RotorMotor

iTrader: (5)

i dont think this is true if it is vented *before* the air flow meter like in the stock setup... then the air flow meter can register a change in flow and inform the ecu to compensate. heath

Sesshoumaru

iTrader: (1)

you can run crazy high boost levels.

some VW or sumtihg runs like 56 psi or sumthing.

detonation is great.......it makes my car move....pre-detonation makes my car not move.........

intake temps go up with higher psi.......Think of the compresses air bottle for your pc's........

when u use them they get really cold.......reverse the process.......

that usually is the killer and reason for not running high psi. That will cause pre-detonation easier since it's closer to the flash point.......

Sesshoumaru

iTrader: (1)

eh....

yeah could be RotorMotor

not sure on this density map bs they changed to.

some day i'll have the gumtion to learn it.

it works that way on a maf

Sesshoumaru

iTrader: (1)

That's correct you wouldnt' be running the same amount of air even though u have the same psi.

well if you tell me your running 10 psi i'm like ok...that doesn't tell me anythign about the CFM's.

but if you telling me ur running 10psi on a t88 i'm like......wow. That's a lot of air.

b/c 10psi on a T88 is more than those hitachi's are capable of putting out at the same psi.

just look at it like that.

RotorMotor

iTrader: (5)

i have to respectfully disagree good sir haha. think about it from the perspective of measuring all pressure right before the TB. If your seeing 19psi at the throttle body and all your intake piping is the same length/diameter after the turbo then you have the same flow of air... am i right? sure those hittachi's are screaming away, while the huge t88 blades are leisurely spinning away, but no matter how its made its still the same PSI. if a cow could fart into your intake and you see a sustained 19psi at the TB then you should have the same flow rate as the beloved t78.

EDIT: ah i may see what your saying.... your thinking about it as measuring the PSI right after the turbo.... maybe some stage 3's would have to register 22psi right after the turbo to make 19psi at the throttle body... but to have a constant measuerment of flow, think about measuring everything from the TB. if your saying that the hitachi's would run out of volume (cant mov enough air) then you would see your psi at the throttle body drop. BNR claims however that their stage 3's can cut it in the flow department, and i believe them. i think that a set of stage 3's would be better than a single cause you can make the same psi but spool faster. heath

Shabib67

i know this may be off topic but does anybody know if they make the turbo xs rfl blow off valve for the fd and how much does it cost and is it a kit or does it require welding

Detbyron

pv=nrt

If the manifold (volume) and intercooler (temperature) remain unchanged, then 19psi from twins or 19psi from a single is the same amount of airflow per minute, right?

You upgrade your intercooler in order to decrease the air temperature (and thus density) so if you have the same 19psi at a lower temperature, now you are moving more air than before, because it's more dense.

But should an upgraded intercooler create more lag? I think no... the psi may be lower because the density is higher, but you still have the same amount of air and thus same power. But with an upgraded intercooler you and same 19psi, now you have more air (power) than 19psi at a higher temperature (because of the air density).

Detbyron

ahhh....

Theoretical numbers:
Twins making 19psi at the TB: spinning at 10,000rpm
Huge single making 19psi at the TB: spinning at 5,000rpm

Now your turbo is not "working" as hard. Thus not as much heat is being generated, and thus being transfered to the intake air.
So, a single turbo at 19psi may have slightly higher density than the twins at 19psi, and thus more power.
I'm droppin' $3k on a huge single for the extra 10hp!!!

***highjacked thread***

Does the BOV do anything? No, you can just use a hose to connect them to each other... the air pressures will cancel each other out.

DCrosby

PSI = Voltage = Pressue
CFM = Amperage = Volume

2 different measures...

This also is proven by the fact that some people lean out in cold weather, because cold air is denser than warm air, even though Atmospheric pressure stays the same.. There is more Oxygen per Cubic Centimeter...

