Lots of snips from BBC with 160 lb injectors

Sat Jan 29 08:17:59 GMT 2000

Hi,
    Maybe some of us have forgotten our math???  160lb x 8 cyl / .5 bsfc =
2560HP....so lets forget about math and try some real world...I have
programmed an Autronics box with 8, 96 lb injectors twin turbo's water/air
intercooler and ran out of injector at 1639HP at 13.1:1 AFR at 5500 rpm so
I'm a little lost on why you need bigger than the 80's to make 1000hp unless
you are planning on something I'm unaware of...This was gasoline...were you
planning on Alcohol???? BTW the Autronics is a great box with great
software, the only thing it could use is some better AE stuff....Lost in
Wonderland??????
-Carl Summers

- --------------------------------------------------------------------------
--

| > You are building a what?.   105 injectors?.
| > To get anywhere near an idle would take P+Hs
| > How big of motor is this?.
|
| 460 inch Big Block Chevy, twin turbo, liquid/air intercooler. 800 HP @
| 6000 RPM currently, requires only 80 lb/hr. However, it is well within
| reason for this setup to put out 1000 - 1100 HP at 6500 RPM, requiring 105
| lbs/hr. I don't think it is such a good idea to install injectors
| sufficient for current, unmodified, output levels, when I can simply turn
| up the boost, and make some other adjustments, to add HP. I want a
| reasonable amount of overhead to add HP over what I've already got.
|
| > Yes,  P+H, perfered cycling 1-5 msec,  Sat 2-10msec.  You can verify in
| the
| > archives
|
| Thanks. That's what I'd heard.
|
| > Yes, there is a day and night difference in flow rates from brand to
| brand,
| > and style to style.  Kinsler can plot things out for you.  Sure, be nice
| if
| > some folks would share their injector flow charts for time on vs
| pressure.
|
| Can you recommend any mfg's that make a better product than others?
|
| - Clay
|
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------------------------------

Date: Fri, 28 Jan 2000 18:09:10 -0500
From: "Bruce Plecan" <nacelp at bright.net>
Subject: Re: Peak and hold vs. saturated injectors

Is this a boat or car?.
If a car I'd really think about staged injectors.  That way use you 80 for
HO, and add a set of 30s for idle cruise.

| 460 inch Big Block Chevy, twin turbo, liquid/air intercooler. 800 HP @
| 6000 RPM currently, requires only 80 lb/hr. However, it is well within
| reason for this setup to put out 1000 - 1100 HP at 6500 RPM, requiring 105
| lbs/hr. I don't think it is such a good idea to install injectors
| sufficient for current, unmodified, output levels, when I can simply turn
| up the boost, and make some other adjustments, to add HP. I want a
| reasonable amount of overhead to add HP over what I've already got.

That's why I was asking if anyone had charts to share.  I'd need to see more
to be able to compare them to make any recommendations.
  The way I see it, for really hi HP applications, use like an oem size
injector, and use some others for when the HP goes crazy, and/or a rising
rate fuel pressure regulator (thou, not for you).

| - Clay

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------------------------------

Date: Fri, 28 Jan 2000 20:33:11 -0800
From: "Walter Sherwin" <wsherwin at idirect.com>
Subject: Re: 105-160 #/Hr Low Impedance P&H  Port Injectors

Clay,

Large injectors, on a BBC engine,  are not quite as problematic as they are
often made to sound.  Lots of wive's tales, but you can ignore most of them,
if you take the right precautions.............

First, assuming that you intend port injection for your BBC project and that
your BBC is to be artificially aspirated, your 105 #/Hr injector benchmark
tells me that you are expecting roughly 1100'ish max HP on gasoline?   If
this is not the case, then please clearly state your assumptions and/or
intended fuel.

You will find that large'ish port style fuel injectors (typically beyond
50-70 #/Hr) are all of the low impedance variety regardless of
manufacturerer, meaning that they are typically less than 4 ohms impedance
each and that they will require an individual peak & hold current driver
(typically 4/1 amp) for proper dynamic operation.  This is pretty much a
universal statement, no matter whether you examine large injectors from
Bosch, Siemens, Rochester, etc.

"Low Impedance" and "Peak & Hold" really describe the same end result, and
are meant to denote that the injectors must be individually switched via a
current controlled driver as opposed to the more common (cheaper) saturated
voltage switch driver.  The combination of an ECU current driver, together
with the electromagnetics built into a typical low impedance injector/coil
assembly, attempts to drive the injector harder & faster than normal in
order to effectively extend both the low and high pulse width flow response
of the injector.  The result is a "wider" dynamic performance envelope for
the injector(s).  This translates into both a superior idle and more
effective top-end liquid flow (relatively speaking).  The DIY & GMECM
archives contain a lot of interesting reading on this topic, if you seek
more knowledge.

When you contemplate the injector flow ranges that you have described, there
are really only two manufacturers to consider  1) Rochester '96s [aka MSD,
Holley, and others], and of course    2) Bosch '160s.

Personally, I would select the Bosch injectors for the following reasons:
quality, cost, spray pattern, linearity, heat tolerance, batch tolerance,
and availability.  Remember, that the Bosch injectors (in particular the
160's that you have mentioned) have been, and still are, the mainstay of
racing venues from Indy down to NHRA & IHRA and even weekend bracketeers.
By virtue of production volumes, and popularity, the Bosch 160's are far
more prevalent and sometimes more cost effective.  The Rochester 96's are
slightly more difficult to source, and are not as precise.  Kinsler, and
others, can feed your cravings for either flavour of injector.

