STG 3 Bar Ultimate Display
chip with readout.
Update
- technical information
What’s a 3 bar chip and why is it better than a 2 bar chip?
To answer this question you must understand the ECM (your engine’s
computer). Late model GM vehicles use one of 2 methods to determine the
engine’s fueling needs: mass air flow or speed density. Mass air flow uses a
sensor that actually measures the amount of air going into the engine, and from
other data (engine speed, throttle position etc) can calculate the exact fueling
needs. Speed density measures the manifold pressure, and its changes (along with
engine speed and other related data) to meter fueling needs. On a naturally
aspirated car (non supercharger/turbocharger) a 1 bar map sensor is needed, as
the engine only operates in vacuum. The 1 bar map sensor can read from about
14.7psi vacuum (or negative pressure) to atmospheric pressure (0 psi). A 2 bar
map sensor can read from 14.7psi vacuum to 14.7psi positive pressure (one bar
vacuum, one bar pressure greater than atmospheric). In the same respect, a 3 bar
map sensor reads from 14.7psi vacuum to 29.4psi positive pressure (one bar
vacuum, two bar of boost pressure).
What are the
disadvantages and advantages of each?
A mass air flow system can take into account different modifications
(cam/heads etc) that are done to increase power, as the sensor can ‘see’ the
additional air going into the engine and will add fuel as necessary. This is as
long as the sensor is not maxed out, as mass air flow sensors have a limit to
their readings. The speed density system is not as forgiving in its
calibrations, as the calibration is usually set for a stock system. When major
changes are performed on the engine, the computer reads the same manifold
pressure levels as a stock engine, and the same amount of fuel is delivered,
when more or less is really needed. So in this respect, a mass air flow system
is better. It also does not use a restrictive sensor to meter air, as the mass
air flow systems do. As I mentioned before, however, the mass air flow systems
can be maxed out, so in a higher performance system, the speed density is the
winner (and this is the main reason speed density is used on aftermarket ECM
systems). In the syty application, however, this benefit did not exist.....
What does all this
have to do with Syclones/Typhoons?
The SyTy’s use a speed density system, BUT the stock setup uses a 2 bar
map sensor. So the ECM can only read up to 14.7psi of boost. So if the boost is
raised above this amount, the ECM will not know the actual pressure, as the
sensor is maxed out. Anything over 14.7psi would be read as 14.7psi by the
computer. So fueling cannot be changed at higher boost, timing cannot be altered
at higher boost levels, and boost control will not function efficiently (as the
SyTy’s ECM controls boost also). So basically, for a person on a budget who
wants a bit more performance out of their truck, it was a risky venture, as
fueling wasn’t being compensated as the boost was turned up, timing would not
be changed at higher boost levels, and the factory boost control was not
operating as well as it could, all very dangerous situations, especially on
vehicles so prone to detonate.
What’s the solution?
A chip calibrated for a 3 bar map sensor, to take advantage of the
extended range of that sensor.
Advantages
FUELING A 3 bar chip now has the potential to add fueling at
boost levels greater than 14.7psi. However, the stock setup is limited as the
stock injectors are nearly maxed out (100% duty cycle). On the STG 3 bar chip,.
the fueling is slightly leaner than stock, so a higher base fuel pressure can be
run to deliver a bit more fuel at higher boost levels.
TIMING The timing can be modified on a 3 bar chip at higher boost
levels, for either safety or performance. On the STG Display chip, there are 3
levels of timing, for different performance levels (to be used with higher
octane gas also). The levels are designated T1,T2,T3 (T3 most aggressive timing,
T1 mild timing, stock like). Also, on each program, the timing is MUCH lower
above the set boost level, in case of a boost spike or creep, the timing will
drop significantly, hopefully enough that no damage would have been done.
BOOST CONTROL The boost control on the 3 bar chips has the
potential to control boost up to 30psi, BUT the stock wastegate is very
undersized. If the stock wastegate is ported or if an upgraded integral is used
on a larger turbo, boost control will be solid, with fine adjustments possible
on the multi chip. So with this chip, there is no need for an aftermarket boost
controller. No boost controller will work well with an improperly sized
wastegate.
Special Features in the STG 3 bar chips:
Limit boost during first acceleration disabled,
Turns on intercooler pump when engine coolant reaches 60ºF thus eliminating the need and disadvantages of hard wiring the intercooler pump to run continuously.
RPM limit raised to 5400RPM,
Overboost fuel cut retained for safety reasons (2-3psi above boost level for that program),
EGR disabled in T3 (aggressive timing) programs, so as to not heat up intake (cruising to/from staging lanes),
Max knock retard raised (the stock amount of retard is limited to 12.66º, we raise this max to 18º).
Performance
Features:
3 different timing curves, from mild to aggressive,
Several boost levels, from stock to 24psi.
Additional
Ultimate Chip Features:
Key lockable switching feature which is nearly impossible to defeat. With the key removed, programs cannot be changed, including a "no start" setting which is an excellent security feature.
Valet setting with significant full throttle power reduction and a 4000RPM limit.
Dimensions on display/switching unit: 6"x4"x2".
Cable length of approximately 5 feet.
Notes:
The program selection will be displayed on the Ultimate Display chip,
showing what timing level (T1,T2,T3), and what boost level (in PSI).
As was mentioned above, speed density ECM’s usually need chip
updates/reprogramming for every little modification. Our programs seem to work
well on trucks with mild modifications (intercooler modifications, turbo
upgrades). Trucks with wild modifications (high lift cams/ported
heads/significantly larger turbos) will not run as well as a lightly modded
truck using these programs. In the future, I hope we can offer programs for
trucks with serious upgrades, and perhaps design some buildup plans that can
utilize our programs, as the alternative (aftermarket ECM) is the only real
solution right now, and is an expensive one.
