Engine and Transmission Tech

Specifically, after market TBI systems ? I'm considering "Powerjection III", by Professional Products. Looks like Holley dual feed, self tuning with lap top overide. I need a system that a. looks like a carb,b. dynamic altitude compensation,(Silver State Classic) c. adequate flow at all times with a more optimized fuel curve vs. carburetion. Anyone out there, use this set-up ? Thanks, roverman.

Hi Art, once the air cleaner is installed, they all look good. Here's a plug and play system that I really like. A friend of mine has one and loves the way it calibrated itself within two or three rides (road test). F.A.S.T. also offers excellent service support. We need more members going to fuel injection; it helps with emission, performance, mileage and most of all, excellent drivability.

[www.fuelairspark.com]

Jacques

What have you got up your sleeve Art?

If you need it to look like a carb there's lots of room for a quartet of injectors in a gutted Holley. Sensors can be mounted in discreet locales. Maximum effort stealth units would have the injectors under the manifold in the valley.
Ecu's are a dime a dozen, just pick out the features that you need.
SDS, Motec, Mega squirt, FAST, Howard engineering, Moates, Electromotive, Hondata are just some of the systems or tuning that I have used in the past. They all get the job done. It just depends upon what you need.
I haven't had any experience with the Powerjection. But it sure is shiny.
The silver state looks interesting. We ran a 180mph Volvo sedan in the one lap in 86,87,88 and this looks like the same kind of fun.
If we talk nice (diamonds) to the lovely Lynne I could probably come over to play.

Got Motor?

Cheers
Fred

Fred, Heads should be done this week. Motor, 2 months-min. I'm going the long route, build wise, because engine "may" get a 6V-71 on top, much later. Cheers, roverman.

I suspect, engines being equal, the injected engine should last longer. Having a properly working knock sensor and always optimal fuel curve =reduced cylinder wear,(no over rich fuel wash of rings), and no pinging/detonation, a potential killer. So do "direct injected" gas engines, like recent chev V6, run without a throttle plate like deisels ? roverman.

Art,

First you need to determine which of the three popular EFI control schemes
your engine will need:

1. mass air flow
2. speed density
3. alpha-n

None of these approaches is best for all engines in all applications. You
need to understand the limitations to understand which is best for your
particular application. They differ primarily in the way they sense engine
load. Speed density systems use manifold vacuum via a MAP (manifold absolute
pressure) sensor to sense load. Fuel is metered using the MAP input, engine
RPM, and volumetric efficiency tables. Mass air systems use a MAF (Mass Air
Flow) sensor to directly measure the amount of incoming air. Those sensors
typically use wires that air exposed to the air flow, though there other
approaches (flapper door, venturi, etc.). As the air flows over the wire,
it changes the voltage drop across the wire. Tables in the computer convert
the voltage drop to air mass. Alpha-N systems are the simplest, using only
RPM and throttle position to determine load. Note that a MAP sensor can be
used with Alpha-N, but it's used as a barometric pressure sensor to detect
altitude changes. You can also blend the authority of Alpha-N and speed
density by directing the authority between the throttle position sensor and
the MAP (manifold absolute pressure) sensor.

Each of these approaches have pros and cons...

Mass air systems don't handle large overlap cams well. Reversion pulses
produce an unsteady flow over the mass air meter which can lead to surging
at idle and lower RPM. A friend runs an EEC-IV mass-air based system in
his drag race Mustang and the engine has a strong surge below 3000 RPM due
to the large overlap of his cam. Wide lobe centers helps some (most 5.0L
"EFI" cams are ground on 112 degree lobe centers for this reason) and some-
times you can tune out the surge by repositioning the mass air meter relative
to the intake valve but the amount of overlap a mass air system can tolerate
is finite. Since the airflow is directly measured, mass air systems can
tolerate larger variations (in cam specs, cylinder head flow, etc.) than
speed density. However, there are still tables in the ECU that may need to
be reprogrammed. Most MAF-based systems still have speed-density modes for
when you're off the range of the MAF or need to go off stoich for accel/decel,
etc. The sensors will need to be recalibrated for different injector sizes.
This can be done in the sensor itself or the calibration curve in the ECU.
Mass air is particularly good for idle and emissions which is why many
OEM systems are mass air.

