Intake plenum and 911 throttle body

[KRAM36]

That's priceless information to me blue2000s, thank you for being patient with non technical educated folks like me.

Curious, if you stick your head back in here. When you did the CFD, was this done as a wide open throttle simulation? I can't make out the charts you have on the right and wondering if the air is staying attached properly to the radius of the 997 Distribution T at wide open throttle.

I want to see Ben offer up a piece that is better then the 997 part. Granted he knows more about this then me, but I need to know before I toss $300 to him, that he is making the part worth that money vs $55 for the 997 piece.

Right now my car is running phenomenal with the 987 air box, 996 TB and 997 Distribution T on it. I'm very hesitant to change anything in the intake, unless I know for sure it will benefit me.

[blue2000s]

Originally Posted by KRAM36

That's priceless information to me blue2000s, thank you for being patient with non technical educated folks like me.

Curious, if you stick your head back in here. When you did the CFD, was this done as a wide open throttle simulation? I can't make out the charts you have on the right and wondering if the air is staying attached properly to the radius of the 997 Distribution T at wide open throttle.

I want to see Ben offer up a piece that is better then the 997 part. Granted he knows more about this then me, but I need to know before I toss $300 to him, that he is making the part worth that money vs $55 for the 997 piece.

Right now my car is running phenomenal with the 987 air box, 996 TB and 997 Distribution T on it. I'm very hesitant to change anything in the intake, unless I know for sure it will benefit me.

The model I ran wasn't dimensionally matched to the car. I just built it to demonstrate the principles.

[jsceash]

KRAM36

Also what about the 997 T being so much larger then the Plenum opening? Is this a huge issue?

The answer to the question you asked is it has some negative effect. Is it a nail in the coffin NO! Does it add to the Disturbed air Yes.

For my part my explanation of the air hitting the back of the tube is easier than trying to explain a boundary layer, molecular bonding in air molecules, or fluid shear.

Any time you go back to the drawing remember this is just a snapshot. You have to understand that it's only true at the flow speed used to graph it. Now look at the white area in the center, that is the eddy(s), I tried to explain in the "Stream post" there is a light blue area surrounding it, which is another separation area of disturbed air. If you compare these 2 areas to the Y pipe below they are larger because the air runs very tightly to the solid wedge diverter in the Y design. Because it does the flow cross section is more constant in the Y design. Also because air velocity affects the stagnant air wedge in the 997 Tube the flow cross section varies more with flow speed.

I agree with Blue2000

The effect of a physical wedge is more likely to disrupt the secondary pulsation supercharging effect of the tuned plenum than it is to help bulk flow in any way.

The flow would be very close in both systems with the Large radius T maybe even having a slight advantage for RPM below the point where the secondary tube damper opens. The second the secondary tube dampener opens, the IPD has the 997 tube hands down. Once the cylinder pulse has a secondary route the wedge no longer has to deal with the back flow.

I get a significant power and torque boost at that point.

[jsceash]

I'm not saying in any of this that the 997 T body mod is bad, or the IPD is the best. Each has it's place and both have compromises. Members of the forum who haven't bought one have justified their decision based in rumor or hear say and COST. I guess the $795 is high when compared to the $299 for Pedro's upgrades (some reason not available for our years any more), but why would Softronic's slam IPD. FYI they make a kit, aluminum T and tune $1975 ouch. Sometime there are ulterior motivation. I'm sure if you called Pedro to solicit an opinion he put down Softronics. I you called IPD they would down play Pedro's Kit. There each in the market to sell their product. Suncoast Porsche sells only IPD products. They state its an improvement over the stock Porsche parts but it's still $795.

[KRAM36]

Originally Posted by jsceash

The flow would be very close in both systems with the Large radius T maybe even having a slight advantage for RPM below the point where the secondary tube damper opens. The second the secondary tube dampener opens, the IPD has the 997 tube hands down. Once the cylinder pulse has a secondary route the wedge no longer has to deal with the back flow.

I get a significant power and torque boost at that point.

That's interesting. I don't get a sensation of extra boost through the RPM band. I get a steady very strong pull across the RPM band. Feels like I'm driving a small block V8, put the throttle down and I get a steady relentless pull to the next gear. After I got done with the intake mods and took it out for the first time, I knew it had added a lot of power.