Naive intake manifold porting question by a novice

General engine tech -- Drag Racing to Circle Track

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MadBill
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Re: Naive intake manifold porting question by a novice

Post by MadBill » Mon Oct 30, 2017 6:55 pm

cgarb wrote:
Mon Oct 30, 2017 6:32 pm
... After the head porting boost went down...
Needs more blower speed now! :)
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Re: Naive intake manifold porting question by a novice

Post by Frankshaft » Mon Oct 30, 2017 8:48 pm

panic wrote:
Mon Oct 30, 2017 5:13 pm
So to say good heads/porting doesn't help boosted applications is ridiculous
Exactly who said that?
You may find that insulting people trying to answer a question causes them to lose interest in your future remarks.
It wasn't directed towards anyone on this thread. Its just something I have heard for years. Its ridiculous.

Boost is just a measure of restriction. That's how you can make more power with the same turbo or blower, at a lower boost pressure.

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Re: Naive intake manifold porting question by a novice

Post by ptuomov » Mon Oct 30, 2017 8:58 pm

MadBill wrote:
Mon Oct 30, 2017 6:55 pm
cgarb wrote:
Mon Oct 30, 2017 6:32 pm
... After the head porting boost went down...
Needs more blower speed now! :)
And a better drive mechanism than a belt...

I just reread a bunch of the various and numerous speedtalk threads on porting for boost. There was no consensus on anything.

So far, all I’ve got is this (cockamamie?) idea that since we’re likely to get close to 1:1 intake to exhaust pressure, I should build it like it’s a “factory appearing” normally aspirated engine with cast exhaust manifolds that’s forced to run with substandard low-octane gasoline of some left-over communist state.
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Re: Naive intake manifold porting question by a novice

Post by cgarb » Mon Oct 30, 2017 9:45 pm

I'm not sure the blowers on the allisons are driven by belt. Evidently the blower shafts are the weak link because if you get too rev happy with it in the pits they are prone to snapping the shafts off. Remember him telling me they had trouble with that happening at times.

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