Speed density systems can be cheaper and more reliable than mass air systems
because they don't require mass air flow sensors. They can also make a bit
more power than mass air systems since a mass air flow sensor is a restriction
in the intake flow path. Speed density is somewhat less sensitive to cam
overlap than mass air but still has limitations as overlap can cause unsteady
vacuum readings. The size and location of the plenum can influence this. The
GM guys have used speed density with fairly hot cams, though. A vacuum
chamber to smooth out the signal helps. Speed density systems are less
tolerant to changes than mass-air systems in the engine before requiring
re-programming of the volumetric efficiency tables. The commonly available
EEC tuning tools (twEECer, PMS, etc.) don't typically support speed density
systems since the majority of Ford performance applications are mass airflow.
However, Ford's Cosworth F1 V8's ran speed density EEC-IV's for many years but
I wonder if they were running in an alpha-n mode. The situation is reversed
on the GM side and many GM guys will change from mass air to speed density.

Alpha-N is best for big lumpy cams. Most of the aftermarket EFI systems
like ACCEL/DFI, Electromotive, Haltech, BigStuff3, etc. are either speed
density or Alpha-N. Electromotive for one will allow a blend between the
two.

The type of manifolding can influence your selection of control scheme.
Speed-density does not work well on highly modified engines that lose
manifold vacuum upon any throttle opening. With independent runner
throttle bodies, throttle position is a better indication of load than a
MAP sensor once off idle. This is because a small opening in the throttle
body will cause manifold vacuum to go to atmospheric. Beyond say 10-15%
throttle opening, there is little response to a MAP. Alpha-N is the way to
go with naturally-aspirated independent runner but it doesn't do much for
part load/part throttle fuel economy. That's where it's beneficial to blend
in the MAP. The engine I'm building for the Pantera has a lumpy cam (238/242
@ 0.050", 300/304 advertised, 0.621"/0.595" lift with 1.7/1.6 rockers, 110
LSA). Mike Trusty has been running IR EFI for many years. It's been his
experience that MAP dependent ECU's don't handle IR systems (with or without
big cams) well. The MAP changes so rapidly, even with a mild cam, that at
just off throttle the MAP goes almost to atmosphere which makes the ECU think
the throttle is wide open even though the throttle position doesn't verify
that. Add in the hard to get rid of pulsations even with manifolded vacuum.
In his experience what works best is a system that can look at both throttle
position and MAP and allow you to give one or the other more authority in
different power ranges. I know some guys give throttle position all of the
authority. That works but doesn't do anything for part load/throttle economy.
Electromotive has a "Blend" mode in their software which is a function that
allows you to blend the authority between the throttle position and MAP.
John Meaney (the guy behind most of the aftermarket EFI systems like FAST
and Big Stuff3) says his latest and greatest Big Stuff3 unit allows the user
to tailor the cell width for both rpm and load (MAP or TPS%) and that by
increasing the resolution I can get the sensitivity I'm after. Still not
sure if I buy that yet.

Supercharged applications tend to have cams with less overlap so speed density
or mass air may be better. Supercharged applications using Alpha-N require a
MAP upstream of the throttle to act as a barometric compensator.

Independent runner manifolding will tame down a big cam. Since the runners
are isolated from each other, reversion from adjacent cylinders does not
foul the intake stroke, allowing a longer cam duration with a streetable
idle. Kirby Schraeder runs a PPC-sourced IR EFI system on his 377 cubic inch
Cleveland stroker (iron 4V heads with Weber lower and 48mm TWM throttle
bodies). He runs a fairly large overlap 288FDP Crower solid flat tappet oval
track cam on the street. Specs on his cam are 254/258 degrees at 0.050"
(288/294 degrees advertised), 0.569"/0.580" lift (0.022"/0.024" clearance hot)
with 105 lobe centers. That's a lot of duration and tight lobe centers for a
street car. According to Kirby, with a 700DP Holley on a Ford aluminum dual
plane intake manifold, it had a wild idle and wouldn't start pulling well
until 3000 RPM (Crower rates the cam range as 3500 to 7000 RPM). When he
installed the independent runner EFI, the first thing he said was "Where'd
my idle go?". He noted it now pulls 5th gear from 1500 RPM. Kirby also
noted it's tough staying off the 7200 RPM rev-limiter in lower gears.

