Opinions on turbo mfgs
#43
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Getting close to 3:1 and some setups 4:1. Bascially 20psi inlet pressure would yield 60psi (using only 3:1) in the exhaust. That is not good and will create high EGT's, reversion, and will cause heads to start lifting off the block. The target is 1:1, but with T4 turbos and smaller T6's you shoot for 2:1.
#44
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Ok, I have a question for ya. They tell ya that there good for say 1200hp. What's the probability that it will actually make 1200hp? I mean, are turbos kinda like new cars, in that they tell ya it comes with 400hp when it only dyno's 350? Would you have to have a near perfect setup to get the stated number, or in some cases can you exceed there rating? If someone wants to make 1200hp, should he go with the next size up to achieve that number?
My CAS uses two custom To4e's with 76mm comp. and 56mm turbines, how much do you think there good for, and would running a log manifold keep those numbers down?
My CAS uses two custom To4e's with 76mm comp. and 56mm turbines, how much do you think there good for, and would running a log manifold keep those numbers down?
#46
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ok, I didn't know that. but it still brings up a question as to if you can reallly achieve a number close to the one rated by the manufacture with the drivetrain loss?
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Quote:
Bascially 20psi inlet pressure would yield 60psi (using only 3:1) in the exhaust.
So your saying, in order to create 20psi of boost in the intake you going to have 60psi on the inlet of the hot side of the turbo.
Bascially 20psi inlet pressure would yield 60psi (using only 3:1) in the exhaust.
So your saying, in order to create 20psi of boost in the intake you going to have 60psi on the inlet of the hot side of the turbo.
#48
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Originally Posted by Bens3rdgen
So your saying, in order to create 20psi of boost in the intake you going to have 60psi on the inlet of the hot side of the turbo.
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Originally Posted by Bens3rdgen
Quote:
Bascially 20psi inlet pressure would yield 60psi (using only 3:1) in the exhaust.
So your saying, in order to create 20psi of boost in the intake you going to have 60psi on the inlet of the hot side of the turbo.
Bascially 20psi inlet pressure would yield 60psi (using only 3:1) in the exhaust.
So your saying, in order to create 20psi of boost in the intake you going to have 60psi on the inlet of the hot side of the turbo.
That is correct
#50
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Jose where would you draw the line for cubic inches with the GT42 76??
I know as cubic Inches rise so does the back presure...... would you say 364 (stock 6.0L Cubes) 370ci, 380ci?? Im saying that from what you stated with the 383ci and stratoshpheric... post![The Jester](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_jest.gif)
How high of EGT's are we talking and what would you not want to be over??
Some good to know info for everyone...
Kyle
I know as cubic Inches rise so does the back presure...... would you say 364 (stock 6.0L Cubes) 370ci, 380ci?? Im saying that from what you stated with the 383ci and stratoshpheric... post
![The Jester](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_jest.gif)
How high of EGT's are we talking and what would you not want to be over??
Some good to know info for everyone...
Kyle
#51
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Originally Posted by NA$TY-TA
Jose where would you draw the line for cubic inches with the GT42 76??
I know as cubic Inches rise so does the back presure...... would you say 364 (stock 6.0L Cubes) 370ci, 380ci?? Im saying that from what you stated with the 383ci and stratoshpheric... post![The Jester](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_jest.gif)
How high of EGT's are we talking and what would you not want to be over??
Some good to know info for everyone...
Kyle
I know as cubic Inches rise so does the back presure...... would you say 364 (stock 6.0L Cubes) 370ci, 380ci?? Im saying that from what you stated with the 383ci and stratoshpheric... post
![The Jester](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_jest.gif)
How high of EGT's are we talking and what would you not want to be over??
Some good to know info for everyone...
Kyle
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346 @16 psi = 86 lbs/min consumption
383 @ 16 psi = 95 lbs/min consumption
Using a map that is available, lets look at the GT42-74.
At those levels
346 = 63% compression effic.
383 = 49% compression effic.
Using those #'s, a 346 will lose ~95-99hp to drive the turbo at that level (ala efficiency, which will net us ~885 hp
Using the same calcs above, the 383 would require ~160hp to drive the compressor at that level, which would in turn net us only ~873hp
![Chug! Chug! Chug!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_chug.gif)
So now you see why small cubes and efficient boost is so important.
#52
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Originally Posted by JZ 97 SS 1500
383 @ 16 psi = 95 lbs/min consumption
http://www.forcedinductions.com/consumption383.htm
383 @ 19psi @ 6700rpm = 95lbs/min. I dont think too many street car 383's will see those boost numbers or rpms.
My plan is 6000rpm @ 15psi which is alot more reasonable requiring 75lbs/min. That pushes the turbo back into a good eficiency range (not as good as an 88m though
![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
Is your link wrong as far as lbs/min? Just wondering because I have been using those numbers fo awhile when calculating.
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Originally Posted by RealQuick
Jose, according to your site:
http://www.forcedinductions.com/consumption383.htm
383 @ 19psi @ 6700rpm = 95lbs/min. I dont think too many street car 383's will see those boost numbers or rpms.
My plan is 6000rpm @ 15psi which is alot more reasonable requiring 75lbs/min. That pushes the turbo back into a good eficiency range (not as good as an 88m though
).
Is your link wrong as far as lbs/min? Just wondering because I have been using those numbers fo awhile when calculating.
http://www.forcedinductions.com/consumption383.htm
383 @ 19psi @ 6700rpm = 95lbs/min. I dont think too many street car 383's will see those boost numbers or rpms.
My plan is 6000rpm @ 15psi which is alot more reasonable requiring 75lbs/min. That pushes the turbo back into a good eficiency range (not as good as an 88m though
![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
Is your link wrong as far as lbs/min? Just wondering because I have been using those numbers fo awhile when calculating.
The #s in the site are based on stock components, just bigger cubes. I based these #'s off a well ported set of LS1 heads and LS1 intake. VE will rise with a good flowing engine. Most of these turbo build on this site use those parts.
#54
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There are no compressor maps for the GT42-76 correct??
I am just wanting to see were my 370 and the 76 would be for lbs/min consumption for 20-22 psi and how much HP its eating and a realistic goal with it.
If its limiting me that much i can forsee the swap to the S88 even sooner.
Thanks JZ
Kyle
I am just wanting to see were my 370 and the 76 would be for lbs/min consumption for 20-22 psi and how much HP its eating and a realistic goal with it.
If its limiting me that much i can forsee the swap to the S88 even sooner.
Thanks JZ
Kyle