Sesshoumaru

iTrader: (1)

Dcrosby is right

the diameter of the hose effected the PSI (pressure) and the water was the CFM

or as he puts Voltage is the hose and amperage is the water.

that's why there' independand

P=VA

if you have a large voltage it takes less current for same power (small turbo high psi, low CFM)

but u can have a small voltage and a large current to do the same power (big turbo, low psi, big CFM)

but then again if there was a cow farting and no one was there.........does it really make a sound?

ReDLiNe@t9

holy *** crap i started a nutty disscussion!

DCrosby

*** crap might be a hazard in cow farting situation

Sesshoumaru

iTrader: (1)

detbryon.....ugh...u scared me with that damn formula....i thought i could for get that after my damn chemistry class

well from that i guess u can say then

p1v1=p2v2

this would relate the psi and cfm for the turbos

p=nrt/v

if you increase the pressure then u decrease the volume. Like squez'n a jar of air so you can fit it in your pocket.....i guess they call them air compressors nowadays.

anyway.....its' that damn conservation of mass that gets in my way........if i could break that law and create a friction less surface i'd be rich.

Sesshoumaru

iTrader: (1)

yeah all things turn to nothing in time

even intelligent ppl

are we talking about chemistry/voltages/bovs or was it washing cars? No wait....it was turbos......

nm......i forgot.

Detbyron

I don't understand what your saying at all with the voltage / current V=IR

CFM = volumetric flow = VA
V = velocity
A = cross-sectional area (TB) = constant

P1/d1 + (V1)^2 = P2/d2 + (V2)^2
P = pressure
d = density
1 = huge single turbo
2 = stock twins

If velocity increases, then pressure decreases. Like lift on an airplane wing.

But my colleague is telling me that even with same pressure, the velocity is still dependant on the suction velocity. So I'm actually just talking out of my ***.

DCrosby

I thought we were talking about *** Crap and Cow Farts !

Re: Nutty Discussion
I belive squirrel turds have come into the whole mix as well !

DCrosby

P= Power (Watts) (HP)
V= Voltage(Volts) (Pressure -> PSI)
A= Amperage (Amps) (Volume -> CFM)

P=V*A

Also Known as
P = I(times)E or P=IE
In this case P=Watts I=Amps E=Volts (don't ask)

The issue is that in reality CFM's are fixed, unless you change intake pipeing and / or Intercooler, etc... since all that has to do with volume...

And usually we change the PSI...

And what that formula states is that you can doubble the pressure and half the volume and still end up with the same amount of work done.. (power)

Sesshoumaru

iTrader: (1)

p1v1=p2v2

only holds true if the intake temps are the same

pv=nrt

so when i meant comparing the turbos i was talking at same temps too.

if the temps were teh same at the tb and the pressure was the same and the volume was.

yeah i'll buy it

Sesshoumaru

iTrader: (1)

gah!

u beat me to it.......but my computer restarted

i musta missed the squirel turds thing.

do they look like rabbit turds?

DCrosby

Yeah just nuttier

RxSeven1

iTrader: (2)

wow thats more physics than i care to know.

anyway here in jersey we have 92-93 octane.

Sesshoumaru

iTrader: (1)

huh.........

i guess u learn something everday.......

but then again.... i don't know why i would need to know the consistancy of squirel dung.........

but if i was a stranded and hungry........

Did we ever answer the question?
what was the question?

wiblergt

to end the thread...

the three reasons an upgraded BOV would be necessary...

1. defective stock BOV
2. you are using a turbo the size of an aircraft carrier
3. you want to make high schoolers squeel

DCrosby

If a blow off valve served a purpose...
As to the Consitancy of squirrel turds, it's a phrase, "he's nuttier than squirrel turds, I guess it's pretty nutty since, nuts are all squirrels eats" eh, humor is a bit tougher over the message boards

Sesshoumaru

iTrader: (1)

i debated on the mean of "nuttier".

but couldn't determine if it was to be witty or descriptive. I suppose it doesn't matter too much.

oh and to answer the question

do bov serve a purpose? ............. yes