As far as raising the fuel pressure you can do so up to a point without
breaking your injectors. We boost loving folks with FMUs run pressures
up to 80# for short periods during peak boost with no harm done to the
injectors. Depends on the design. Pintle valve design can withstand 80 -
90lb (during WOT). "Disk" types can't really withstand more than 60lb.
You don't want your injector to seize up. Just think what would happen
if they are stuck open or closed. Not pretty.
What will kill an injector is by exceeding 80-90 percent of injector
cycle for extended periods of time. My injectors go static (100%) on
extended WOT runs but since it only does so for short periods they
continue to work fine after 3 years.
I think Ford and CC use about 36 - 40lb or pressure at static (vaccum
disconnected=WOT).
I was wonder why the guys who are running a BIT on the lean side (with
proper mods) don't use an adjustable FPR instead of buying new
injectors.
Alan
'98 Dakota R/T (Headers, FABM & waiting for Shift kit)
'89 Mustang GT (347, Griggs, S-trim...)
Ducati 916 (someday)
-----Original Message-----
From: Wisotzkey, Rich
[mailto:Rich.Wisotzkey@gsc.gte.com]
Sent: Thursday, October 08, 1998 12:48 PM
To: 'dakota-truck@buffnet.net'
Subject: RE: DML: Injector Pressure - (The new
guy )
Bill,
Maybe this will help in your decision making equation.
Jacking the pressure
up through the usage of an adjustable pressure regulator
alone will shorten
the life of the injectors. What happens is this:
Driving the pressure up on the stock injectors will
indeed deliver more fuel
into the cylinder. This additional pressure takes its
toll on the internal
components of the injector and will shorten its useful
life. Also, the
proportional return on the pressure increase in
non-linear. Another words,
if you double the fuel pressure, you will not get double
the fuel delivery.
It will be a diminished percentage.
Increasing the size of the injector will give you more
fuel delivery without
decreasing its life expectance. But you don't want to
large of an injector.
If to large an injector is selected, the fuel will not
properly atomize
exiting the nozzle, and your performance will suffer
from a poor burn rate.
(Standard formula for this: .5 pounds per hour per
horsepower.)
Also, at WOT you will more that likely suffer from fuel
starvation if the
fuel pump cannot deliver an adequate supply of fuel to
the injectors. In
this case, you will also want to consider a higher
pressure fuel pump. Keep
in mind also that over time, the fuel pump delivery rate
is going to
decrease over time due to wear. This will further add
to the fuel
starvation dilemma.
Increasing one or maybe two injector sizes will probably
work fine, but
anymore than this really warrants upgrading of the
entire system. I hope
this helps.
Rich - Ashburn, VA
----Original Message-----
From: Bridges, Bruce [mailto:bbridges@alarismed.com]
Sent: Thursday, October 08, 1998 1:46 PM
To: 'dakota-truck@buffnet.net'
Subject: RE: DML: The new guy
Bill,
Dont jump too fast. You only get a lean condition with
the 52mm 700+cfm TB,
not the Stage 1s or the home style port and polish
units. I dont think you
can increase the FI pressure to get a richer mixture
though (I could be
wrong...) We should have some good data for DML review
by the end of next
week/ week after if you can wait so you can make a more
informed decision.
BKB
-----Original Message-----
From: William Blount Arthur
[mailto:m990198@nadn.navy.mil]
Sent: Wednesday, October 07, 1998 9:53 PM
To: dakota-truck@buffnet.net
Subject: Re: DML: The new guy
Yeh, especially if I dont have all that crap in the
truck. I am thinking
maybe I want to get some 24 lb injectors. that guy said
the Jet leaned it
out too much. Maybe I should just try to get an
adjustable pressure
regulator like the 5.0 guys use? Later
Bill
On Wed, 7 Oct 1998 Boog318@aol.com wrote:
> Bill
> I was running in 68deg. with 95 % humidity. Search
the archives for
"Boogs
> Racing Times" Yeah you have to run up at Cecil Cty.
You will probably
run
> faster.
> Oct 23rd.
> Boog
>
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:10:35 EDT