A bunch of Pro & Otherwise racers around here use the Bosch 160's, and are
able to produce clean/stable/reasonable idles with a variety of ECU hardware
and software packages.  The trick is to control each of the large injectors
via its own P&H driver and to use ECU software that intentionally
encompasses wide dynamic injector ranges and firing schemes.  You should
personally discuss your injector thoughts with Electromotive, in order to
determine the best software control strategy and selection (kinda surprised
they did not want to sell you an injector set to match your application at
the time of sale???).

If you are interested, I can forward you photo images of both the Bosch '160
and the Rochester '96 injector spray patterns as photographed on my flow
bench, during rated psig operation.  As you will note, each is different and
satisfies differing needs in terms of desired injector targeting and wall
wetting parameters.  In theory for multiport operation, you want to target
the injector spray directly toward the backside of the intake valve face
from 3-4 inches distance away.  However, the physical dimensions of a BBC
make this difficult/impossible.   Practical theory reveals that if a person
can somewhat incline the injector spray plume into the cylinder head runner
tract, then the resultant distribution and effect should be okay.

Good luck with your project, and remember that many of the injector and/or
ECU companies often have "1-800" numbers.   Don't feel bad about asking them
a zillion questions.  It's their dime..............

Walt.

------------------------------

Date: Fri, 28 Jan 2000 18:43:32 -0700
From: bearbvd at cmn.net (Greg Hermann)
Subject: Re: Peak and hold vs. saturated injectors

>Is this a boat or car?.
>If a car I'd really think about staged injectors.  That way use you 80 for
>HO, and add a set of 30s for idle cruise.
>
>| 460 inch Big Block Chevy, twin turbo, liquid/air intercooler. 800 HP @
>| 6000 RPM currently, requires only 80 lb/hr. However, it is well within
>| reason for this setup to put out 1000 - 1100 HP at 6500 RPM, requiring
105
>| lbs/hr. I don't think it is such a good idea to install injectors
>| sufficient for current, unmodified, output levels, when I can simply turn
>| up the boost, and make some other adjustments, to add HP. I want a
>| reasonable amount of overhead to add HP over what I've already got.
>
>| > Yes,  P+H, perfered cycling 1-5 msec,  Sat 2-10msec.  You can verify in
>| the archives
>| Thanks. That's what I'd heard.
>| > Yes, there is a day and night difference in flow rates from brand to
>| brand,
>| > and style to style.  Kinsler can plot things out for you.  Sure, be
nice
>| if
>| > some folks would share their injector flow charts for time on vs
>| pressure.
>| Can you recommend any mfg's that make a better product than others?
>
>That's why I was asking if anyone had charts to share.  I'd need to see
more
>to be able to compare them to make any recommendations.
>  The way I see it, for really hi HP applications, use like an oem size
>injector, and use some others for when the HP goes crazy, and/or a rising
>rate fuel pressure regulator (thou, not for you).
>
And--furthermore--ditch the Electromotive, and check out Autronics. There
is a link to them on www.turbofast.com.au (Ray Hall). LOTS of the Autronics
ecu's on engines like what you have, and they are MUCH better suited for
doing what you will need to keep the thing together. Richard Lee, Lee
Performance, in Lake Elsinore, CA also does lots of this sort of stuff, at
least for boats. He deals the Autronics, but I doubt if for the best deal.

Greg
>| - Clay
>
>
>
>----- Original Message -----
>From: Anthony Buccellato <clayb at sonic.net>
>To: <diy_efi at diy-efi.org>
>Sent: Friday, January 28, 2000 11:55 AM
>Subject: Re: Peak and hold vs. saturated injectors
>
>
>| > You are building a what?.   105 injectors?.
>| > To get anywhere near an idle would take P+Hs
>| > How big of motor is this?.
>|
>| 460 inch Big Block Chevy, twin turbo, liquid/air intercooler. 800 HP @
>| 6000 RPM currently, requires only 80 lb/hr. However, it is well within
>| reason for this setup to put out 1000 - 1100 HP at 6500 RPM, requiring
105
>| lbs/hr. I don't think it is such a good idea to install injectors
>| sufficient for current, unmodified, output levels, when I can simply turn
>| up the boost, and make some other adjustments, to add HP. I want a
>| reasonable amount of overhead to add HP over what I've already got.
>|
>| > Yes,  P+H, perfered cycling 1-5 msec,  Sat 2-10msec.  You can verify in
>| the
>| > archives
>|
>| Thanks. That's what I'd heard.
>|
>| > Yes, there is a day and night difference in flow rates from brand to
>| brand,
>| > and style to style.  Kinsler can plot things out for you.  Sure, be
nice
>| if
>| > some folks would share their injector flow charts for time on vs
>| pressure.
>|
>| Can you recommend any mfg's that make a better product than others?
>|
>| - Clay

MSD fuel injection injectors (blueprinted Rochesters) are purported to work
the best for this sort of stuff--supposedly have better dynamic range than
the big Bosch stuff. You WILL need good dynamic range.
I AM with Bruce on this, staged, 1/3 primary, 2/3 secondary is the best way
to go.

Greg

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