I'm not a proponent of a larger injector with a factory or MP PCM unless A/F
mandates the need to go bigger.
Look at the rwhp numbers I'm kicking out with Design III 19 lb/hr (rated 3
bar) injectors!! 278 rwhp full belt, 285 with a short belt (race setup),
292 no belt.
Before the M1 and Design IIIs I was running a little lean (for my tastes) on
the dyno, so when I installed the M1 2bbl, I upped the fuel ante just a
smidgen (spec'd at 19.8 SAE) with the Design IIIs. A/F ratios were between
12.5 and 11.5 during the best hp and ft/lb areas of the pull with the M1 and
Design IIIs (right where I wanted them).
The 408 project is an entirely different animal though. Accel DFI to
control a cam with 288/293 gross duration, 236/242 @ .050
lift 555/576 - 1.6 ratio, 66 degree overlap, intake open 32 btdc exhaust
close 34.5 atdc and dual stage NO2 (dry), so I'll be using SIZEABLE
injectors (probably around 55 - 65 lb/hr) to help cover the NO2 load. Heads
are be out to 2.08 on the intake, and 1.62 on the exhaust. Castings are
Magnum R/T and heavily ported. But this will basically be a race motor.
Expectation is around 400 rwhp NA. I'll have to see once it is in and
tuned.
I posted a challenge for Merx/Damon/ScottQ/etal to be ready to duke it out
next year for the R/T nats ;-) We all better have cages if we want to keep
racing hahaha
TonyC
-----Original Message-----
From: Bob Mankin <bob@coralfarms.com>
To: dakota-truck@dakota-truck.net <dakota-truck@dakota-truck.net>
Date: Friday, August 22, 2003 12:17 AM
Subject: RE: DML: injectors
>
>Tony, don't forget to take the square root of that driven/test pressure.
>That would put them at ~22.5# with a rail pressure of 50 psi.
>
>Another data point: I currently run Design II Accel 24# injectors in my
R/T.
>Purposely changed the connectors out some months ago in anticipation of
>eventually going to 36# FMS units. For those that don't know, you can't get
>the newer Design III in larger sizes just yet, so it was the only option.
>LTFT is right close to -25 with these 24 lb units. You do the math. Does
>that suggest 19 or 21 lb injectors are a better fit?
>
>BTW, that's with a 215/218 @.050 .521 lift cam, heavily ported 2.02 R/T
>heads, 52x55mm TB, M1 intake, full exhaust, etc. Still think an injector
>upsize is an absolute necessity for heavy mods????? Caveat: the truck
>doesn't get alot of WOT work in it's present condition.
>
>I've never seen a definitive for where the 21# figure came from. A book is
>nice, but eventually you have to put it down and get in the real world.
I've
>seen Bernd's posting and once I wade through the confusion I see a spec for
>the injector flow rate and I see a spec for the fuel pressure. Two
different
>specs, not two parts of the same spec. An injector is assumed to be rated
at
>43.5 psi or 3 bar(industry standard) unless otherwise stated.
>
>Real world testing was done yesterday with a brand new injector for an '02
>Ram 5.9L application. Take it for what it's worth.
>
>All done.....now back to your regularly scheduled programming :-)
>
>Bob
>
>> -----Original Message-----
>> From: owner-dakota-truck@bent.twistedbits.net
>> [mailto:owner-dakota-truck@bent.twistedbits.net]On Behalf Of Tony
>> Cellana
>> Sent: Thursday, August 21, 2003 7:18 PM
>> To: dakota-truck@dakota-truck.net
>> Subject: Re: DML: injectors
>>
>>
>>
>> Rough math (ballparking it) puts the 01/02 injector at 24.1
>> in our trucks
>> then.
>>
>> driven pressure/test pressure * rate at test pressure
>> (50/43.5) * 21.0 = 24.1....
>>
>> TonyC
>>
>>
>> -----Original Message-----
>> From: Bernd D. Ratsch <bernd@texas.net>
>> To: dakota-truck@dakota-truck.net <dakota-truck@dakota-truck.net>
>> Date: Thursday, August 21, 2003 9:53 PM
>> Subject: RE: DML: injectors
>>
>>
>> >
>> >Oops...that should state as follows:
>> >
>> >Engine Years Flow rate in lb/hr
>> >5.9 Magnum 93-95 24.5 - Factory Fuel Pressure (40psi average
>> - spec is
>> >35-45 psi)
>> >5.9 Magnum 96-00 23.2 - Factory Fuel Pressure (50psi average
>> - spec is
>> >49psi +/-5)
>> >5.9 Magnum 01-02 21.0 - Tested @ 43.5psi (Outside source)
>> >
>> >Sorry for the typo - pasted in the wrong spot.
>> >
>> >- Bernd
>> >
>> >
>> >
>>
>
>
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