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Discussion Starter · #1 ·
Thanks you for your reply to my Boost question. One more question for you, assumming you are equipped with turbo, with the car siitng (not on dyno) if you revved your engine to 5k rpm, your boost gauge won't register pressure?
If not, what registers on the guage?
Thanks
Tom
 

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Anytime there is a no-load situation, a running engine will produce vaccuum in the intake manifold. This is for turbo and n/a motors. Vaccuum decreases as the load increases. In the case of a turbocharged engine, as the load increases, at some point, the turbo will start making boost pressure. That point is determined by the specific dynamics of that particular engine and no two engines are exactly the same. That is also true with n/a motors. BTW, vaccuum will also change if the throttle position changes. In some turbo engines, a small amount of boost may be produced if the throttle is opened rapidly with no load on the engine. This is due to the rapid acceleration of the turbo.

Ian
 

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Hi Tom,
Again, I am not an expert at this, but Tom remember that turbo "kick" you feel when you are accelerating, you only going to feel that kick when you are accelerating hard, it is not "kicking" when you are SLOWLY bring the engine beyond 3000rpm. Same thing, when your engine is sitting in one place, it does not have to pull against any thing and therefore reving it while it is sitting is not going to show you any significant boost. Turbo engines operate using exhaust gas( thermal energy), so, you want your engine to produce a lot of these "gas" and the best way to do this is to have your engine operating under some load ( driving hard) Good luck
 

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RE: Ian is absolutely right. Good answer Ian.

It is said that vaccuum decreases as load increases(true), and some even said that at WOT vaccuum is zero ( not true). Any ways, in your case Tom
anything comes beyond this zero vaccuum mark is BOOST
Huy 260Z
 

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Discussion Starter · #5 ·
my next stupid question

Do turbo engines run vacuum advance? If you're creating positive pressure how does that work?
 

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RE: my next stupid question

The ignition timing on a turbocharged engine is critical to its performance. Turbocharged engines do not require as much total advance as a n/a engine. We are talking about 24-26 degrees advance as opposed to 36-38 degrees for a n/a motor. However, due to low compression ratios that turbocharged engines usualy have, a lot of initial advance is used to increase throttle response off boost. For example on an L28ET, The initial (idle) advance is 20 degrees. The computer then decides how much advance should be dialed in according to how much vaccuum or boost is being produced. In the case of the L28ET, the knock sensor also helps the computer decide the timing. Whenever knock is detected, the computer retards the timing. This is useful when less than desirable gasoline must be used.

Ian
 

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Discussion Starter · #8 ·
RE: another stupid question

well it's actually a secret but I'll tell just you!
Ü£¥¢Öÿûùòö¶_ß___¶¦_ß__+ú__+_
µ_+++_¦++_¦_PµÜnÅÅny+_îïìÄæÆdefgѪóƒáóúªªª
As you can see here I couldn't remember the correct number but I was in the right vicinity. Do this-- 1.put your number pad in number lock. 2. press "alt" button. 3. enter in numbers 678 on the munber pad. 4.Release the "alt" button. There you have the squared.
As you can see, there are other unique letters. Have at it!
Tom
 

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Discussion Starter · #9 ·
RE: my next stupid question

WTG Ian you figured to knock off any following stupid questions in a single blow, Well put, I understand completely, thanks
 
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