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"boost saver" - silly idea or invention of the century?

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Old Jun 13, 2010 | 10:26 PM
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Default "boost saver" - silly idea or invention of the century?

OK now that i've got you this far

Here's an idea i had today while driving around.

Would it be possible / feasible to build a 'split' intake tract which can be selected via some kind of fast acting soleniod? The purpose of this would be to capture built boost in the intake tract and 'hold' it until it's needed again.

As i was driving around it just hit me that every time i shift the bypass valve would actuate and i'd lose all my boost momentum as i shifted between gears...

I thought it would be neat if somehow you could have a direct pipe that bypassed the intercooler and could be near-instantly switched on (via TPS or vacuum input?) and the intercooler tract could be completely sealed up (at full boost pressure) until needed again a half second or so later.

Code:
Turbo 
  |
  |
  X======[ Intercooler  ]==== Throttlebody
  |                                                                    |
   \____________________________________/
                            direct path

  x = diverter
Old Jun 13, 2010 | 10:50 PM
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...
Old Jun 13, 2010 | 10:52 PM
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... X2

wtf

Even if this theory worked (which it wouldnt) it would be no more effective than one of those "electric superchargers"
Old Jun 13, 2010 | 10:53 PM
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Well, lets take a look at a 200WHP Miata. Thats about 20LBs of air per minute at about 10 psig give or take. I am rusty to the point of needing a Tetnus shot on this crap, but I do remember the most basic stuff hammered into my brain about a decade ago:

PV=nRT

P is pressure, V is volume, n is the amount of air, R is the universal gas constant, and T is Temperature. IN non-metric units, IIRC P is absolute pressure (which is basically what your guage says plus 14.7), V is cubic feet, n is lbs of air per minute (about 20 for a 200WHP Miata give or take), R is 10.73 and no I dont know exactly what the units are on it, and T is temp in Kelvin, which is whatever it is in F plus 460.

So lets see how much storage we need for one second of full beans air for the engine as the turbo provides it:

So, we have a 24 PSIA setup (10 PSI on the guage) for P. We have V, which is what we want to know about since it will tell us what size reservoir we need. We have n at .33LB of air (20LBs per minute divided by 60 seconds in a minute). We have R at 10.73, and we have T at 530K (l70F)

I get a volume of just under 76 cubic inches (I think). Thats a container about 4.2 inches per side. Which sounds good, but I dont know that a single second of airflow is worth it. Especially since you had to take that from some other boosted moment. Maybe it will help spool the turbo, but I doubt it.

Doing it as outlined here wher ethey fed me some units I am not sure about, I get a volume of 2.6 cubic feet needed at 10 psig to supply one second of air, which I think agrees with the other calc. http://www.gnttype.org/techarea/turbo/turboflow.html
Old Jun 13, 2010 | 10:57 PM
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stfu or you're banned.
Old Jun 13, 2010 | 10:59 PM
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It's such a small amount of air that it wouldn't be worth capturing at all. When you're shifting gears the car isn't under load and the turbo isn't making the boost. You have like this split second of air to capture and then feed back when the car is back under load and making boost again... seems 100% pointless. Please don't think and drive.
Old Jun 13, 2010 | 11:05 PM
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@Sparetire - I didn't take the time to do any calculations as you've so graciously done (i'm rustier than you, and it's only been 10 years), however a typical intake tract including intercooler is going to have significantly more than 76 cubic inches of air capacity no?

Assuming 2.5" diameter intake pipe length of 36", that works out to 141ci, around 2 seconds' worth of 'boost' stored in the charge pipes..

i dunno, just a thought
Old Jun 13, 2010 | 11:05 PM
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Originally Posted by hustler
stfu or you're banned.
agreed
Old Jun 13, 2010 | 11:09 PM
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You could just take the exhaust and feed it back into the intake manifold! Unlimited power!!!!!!!!!!!!!!!!
Old Jun 13, 2010 | 11:09 PM
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electric supercharger

my idea isn't to feed the compressed air back to the turbo, it's to make it available to the engine immediately when you get back on the gas while the turbo spools.

it was just a thought, i'll stfu and gbtw now
Old Jun 13, 2010 | 11:15 PM
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if your that worried about losing that lil bit, just make your car an automatic. there problem solved. constant boost!
Old Jun 13, 2010 | 11:15 PM
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Old Jun 13, 2010 | 11:26 PM
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Think about how fast the pressure would go away once that valve opened - it would do basically nothing.
Old Jun 13, 2010 | 11:27 PM
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why all the hostility? it was an idea, and i threw it out there.. i'm still not convinced it's a stupid idea, though you all seem to be!

people spend plenty of time and money on EBCs, blowoff and bypass valves, turbo blankets, new intercooler pipe routes, bar and plate vs tube & fin intercoolers, tubular manifolds, seperated gases downpipes, tuning, etc.

obviously people care about extracting the last bit of performance from their cars, so why not consider a new idea? (at least one i haven't seen tossed around).

Also i should probably clarify -- the subject of the thread was meant as a joke / to get people to read the thread... i obviously didn't htink this was the invention of the century, if that's what rankling your collective cankles
Old Jun 13, 2010 | 11:36 PM
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i have seen no hostility in this thread...........
Old Jun 13, 2010 | 11:39 PM
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lol.. maybe i'm just being a bit sensitive
Old Jun 13, 2010 | 11:41 PM
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Let me help.
Old Jun 13, 2010 | 11:46 PM
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It sounds a lot like you're trying to invent the bypass valve.
Old Jun 14, 2010 | 12:40 AM
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I'm not the most well informed about turbo dynamics but I know enough to be aware that this idea sucks.
Old Jun 14, 2010 | 12:45 AM
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danger to manifold



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