR/cam, everything.
I will overlay the turbo and sc dyno curves, but the turbo has ALOT more average HP and torque. (And also much more peak torque)
The supercharger had an air/water intercooler, which, may be optimal for one dyno run but it's unlikely that it was efficient enough for me to actually see 634rwhp by the time I'm going through the traps. I wouldn't be suprised if my car was actually faster at 12psi now than it was before (even considering it dynoed less).
Another thing is the turbo peaks at 5,500 and the SC peaked at 6,100.
I posed the same question to Innovative as to why I wouldn't see the same amount of HP at the same boost level, and they said that boost PSI does not equal CFM. They said that while the S-trim at 12psi was at the peak of it's efficiency and airflow, the GT80 turbo is only beginning to work.
They also said that only a roots blower makes boost because of the restriction the engine poses, and that a centrifugal blower or turbo actually compress the air before it reaches the engine. An example would be you can drive the turbo and leave the outlet open to atmosphere but still get a boost reading. Meaning, boost PSI does not equal CFM.
I would also consider a cam change to something more turbo specific, but I'm not sure what or when.
I'm by no means a turbo expert, but I'm happy with the results even if it makes less PEAK hp at the same PSI.
My headers are 1 5/8. Crossover is 2.5. The engine is exactly the same as when I had the blower on it. Same CR/cam, everything.
I will overlay the turbo and sc dyno curves, but the turbo has ALOT more average HP and torque. (And also much more peak torque)
The supercharger had an air/water intercooler, which, may be optimal for one dyno run but it's unlikely that it was efficient enough for me to actually see 634rwhp by the time I'm going through the traps. I wouldn't be suprised if my car was actually faster at 12psi now than it was before (even considering it dynoed less).
Another thing is the turbo peaks at 5,500 and the SC peaked at 6,100.
I posed the same question to Innovative as to why I wouldn't see the same amount of HP at the same boost level, and they said that boost PSI does not equal CFM. They said that while the S-trim at 12psi was at the peak of it's efficiency and airflow, the GT80 turbo is only beginning to work.
They also said that only a roots blower makes boost because of the restriction the engine poses, and that a centrifugal blower or turbo actually compress the air before it reaches the engine. An example would be you can drive the turbo and leave the outlet open to atmosphere but still get a boost reading. Meaning, boost PSI does not equal CFM.
I would also consider a cam change to something more turbo specific, but I'm not sure what or when.
I'm by no means a turbo expert, but I'm happy with the results even if it makes less PEAK hp at the same PSI.
That old blower cam might be a factor.
I think Jordan is selling his mild turbo cam that he was running.
West South Central Moderator / Special Guest
Joined: Dec 1998
Posts: 1,650
From: Coppell, TX USA
yea, the cam would fit your setup well.
Billet, 217/213 .525ish lift 114ls
custom from Cam Motion
Sell for $200.
Billet, 217/213 .525ish lift 114ls
custom from Cam Motion
Sell for $200.
Last edited by JordonMusser; Jun 11, 2003 at 06:32 PM.
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Joined: Nov 1998
Posts: 762
From: Huntsville, Alabama
Jim, I would bet money that most of your power is going right out of the exhaust. That exhaust duration is hurting you. I would bet swapping cams to a reverse split or dual pattern you'll probably see the boost go up with nothing more the then cam swap.
Jose
Jose
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