So Among my other projects, I'm making a boost a pipe. I'm using a 3.5" 90* chrome pipe for the main inlet at the s/c and a 3.25"id PVC pipe to go to the fender. My question is, Has anyone here ever made their own BAP? Do they really add Boost or am I waisting my time. If they do, whats the average boost they add?

 

all the supercharger companies say that the max boost you should run on a stock engine is 8-9 psi. your car may be working fine now, but eventually you're gonna blow something

 

I would lie to you and tell you I value your opinion but you can't stay on topic soooo, I don't.

 

Mike tells no lies. BTW how you do in ECON? I would give you my opinion on the pipe, but I can't cause I have yet to feel boost.

 

I am very interested in this idea also, especially since a power pipe cost so much. I mean its a pipe that cost almost $300, thats ridiculous.

 

What I don't understand is why they are 4" in diameter.....It's not like all that air can be sucked in....

 

I bit down a bought a powerpipe from AFM last week and will be installing it along with the blower hopefully tomorrow. The stock intake tube becomes a restriction at higher boost levels. The boost readings should increase a little. You are actually flowing the exact same amount of air, but the less force required to induct the air on the intake side of the blower will translate into more force on the other side. And the blower will take less power to spin. Most people experience 1-2psi jump and ~20hp depending on what your sitting at before.

 

This may be more than you want to know, however I am a semi-retired insomniac so here goes...[/align][/align]Keep in mind in order to make "boost" a quantity of air greater than that which the engine would normally aspirate at anyrpm has to be forcefully induced in to the engine.10 psi of boost requires that roughly* twice as much air as the engine would normally suck in, be forced in by the compressor--so making the inlet to the compressor less restrictive by a significant factor can pump up (no pun intended) boost by making more air, more freely available to be compressed.[/align][/align]To put some real numbers on this, the theoretical maximum amount of air our engines can pump at (without being force-fed) is 528 cfm @ 6500 rpm (281 / 2 * 6500 / 1728) . However because of empirical reality often being out of synch with theory the engine cannot actually suck in this much air, with volumetric efficiencies for 2V engines typically being cited as 80% to 85%.[/align][/align]My experience has been that those are best case numbers, but let'spick 85% for sake of argument. That makes the most air our 281 inĀ³ engines could suck in @ 6500 rpm= 422 cfm**; and that if we wanted to make 10 psi at 6500 rpm we'd need to take in 844 cfm at the supercharger intake--that's why the big pipe can provide a bit of an edge.[/align][/align]-------------------------------[/align]* - There are a whole slew of other factors involved in determining the volume of air required to produce "X" amount of boost, however for this discussion 2X for 10 psi is a valid guesstimation.[/align][/align]** - This is also why by themselves an aftermarket TB/plenum will produce no spectacular power gains. The OEM set can flow (per Accufab's data) 425 cfm at a1.7 inHg differential (I.e.1.7 inHg manifold vacuum), so the aftermarket stuff can only improve on this a bit.[/align]

 

^^ Your my hero

 

That's why he's me father!