I am nowhere near knowledgeable enough to guess at what changes overall airflow and enhances efficiency in a manifold. I ask you, the professionals, for help. I have a Clifford Hyper Pack and am not afraid to alter it; what changes can I do to the design of the intake to make it more efficient on the street and the strip?... without cutting off the runners or changing the outside appearance of the manifold. Thanks.

D. Alexander W.

Others will have more specific comments, but me, I can't reconcile "Hyper Pak" and "efficient on the street" very easily.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Put EFI bungs in each runner near the head and do port EFI...

Lou

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Home of Slant6-powered fun machines since 1988

You'll want to look at all my past posts on "HPak" for the street, best bet is to "split" the plenum in the middle with a divider and that makes better midrange torque/power...

-D.idiot

Vote # 2 for dividing the plenum area.
Also, find a way to get some heat into the intake manifold and / or the air going into the carb.
DD

Has anyone ever contemplated using a electric heater to heat the base of the manifold to optimum temperatures, giving the surface area a even distribution of heat as opposed to a riser of a header tube or manifold? Is this even necessary if I were to use a TBI system which is "perfectly" calibrated for proper Air:fuel mixture?

First of all, there is no such thing as perfect. But aside from that, many of the problems with long runner designs derive from the fact that the fuel has so far to travel before reaching the intake port. The addition of heat helps to vaporize the fuel so that it doesn't puddle in the floors of the runners. The better solution is port fuel injection where the fuel is sprayed at or very near the intake port. TBI is easier to implement but it has most of the problems of carburetion and few of the benefits of port injection.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

x2 Been there, learned the first time on the way back from Seattle when a homemade rear dutra exhaust leak kept the under hood temps up and allowed for some really good gas mileage...I'm still contemplating a heated air intake for my street hpak, but I know the heated box does work especially when the mornings are under 43 degrees...the split manifold helps dial in perfect mix...

TBI will have all the same problems the carb does (if the intake is cold the TBI will just run the injectors richer for longer to make up for the A/F ratio until the heated intake vaporizes the surplus gas in the plenum then it will go very rich until it clears, or washes down the cylinder walls). You may also have side to side temp/ mix variances so you may need one injector to fire a bit more than the one closest to the fire wall if you mount the TBI with 1 injector for 1-2-3, and the other for 4-5-6...

MPEFI will be as good as it gets, but you will have to dial in a fully custom map..from scratch...

You might experiment with the electric heater, but the clifford intakes are made of some kind of aluminum scrap floor scrappings and they take a while to heat up (One of my first temp checks showed the warmed up engine could have 150 degree F surface temp at the head, but the plenum temp would be 80-100 degrees...

Now get out to the garage mock up your setup and start some garage engineering!!!!

-D.Idiot