Independent runner also allows tuning of the inlet tract length generally not
possibly with single 4 barrel plenum type intakes. I know a lot of people
like the looks of the cross runner manifold but I suspect for many applications
the runners may be too long. I ran a series of Dynomation simulations to pick
the runner length for my Fontana stroker. On that engine, the short stacks
that fit under the stock Pantera engine cover and decklid is close to ideal
length. Longer runners increased low and mid-range torque but that came with
a big loss of HP in higher RPM ranges. With a converted carb intake, you're
stuck with the runner lengths cast into the intake.

A big benefit of EFI is being able to adjust the spark curve easily in ways
a mechanical system won't permit. If you want to lean out the mixture at
cruise for best fuel economy, you'll also need to adjust timing. Combustion
gets much slower under lean conditions and if you don't adjust spark timing,
the combustion occurs much later and exhaust temperature climbs. That's bad
for the seats and valves. However, if you adjust for MBT spark at each A/F
ratio, exhaust temperature will actually decrease relative to stoichimetric.

Narrow band O2 sensors have a very steep voltage output versus O2 content
and basically just toggle between rich or lean trying to hold the air-fuel
mixture at stoichiometric (around 14.7:1 for typical pump gas). Narrow
band sensors are employed because catalytic converters are happiest at
stoich. For power you want to go slightly rich and for economy you want
to go slightly lean. For tuning purposes (a human using the output to tune
a carb or EFI), a narrow band is all but useless. In a computer, you may be
able to datalog and get usable info. In general, wide band O2 sensors will
yield a much more usable output. Narrow band 02 sensors are generally only
closed loop during cruise. At wide open throttle, the control schemes
usually revert to tables. Some of the latest aftermarket controllers (e.g.
BigStuff3) are using wide-band O2 sensors for data logging and also in "learn"
modes. They also have a simple model built in to get you in the ballpark for
start-up operation. You simply enter your bore, stroke, compression ratio,
etc and the computer defines a start-up map. A downside to using a wide band
O2 sensor closed loop all the time is when the sensor fails it could lead to
a dangerous lean condition that could melt a piston.

BTW, many of the controllers are designed around serial data interfaces
but most of the laptops have gone to USB ports. There are supposedly
USB-to-serial adapters but you may need driver software upgrades.

One big thing in favor of Ford or GM-based systems is built-in test (BIT).
I'd wager a majority of the code in those ECM's is for built-in test and
diagnostics. That helps a huge amount when trying to debug a system.

and that's just some of the basics...

Dan Jones

Dan, Some ? You might want to check "Professional Products" site for Projection III. Features MAP sensor, throttle position sensor and pwm. 750 cfm., 4150 style throttle body, should have enough flow,I suspect for 290 cu.in. at say 7,000 ? Up to 500 hp. does not require a fuel return. Intake manifold will be the Wildcat single plane 4bbl,(near identicle to Wilpower).Thanks, roverman.

Does anyone have any direct experience of the off the shelf aftermarket EFI systems.

I would like to fit one to my project but I am concerned that they are all made for much larger engines than my 215 CI V8.

Any comments would be greatly appreciated.

Doug, TBI ? If so, Holley has a 2bbl.,complete conversion system for approx.1k$.(Jegs etc.). May want to peep Holley website. Good Luck. roverman.

I had contacted a few people about these TBI systems and the general feeling was that they were too large (650 cfm and up) for my 215 CI engine.
I was just wondering if anyone on the forum had experience of these kits (FAST EFI, EAZI-EFI, Holley etc) and how well they perform on our little V8s?

If anyone has fitted one to their Rover engined car please post some details, thoughts and pictures if possible.

Regards,

Does anyone here have experience with Bosch/Lucas injection from 1980 Rovsr Sd1? My 77 has a 215 with a RV grind and I'm having trouble getting a steady idle. I have been checking for vacuum leaks, but nothing seems to help so far. What else can I check? I'm not that good with vehicle electronics.

I have done port systems with GM, Ford, FAST, Accel, AEM, and Big Stuff. I have some friends who have tried Professional Products.
I had some success with all I tried.
I have banned Professional Products from anything I work on because of their previous products that I have found to be substandard.

Robert, Any specifics ,of why not Projection III ? They are close by, may help ? I will dyno the motor with TBI. Thanks,Art.