Hey Kevin...

How much is your Amour All bill each month... you sure have some shinny stuff in there

 

Yo,

Ask and you shall receive:



BTW, it's 2.75" pipe. *grin* Okay, I gotta run!

Kevin
1989 GTUs "I gotta work out!"

 

I don't see a water bypass. Don't drive through any puddles.

 

Looks good, I like the back yard engineering with the mesh file tray too!

And don't worry about the sound...almost nothing compares to the intake bark of a B16 with an AEM.

 

Yo,

Yeah, I doubt I can make snuffling dogs snap their heads out of the grass when I go by and hit VDI. *grin* That was hella funny. Kinda made me all mad again your car got stolen by those bastards.

Oh well, three strikes and you're out!

Mark, I just used a little McGuiers(sp!) Natural Shine here and there. Someone needs to have a clean engine bay, might as well be me!

Kevin
1989 GTUs "Now at work..."

 

I am going to have to disagree with that. A larger pipe also has more total internal surface area, it reduces the air velocity (and therefore inertia), and increases the volume which reduces throttle response. Additionally, neck-down or neck-up points create pressure drop, and larger diameter pipe must be bent to a tighter radius to fit in the same space as smaller diameter pipe. I believe that the "right" size is better than arbitrarily choosing the largest size that will physically fit.

 

Haha...that was the best, watching the dog shoot straight up in the air...

Almost as good as the time I scared a bunch of teeny boppers with it, it was almost like domino's!

 

I think he missed a spot!!

Steve

 

Rice! :P






J/K Looks outstanding Kevin. How's the butt dyno?

Brian

 

Yo,

Bastard! Heh. I will now get an AEM vinyl stickers and put 'em on the side 'cause I got the Cold Air Intake!

Thanks for the compliments. Butt dyno is good, doesn't feel like it's working as hard up in the high R's, like 7000 to 8600. Pulls past buzzer and keeps climbing.

I am trying to set an appointment for dyno on this Wednesday, so the 13B will talk or the bullshit walks. I hope the dyno doesn't dash my hopes like it always does. *chuckle*

Kevin
1989 GTUs "Any bolt on's I missed?"

 

Bottom line is that pressure drop through the pipe is reduced. Less work is required to move the same amount of air. This is not a inlet or exhaust manifold, where velocity and inertia are far more important for tuning purposes, it's just a piece of pipe.
One neck-down onto the AFM is still less restictive than doing the whole length in smaller pipe. Plus most S4 AFM adaptors are 3" anyway.
True, but if you're comparing 2.5" vs 3" pipe this is a very minor factor. The 3" pipe is still considerably bigger in area.
I think you're over-complicating this. Bigger inlet pipes to airboxes and AFM's have been proven many times to improve performance. In the same way that post-turbine exhausts should be as big as possible for maximum power, intakes should be sized for minimal restriction.

 

1) So why not use a 20" pipe for the inlet or post-turbine exhaust?

2) So why use air horns (intake trumpets) with only a slight 3-10deg taper? Why not use a 45deg or larger taper to make the inlet as large as possible?

 

That's just being silly...
Air horns are totally different, being only a one or two diameters long. The shape is more important than the diameter.

But as you said, step-ups and step-downs cause pressure drop. The shallower the angle, the less the pressure drop. If you want to change pipe size, you pick a length that gives your transition the shallowest angle practical. For our intake pipe, the transition is just a small part of the overall restriction.

I don't think I'm telling you anything you don't already know here.