Is 4.6L Superior to 5.4L
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From: WINDSOR, ONTARIO, CANADA
Originally Posted by royalblue150
"HI".... neal, no bs, just jumping ahead of myself. Haven't gotten it dyno tuned just yet. But the thing is that I was doing low 14s high 13s before the boost. Just waiting for my SCT to come in then I'll get it on the dyno.
P.S : Were just horse shytting around here so don't take us too seriously! LOL!
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Originally Posted by Neal
P.S : Were just horse shytting around here so don't take us too seriously! LOL!
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From: Fort Worth,Tx
Originally Posted by tritonpwr
Boost school is now in session. Your tuner is full of crap.
If an engine, a stock engine, can make 225hp at the crank at sea level, that engine _could_ make an absolute maximum of 450hp at 14.7psi (+1 bar). Static pressure at sea level is 1 bar, or 14.7psi. If you are running 14.7psi boost (+1 bar), pressure is doubled, and so is density. In a perfect system, 14.7 psi of boost could produce 450 hp max (exactly double the N/A hp), period, never more. In order to double the horsepower with +1 bar, the boost system (turbo in this case) must be 100% efficient, and turbo's, while much more efficient than their supercharger brethren, are not 100% efficient, it takes some horsepower to operate. Real world turbo loses can range anywhere from 5-20%, every turbo is different, every trim is different. That places actual hp (if we split the difference and say 12.5% loss) from a 225hp engine on 14.7 psi at 394hp (with a theoretical max of 450 in a lossless system).
In order for your "tuner" to get 489 rwhp out of a 4.6 with 10 psi, IF the turbo was 100% perfectly efficient, the motor would have to turn out 280 rwhp on it's own, N/A. There isn't any F150 anything with a stock 4.6 on the face of the planet that can do 280 rwhp N/A.
Wait, it gets worse....
If we calculate that same 12.5% loss from the turbo, the motor would have to generate almost 320 rwhp N/A to generate 489 rwhp under 10 psi of boost. I am equally unaware of any F150 that came with a stock 4.6 that made 320 hp.
Boost has rules, and they all work on PSI. To calculate base gains at sea level without taking loss into consideration, divide actual boost by14.7 (10/14.7=.68), multiply that number by the engines base hp (225*.68=153), and then add the total the base (225+153=378 378 is the max lossless hp from 10 psi on a 225 base hp engine). In actuality, a really good stock 4.6 F150 cranks out only about 180 rwhp. On 10 psi with 0 loss, a max hp of 302 rwhp is all it will ever do on 10 psi, ever.
Like Neal for instance. If he is making 360 rwhp, on 10 psi, with 0 loss, he would be making 604.8 rwhp. With loss calculated, (also assuming there are no restrictions on the intake, exhaust, etc), he would be making 531 rwhp.
Sorry dude, your tuner's blowing smoke up your butt.
If an engine, a stock engine, can make 225hp at the crank at sea level, that engine _could_ make an absolute maximum of 450hp at 14.7psi (+1 bar). Static pressure at sea level is 1 bar, or 14.7psi. If you are running 14.7psi boost (+1 bar), pressure is doubled, and so is density. In a perfect system, 14.7 psi of boost could produce 450 hp max (exactly double the N/A hp), period, never more. In order to double the horsepower with +1 bar, the boost system (turbo in this case) must be 100% efficient, and turbo's, while much more efficient than their supercharger brethren, are not 100% efficient, it takes some horsepower to operate. Real world turbo loses can range anywhere from 5-20%, every turbo is different, every trim is different. That places actual hp (if we split the difference and say 12.5% loss) from a 225hp engine on 14.7 psi at 394hp (with a theoretical max of 450 in a lossless system).
In order for your "tuner" to get 489 rwhp out of a 4.6 with 10 psi, IF the turbo was 100% perfectly efficient, the motor would have to turn out 280 rwhp on it's own, N/A. There isn't any F150 anything with a stock 4.6 on the face of the planet that can do 280 rwhp N/A.
Wait, it gets worse....
