DeTomaso Mailing List: March 2001, Message #151

Hello Everyone,
I have been trading emails with Gregg Essakoff about fuel injection. Gregg
was nice enough to give permission to post this to the group for all to
benefit.
I will send this thread in one chunk so start from the bottom and work up.
Thanks again Greg, you have helped me clarify some of my choices.
Nolan


----- Original Message -----
From: "Gregg Esakoff" <gesakoff@etcconnect.com>
To: "'Nolan Scheid'" <nolan@clipper.net>
Sent: Thursday, February 15, 2001 5:00 PM
Subject: RE: Fuel injection


> Nolan,
> Feel free to post my reply with the news group.
>
> I do not have my files with me, but I recall the approximate length of the
> "complete intake runner system" was about 14.5" modeled and 13.75" dyno'd,
> limited to the available room above the engine. This length was optimum
for
> peak HP to occur around 7000 rpm based on my specific cam timing, with
> 345cfm @.700" intake port flow @.700" valve lift and 410cid.
>
> I would agree that the crossram manifold will be more adaptable for
plumbing
> twin turbos, but is the turbo arrangement for a road race application or
> street/show? What kind of block, bore/stroke ration, and bottom components
> are you planning on using? Personally, I would not use a turbo for track
> applications due to the narrow margin of error for tolerable lean
conditions
> with a pressurized system. I can tell you from my own experience that 700+
> HP at the crank is more than necessary to be quick around the track and
> pretty sure that I can equal my times if there was only 550HP available.
> Currently I am scratching 1.29's at Willow Springs and my biggest handicap
> for probably a while is my own ability, not lack of HP.
>
> Placing the injectors upstream primarily improves dwell time for atomizing
> the fuel. Fuel separation from the airstream is usually a problem related
to
> excessive port size/low velocity conditions combined with use of a
> carburetor or excessively sized injectors at low duty cycle. I use a
smaller
> ~48lb. injector but at 72~74psi to improve atomization while not exceeding
> the 90% duty cycle limit of the injector.
>
> As for throttle diameters, my system modeled at 2.25~2.375" diameter for
> best results. However, the engineer at Kinsler who reviewed my model along
> with his file of similar motor projects for sprint car motors suggested
that
> I use the 2.5". You will need to experiment with the simulation software
and
> system specs to come up with your optimum arrangement and probably just
> round up to the closest larger diameter if you are planning twist it
tight.
>
> I'll gather a few picture of my engine over the weekend (I'm out on
Fridays)
> and email them to you next week. By the way, Looking at my invoice from
> Kinsler dated 2/97, I paid $2,069 for the EFI manifold (same for aluminum
or
> magnesium)and the rest of the upgrades, ramtubes, injectors, linkage, and
TP
> sensor was an additional $1800.
>
> Gregg
>
>
>
> -----Original Message-----
> From: Nolan Scheid [mailto:nolan@clipper.net]
> Sent: Thursday, February 15, 2001 4:02 PM
> To: Gregg Esakoff
> Subject: Re: Fuel injection
>
>
> Hello Greg
> Thank you so much for the in depth reply. Would it be OK with you if I
> posted this email to the Pantera news group? I Think this would be
valuable
> to other Pantera owners.
>
> What lengths did you end up with?
> The crossram  really moves me but I don't have any flow or computer data
to
> decide that it will work better. I do also like the crossram because it
> would be very easy to use the manifold and step to dual plenums with twin
> turbos and an intercooler.
> That is very interesting about placing the injectors farther up stream .
Can
> I assume it works better because the fuel cools the air charge? I would
> think the injectors would need to be closer on a crossram to keep the fuel
> from falling out of stream. what are your thoughts?
> My motor is about 414 C.I.. Do you think the 2.5" butterflies would be
about
> right? One of my concerns about some of the easily available down draft
> system is the limited flow of the TWM 2" throttle bodies.
> I will try a copy of your suggested software. that should teach me a
bunch.
> I have already purchased the Speed-pro computer. as far as I can gather,
it
> and Motec are way ahead of the game over Electromotive and Haltek.
> The main reason I chose Speed-pro was because they are well represented in
> my area by Jim Messler. Jim is a has been a dealer for Electromotive
> ,Speed-pro and Haltek.
