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Engine Forge Intake and BOV

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Sure I used this formula. Pout seems to usually be about 1-2 psi over Pin and Eff is usually around 70% so I just used those since I don't have super accurate information. All temps are in Rankine degrees, which by the way is a fucking weird almost pointless scale considering how close it is to Kelvin but that's what they used.

Tout = Tin + [[Tin x (-1 + (Pout/Pin)^0.263)] / Eff]

Tin = Inlet temperature in °R
Tout = Outlet temperature in °R
Pin = Inlet pressure (psia)
Pout = Outlet pressure (psia)
Eff = turbo efficiency (0 to 1)
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Yeah there's a lot of back an forth everywhere on the internet about stuff like this when I'm researching. I don't have much practical experience with cars but I'm a computer engineer by trade so the cold hard numbers are what I trust and understand.
 
Jigbits said:
Sure I used this formula. Pout seems to usually be about 1-2 psi over Pin and Eff is usually around 70% so I just used those since I don't have super accurate information. All temps are in Rankine degrees, which by the way is a fucking weird almost pointless scale considering how close it is to Kelvin but that's what they used.




Yeah there's a lot of back an forth everywhere on the internet about stuff like this when I'm researching. I don't have much practical experience with cars but I'm a computer engineer by trade so the cold hard numbers are what I trust and understand.
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Turbo efficency is a constantly changing variable though, we would need a compressor map for the stock turbo to get exact numbers, but 70% is a good starting point. Do note, that turbo efficiency drops off a cliff as we try to push more boost at high RPM from such a small turbo, I wouldn't be suprised if it was less than 60% at 6000rpm and 14psi. That is why you see such large increases in IAT at high RPM.
 
^ Elementary understanding.
@R Veloster N Not entirely sure why you brought that up but yeah that's true BOV's do not change IATs.
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^You have a PM.
Yep most assuredly, after observing a few comments. Especially, the one on a "BOV lowering IAT's".;)(Nice delete by the way!):p A correctly designed intercooler will make more horsepower, lower IAT's, along with water or meth injection, as well. This is all known and been put into practice on multitudes of occasions past and present.

The rest is; simply plagiarized semantics, directly copied off reddit etc.;)
 
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So my Forge intake came in today and I figured I should touch back on this thread for anyone else contemplating the open Forge intake.

Mods on my car: JB4, NGK R plugs, Turboxs hybrid bov, custom cut grill, and now Forge intake.

With stock airbox and stock filter:
35c ambient (90% humidity) -> 41-46c cruising and 50-56c stopped

Forge intake:
35c ambient (90% humidity) -> 40 - 47c cruising and 52-58c stopped

Honestly the difference is less than 5% in most cases and in some cases the Forge was lower. On average I'm around 7-8c over ambient which stayed true with the Forge. I pulled into my garage at 4pm with the stock intake and pulled out at 5pm with the Forge. Not the most scientific test but the ambient temps were the same. There were a lot of factors that changed the IAT noticeably; head wind, car in front of me, lower speed vs higher speed.

The biggest difference is how fast the heatsoak set in. With the stock box it would slowly creep up while at a stop light but with the Forge it would go straight up over 50c in a matter seconds. Then again it would go straight down once I started moving and the stock box would take a few seconds to get back down.

I have a lot of JB4 logs from before the intake was swapped so I'm going to compare the actual numbers once I get a little more from the Forge. If it stays how it was today I can live with 5% in the worst case. The grill dropped my IATs 10-15% so overall it's still a net positive from completely stock.

Stock intake JB4 log: https://datazap.me/u/jigbits/log-1565314092?log=0&data=1-4-6

Forge intake JB4 log: https://datazap.me/u/jigbits/log-1565314076?log=0&data=1-4-6
 
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Jigbits said:
So my Forge intake came in today and I figured I should touch back on this thread for anyone else contemplating the open Forge intake.

Mods on my car: JB4, NGK R plugs, Turboxs hybrid bov, custom cut grill, and now Forge intake.

With stock airbox and stock filter:
35c ambient (90% humidity) -> 41-46c cruising and 50-56c stopped

Forge intake:
35c ambient (90% humidity) -> 40 - 47c cruising and 52-58c stopped

Honestly the difference is less than 5% in most cases and in some cases the Forge was lower. On average I'm around 7-8c over ambient which stayed true with the Forge. I pulled into my garage at 4pm with the stock intake and pulled out at 5pm with the Forge. Not the most scientific test but the ambient temps were the same. There were a lot of factors that changed the IAT noticeably; head wind, car in front of me, lower speed vs higher speed.

The biggest difference is how fast the heatsoak set in. With the stock box it would slowly creep up while at a stop light but with the Forge it would go straight up over 50c in a matter seconds. Then again it would go straight down once I started moving and the stock box would take a few seconds to get back down.

I have a lot of JB4 logs from before the intake was swapped so I'm going to compare the actual numbers once I get a little more from the Forge. If it stays how it was today I can live with 5% in the worst case. The grill dropped my IATs 10-15% so overall it's still a net positive from completely stock.

Stock intake JB4 log: https://datazap.me/u/jigbits/log-1565314092?log=0&data=1-4-6

Forge intake JB4 log: https://datazap.me/u/jigbits/log-1565314076?log=0&data=1-4-6
Click to expand...

Aside from the sound, hows the butt dyno feeling with that intake?
 
stewartevan said:
Aside from the sound, hows the butt dyno feeling with that intake?
Click to expand...

Honestly I can't tell much difference in power but I have a JB4 pushing almost 21psi so it's kinda hard to tell honestly. I will say the RPM range is incredibly smooth now. I felt like the stock airbox was starving the engine because when I'd mash the gas it would jerk a bit when getting up to 20+psi. The jerk is completely gone now, baring my earlier issue some may know of, and it feels so so smooth. I'm very happy with it and I'm sure it's a noticeable improvement over completely stock.
 
3DoorMadness said:
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Is there any difference in performance? Did u remapped after installing ur intake ?
 
Nothing including an FMIC, Downpipe, Intake and exhaust need to be remapped. If you desire optimal performance from the car with these bolt on modifications you tune. :)
 
The main purpose is to take the load off the turbocharger when the throttle is suddenly closed. When you shift or lift the throttle the BOV vents. Blow Off Valves are used to prevent compressor surge, a phenomenon that occurs when lifting off the throttle of an unvented, turbocharged engine.

A blowoff valve is connected by a vacuum hose to the intake manifold after the throttle body. When the throttle is closed, the relative manifold pressure drops below atmospheric pressure and the resulting pressure differential which operates the blow off valve piston. The excess pressure from the turbocharger is then vented into the atmosphere or recirculated into the intake upstream of the compressor inlet.
 
NULLOBANDITO said:
But could I adjust the valve in such a way that I get a bit more turbo flutter?
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Why would you want to first off? The proper operation of the BOV depends upon its correct settings. First off what you're hearing is not turbo flutter. Turbo flutter, also known as compressor surge, occurs when there is an abundance of pressurized air in the turbo system. When the engine is not able to combust the full amount of air pressurized by the turbocharger, this excess air will build up in the intercooler system.

Here's some good reading to explain;
drivetribe.com

What Causes Turbo Flutter?

Turbo 'flutter' noise is present on many cars with aftermarket modifications, but why does it occur?
drivetribe.com drivetribe.com
 
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