From: Todd.A.Austinson ([email protected])
Brian Green and I are finally
ready to make the STG 3 bar multichips available. The chip will be available in
two forms, unless you have purchased a 2 bar chip previously, then you have a
third option which will be described below.
The first option is simply called the STG 3 Bar Multichip. It has 4
programs that can be selected with a small pushwheel microswitch, similar to the
Todd A. 4-1 2 bar chip. This unit's first program is a reduced power program,
with all stock limits in tact, reduced timing, and no intercooler pump
operation. This could be thought of as a "valet" setting.
The second is a "street" program designed for 93 octane fuel,
and will run 16 psi of boost if ecm boost control is used. The third is a
"street/strip" program, running 18 psi of ecm controlled boost, and
requiring greater than 93 octane. The fourth is a "strip" program runs
20 psi of ecm controlled boost, disables EGR function, and also requiring
greater than 93 octane. The actual octane requirements will vary from truck to
truck, and it is best to use a scan tool to determine safe levels.
As a rough rule of thumb, the "street/strip" should have at
least 95 octane, and the "strip" 104 octane. All three performance
programs will turn the intercooler pump on at a 60 degree engine coolant
temperature, 5400 rpm limit, and no mph limit. Only the "valet" and
"street" settings have programmed boost limits, both occurring at 18
psi. This allows the user to use an external boost controller without hitting
any pre-programmed limits while operating the #3-4 settings. Price for this chip
will be $200.
The second option is the most interesting. It is unofficially called the
STG Ultimate Chip for now and is actually a timing/boost controller in one chip.
It has a digital display/control unit that will indicate the selected timing and
boost level, as well as a key operated lock-out to prevent setting changes when
the key is removed. A pushbutton is used to select the programs when the unit is
enabled by the key switch. There are 3 levels of timing and 6 levels of boost,
from 16 -24 psi, that can be selected. In addition there is a valet and security
setting which is nearly impossible to defeat due to the lock-out function of the
display/control unit. There is really no way to defeat the lock out by any means
other than breaking open the display/controller and re-wiring the internal
circuits, requiring a good working knowledge of the system. Simply cutting the
cable and getting "lucky" by shorting the correct wires together will
only result in blowing the ECM B fuse, disabling the truck even further. In
other words, it's a pretty good security system, minus a blaring alarm. Similar
precautions will be needed as expressed above in determining safe octane levels
for use with this chip. The high timing level can be run with 24 psi of boost,
necessitating 107+ octane. I want to add that the higher boost settings (20+)
might not be very usable with stock turbos due to their limited capacities. The
12.17 @ 112.1 that I ran last fall with my Typhoon was accomplished using the
high timing program level with 22 psi of boost. I have been running a prototype
version of this chip since last October. The high level timing selections also
have the EGR disabled. Price for this chip will be $350.
The last option applies to those who already have one of the 2 bar
multichips. These can be upgraded to a 3 bar chip by several methods. The first
is to simply send the original back to me for reprogramming. You will get your
chip returned with 4, 8, or 10 3 bar programs loaded, depending on what type of
chip you have. The cost for this will be $50 for the new programs. The 4-1's
will have the same programs as described for the STG Multichip. The 8-1's will
get security, valet, 16 psi and 17 psi street, 18 and 20 psi street/strip, and
18 and 20 psi strip settings. The 10-1's will get an 18 psi street and 22 psi
strip in addition to the 8-1 programs listed. The other option is to upgrade to
the "Ultimate Chip" by returning your original to me plus $150.
All these new 3 bar chips will be easily upgradable due to hardware
changes if and when software improvements are made. We will keep this cost at
minimum to the 3 bar users. We are shooting for something in the ballpark of $25
for these upgrades.
The STG Multichip is avalable now and can be ordered through Brian
Green. The "Ultimate" will be available in about 3-4 weeks, but if
you want one of these I'd like you to contact Brian (or me if this will be an
upgrade) now so that he can relay to me how many I need to make. I'm sure Brian
will have something to add to this so stay tuned.
Todd Austinson
'92 Ty #1548
12.17 @ 112.1
STG
From: Brian Green
To upgrade to a 3 bar chip, we will need a 3 bar map sensor right?
Yes. GM/ AC Delco part number 1604-0749 - sensor assembly.
All these new 3 bar chips will be easily upgradable due to hardware
changes if and when software improvements are made. We will keep this cost at
minimum to the 3 bar users. We are shooting for something in the ballpark of $25
for these upgrades.
If you have questions, concerns, or want to order one of the chips, email
me with "STG 3 bar chips" in the subject.
For those of you interested in the display, I don't have much information
on it yet, as Todd is still working on it and changing it. When we have it
ready, we'll probably have a webpage with pics and description of it.
Thanks
Brian Green
syclone 160
STG Racing
From: Todd.A.Austinson ([email protected])
Some things I inadvertently omitted while writing the initial message.
That's what you get when you try to write a lengthy note while holding 2-3
instant message conversations.
First of all, it has been pointed out that I should have mentioned that a
GM 3 bar MAP sensor is needed (replacing the stock 2 bar) to run these chips.
The display/control unit will be shown shortly on a web site, but this
hasn't been completed yet. The display will indicate which particular program is
being executed, e.g., security, valet, timing, and boost level. As you toggle
through the selections the display will update. The best way I can describe the
size and appearance of the display/controller is that it will look like a G-tech
performance meter or small radar detector.
Todd