Super charger and turbo question

[Mark J. Besso]

See if you can dig up any technical information on the Lancia Delta S4.
(Yes, the very same vehicle that led to the demise of Group-B rally cars)
That car used a combination on supercharging and turbocharging.

My memory is failing me right now, but I know there was a car in Hot Rod
magazine that used a combination of them too.  I think it used the
turbochargers (one per cylinder bank) to feed the supercharger.  It also had
nitrous oxide injection!  The car was driven on their "Power Tour" so it
wasn't just for show.

~Mark


----- Original Message ----- 
From: "Eric Sanborn"
Subject: Re: Super charger and turbo question


> ScottyCBoy at aol.com wrote:
>
> >In my search for more power I've gone insane...
> >
> >
> >Any body have comments one something like this? Most books I have seen
only mention either turbos or superchargers, and not both..
> >
> >
> >
> The turbocharger is as you would imagine a turbine pump.  The volume air
> flow is dependant on speed as well as pressure differential.  The Eaton
> you are looking at is postive displacement.  This "pump" moves a preset
> amount of air every revolution of the shaft.  If you have two pumps in
> series you will run into cavitation problems if they don't flow the
> exact same amount.  If you put them in parrallel I don't know what would
> happen.  Likely at low RPM/high boost from the eaton the turbo would
> want to run backwards, but would be counter acted by the exhaust gasses.
>
> I don't know it is starting to make my head hurt thinking about it.  The
> reason you never see it could be for no other reason than complexity and
> cost.  I seem to recall my internal combustion engineering text book
> from college had it as a possible type of system.  I would think you
> would need to tune the two systems separately.  Eaton for idle to say
> 3500 rpm, turbo from there up.  I just see problems written all over it.
>
> (I appologize in advance for my blasphomy against all that is turbo).
> Ditch the turbo idea.  Get a big IC and run the eaton with 12 to 14
> lbs.  If I remember correctly the T-Bird has a 3.8.  Your V-8 is likely
> a 3.6 so this eaton (size 62?) is a very good fit).  Somewhere out there
> is a good site where someone added an IC to a T-bird and had very good
> results with more boost.   I think that route would be easier since you
> could use the factory exhaust manifolds still and you would just have to
> make a bracket for the SC and add some plumbing (which would be simpler
> than the plumbing for 2 turbos).
>
> If you are concerned about an SC's ability to make top end power see if
> you can find anyone who still has a G60 Corrado on the road.  A good
> friend of mine had one running 17 lbs of boost.  It was very fun :)
>
> -- 
> Eric Sanborn
> '85 4ktq