> He has pretty much stopped selling anything but the Speed-Pro.
>
> I have saved a picture of your car for my computer wallpaper. Can you
email
> me some picture of your motor?
> Thanks again for all your help,
> Nolan
>
>
>
> ----- Original Message -----
> From: "Gregg Esakoff" <gesakoff@etcconnect.com>
> To: "'Nolan Scheid'" <nolan@clipper.net>
> Sent: Thursday, February 15, 2001 2:07 PM
> Subject: RE: Fuel injection
>
>
> > Hi Nolan,
> > The choice of manifold for an EFI system would be based on intended
> > application, RPM range, and budget. This is the short version brain dump
> of
> > what I would include in your evaluation list of possible manifold
choices:
> >
> > 1)Runner Length: As you are probably aware of, this is the area of most
> > potential for a normally aspirated system. When properly matched to the
> cam
> > timing and exhaust system for the "specific application", significant
> power
> > gain, throttle response, and   a broad torque range are attainable. For
> > optimum results, the runner length should be adjustable for engine dyno
> > tuning, which typically is accomplished by varying the ramtube length.
> This
> > requires more time on the dyno and a person very experienced with your
> > engine management system for tuning the fuel and ignition maps, but the
> > extra day or so on the dyno is worth the effort (More about the dyno
> session
> > below). The runner cross sectional area and taper angle are also
important
> > considerations, but secondary to the correct system runner length.
> >
> > The lack of coordination between the intake runner length and the cam
> timing
> > can significantly reduce power output and create a choppy torque curve.
> > There are excellent software programs now available (and for very low
> cost)
> > that are capable of simulating and predicting the results of infinite
> > combinations of runner length and cam specs, and I would encourage you
to
> > utilize such a tool regardless of your choice of expert advisor/engine
> > builder/dyno tuner. I reviewed three programs before choosing the one I
> use.
> > They were Dynomotion (way too expensive for a hobbyist engine builder),
> > Desktop Dyno (very cheep, but too many general assumptions in the
program
> > and over optimistic results), and Engine Analyzer 3.0 by Performance
> Trends
> > (www.performancetrends.com) which was my final choice for many reasons.
> With
> > this program, if you input very accurate data for head flow (corrected
for
> > barometric pressure) and are realistic about humidity/elevation/air temp
> > environmental conditions, the power output predicted by the program is
> very
> > accurate. From my experience, my final dyno results were within 20~25 HP
> and
> > Lbs.Tq. of the simulated output and the peaks were within ~200 rpm. Not
> many
> > people have the resources or time to experiment enough with an actual
> engine
> > or test all the many variables for the optimum combination, but now you
> can
> > get very close using a proven software program!!
> >
> > 2)Injector Placement: There are varying opinions on this subject, but I
> have
> > accepted the consistent recommendation of a few experts involved with my
> > project (Paul Pfaff of Pfaff Racing Engines, George Clarke of Motec USA,
> and
> > Tom Payne of Kinsler Injection) and all generally agree that placing the
> > injector further upstream in the runner and aiming it toward the high
> > velocity side of the runner produces the most power. In some
applications
> > they even place the injector near the top of the ramtube!!
> >
> > 3)Throttle Body: There are two basic choices here, an individual
throttle
> > body per runner, or a common throttle body into a plenum. My experience
is
> > limited to the individual throttle body type manifold and ultimately was
> > chosen because of its benefits for road race applications. There is
> probably
> > not much difference between the two types of manifolds when comparing
peak
> > WOT power output, including that of a carborated system of equal runner
> > length. But the individual runner throttle body produces quicker
throttle
> > response for both accel and de-accel conditions. It also eliminates
pulse
> > interference between the cylinders and low vacuum conditions for an
> > extremely smooth idle, which causes the motor to sound like your using a
> > near-stock cam despite the radial specs. If you want the bumpy idle
sound
> of
> > a prostock drag engine, don't use the individual throttle body and save
> your
> > money.
> >
> > 4)Linkage: This is an area that can be easily over looked. It is a
> non-issue
> > with a single throttle body system, but important for the tunibility and
> > consistency of an individual throttle system. Depending on the manifold
> > design and construction, the butterfly positions in relation to
eachother
> > will change as the system heats and cools, and this has an impact on the
> A/F
> > ratios particularly at part-throttle and idle positions. Ease of
> > adjustability is important, but stability and constancy of the linkage
> > system is the real issue to evaluate when comparing systems.
