Hi Ron
Some people watch soap operas during the day, I watch GreggPenn threads. 
Is this a problem with TPI plenums?
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Is this a problem with TPI plenums?
After looking at the TPI shootout recently linked, I noted no large-tube setup produced near the power of a short-runner setup. However, the superram got pretty-darn close with a mid-length setup.
The article also said it was surprising that the semi-siamesed ASMs didn't do better at high rpms. (They were hooked to a standard, ported plenum).
Now I'm wondering if the opposing tubes (esp in the middle) affect flow of the tubes on the opposite sides. IOW, would the force of air being drawn to one side of the plenum lower the speed of the pulses trying to go the other way?
I wonder if a "longitudal" partition was ever considered to separate the plenum in two air chambers -- each side fed by one TB opening.
gp
The article also said it was surprising that the semi-siamesed ASMs didn't do better at high rpms. (They were hooked to a standard, ported plenum).
Now I'm wondering if the opposing tubes (esp in the middle) affect flow of the tubes on the opposite sides. IOW, would the force of air being drawn to one side of the plenum lower the speed of the pulses trying to go the other way?
I wonder if a "longitudal" partition was ever considered to separate the plenum in two air chambers -- each side fed by one TB opening.
gp
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
No. Because the opposing tubes are staggered from each other. The pressure distribution would actually be fairly equal. They will have some effect on the runner they're paired with though.
Think of the plenum as a long rectangular strip of grass with sprinklers. If the sprinklers are spaced out along both sides, staggering them gives more even watering. The circular pattern of the water is analogous to the low pressure region caused by that cylinder's intake cycle.
Now let's get back to that TQ vs HP thread.
Think of the plenum as a long rectangular strip of grass with sprinklers. If the sprinklers are spaced out along both sides, staggering them gives more even watering. The circular pattern of the water is analogous to the low pressure region caused by that cylinder's intake cycle.
Now let's get back to that TQ vs HP thread.
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This stuff makes me glad I bought a ZR-1. There isn't much to think about in terms of upgrades. What intake manifold to use? Well, there's only stock. What heads? Stock. What cams? Stock. And now there is only one header maker as well. 
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I hear what your saying however.
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I guess you will have to settle with less then 400hp. Thats not so bad.
Take it easy! Too bad that there is a limit with the ZR1, then you have to spend the big bucks.
BTW, The stock "TPI" sucks for making power. Pure and Simple!!
Take it easy! Too bad that there is a limit with the ZR1, then you have to spend the big bucks.
BTW, The stock "TPI" sucks for making power. Pure and Simple!!
Last edited by 88BlackZ-51; Dec 20, 2007 at 06:34 PM.
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From: port charlotte fl
They are much like the jaguar V-12's.Over engineered and underpowered.A 1.6 litre Coventry Climax twin overhead cam motor puts out more oomph.I believe originally they were intended as a marine engine as mercruiser traditionally used GM blocks and sticking them in a car was an afterthought.