LS Power!! Twin 76mm Turbo 4.8L 1200HP & still going!!
07-27-2011, 06:04 PM
#91
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Your missing 2 key details to support your claim of "not enough fuel".
-What fuel pressure?
-What duty cycle?
Have you looked in the drag racing section lately.Some pretty strong number have been posted by trucks with 4.8l's.Im not implying that there putin 1200fwhp out.Jus sayin that for me they seem to be holding together under big power for a 1/4 mile run.As opposed to one complete pass on the engine dyno which in comparison is less stress on the engine it self.The numbers makes sense at every pass pointed out in the artical imo.You gonna run around here and say nay then bring the facts not assumtions.
07-27-2011, 06:12 PM
#92
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For the 75lbers to support it, they need 120psi of fuel pressure at the rail. They ran 26 psi of boost, so if they had a 1:1 fpr then the fuel pressure would have been 84psi (stock 58psi plus 26psi). There still short 36psi. Maybe they ran a 2:1, but by the numbers that still short, but a 2:1 would be believable. All of it is at 80% duty cycle. Not saying the motor WONT HOLD IT, i mean im just saying N/A a 4.8 at 451hp? Idk. Its kind off believable maybe the dyno is just happy. So then they add boost and it makes 1200hp, which for the the size of turbos and boost, its believable. But when they dont back it up with enough fuel is when its just NOT believable.
Last edited by jeffreycastgsx; 07-27-2011 at 06:18 PM.
07-27-2011, 08:06 PM
#96
For the 75lbers to support it, they need 120psi of fuel pressure at the rail. They ran 26 psi of boost, so if they had a 1:1 fpr then the fuel pressure would have been 84psi (stock 58psi plus 26psi). There still short 36psi. Maybe they ran a 2:1, but by the numbers that still short, but a 2:1 would be believable. All of it is at 80% duty cycle. Not saying the motor WONT HOLD IT, i mean im just saying N/A a 4.8 at 451hp? Idk. Its kind off believable maybe the dyno is just happy. So then they add boost and it makes 1200hp, which for the the size of turbos and boost, its believable. But when they dont back it up with enough fuel is when its just NOT believable.
07-27-2011, 09:20 PM
#98
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Foose I was reading your earlier comment about the cam choice.
I read in the article that they were just trying to see what it took to blow it up.
Maybe they just chose the cam because it was lying around and a readily choice.
or maybe I just read wrong or missed something...idk
Just my .02
I read in the article that they were just trying to see what it took to blow it up.
Maybe they just chose the cam because it was lying around and a readily choice.
or maybe I just read wrong or missed something...idk
Just my .02
07-27-2011, 11:13 PM
#99
If you guys want I can try to find out what the fuel pressure was. No guarantee's but I'll give it a shot.
We're also so used to comparing numbers in vehicle and not on a engine dyno that there's probably a few more variables that were forgetting that is affecting the numbers. Either way it's cool and I just find it hard to believe HR lied without seeing a smoking gun in hand.
We're also so used to comparing numbers in vehicle and not on a engine dyno that there's probably a few more variables that were forgetting that is affecting the numbers. Either way it's cool and I just find it hard to believe HR lied without seeing a smoking gun in hand.
07-28-2011, 06:03 AM
#100
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what would you folks say the drive train loss on my setup would be??
5.3, 3400 circleD 10.5" billet stall UNlocked (weighs 45lbs), 4l80e, heavy *** 2 piece steel drive shaft thats about a mile long (ext. cab), 3.73 gears, true trac, ~60lb wheel/tire setup??
im guessing around 25%
if we go with 25% then we can figure out my crank HP based on my 780hp dyno pull (on a mustang, so it could have been higher on other dynos, but lets not get into that argument...) and at that point my setup was VERY inefficient and not gaining near the power it should have at any given boost level. AND my IDC was at 72% iirc on 80lb bosch injectors with a base pressure of 52psi
now you ladies have some solid facts to argue about to compare to what the magazine said....
5.3, 3400 circleD 10.5" billet stall UNlocked (weighs 45lbs), 4l80e, heavy *** 2 piece steel drive shaft thats about a mile long (ext. cab), 3.73 gears, true trac, ~60lb wheel/tire setup??
im guessing around 25%
if we go with 25% then we can figure out my crank HP based on my 780hp dyno pull (on a mustang, so it could have been higher on other dynos, but lets not get into that argument...) and at that point my setup was VERY inefficient and not gaining near the power it should have at any given boost level. AND my IDC was at 72% iirc on 80lb bosch injectors with a base pressure of 52psi
now you ladies have some solid facts to argue about to compare to what the magazine said....