This was just posted on the email list.

http://mywebpages.comcast.net/p-928/749.html

Prety cool

 

Cool concept, but I wonder why the fellow didn't just weld a new plenum?

 

I guess he just dosen't have the cool auto darkening welding helmet like you do Porken.

Andy K

 

GoRideSno,

An auto-darkening-welding-helmet separates the wheat from the chaff!

All I need is a regulator and some noble gases. Then I can really make some... trouble!

 

one word interested that type of set would soooo clean up the engine compartment
more info more info

oh why not place the throttle body facing front and take advantage of some ram air????? where there issues with this???

 

pvoth, if you look at 928developments.com, phil already did it that way and it seems to work well in carbon fiber...can't imagine metal wouldn't work either...looks better in metal, but I wonder about heat absorbtion being slightly higher with metal also...perhaps insignificant for most of us though...

 

Hi guys,

That would be my plenum. As Andy K guessed, I didn't 'just weld up a new plenum' because I don't have the auto-darkening helmet. Or the welding rod. Or the welder. Or the skills. I had the stuff welded up.

Bill
'84 s 5 sp.

 

Oh, and Paul, placing the throttle body forward would interfere with the oil filler and the Vortech.

Bill
'84s 5 sp.

 

the highest pressure is at the base of the windshield, not the air moving over the radiator. both are probably close to the same for argument sake. also keep in mind that the max pressure you would EVER get from ram is under .4psi at 160mph and around .08psi at speeds of 80mph. (and thats with a monster dragster, 75% efficient , out of the boundary layer, hood scoop!!! . So, its much less than that with the stock air entry system. so, the base of the windshield becomes the next or equal best place to put a air entrance to the engine

MK

 

transient time of the heat would not be an issue. 500cfm rolling through a metal intake wouldnt raise the temp that much more than a CF intake. the main heating of the air happens in the last few inches anyway.

every little bit helps, but the main thing about the CF intake is the reduction of restriction and pressure drops.

MK

QUOTE]Originally posted by rob rossitto
pvoth, if you look at 928developments.com, phil already did it that way and it seems to work well in carbon fiber...can't imagine metal wouldn't work either...looks better in metal, but I wonder about heat absorbtion being slightly higher with metal also...perhaps insignificant for most of us though... [/QUOTE]

 

Looks neat, but non-symmetrical intake manifolds are inherently unbalanced. Space efficient, but fluid dynamically speaking, unbalanced.

This is why the serious replace the factory 951 intake manifold.

But it does look neat.

Greg

 

hey mark, didn't think metal would matter much, was surprised on the windshield pressure, though I've heard similar remarks from pro drag racers regarding hood scoops...has anyone done something similar w/the 5.0 motors? $3,400.00 for a carbon intake (and approx 50hp) may be worth it, but if the same result could be obtained for less....

 

I like the 50hp intake, and if we can do it for less, I would sure like to know.
Tom has an intake mod for the S4 that we may try, and it is supposed to be around 30hp and a lot cheaper.

hood scoops as good as they are (when really tall and out of the boundary layer) are still only 75% efficient. Just think how any other intake scoop would fare, especially with the total potential only being in the .36psi range at 160mph!!!!!!

mk

 

Is this non-symmetrical? What's non-symmetrical about it? I don't see it. Sure the 951 intake is non-symmetrical, half of it is missing! :-)

Bill

 

Bill,

'Non-symmetrical' in this scenario means that there is not a (basically) equal distance between the air inflow (in this case, TB) and the outflow (the runners).

A factory 951 intake feeds air in the front, into the 'log', then the cylinders grab what they can. The problem is, they don't all get a fair shake in the 'air grab'. The guys up front get the best access, and take all they can. The guys at the back get the scraps. Feed it in equidistant from all the cyls. and everybody gets (essentially) the same shot at the air; they may not get all they could take, but they all get about the same.

The factory 928 (2 valve) manifold actually is relatively efficient in this manner.

As in (though likely not as bad as) a 951 factory manifold, one is feeding the air in very close to some cylinders, and (relatively speaking) farther away from others.

This leads to a scenario where the airflow is unbalanced, ie, some cylinders will get better flow than others by virtue of their place 'in line' as it were.

The cylinders at the back of the line, will not flow air at the same rate as the ones at the front, even under boost.

But it does look neat, and may solve a particular packaging issue that is more important to the user than the loss of performance compared to a symmetrical intake.

Greg