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Old 02-19-2005, 03:24 AM
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DangerMouse DangerMouse is offline
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Join Date: Dec 2003
Location: Northern Virginia
Posts: 119
Chevota,

I am sorry to read that you still do not believe me. Your statements about volumetric efficiency and "all the #s are wrong" are wrong themselves.

The factory M119 is not a race-prepped engine where < 1in-hg vacuum at peak airflow is a desireable condition. The difference between full-throttle requirements at 1.5in-hg and (if it were possible) 0.1in-hg might be 10% at the top of the power band, much less with a realistic vacuum. Ask your favorite engine tuner if you do not believe me.

Regarding effects of intake air temperature and volumetric efficiency... not just another theory of mine. I get a sense that physics is just not your cup of Joe. Fair enough.

Here's what someone else has to say about it: http://www.procharger.com/intercooled.shtml

If you can stomach some real-world numbers:
The engines I built were pulling 55in-hg at peak boost (10psi) through a six-inch cone filter. Calculated peak airflow requirements using the formula were 436cfm at a 5500rpm engine speed, real-world measurements at the MAF were 407cfm. The formula does not take into account thermal inefficiency, but let's ignore that -- it is still within 7%. That is a reasonable margin of error.

I honestly believe you have a little knowledge about a technical subject, which can be a dangerous combination. No offense intended here. If you actually want to understand how to tune the internal combustion engine and induction systems, the following texts are a great primer:

Bosch Automotive Handbook (Bosch)
Advanced Engine Technology (Heisler)
Supercharged! (Bell)

Since this is pretty far off-topic, I am going to drop off this thread. Good discussion.

Regards,
-DM
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