Hello Tom,

Interesting. I think another factor into this equation is that a turbo
doesnt just pump a fixed volume of air, but is regulated by the
wastegate as well, though I can see your point. Pauls example would
seem to back you up on this as well.

Saturday, July 27, 2002, 5:21:07 PM, you wrote:

TR> Bob,

TR> Good point, however, in an automotive induction system, the point of 
TR> lowest pressure is actually the point where all the air is exiting the 
TR> system- the inlet runners.  In a system of constant volume, the pressure 
TR> would be double, as the number of molecules would double due to two 
TR> pumps instead of one (ideal gas law: PV=nRT)  However this only applies 
TR> to closed systems, so in this case where there is a pressure drop in the 
TR> system (the throttlebody) the best explanation I can come up with (since 
TR> I don't have a physics degree) is to approximate it somewhere between 
TR> the same pressure and double the pressure!  Things like turbo efficiency 
TR> and dynamics would come into it.. so twin turbos on 10psi each at 
TR> constant rpm would be about 16psi....or something... I think....!

TR> - Tom



TR> Bob wrote:

>>I think you would find that the pressure from the turbos is not going
>>to add together to give twice the boost. If this were the case, in the
>>piping leading from each of the turbos you would see 10psi, and in the
>>plenum you would see 20psi. Liquids/gasses always try to flow from
>>high pressure to low pressure points, so the air would then be trying
>>to flow back from the plenum to the turbos if that were the case.
>>
>>As I understand it there are basically two types of twin turbo setups
>>used on cars, one where you have two smaller turbos of the same size
>>which should spool up identically etc and not have the syncronisation
>>problem, which allows you to use small turbos to get less lag without
>>as much restriction at the top end, and the second type like on late
>>model 13Bs where it has a small turbo to cover the bottom end, and a
>>big turbo for the top end. I read a report once where the engineers
>>were commenting on the setup of it, apparently its a real bitch to get
>>right.
>>
>>Saturday, July 27, 2002, 12:00:19 PM, you wrote:
>>
>>DA> Ummm, correct me if i'm wrong Mark, but the only time one turbo shitting 
>>DA> itself would cause diff intake into those two cylinders would be if you 
>>DA> were running two separate intake manifolds yes? If both turbos go to the 
>>DA> one intercooler, then to a single throttle body, single plenum, and into 
>>DA> all 4 you shouldn't have that problem.
>>
>>DA> Oh and two turbos at 10 psi is 20 psi the engine would see. To get 10 psi 
>>DA> out of a twin setup you'd only need each to be at 5 psi. Is this correct?
>>DA> Regards,
>>
>>DA> Dave
>>
>>  
>>
>>>>>>>>>>>>>>>>>>>>>Original Message <<<<<<<<<<<<<<<<<<
>>>>>>>>>>>>>>>>>>>>>                                        
>>>>>>>>>>>>>>>>>>>>>
>>
>>DA> On 7/27/02, 10:42:22 AM, "Paul Stanley" <[EMAIL PROTECTED]> wrote regarding 
>>DA> Re: please explainnnnnnnnnn.......:
>>
>>
>>  
>>
>>>>If syncronisation is a problem what about a custom turbo with seperate
>>>>turbines all connected to the one shaft?  Is that possible?  While you're 
>>>>      
>>>>
>>DA> at
>>  
>>
>>>>it... you could go the whole hog and make it a quad turbo.
>>>>      
>>>>
>>
>>
>>  
>>
>>>>From: Paul Stanley
>>>>      [EMAIL PROTECTED]
>>>>      
>>>>
>>
>>
>>
>>  
>>
>>>>----- Original Message -----
>>>>From: Rick White <[EMAIL PROTECTED]>
>>>>To: <[EMAIL PROTECTED]>
>>>>Sent: Saturday, July 27, 2002 2:33 AM
>>>>Subject: Re: please explainnnnnnnnnn.......
>>>>      
>>>>
>>
>>
>>  
>>
>>>>>Mark.
>>>>>I could maybee se a problem with having one per two cylinders.
>>>>>if one decides to shit itself one half of the engine would get totally
>>>>>        
>>>>>
>>>>different air fuel ratios and maybee the whole thing going bang big time.
>>>>      
>>>>
>>>>>Like half of the engine would like kinda stall and the other half would 
>>>>>        
>>>>>
>>DA> be
>>  
>>
>>>>fueled and boosted up big time so the half with the dead turbo would
>>>>probably lean out??
>>>>      
>>>>
>>>>>I recon one turbo is enough of a worry with out adding another to the
>>>>>        
>>>>>
>>>>equasion.
>>>>      
>>>>
>>>>>But two spooling up to ten psi would happen quicker with only half the
>>>>>        
>>>>>
>>>>induction  needed so you would be really getting like maybee 18maybee psi 
>>>>      
>>>>
>>DA> in
>>  
>>
>>>>real terms?
>>>>      
>>>>
>>>>>Just my thinking really.
>>>>>maybee I am way off track here. dunno.
>>>>>Later mate.
>>>>>Rick White.
>>>>>
>>>>>
>>>>>--- "mark krawczuk" <[EMAIL PROTECTED]> wrote:
>>>>>        
>>>>>
>>>>>>hi,   if you have a  single turbo at 10 psi, feeding 4 cyls,  would  it
>>>>>>          
>>>>>>
>>>>go
>>>>      
>>>>
>>>>>>better/or what would happen if you have two turbos at 10 psi,  with each
>>>>>>turbo feeding 2 cyls?
>>>>>>
>>>>>>i was fairly ,sorta on the track explaining to my  bro, but then he said
>>>>>>amongst other stuff, that he cant see any reason why two are better than
>>>>>>one.....
>>>>>>
>>>>>>mark k
>>>>>>
>>>>>>          
>>>>>>
>>>>>_____________________________________________________________
>>>>>Get Your free Ozdat Email Account
>>>>>---> http://www.ozdat.com
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>>>>>
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>>>>      
>>>>
>>>>>        
>>>>>
>>
>>
>>
>>
>>
>>
>>  
>>






-- 
Best regards,
 Bob                            mailto:[EMAIL PROTECTED]

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