> >
> > 5)Airbox: This subject can make the difference between attaining(or not)
> the
> > potential power gains from whatever system you choose. You have probably
> > seen some cars with very impressive intake systems, but "capped off"
with
> > some type of compact or low profile air cleaner, which to a large degree
> > acts like a choke at high rpm's. In your evaluation of EFI manifolds,
> > compare the possible placement and efficiency of the airbox with
emphasis
> on
> > maximum filter surface area, minimum bending of flow path, and a
location
> > for cool air pick up. Pressure assist by use of a scoop is nice if your
> > engine management system has high enough resolution and can compensate
> fast
> > enough to maintain A/F at all speed and buffeting conditions, but the
> three
> > items mentioned above will produce or defeat most of the attainable
> benefit.
> >
> > 6)General comments: The results of EFI systems and their owner's
> > satisfaction seem to differ wildly among the people who have or had them
> at
> > one time. Over all, comments about aftermarket EFI systems seem to be
> > generally negative ranging from "I can get the same HP using a carb" or
> "the
> > engine doesn't run as good as it did when I had a carb". The things that
I
> > found most common with people who had poor results using their EFI
system
> > was 1)inadequate or omission of dyno use, or 2)an inconsistent setup
> between
> > the dyno and the engine once installed in the car.
> >
> > One thing that I would strongly recommend with your project would be to
> use
> > every "actual" engine component that you will be using in your car, but
on
> > the engine dyno. This means every sensor, engine harness, fuel pump(s),
> > regulator, filter(s), headers, thermostat, airbox or approximated
mock-up,
> > and alternator if possible. All of these items will alter the engine
> > management system or A/F ratio in some manner if changed after the dyno
> > tuning process. It is also highly recommended to pay the extra ~$200 for
a
> > "matched-flow" set of injectors when you buy them.
> >
> > As for your choice of the engine management system, if you haven't
already
> > done so, I would encourage you to obtain and carefully review the Users
> > Manuals and Installation Guides of each system that you are considering
> > before deciding  on your choice. Even better, request demo software of
all
> > the options you are interested in and work with it a bit to understand
and
> > compare ease of use between the various systems. Call the manufacture
and
> > inquire what are the typical problems or tech support issue that occur
> with
> > their system and ask who has the most experience working with it that
you
> > can also call. As for myself, I briefly owned an Electromotive system
and
> > ended up selling it still in the box, and finally selected a system from
> > Motec. At that time no information and documentation for the Speed-pro
was
> > available for evaluation, however a friend of mine at my at Motec,
George
> > Clarke (http://www.motec.com/home.htm) has become familiar with
> Speed-pro's
> > spec and support characteristics and you may be interested to call or
> email
> > him to get his point of view on it and other various subjects as you
> compare
> > different systems. I am extremely pleased with my M48Pro system's
> > performance, ease  and simplicity of use, and tech support and would
still
> > make the same choices today if I were doing it again.
> >
> > The picture of the system you sent looks awesome and priced as I would
> > expect, if it includes the cross linkage. I went a with 2.5" Kinsler
> system
> > which ended up around $3850 for everything including custom length ram
> > tubes, matched-flow injectors, cross linkage kit, CNC port matching, and
> > shipping. Airbox, pumps, regulator, and plumbing were not included.
> >
> > Hope this is helpful for your project.
> > Gregg
> >
> > -----Original Message-----
> > From: Nolan Scheid [mailto:nolan@clipper.net]
> > Sent: Wednesday, February 14, 2001 8:40 PM
> > To: gesakoff@etcconnect.com
> > Subject: Fuel injection
> >
> >
> > Hello Greg
> > I have purchased John Parsons stroker Cleveland for my 72 Pantera.  I
have
> > gathered most of my fuel injection components including the Speed-pro
> > computer. I still need, to decide on the manifold. I am considering the
> one
> > in this picture. The main drawback is the $4500 price.  I understand
that
> > you went to a bunch of effort to get your FI working good. I'm wondering
> > what combination you are using and what you would do different next
time.
> > Regards,
> > Nolan Scheid
> > P-car #2772
> >
>