Manifold Spacer!?!?

[Maxx]

Was looking at http://www.streetandperformanceelectronics.com/lead.htm
and seen that they have a manifold spacer for our 4.3L. The VMax manifold spacer.

Don't know what to think of them, myself.

[ZR1-S10]

Looks promissing! By incressing the pleum volume high-end horsepower (where our trucks lack) should go up greatly. On question, being 1" tall will it fit under the stock hood with a FIPK2?

[bvr775]

hum!!!!!!! that might actually work. who want's to be the guinie pig?

[Krazny]

Wonder what it runs pricewise. . .

[ZR1-S10]

Well someone needs to find out the price and where to buy. It would be great if we can get a N/A and a blown engine to test it on.

[bvr775]

I sent them an email and I'm waiting on a reply.

[Supercharged-ZQ8]

While waiting on the AFI manifold, I'd be willing to give it a try. . . I just need to know HOW MUCH and WHERE.

Let us all know when you hear back from them, bvr! I'll be the blown guinea pig.

[extreme gmc]

i'll be the n/a guinea piggy...

[OBI WAN]

I have a major problem with the ideal of this spacer.

Anyone want to tell me why our intake falls flat on its face around 4400 rpms?

What I have been told, theorized and everything else is this.

The LARGE plenum we currently have was so when you tipped in on the throttle the motor had plenty of air within the plenum to get going as it built reserves up and got flow moving. This is why the 4.3 is so torquey to begin with.
As rpm increase the air speed also increases. This increase of useage and speed within a large plenum such as ours then begins to empty out faster than it can be refilled. Pressure drops and then the air begins to slam the plenum floor and begin and uproll youve seen on TV's when they show aircraft taking off etc. The air swirls upwards and curls in creating a turbulance. Then with each cylinder commanding air it begins to try to tornado it in movement. Massive turbulence to the point that the cylinders begin to run out of air cause it must fight this to gain air. Also the floor of the plenum is lower than the runner which creates its own nature of problems.If you look at never intake and or the old TPI ones, you'll notice the plenum is smaller for one and also the way the runners run off of them. The runners are very close to the size of the plenum in diameter. The throttle body is faced forward and the plenum does not extend beyond the last runner. Tis whole fashion of make and forward movement fills the plenum from rear to front and also alot have a air foil within the opening to direct the air towards each bank.
Larger plenum would do what?? It may slow the slamming effect, but how much or if at all? Also going on why plenums are created large, it would aid bottom end more than top end. Where does the 18 h.p. come from??? Why doesnt a 1 inch spacer then show more promise under the throttle body then it does and we've seen. After all its enlarging the plenum volume as this would! Even go look at intakes available on older motors! Does any of them run such large plenums or are they nearer the size of a carb or TBI unit? WHY?

Now what I would like to see done is the idea I have stuck in my head. This spacer has been out now for about 2 months and Ive looked it over time and time again and shared and ideal with one person, HUH SUPERCHARGED! Why not use this spacer reworked to solve some of the problems I and other inherently believe as our #1 culprit in higher rpms. Machine a new one with the outter rim where our plenum mounts to the same one inch. The center near the throttle body could rise 2 or so inches. Then from this 2 or so point, split the center into a ^ like a slide to ramp the air toward each bank!!

[bvr775]

I understand were your comming from jedi, but I want to try this. as soon as I get some info I'll let ya'll know.

[Supercharged-ZQ8]

I have a major problem with the ideal of this spacer.

Anyone want to tell me why our intake falls flat on its face around 4400 rpms?

What I have been told, theorized and everything else is this.

The LARGE plenum we currently have was so when you tipped in on the throttle the motor had plenty of air within the plenum to get going as it built reserves up and got flow moving. This is why the 4.3 is so torquey to begin with.
As rpm increase the air speed also increases. This increase of useage and speed within a large plenum such as ours then begins to empty out faster than it can be refilled. Pressure drops and then the air begins to slam the plenum floor and begin and uproll youve seen on TV's when they show aircraft taking off etc. The air swirls upwards and curls in creating a turbulance. Then with each cylinder commanding air it begins to try to tornado it in movement. Massive turbulence to the point that the cylinders begin to run out of air cause it must fight this to gain air. Also the floor of the plenum is lower than the runner which creates its own nature of problems.If you look at never intake and or the old TPI ones, you'll notice the plenum is smaller for one and also the way the runners run off of them. The runners are very close to the size of the plenum in diameter. The throttle body is faced forward and the plenum does not extend beyond the last runner. Tis whole fashion of make and forward movement fills the plenum from rear to front and also alot have a air foil within the opening to direct the air towards each bank.
Larger plenum would do what?? It may slow the slamming effect, but how much or if at all? Also going on why plenums are created large, it would aid bottom end more than top end. Where does the 18 h.p. come from??? Why doesnt a 1 inch spacer then show more promise under the throttle body then it does and we've seen. After all its enlarging the plenum volume as this would! Even go look at intakes available on older motors! Does any of them run such large plenums or are they nearer the size of a carb or TBI unit? WHY?

