Factory Airbox on SC engine
#51
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Roc, you and I don't have to worry about that. We've got a big ol vacuum cleaner sucking in the air we need
Forced induction. We don't have to rely on speed to ram it in there.
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Forced induction. We don't have to rely on speed to ram it in there.
#52
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Is your 4 tenths improvement just the CAI or also with your 3.4" Pulley? And a quick question, you put Exhaust crossover Heat Shield in your mod list. The crossover is already heat shielded. Did you thermal wrap it or just say it'* heat shielded....
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The CAI took it from 6.9 to 6.5.
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So as you can see the CAI made almost as much difference as the pulley.
I know the pulley is quoted at 30 hp and 50 ft-lbs increase, so I don't have any difficulty believing 15-20 hp from the CAI.
I purchased the exhaust crossover from the GrandPrix store. I know the original exhaust crossover has a heat shield over, and it does a pretty good job of decreasing the 450 degree pipe temperature to aroung 200 degrees, but the additional shield brings it down to about 120 F.
"Because space is limited in the engine bay, the exhaust crossover pipe runs right underneath the throttle body and intake tubing. Our exhaust heat shield, which is made of 22 gauge bright annealed T-304 stainless steel, bolts on right below the throttle body, protecting it from the harmful radiant heat. As an added bonus, the shield allows air from the radiator fan (and pass through air) to flow between the exhaust pipe and shield, dramatically increasing its effectiveness and lowering underhood temperatures."
#54
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Roc, you and I don't have to worry about that. We've got a big ol vacuum cleaner sucking in the air we need Forced induction. We don't have to rely on speed to ram it in there.
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The key is minimizing all restrictions.....like the factory box and that smaller surface area flat filter. That'* why you go to a cone. Less restriction. That'* why you go to a K&N type. Less restriction. That'* why you go to the largest size intake pipe. Less restriction. It all adds up to more power.
The idea of ram is more one of getting the cold air into the area where the inlet is located so it is not sucking up any heated underhood air.
The ram air set-up on my Firebird does little to actually pressurize the filter box, it merely scoops the cold air from under the front bumper and rams it through twin 4" hoses that are about 4 feet long.
Any ram effect is negated by the friction loss inside the hoses.
I measured the temperature drop with this setup over just a plain 14" dia x 4" K&N under the hood. Before it was 130 F and now after it never rises above outside temps. Normally 50 F. So that'* a 8% gain in hp over 330 hp = 26 hp
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#55
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I have a question about the choice of intake filter. If the duct feeding the TB is 3 inches diameter, than the surface area of the filter should matter less, as long as its free flowing, right? I mean, save for an effective method of boost (ram effect, or mechanical) there is only so much air that'* going to enter the tube anyway, right? Thats assuming there isn't a restriction like a small inlet hole or something.
Example, if I tore off the front part of the stock box, inserted a K&N filter to replace the delco paper job it came with, the flow should be about the same as if I removed the box entirely, and added a cone filter to the front of the existing intake tube? Or is there a venturi effect that'* going to let in more air with the cone? Again, I am assuming the outlet of the box to be roughly the same diameter as the tube feeding the TB.
Example, if I tore off the front part of the stock box, inserted a K&N filter to replace the delco paper job it came with, the flow should be about the same as if I removed the box entirely, and added a cone filter to the front of the existing intake tube? Or is there a venturi effect that'* going to let in more air with the cone? Again, I am assuming the outlet of the box to be roughly the same diameter as the tube feeding the TB.
#57
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have a question about the choice of intake filter. If the duct feeding the TB is 3 inches diameter, than the surface area of the filter should matter less, as long as its free flowing, right? I mean, save for an effective method of boost (ram effect, or mechanical) there is only so much air that'* going to enter the tube anyway, right? Thats assuming there isn't a restriction like a small inlet hole or something.
Example, if I tore off the front part of the stock box, inserted a K&N filter to replace the delco paper job it came with, the flow should be about the same as if I removed the box entirely, and added a cone filter to the front of the existing intake tube? Or is there a venturi effect that'* going to let in more air with the cone? Again, I am assuming the outlet of the box to be roughly the same diameter as the tube feeding the TB.
Example, if I tore off the front part of the stock box, inserted a K&N filter to replace the delco paper job it came with, the flow should be about the same as if I removed the box entirely, and added a cone filter to the front of the existing intake tube? Or is there a venturi effect that'* going to let in more air with the cone? Again, I am assuming the outlet of the box to be roughly the same diameter as the tube feeding the TB.
The cone has another advantage. More laminar flow. The air coming out of the stock box is very turbulent. That'* one of the reasons GM uses the MAF screen, to smooth out the flow before the MAF sensor, to give a consistent reading. The accordian tube does not help with turbulence either.
I was really surprised that when you removed the MAF screen, with the turbulence of your stock system, that it didn't make a difference. Good for you.
I was a little more cautious an waited until after the cone install.
The flow path inside the stock box is 3 3/4" diameter. And so is the stock rubber hose. Not that bad. The problem is the square filter. If you pull it apart, you will see a small area of filter that is dirtier than the rest. That is where the inlet air impinges on it. Filtering is not as effective as withmething.
Example, if I tore off the front part of the stock box, inserted a K&N filter to replace the delco paper job it came with, the flow should be about the same as if I removed the box entirely, and added a cone filter to the front of the existing intake tube? Or is there a venturi effect that'* going to let in more air with the cone? Again, I am assuming the outlet of the box to be roughly the same diameter as the tube feeding the TB.[/quote]
Rocco - The larger the surface area, the less restriction, for the same amount of air.
The cone has another advantage. More laminar flow. The air coming out of the stock box is very turbulent. That'* one of the reasons GM uses the MAF screen, to smooth out the flow before the MAF sensor, to give a consistent reading. The accordian tube does not help with turbulence either.
I was really surprised that when you removed the MAF screen, with the turbulence of your stock system, that it didn't make a difference. Good for you.
I was a little more cautious an waited until after the cone install.
The flow path inside the stock box is 3 3/4" diameter. And so is the stock rubber hose. Not that bad. The problem is the square filter. If you pull it apart, you will see a small area of filter that is dirtier than the rest. That is where the inlet air impinges on it. Filtering is not as effective as with the cone that draws air in from all around.
I went one better and chose a 4" inlet x 7" long *&B cone. It has filter area in the end also. I was hoping to connect it to the stock fender opening, but the computer box got in the way.
Before I installed the cone, I had already replaced the stock paper filter with a flat K&N filter. It didn't make much noticeable difference. Well maybe just a little, about 4 hp. The advantage over an open cone was the cold air the stock box drew in thru the fender opening.
IMO, switch to an aftermarket tube and cone....but include a heat shield or sealed box for true cold air induction. It really does make a difference.
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Yeah. Hector has mentioned once or twice about the stock box. I actually have a system in mind. Just looking to answer some questions I came up with before I start fabrication.
I did get an intake from Ty'* outfit. I'm still debating whether to use it or return it for various reasons. What I need is a nice warm weekend to get out there and spend some time under the hood.
I did get an intake from Ty'* outfit. I'm still debating whether to use it or return it for various reasons. What I need is a nice warm weekend to get out there and spend some time under the hood.
#59
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What all of this boils down to is that it'* far more critical for the guys with the "i" to get major flow, by any means possible. This can't be done with the stock box, unless you cut the hell out of it, and even then, it'* really not optimum. I'm hoping for a big improvement from the ADTR, even over my gutted box.
What was wrong with the intake you bought? The fit?
What was wrong with the intake you bought? The fit?
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