If we calculate that same 12.5% loss from the turbo, the motor would have to generate almost 320 rwhp N/A to generate 489 rwhp under 10 psi of boost. I am equally unaware of any F150 that came with a stock 4.6 that made 320 hp.
Boost has rules, and they all work on PSI. To calculate base gains at sea level without taking loss into consideration, divide actual boost by14.7 (10/14.7=.68), multiply that number by the engines base hp (225*.68=153), and then add the total the base (225+153=378 378 is the max lossless hp from 10 psi on a 225 base hp engine). In actuality, a really good stock 4.6 F150 cranks out only about 180 rwhp. On 10 psi with 0 loss, a max hp of 302 rwhp is all it will ever do on 10 psi, ever.
Like Neal for instance. If he is making 360 rwhp, on 10 psi, with 0 loss, he would be making 604.8 rwhp. With loss calculated, (also assuming there are no restrictions on the intake, exhaust, etc), he would be making 531 rwhp.
Sorry dude, your tuner's blowing smoke up your butt.
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From: Texass
Originally Posted by Neal
HI!... That would be 354RWH.P all N/A baby!!!!!! LOL!
Note to JMC
I was thinking about it some more and I think I misunderstood part of what you had to say.
Yes, the taller deck height does serve to lower compression. But that's only in the case of the 5.4, which is essentially a factory OEM stroker, an OEM application, using OEM pistons. In the rest of the world, you cannot just go to a higher deck height to make a longer stroke work. However, I was thinking that you were trying to say that that's all it does. But, in re: to the deck height, it does both. It provides the longer cylinder to accommodate the longer stroke so the pistons don't crash through the head, AS WELL AS provide some distance between the piston face and combustion chamber to lower compression. So it does both really
.Still can't take a motor and make it a stroker with stock pistons tho.
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From: Vienna, Georgia
Originally Posted by tritonpwr
HA! Lets split hairs! LOL!
Note to JMC
I was thinking about it some more and I think I misunderstood part of what you had to say.
Yes, the taller deck height does serve to lower compression. But that's only in the case of the 5.4, which is essentially a factory OEM stroker, an OEM application, using OEM pistons. In the rest of the world, you cannot just go to a higher deck height to make a longer stroke work. However, I was thinking that you were trying to say that that's all it does. But, in re: to the deck height, it does both. It provides the longer cylinder to accommodate the longer stroke so the pistons don't crash through the head, AS WELL AS provide some distance between the piston face and combustion chamber to lower compression. So it does both really .
Still can't take a motor and make it a stroker with stock pistons tho.
Note to JMC
I was thinking about it some more and I think I misunderstood part of what you had to say.
Yes, the taller deck height does serve to lower compression. But that's only in the case of the 5.4, which is essentially a factory OEM stroker, an OEM application, using OEM pistons. In the rest of the world, you cannot just go to a higher deck height to make a longer stroke work. However, I was thinking that you were trying to say that that's all it does. But, in re: to the deck height, it does both. It provides the longer cylinder to accommodate the longer stroke so the pistons don't crash through the head, AS WELL AS provide some distance between the piston face and combustion chamber to lower compression. So it does both really
.Still can't take a motor and make it a stroker with stock pistons tho.
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From: Windsor,Ontario,Canada
tritonpwr,
It is very hard to to show hand gestures using the key board. But if you could have seen my hands all twisted up trying to demonstrate how the piston would move up and down and how the rod would turn rounfd the crank it would have had you rolling on the floor.
If the 4.6 piston goes right up to the top of the deck then it cannot be done unless you use a shorter rod. But that will lower the CR and create all kinds of potential geometric nightmares at BDC. I thought that the 4.6 piston had some room to spare in the cylinder. My bad. oops!
JMC
It is very hard to to show hand gestures using the key board. But if you could have seen my hands all twisted up trying to demonstrate how the piston would move up and down and how the rod would turn rounfd the crank it would have had you rolling on the floor.
