Great info , Shaun !
Thanks !
At 09:34 AM 1/22/1999 -0800, you wrote:
>Seems I let a monster out of the closet! ^_^
>
>Jon:
>
> Turbo pressure is not additive, 2 5psi turbos produce a whopping total of
>5psi to the engine, but a higher volume of air so the psi is more
constant. A
>single turbo vary's it boost more wildly than a twin setup.
>
>Jack:
>
> My Shadow had over 79,000K on it before it's untimely demise. ZERO oil
>leaks.
>
>The Single turbo groupees:
>
> Twin turbos don't eliminate lag, they slightly reduce it. The concept is
>that 4 cylinders can generate pressure X out of the exhaust. 8 can generate
>more pressure but a single large turbocharger is harder to spin up than a
>small one, even with the added pressure of the additional 4 cylinders. Gale
>Banks had an article (this was years ago) with full statistics on Quad, Twin
>and Single turbo setups for cars. The Twin seems to have the most
preformance
>increases. The Quad didn't do well with any engine less than 12 cylinders,
>and the Single didn't preform any better with 8 cylinders than it did with 6.
>Two smallish Turbos produced incredible effects with a V8. With a single
>turbo there are interesting pressure differences from cylinder to cylinder
(on
>the exhaust side of things), and unless the turbo is in the exact middle of
>the header to header arrangement it becomes less efficient. The nice thing
>about the Twin setup is that the turbos are symmetrical off of the headers
and
>the boost is very stable and consistent when correctly setup.
>
>The Twin turbo groupees:
>
> Two turbos are twice the headache. You have to run vastly longer oil and
>water lines. The heat into the pressurized air is much higher and an
>intercooler is mandatory, water injection or extremely high octane gas is
>recommended on boost setups over 15 psi. While preformance is higher, it's
>not exceptionally so. Single turbos are easier to maintain and adjust. If
>you don't have the twins setup right, you get imbalances (on the intake side
>of things) that can cause some wierd effects at different RPM's. Race teams
>tend to use single turbos under the "Keep it Simple Stupid" rule. Hot car
>makers tend to use twin setups: Ferrari, Vector, Maserati, etc.. have all
used
>multi-turbo setups for production street monsters, but these cars love their
>mechanics and see them often... ^_^
>
> Yes, to truely use over 7psi of boost, you do need high preformance
>pistons, heads and shafts. The block doesn't need any real mods though...
but
>I wouldn't try it on a "bored" block. However, keep in mind that the person
>who is looking at these mods has thousands of dollars to toss about.
Changing
>things like pistons, cams and cranks shouldn't bother them too much. I would
>also want a programmable engine controller to handle the motor. I don't
think
>a factory or even preformance controller can use the added boost to it's best
>purpose...
> That's about the limit of my turbo memory. I'll let the turbo guru's
argue
>it out from here, I'm a turbo novice.
>
>Shaun H.
>
>
----------------------------------------------
Jack Hilton III
Black 1998 Dodge Dakota R/T Club Cab
Charter Pipeline......the Next Wave.....
http://webpages.charter.net/hemi/jbd1.html
----------------------------------------------
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:12:10 EDT