3 Bar Ultimate Chip
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). 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 14.7
psi 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.
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. A speed density however 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.
The 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 3 bar Ultimate 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 Ultimate 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 24psi, BUT the stock wastegate is undersized. If the
catalytic converter is removed, 2-3 psi boost spikes may be experienced in
certain situations, such as 2 nd or 3 rd to 1 st gear downshifts while cruising.
This is not a characteristic of this chip alone, all chips/boost controllers will
do this due to the stock wastegate size. If an upgraded integral is used on a
larger turbo, boost control will be solid, with fine adjustments possible by
adjusting the wastegate rod. So with this chip, there is no need for a boost
controller. Simply select a boost level via the chip, and the computer will
control boost to that level. Some minor adjustment to the wastegate rod
length may be necessary on some trucks depending on age and
modification. This is a simple procedure described in the chip instructions.
Special Features in the 3 bar Ultimate chip:
* Intercooler pump turn on earlier, occurring when the engine coolant
reaches 60 degrees F, thus eliminating the need for hard wiring the
pump to run continuously.
* Rev limiter raised to 5400 rpm.
* Over boost fuel cut retained for safety reasons (2-3psi above boost
level for that program)
* EGR disabled in all settings but the T1-15 and valet, so as to not heat
up intake.
* Knock retard is more aggressive (when knock is detected, timing will
be pulled out faster than stock)
* Max knock retard raised (the stock amount of retard is limited to 12.66
degrees, we raise this max to 18 degrees)
* Wide Band 02 sensor compatibility
* Faster turbo spool-up due to timing and fueling changes.
* First time boost disable eliminated, allowing full boost after start-up.
The factory and many aftermarket calibrations limit boost the first time
it is seen by the engine, creating difficulties at the track.
* The Ultimate chip comes with a display/switch unit, the size of a small
radar detector, or enclosed in a 2- 1/16” gauge enclosure to select
and view the current program. The gauge version fits in all 2 1/16”
gauge pods and comes with an 8+’ cable to easily reach the “A” pillar.
See pictures below.
* Knock indicator light.
* 3 different timing curves, from mild to aggressive.
* Several boost levels, from stock to 24psi.