Now what I would like to see done is the idea I have stuck in my head. This spacer has been out now for about 2 months and Ive looked it over time and time again and shared and ideal with one person, HUH SUPERCHARGED! Why not use this spacer reworked to solve some of the problems I and other inherently believe as our #1 culprit in higher rpms. Machine a new one with the outter rim where our plenum mounts to the same one inch. The center near the throttle body could rise 2 or so inches. Then from this 2 or so point, split the center into a ^ like a slide to ramp the air toward each bank!!
We haven't ironed out the whole idea yet. I understand almost exactly what you mean, but I want to "polish" the idea a little -- go over it with you again to make certain we're on the same page. At that point I will make the necessary contacts. In fact, I was contemplating buying one and looking it over and then figuring the next move from there.

[ZR1-S10]

Thats not really true Jedi. Wave action tuning is a relatively easy way to augment volumetric efficiency within the cylinders. It stems from a simple phenomenon: as the intake valve opens, the downward motion of the piston causes the mixture to be literally sucked into the cylinder. When the intake valve closes, this accelerated air stops against the valve and stacks up on itself, creating a high-pressure area. This causes a high-pressure wave to make its way up the primary intake runner away from the cylinder. When it reaches the end of the intake runner, where the runner connects to the plenum, the pressure wave is reflected on the opposite wall and is sent back down the intake runner.

Sizing the runner appropriately will enable the pressure wave to arrive back at the intake valve as it opens for the next cycle. This extra pressure will make more mixture enter the cylinder, thus having a supercharging effect.

Buy making the plenum larger the wave takes a longer time to return to the valve causing the ram effect to happen at a high RPM. Adding volume also helps dampen the reversion pluses. It also inprovess "sharing" of the runners.

You may have seen some aftermarket manifolds with a divider plate down the middle of the plenum. The Edelbrock manifolds have this and you can noice that the divider plate is smaller on the performer-rpm intakes then the standard performer intakes. The smaller plate incresses the plenum and ups the wave tune to a high range for better high-end power.

[bvr775]

with all the incomplete theorys and myths surronding the GM engine designs that are at this time veiwed as fact, without a dedicated lab and a vertually unlimmited budget sometimes the only way to figure something out is to try it.I can't afford to spend the money to have french grimes design a manifold for my truck on a theory. This spacer dose pretty much what I had in the design. If this works it opens up a whole new can of worms and people need to start rethinking what they veiw as fact

[OBI WAN]

You may have seen some aftermarket manifolds with a divider plate down the middle of the plenum. The Edelbrock manifolds have this and you can noice that the divider plate is smaller on the performer-rpm intakes then the standard performer intakes. The smaller plate incresses the plenum and ups the wave tune to a high range for better high-end power.

No arguement of the pressure wave theory. If the plenum was not so odd shaped and runner rans off of them correctly, which by the way is the TPI and newer design, then adding plenum volume could be a good thing. This last statement you made is the idea I have within this little. Divide it so each bank may have it own pressure wave area to work within and the slide effect ramping keeps it contained and pointed toward the runners, so as the wave makes a return of direct it pointed at the runner and not a side wall or floor of the plenum.

Really I do think there is not a bench flowing process being done here. I really can say with a great deal of accuracy I believe, that there basing this as just a different way to make money off the idealism of the throtle body spacer which has been put to its death, forum wise etc on dry intakes. To take a 1+thick piece of alum and program a CNC to cut it, the time to cut it at $45+ and hour, gaskets etc, this part I believe will run in excess of $250. probably more like $350.
Give me the divider, some ramping and I would be all over this! Need something to correct the shape of our intake at least!

[biglouie_underpressure]

ok ok i'll talk to my hook up tomorrow...jeez i already have boost at idle,That intake idea should work out fine. infact, i'm not doing anything all week and maybe i'll get a stock intake and take it to the machine shop and have something fabricated.Do you think that idea would add more cfm from the blower to the runners?

[extreme gmc]

i will chekc tomorrow if it will fit under a factory hood witha k and n intake...

[OBI WAN]

It will> If you take off the K&N adapter and its rubber connector, then attach the K&N bonnet right to the Throttle Body it will fit. Same problem arises when you add the 1 inch spacer under the throtte body itself, same solution. Actually when I had the K&N setup, it kept creeping apart no matter what I did until it had time to settle, but when I would do my biyearly throttle body clean I would go though that again. So one day when I was to put it back together again I found the bonnet for the K&N allready fit snug and I just clamped it on. Check for air leaks and found non and I think thats the only reasons they do it this way was to guard again a bad connection that would leak. I figured if it did leak and O ring or just a dab of chaulk would have cleared it up anyhow!

[biglouie_underpressure]

bvr someone asked to send me one to try out before this thing ever came out.I don't like to feel as if my time is being waisted or else i would of had this thing on 3 months ago. I may still try it tho.

[Supercharged-ZQ8]

bvr someone asked to send me one to try out before this thing ever came out.I don't like to feel as if my time is being waisted or else i would of had this thing on 3 months ago. I may still try it tho.
Have you had it installed? I'm curious as to how it works in a boosted application. I understand the theory behind it, but real world results are so muc better.

Of course, the idea Jedi Master has may be considerably better -- if it can be done (well, if SP can be convinced to do it).

[extreme gmc]

well if it cannot fit witha k and n i am out...

[biglouie_underpressure]

no i haven't tried it yet but i'm still thinking about it.On a boosted motor the extra volume would make the boost come on later.

[bvr775]

it retails at $357.77. you have to call them directly to order, but i'm going to see what the speed shop can do for me on this one.

[biglouie_underpressure]

the gains are 8hp and 15 tq on the 96+ 4.3's.group buy would be 10 members @ $257.50.