If the 4.6 piston goes right up to the top of the deck then it cannot be done unless you use a shorter rod. But that will lower the CR and create all kinds of potential geometric nightmares at BDC. I thought that the 4.6 piston had some room to spare in the cylinder. My bad. oops!JMC
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From: Texass
Originally Posted by Faster150
il get the dyno sheet from him.. and also u have to take into consideration stock compression ratio.. and alot of other factors that play into velocity air density and such. and the current temperature in arizona during the winter.
You have to keep in mind, the 100% boost in hp with 14.7 psi is if EVERYTHING is perfect. Having a CR, or cam, or WTF ever that is more accommodating to a turbo only serves to get closer to 100%. You can NEVER surpass 100% without FAR exceeding +1 bar, period. It's physically impossible.
What you are failing to understanding is that the only thing boost is is increasing the amount of air in each cylinder, that's it. You squirt in more fuel so the a/f ratio stays constant, but that's all boost is, that's all there is to it. At 14.7 psi, there is twice as much air, and twice as much oxygen, no more. You can only get less than 100%, not more. All of the same restrictions that limit that amount of horsepower an engine can make N/A are still there with a turbo. Nothing magic takes place in there that can overcome the laws of physics. If you were able put an engine in a pressure vessel that was at +1 bar, it would make the same power as if it were running a turbo at sea level (a little more actually, it's free hp).
Besides, he's trying to make you believe a stock 4.6 can hold up to 600hp at the crank. That's absolute crap. Those POS factory pistons would be shattered LONG before you got that high, and the rods, and the rod bolts, and probably the crank too. Bulls^^t.
Sorry dude, that's just crap. Not that you're full of it, but whoever told you that mess was either a total BS'er or an idiot.
I have been running and racing SC's and turbos for YEARS. Believe me, I have this boost business down pat.
I did the math for you. On a stock 4.6, it would take right at 30 pounds of turbo boost to make the power he's claiming. Good luck with that!
Air density? Well, let me put it to you this way, you would need to be about 150,000' below sea level to make that kind of power! LOL! I doubt there's many roads nearly 30 miles underground.
Last edited by tritonpwr; Dec 14, 2006 at 07:08 PM.
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From: Texass
Originally Posted by JMC
tritonpwr,
It is very hard to to show hand gestures using the key board. But if you could have seen my hands all twisted up trying to demonstrate how the piston would move up and down and how the rod would turn rounfd the crank it would have had you rolling on the floor. If the 4.6 piston goes right up to the top of the deck then it cannot be done unless you use a shorter rod. But that will lower the CR and create all kinds of potential geometric nightmares at BDC. I thought that the 4.6 piston had some room to spare in the cylinder. My bad. oops!
JMC
It is very hard to to show hand gestures using the key board. But if you could have seen my hands all twisted up trying to demonstrate how the piston would move up and down and how the rod would turn rounfd the crank it would have had you rolling on the floor.
If the 4.6 piston goes right up to the top of the deck then it cannot be done unless you use a shorter rod. But that will lower the CR and create all kinds of potential geometric nightmares at BDC. I thought that the 4.6 piston had some room to spare in the cylinder. My bad. oops!JMC
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Joined: Dec 1997
Posts: 9,417
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From: Windsor,Ontario,Canada
This has to be the hardest thread to follow yet. Not only are there 4 or 5 different sub topics but by the time you answer a post there are 10-20 more posts that you have to sort through. At one point I could not read fast enough. Some where around page 49 this morning I was 3 pages behind so that means that page 52 was current. By the time I was done 49 page 53 was current. 
Now the damed banana stopped moving again......
JMC
Now the damed banana stopped moving again......
JMC
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From: Vienna, Georgia
Originally Posted by tritonpwr
If you were able put an engine in a pressure vessel that was at +1 bar, it would make the same power as if it were running a turbo at sea level (a little more actually, it's free hp).
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From: Texass
Originally Posted by JMC
This has to be the hardest thread to follow yet. Not only are there 4 or 5 different sub topics but by the time you answer a post there are 10-20 more posts that you have to sort through. At one point I could not read fast enough. Some where around page 49 this morning I was 3 pages behind so that means that page 52 was current. By the time I was done 49 page 53 was current.
Now the damed banana stopped moving again......
JMC
Now the damed banana stopped moving again......
JMC