The numbers are in: 576 rwhp @ 4.5 psi SAE
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11-03-2006, 04:31 PM
#83
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Originally Posted by obZidian
heres a thought. Just reading through the vince thread on cams, it was stated that, for example, if you have a more restrictive setup that makes 600rwhp @10psi and you increase flow capacity, that psi reading will show lower than 10psi, hyperthetically 4.5psi, however producing the same amount of power or close to as before.
A larger cam than usual for boost motors, meaning more overlap or long durations creating more scavanging of cylinder charge, will yield a less restrictive flow characteristic. Wouldn't this be a representation of this or something close to it? IT would seem logical, that at that boost level, 600rwhp+ is a bit far stretched, however, those turbos aren't slouches, and when matched, it could yield a similar number.
Now, my concern with the graph is to see where this combo makes its power. Is it all around or more like a supra graph... all ontop.
anyone please correct me with im wrong....
A larger cam than usual for boost motors, meaning more overlap or long durations creating more scavanging of cylinder charge, will yield a less restrictive flow characteristic. Wouldn't this be a representation of this or something close to it? IT would seem logical, that at that boost level, 600rwhp+ is a bit far stretched, however, those turbos aren't slouches, and when matched, it could yield a similar number.
Now, my concern with the graph is to see where this combo makes its power. Is it all around or more like a supra graph... all ontop.
anyone please correct me with im wrong....
John
11-03-2006, 05:26 PM
#84
Originally Posted by obZidian
heres a thought. Just reading through the vince thread on cams, it was stated that, for example, if you have a more restrictive setup that makes 600rwhp @10psi and you increase flow capacity, that psi reading will show lower than 10psi, hyperthetically 4.5psi, however producing the same amount of power or close to as before.....
You are talking about a SC'd application... The boost is proportional to RPM (centrif) and a pulley decides the speed it's gonna turn at. The boost made by the turbo is referenced from the intake and regulated by the boost controller or gate spring... add all the heads and cam you want, that gate is still gonna open at the previous setpoint.
11-03-2006, 05:49 PM
#85
i am running 0.4 bar wastegate springs btw..
THEY ARE SO LIGHT!! i'm so used to putting together wastegates for Supras which have crazy springs that can murder in the wrong hands (like you need 5 people to hold down the wastegate top or it will shoot off and impale your face) but when i put together these wastegates it was like there was no spring there at all... so soft to put in. in fact i can easily move the valve itself after the gate is together up and down with no effort at all.
THEY ARE SO LIGHT!! i'm so used to putting together wastegates for Supras which have crazy springs that can murder in the wrong hands (like you need 5 people to hold down the wastegate top or it will shoot off and impale your face) but when i put together these wastegates it was like there was no spring there at all... so soft to put in. in fact i can easily move the valve itself after the gate is together up and down with no effort at all.
11-03-2006, 06:19 PM
#87
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Originally Posted by Frost
You are talking about a SC'd application... The boost is proportional to RPM (centrif) and a pulley decides the speed it's gonna turn at. The boost made by the turbo is referenced from the intake and regulated by the boost controller or gate spring... add all the heads and cam you want, that gate is still gonna open at the previous setpoint.
11-04-2006, 09:51 AM
#88
Originally Posted by obZidian
no... im talking about turbo boost. Intake restriction and cam selection, as it has being established, affects the way we see that set boost. More intake restriction, more build-up pressure before the cylinder, therefore higher boost readings. You get the same package, add a less restrictive intake, or a cam with more overlap, you'll see a drop in boost pressure since there is now a decrease in pressure before/in the cylinder. The CFM is the same, which i believe is preset with the wastegate, however, boost will vary on setup.
IF a SC'd car adds mods like heads/cam they have to re-pulley to bring the boost back to the same level but your turbo's output (in psi) is controlled by the gate's spring or the controller, like I said. IF you have a 7lb spring and you are actually seeing say 7.2psi you can add all the mods you want; the gate spring still isn't going to crack open until the same point it used to. The turbo's CFM won't be the same (again you are talking about a SC with a FIXED speed) it will go up, but the boost will stay the same; that's how it works. It is not a question of how things flow, it's that we are physically holding the gate shut until it's setpoint in PSI.
