Since I have never owned a supercharger - you are probably right on all accounts.
I guess I'm trying to learn. I also am rarely pleased by an out-of-the-box install
especially when it is destined for such a wildly varying target. I think we all
agree that the best that could be had would be a measurement of our current
situation (A/F ratios at all rpm steps) and then to have the ability to quickly,
and cheaply get it under the desired conditions "with the turn of a knob" - kinda
like you IAT adjuster ;-).
Question is: Where are we now? Even after my mods - I'm rich under almost all
conditions.
Latr,
Shane
bernd@texas.net wrote:
> Misleading?? Shane, nothing against you here...but i've installed Paxton,
> Vortech, ATI, and Powerdyne's on many vehicles over the years and have never
> seen any problems on the daily street driven vehicles at all. As long as the
> auxilliary fuel system was installed properly, the fuel enrichment works just
> fine. On the Powerdyne, in this specific case, the FMU plate can be adjusted
> from a 4:1 - 16:1 depending on the modifications. From what Shawn described,
> it's nothing that the PD FMU system can't handle.
>
> On the "Big Boys" who use seperate controllers, yes...there is a big difference
> and tuning is required...depending on the type of system they're using. Larger
> injectors, timing curve changes according to rpm and boost, fuel pressure
> changes, etc. But again, the systems available to the regular "walk-in"
> customer are more than adequate for what most are doing. (Those with the 12-
> second and quicker vehicles will obviously require some extra tuning.)
>
> I'll use my truck as an example (V8's should stick to the 12:1 FMU plate right
> from the start and prefer 24# injectors):
>
> (1) Powerdyne w/6# Pulley, factory injectors (or FMS 19# High-Flow), 48mm V8
> TB, Headers, Exhaust, Ignition, and mild intake "cleanup": 10:1 FMU w/no retard
> required.
> (2) Powerdyne w/9# Pulley, FMS 24# injectors, 50mm Billet TB, Headers, Exhaust,
> Ignition, and mild intake "cleanup": 12:1 FMU, ICON custom curved to retard
> in .5 degree increments (up to 3 degrees total) from 2200-5500rpm.
> (3) Powerdyne w/10# Pulley, FMS 24# injectors, 50mm Billet TB, Headers,
> Exhaust, Ignition, and mild intake "cleanup": 12:1 FMU, ICON custom curved to
> retard in .5 degree increments (up to 3.5 degrees total) from 2200-5500rpm.
>
> - Bernd
>
> > bernd@texas.net wrote:
> >
> > > With the fuel curve, most of all the Supercharger kits come with a fuel
> > > enrichment circuit of some sort. Leave the fuel enrichment up to the
> external
> > > systems (FMU/Pump, Boost-A-Pump, etc.). They control the enrichment under
> all
> > > conditions and only under boost.
> >
> > Thats a little bit misleading tho because whenever you increase the boost by
> > changing pulleys, open up the breathing by porting heads, going w/the new RT
> or
> > ported aluminum heads, larger throttle body, headers, etc. you will again be
> on
> > the lean side where you need to manipulate the fuel delivery curve. None of
> those
> > external systems will compensate for that. Thats why the big boys use real
> > controllers - you know where you are actually in control - not at the mercy
> of
> > someone else's expected outcome.
> >
> > Latr,
> >
> > Shane
> >
-- '96 IndyRam-HisIndy-MPI/TB/Pulleys/AccelCoil/MPComp/HookerSuperComps/CompTAs '96 IndyRam-HerIndy-numbered(#142)"Track Truck" '74 Triple-Black Dodge Challenger Rallye 360 home-brew EFI R&D vehicle '68 Black Corvette Convertible 427 (For Sale)
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:01:28 EDT