With a twin turbo setup, you can optimize one turbo for low RPM's and try
to diminish the turbo lag.
In general, a turbo can reach much greater boost levels than a SC.
Remember too that a SC has to be driven by the engine itself which is a
substantial parasitic loss. For example an SC providing an 8PSI boost
level might take away 50+hp from the engine just to turn it! The turbo's
are turned by the exhaust flow. If there isn't any exhaust flow, there
isn't any boost! Hence the reason for "turbo lag" at low RPM's. SC cars
have the power almost immediately. Much superior for low rpm/high torque
needs. But you're not going to get a street SC with much more than 10 PSI.
Even relatively small single turbo's can make 10PSI look like child's play.
So the short answer is that a twin turbo setup will probably kick an SC,
BUT!!! You can't simply slap major boost on a stock 3.9 (or nearly any
stock engine). I really couldn't imagine putting more than 8 psi through a
stock 3.9. I know I'm pretty conservative, but for most of you I doubt if
you're really looking for dedicated drag toys. For 8 psi, twin turbos is
major league overkill!
Now if somebody wants to completely rebuild and modify their 3.9, then you
can have some serious fun with a twin turbo setup!!!
Steve Ekstrand, Pasadena, CA Driver: '00 Dakota CC SLT+ 4.7L 3.92SG 255's
Stacey's Driver: '00 Inferno Red Intrepid ES-3.2L-24V Autostick w/Leather
Race Car: 69 1/2 Road Runner 440-6 (ex-NHRA SS/GA future B or C/SA???)
Project Car: 69 Barracuda Notchback (Orig. 318, now 360w/Edelbrock Heads)
Homepage: http://sites.netscape.net/professormopar/homepage
----- Original Message -----
From: "Chuck Robbins" <intense99dak@home.com>
To: <dakota-truck@buffnet.net>
Sent: Wednesday, April 26, 2000 11:50 AM
Subject: DML: Re: Re: SciTeck-twin turbos (Jason)
| I'm still learning about all of this and there are a lot of
| other membrs who could explain better then I can, but ...
| This twin turbo set-up (for v6's) involves two sequential
| turbos. The first kicks in with low rpm's and the second kicks in
| with mid to high rpm's. Therefore virtually eliminating any
| turbo lag.
| How do they compare to a supercharger? First and foremost
| the supercharger is a lot simpler to install & maintain. I don't
| know specifics, but that is the impression I've gotten from the DML
| and a few others. As for horsepower & torque, I'm inclined to
| say the the twin turbo set-up will blow the doors off a supercharger.
| I know that this leaves a lot open and I'm hoping someone with
| more knowledge steps in. I have yet to talk to Sciteck personally,
| so there are a lot of unknowns in this.
|
| Chuck Robbins
| '99 Dakota Sport
| http://www.members.home.com/clrobbins/dakota.htm
|
| > What are twin turbos and how do they compare to a supercharger?
| >
| > Jason
| >
| >
| > > I just received an email from Sci-Teck saying that pricing
| > > is going to take another week or so. I guess they would like
| > > to see a few more people at least interested in the turbos.
| > > If you are interested, give them an email at
| > > SciTeckMiami@aol.com You don't have to committ now, just
| > > "show an interest".
| > > Hopefully there will be a few more interested people as I am
| > > really looking forward to having the turbos on my Dak :)
| > >
| > > Chuck Robbins
| > > '99 Dakota Sport
| > > http://www.members.home.com/clrobbins/dakota.htm
| > >
| > >
| > >
| >
| >
| >
|
|
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:50:56 EDT