11-04-2006, 12:42 PM
#89
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ok... im understand you reason... but here is how i look at it. I could be wrong, dude, but that is the way things go, right! So please don't lecture me like a child... we are all educated people here in the same boat.
Our issues here lies with turbo CFM.. boost will vary depending on intake setup and how much you preset your max boost with yor gate, right? that is why you have it gated for 7psi and see 7.2 on the gauge, right? Am i understanding this correctly? If you mod your intake setup/cam/etc.... you will have a drop in boost pressure, let say 6.7, however, you are still gated at the 7psi. Therefore making the same amount of power with less boost. Right?
Question: Now, the turbo will push a given cfm at that 7.0psi. If your read 7.2psi on the gauge, that would mean that you are not getting that entire load of cfm into the cylinder due to restrictions. IF you see 7.0psi, than you are getting all of it. Well, if you see 6.9psi or less, still gated at 7.0psi, you are still moving the same amount of CFM now but will less restrictions or will the gate adjust until you reach your NEW 7.0psi, thus increasing your CFM flow?
you said, "it will go up, ...that is how it works" Is this what you meant.
Also, this thread is about how things flow through the intake path and a cams effect of boost pressure, i understand that the gate dictates the amount of pressure, that is obvious, just trying to see the other properties of boost on an engine.
Our issues here lies with turbo CFM.. boost will vary depending on intake setup and how much you preset your max boost with yor gate, right? that is why you have it gated for 7psi and see 7.2 on the gauge, right? Am i understanding this correctly? If you mod your intake setup/cam/etc.... you will have a drop in boost pressure, let say 6.7, however, you are still gated at the 7psi. Therefore making the same amount of power with less boost. Right?
Question: Now, the turbo will push a given cfm at that 7.0psi. If your read 7.2psi on the gauge, that would mean that you are not getting that entire load of cfm into the cylinder due to restrictions. IF you see 7.0psi, than you are getting all of it. Well, if you see 6.9psi or less, still gated at 7.0psi, you are still moving the same amount of CFM now but will less restrictions or will the gate adjust until you reach your NEW 7.0psi, thus increasing your CFM flow?
you said, "it will go up, ...that is how it works" Is this what you meant.
Also, this thread is about how things flow through the intake path and a cams effect of boost pressure, i understand that the gate dictates the amount of pressure, that is obvious, just trying to see the other properties of boost on an engine.
11-04-2006, 01:07 PM
#90
Originally Posted by obZidian
.. boost will vary depending on intake setup and how much you preset your max boost with yor gate, right? that is why you have it gated for 7psi and see 7.2 on the gauge, right? Am i understanding this correctly? If you mod your intake setup/cam/etc.... you will have a drop in boost pressure, let say 6.7, however, you are still gated at the 7psi. Therefore making the same amount of power with less boost. Right?
11-04-2006, 04:00 PM
#92
i say we hold the discussion until i redyno. I'm not putting it beyond Autometer that my boost guage is a piece of ****. Its one of the new Nexus ones, electronic, and i have been very unhappy with the quality of the rest of it, so the accuracy is probably up in the air too. I just assumed it to be somewhat accurate as i am running no boost controller and my WG springs are .4 bar. (two 38mm wastegates)
11-04-2006, 05:22 PM
#93
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thus more CFM flow with the same amount of boost, due to th mods done to decrease the restrictions in the intake system. More CFM, more charged air at the same preset, gated, psi, more power productivity.
11-04-2006, 05:45 PM
#94
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extremely high for a mustang dyno. at 4.5 psi that means the car is making roughly 430 rwhp with no boost, something really seems off, try a dynojet AND/OR go to the track.
Edit, it could be a monster cam helping this car as well, that is possible, but I would have to say it would be fairly big.
Edit, it could be a monster cam helping this car as well, that is possible, but I would have to say it would be fairly big.
Last edited by Nickn20; 11-04-2006 at 05:58 PM.
11-26-2006, 05:15 AM
#97
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Originally Posted by Pro Stock John
600rwhp in a 3500 lb car is ~ 135mph.
140mph in a 600rwhp (non-gutted car) isn't all that realistic.
Regarding the dyno numbers at 4.5psi, was the dyno fan blowing
nitrous?
j/k 
11-30-2006, 03:58 PM
#99
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dyno sheet yet??????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????
