Swaping out intake manifold

[cobras]

thanks for the reply

"so I am guessing you want
TORQUE... which would be the Edelbrock Performer RPM dual plane manifold...not the Victor Jr."

so would this manifold give me a loss in hp #s from what i have now, what are the diffrences in a dual plane or a single plane

i would have to say yes to the torque, i dont plan on making any new speed records, i just want it to pull hard off the line and have a good strong pull up through the gears, but also dont want to loose too much HP in doing so


here are the specs from the ford web site



392 cubic inch

475 hp @ 5600 rpm (with headers, and a 750 CFM Holley carburetor not included)

495 lb.-ft. @ 4400 rpm

10:1 compression ratio (nominal)

Forged pistons

Forged steel cap screw connecting rods

Hydraulic roller camshaft, .580" lift intake and .602" lift exhaust, duration at .050" is 232 degrees intake and 240 degrees exhaust

Double roller timing chain set M-6268-A302

Forged steel crankshaft

High-performance T-sump oil pan

MSD billet distributor

Ford Racing aluminum "Z" cylinder heads M-6049-Z304DA with 2.02" intake valves and 1.60" exhaust valves

Roller rocker arms M-6564-F351

Single plane “Victor Jr.” intake manifold M-9424-V351

New heavy-duty 5.8L “Sportsman ” block, oil and water pumps, performance oil pan, steel billet flywheel and high-performance harmonic balancer

[Pete Munroe]

We always have fun changing stuff to be exactly what we want, but for me there is a point of diminshing returns.

There is not much you can do to an engine, beyond spark plugs!...that is easier than swapping out, or replacing gaskets on a intake manifold.

Drive the thing for a year or so...figure out for yourself it it too peaky or undriveable...

Leave the frick'en thing as it is and spend your time/money somewhere else...late on, if it is so important, change it out.

A Cobra is so light that the Vic Jr. manifold on the street is probably of not much consequence...so leave it alone and next year change it out if you need more of something...you are not sure which way you want to go...leave it alone...you can change it in an afternoon...

Have fun by not being obsessive about the way it "looks" or to get performance you can't describe or specify.

Not meant to be critical, just take the easy route...a manifold is an afternoon and another $150 ...for what?

Have fun and drive the car for a season or two.

Pete

[dlang14]

Originally Posted by cobras

"so I am guessing you want
TORQUE... which would be the Edelbrock Performer RPM dual plane manifold...not the Victor Jr."

so would this manifold give me a loss in hp #s from what i have now, what are the diffrences in a dual plane or a single plane

i would have to say yes to the torque, i dont plan on making any new speed records, i just want it to pull hard off the line and have a good strong pull up through the gears, but also dont want to loose too much HP in doing so

Sounds like Performer RPM or Air Gap RPM would be the way to go. On my Roush 427R motor (351w) I went with the Performer RPM over the Victor Jr. Roush didnt have dyno numbers on the air-gap so that was harder to compare and I didnt look at it closely

It is true that the performer RPM will lose peak horsepower compared to the victor jr, but at lower RPM bands it makes more horse and torque. If I remember the cut over on the Roush dyno sheets was at 4800rpms, and if you compared the average from 3K-6K the performer RPM made better average hp and tq. These numbers will be different on your motor but it should still give you a relevant data point. Good luck and have fun!